feat(desktop): contact requests, auto-update banner, packaging polish (v2.2.0)

Closes the v2.2.0 roadmap. Desktop client is feature-complete and
ready for first installer builds.

Contact request flow (fills a real gap flagged by the user):
  * lib/tx.ts grows buildContactRequestTx / buildAcceptContactTx /
    buildBlockContactTx with canonical bytes matching mobile.
  * lib/api.ts: fetchContactRequests + ContactRequestRaw.
  * New contact modal — sections/contacts/NewContactModal.tsx — resolves
    @username / DC-address / hex pub via resolveAccount, shows identity
    preview (incl. "has encryption key / key not published" hint),
    fee tier picker (5k / 10k / 50k µT), optional 280-char intro,
    balance guard.
  * Requests inbox — sections/contacts/RequestsList.tsx — polled every
    15 s via /relay/contacts, filters pending, Accept submits
    ACCEPT_CONTACT + adds the peer to local contacts with their
    identity.x25519_pub pre-cached, Block submits BLOCK_CONTACT.
  * ContactsList grows a two-tab header (Contacts / Requests with a
    pending-count badge) + "+ New" button next to the filter input.

Auto-update:
  * hooks/useUpdateCheck.ts — polls /api/update-check on mount and
    every 6 hours; loose semver compares the Gitea release tag
    against this build's app.version (from Electron IPC), ignores
    the node's own update_available flag (it compares vs. the node,
    not the desktop).
  * shell/UpdateBanner.tsx — thin strip above the status bar with
    the new tag, Download button (opens the release URL in the
    default browser), and a dismiss-for-this-tag × so once-seen
    updates don't nag.

Packaging — electron-builder config tightened:
  * artifactName pattern includes version + os + arch.
  * Mac: hardenedRuntime on, dmg + zip outputs, social-networking
    category.
  * Windows: NSIS (full installer, per-user or per-machine) +
    portable exe.
  * Linux: AppImage + deb.
  * Strip source maps and test folders from the asar.
  * publish: null — no auto-publisher yet; Gitea releases are
    uploaded manually for now.
  * directories.output = release/, directories.buildResources =
    resources/ so icons land in a predictable place once we add them.

Version bumped to 2.2.0 in package.json. docs/ROADMAP.md marks
v2.2.0 row complete; remaining work (attachments, code signing,
group chats) moved to a post-v2.2.0 bucket.

blockchain/chain.go

@@ -54,6 +54,9 @@ const (
 	prefixRelay         = "relay:"         // relay:<node_pubkey> → RegisterRelayPayload JSON
 	prefixRelayHB       = "relayhb:"       // relayhb:<node_pubkey> → unix seconds (int64) of last HB
 	prefixRelayProof    = "relayproof:"    // relayproof:<envelopeID> → claimant node_pubkey (1 claim per envelope)
+	// Multi-device registry (v2.2.0)
+	prefixDevice          = "device:"        // device:<x25519_pub> → DeviceRecord JSON
+	prefixDevicesByOwner  = "devicesbyowner:" // devicesbyowner:<master_pub>:<x25519_pub> → "" (reverse index for O(k) listing)
 	prefixContactIn     = "contact_in:"    // contact_in:<targetPub>:<requesterPub> → contactRecord JSON
 	prefixValidator     = "validator:"     // validator:<pubkey> → "" (presence = active)
 	prefixContract      = "contract:"      // contract:<contractID> → ContractRecord JSON
@@ -771,6 +774,99 @@ func PayChanCloseSigPayload(channelID string, balanceA, balanceB, nonce uint64)
 	return payChanCloseSigPayload(channelID, balanceA, balanceB, nonce)
 }
 
+// DevicesOf returns the active (non-revoked) device records for a master
+// identity. Sender fan-out reads this to decide how many envelopes to
+// produce per outgoing message. Empty slice (not error) for identities
+// with no registry entries yet — caller should fall back to the legacy
+// single-X25519 path via IdentityInfo.
+func (c *Chain) DevicesOf(masterPub string) ([]DeviceRecord, error) {
+	var out []DeviceRecord
+	err := c.db.View(func(txn *badger.Txn) error {
+		prefix := []byte(prefixDevicesByOwner + masterPub + ":")
+		it := txn.NewIterator(badger.IteratorOptions{Prefix: prefix, PrefetchValues: false})
+		defer it.Close()
+		for it.Rewind(); it.Valid(); it.Next() {
+			key := it.Item().KeyCopy(nil)
+			// key layout: devicesbyowner:<master>:<x25519> — take the suffix
+			x25519Pub := string(key[len(prefix):])
+			recItem, err := txn.Get([]byte(prefixDevice + x25519Pub))
+			if err != nil {
+				// Reverse index points to a missing record — stale entry,
+				// skip silently (shouldn't happen unless the DB was tampered
+				// with, but we don't want to fail the whole call).
+				continue
+			}
+			var rec DeviceRecord
+			if verr := recItem.Value(func(v []byte) error {
+				return json.Unmarshal(v, &rec)
+			}); verr != nil {
+				continue
+			}
+			if rec.RevokedAt != 0 {
+				continue
+			}
+			out = append(out, rec)
+		}
+		return nil
+	})
+	return out, err
+}
+
+// countActiveDevicesForOwner walks the reverse index (entries there are,
+// by construction, non-revoked — UNLINK_DEVICE deletes the index row).
+// O(k) where k = active device count, bounded by MaxDevicesPerOwner.
+func (c *Chain) countActiveDevicesForOwner(txn *badger.Txn, masterPub string) (int, error) {
+	prefix := []byte(prefixDevicesByOwner + masterPub + ":")
+	it := txn.NewIterator(badger.IteratorOptions{Prefix: prefix, PrefetchValues: false})
+	defer it.Close()
+	n := 0
+	for it.Rewind(); it.Valid(); it.Next() {
+		n++
+	}
+	return n, nil
+}
+
+// validateDevicePubKey checks the wire-level format of a device X25519
+// public key: 64 hex characters (32 bytes). Does NOT check that the key
+// is a valid curve point — senders learn that at encrypt time, and an
+// invalid point there just yields garbage ciphertext which the device
+// can't decrypt (self-punishing).
+func validateDevicePubKey(hexPub string) error {
+	if len(hexPub) != 64 {
+		return fmt.Errorf("x25519_pub_key must be 64 hex chars (got %d)", len(hexPub))
+	}
+	// Enforce strict lowercase-hex to keep keys canonical across clients —
+	// two clients hashing the same bytes with different letter cases would
+	// produce different registry lookups, which breaks sender fan-out.
+	for _, r := range hexPub {
+		switch {
+		case r >= '0' && r <= '9':
+		case r >= 'a' && r <= 'f':
+		default:
+			return fmt.Errorf("x25519_pub_key must be lowercase hex")
+		}
+	}
+	return nil
+}
+
+// validateDeviceName enforces the UX constraint that device labels stay
+// short and printable — this field gets displayed in Settings → Devices
+// and has no business carrying newlines, control chars, or 2KB blobs.
+func validateDeviceName(name string) error {
+	if name == "" {
+		return fmt.Errorf("device_name is required")
+	}
+	if len(name) > MaxDeviceNameLen {
+		return fmt.Errorf("device_name %d bytes > max %d", len(name), MaxDeviceNameLen)
+	}
+	for _, r := range name {
+		if r < 0x20 || r == 0x7f {
+			return fmt.Errorf("device_name contains a control character")
+		}
+	}
+	return nil
+}
+
 // Reputation returns the reputation stats for a public key.
 func (c *Chain) Reputation(pubKeyHex string) (RepStats, error) {
 	var r RepStats
@@ -1261,6 +1357,127 @@ func (c *Chain) applyTx(txn *badger.Txn, tx *Transaction) (uint64, error) {
 			return 0, err
 		}
 
+	case EventLinkDevice:
+		// Master Ed25519 (= tx.From) publishes a per-device X25519 pub.
+		// Validation:
+		//   1. Payload well-formed, X25519 pub is hex(32 bytes).
+		//   2. Device name is short + printable.
+		//   3. X25519 pub isn't already registered to a DIFFERENT owner.
+		//   4. Same owner re-linking the same pub is a no-op refresh
+		//      (updates device_name / added_at — useful for rename).
+		//   5. Owner has < MaxDevicesPerOwner active (non-revoked) devices.
+		//
+		// Fee: standard tx.Fee is debited from master's balance — cheap
+		// anti-spam. Block validation already enforced `tx.Fee >= MinFee`.
+		if err := c.debitBalance(txn, tx.From, tx.Fee); err != nil {
+			return 0, fmt.Errorf("LINK_DEVICE debit: %w", err)
+		}
+		var p LinkDevicePayload
+		if err := json.Unmarshal(tx.Payload, &p); err != nil {
+			return 0, fmt.Errorf("%w: LINK_DEVICE bad payload: %v", ErrTxFailed, err)
+		}
+		if err := validateDevicePubKey(p.X25519PubKey); err != nil {
+			return 0, fmt.Errorf("%w: LINK_DEVICE: %v", ErrTxFailed, err)
+		}
+		if err := validateDeviceName(p.DeviceName); err != nil {
+			return 0, fmt.Errorf("%w: LINK_DEVICE: %v", ErrTxFailed, err)
+		}
+		devKey := []byte(prefixDevice + p.X25519PubKey)
+		if item, err := txn.Get(devKey); err == nil {
+			var existing DeviceRecord
+			if verr := item.Value(func(v []byte) error {
+				return json.Unmarshal(v, &existing)
+			}); verr == nil {
+				if existing.Owner != tx.From {
+					return 0, fmt.Errorf("%w: LINK_DEVICE: x25519 pub already linked to a different owner",
+						ErrTxFailed)
+				}
+				// Same owner — rename/refresh path. Keep AddedAt.
+				existing.DeviceName = p.DeviceName
+				existing.RevokedAt = 0 // re-link cancels a previous revoke
+				refreshed, _ := json.Marshal(existing)
+				if err := txn.Set(devKey, refreshed); err != nil {
+					return 0, err
+				}
+				// Restore reverse index too — UNLINK_DEVICE deletes it, so
+				// a re-link after revoke must recreate it or DevicesOf
+				// will skip the record.
+				idxKey := []byte(prefixDevicesByOwner + tx.From + ":" + p.X25519PubKey)
+				if err := txn.Set(idxKey, []byte{}); err != nil {
+					return 0, err
+				}
+				break
+			}
+		}
+		// Count owner's active devices.
+		active, err := c.countActiveDevicesForOwner(txn, tx.From)
+		if err != nil {
+			return 0, fmt.Errorf("LINK_DEVICE count devices: %w", err)
+		}
+		if active >= MaxDevicesPerOwner {
+			return 0, fmt.Errorf("%w: LINK_DEVICE: owner already has %d devices (max %d)",
+				ErrTxFailed, active, MaxDevicesPerOwner)
+		}
+		rec := DeviceRecord{
+			Owner:        tx.From,
+			X25519PubKey: p.X25519PubKey,
+			DeviceName:   p.DeviceName,
+			AddedAt:      tx.Timestamp.Unix(),
+		}
+		val, _ := json.Marshal(rec)
+		if err := txn.Set(devKey, val); err != nil {
+			return 0, err
+		}
+		idxKey := []byte(prefixDevicesByOwner + tx.From + ":" + p.X25519PubKey)
+		if err := txn.Set(idxKey, []byte{}); err != nil {
+			return 0, err
+		}
+
+	case EventUnlinkDevice:
+		// Revoke (soft-delete) a device record. Mark RevokedAt and keep
+		// the row — clients wake up, notice their own pub is revoked, and
+		// wipe local state. A permanent delete would let a sender that
+		// missed the revoke keep encrypting for the old pub silently.
+		if err := c.debitBalance(txn, tx.From, tx.Fee); err != nil {
+			return 0, fmt.Errorf("UNLINK_DEVICE debit: %w", err)
+		}
+		var p UnlinkDevicePayload
+		if err := json.Unmarshal(tx.Payload, &p); err != nil {
+			return 0, fmt.Errorf("%w: UNLINK_DEVICE bad payload: %v", ErrTxFailed, err)
+		}
+		if err := validateDevicePubKey(p.X25519PubKey); err != nil {
+			return 0, fmt.Errorf("%w: UNLINK_DEVICE: %v", ErrTxFailed, err)
+		}
+		devKey := []byte(prefixDevice + p.X25519PubKey)
+		item, err := txn.Get(devKey)
+		if err != nil {
+			return 0, fmt.Errorf("%w: UNLINK_DEVICE: device not found", ErrTxFailed)
+		}
+		var existing DeviceRecord
+		if verr := item.Value(func(v []byte) error {
+			return json.Unmarshal(v, &existing)
+		}); verr != nil {
+			return 0, fmt.Errorf("UNLINK_DEVICE decode: %w", verr)
+		}
+		if existing.Owner != tx.From {
+			return 0, fmt.Errorf("%w: UNLINK_DEVICE: signer is not the owner of this device",
+				ErrTxFailed)
+		}
+		if existing.RevokedAt != 0 {
+			// Already revoked — idempotent success, don't error.
+			break
+		}
+		existing.RevokedAt = tx.Timestamp.Unix()
+		updated, _ := json.Marshal(existing)
+		if err := txn.Set(devKey, updated); err != nil {
+			return 0, err
+		}
+		// Drop reverse index so countActiveDevicesForOwner is O(k_active).
+		idxKey := []byte(prefixDevicesByOwner + tx.From + ":" + p.X25519PubKey)
+		if err := txn.Delete(idxKey); err != nil {
+			return 0, err
+		}
+
 	case EventContactRequest:
 		var p ContactRequestPayload
 		if err := json.Unmarshal(tx.Payload, &p); err != nil {

blockchain/devices_test.go

@@ -0,0 +1,413 @@
+package blockchain_test
+
+// Multi-device registry tests (v2.2.0). Cover happy-path link + list,
+// unlink idempotency, ownership validation, max-devices guard, and
+// backward-compat sender fall-back semantics (empty list for unknown
+// master). HTTP-layer tests live in the node package; these stay at
+// chain level — applyTx + state-shape only.
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"strings"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"go-blockchain/blockchain"
+	"go-blockchain/identity"
+)
+
+// uniqueTxID sidesteps the `chain_test.go:txID` race where two helper
+// calls in the same nanosecond produce identical tx IDs → chain.AddBlock
+// dedupes the second as "already committed". We add a strictly-monotonic
+// counter so every tx built in the same test gets a fresh ID even on
+// fast machines.
+var devicesTxIDCounter atomic.Uint64
+
+func uniqueTxID() string {
+	n := devicesTxIDCounter.Add(1)
+	h := make([]byte, 16)
+	_, _ = rand.Read(h)
+	return hex.EncodeToString(h) + ":" + time.Now().Format("150405.000000000") + ":" + itoa(n)
+}
+
+func itoa(n uint64) string {
+	// tiny local conversion to avoid importing strconv just for tests.
+	if n == 0 {
+		return "0"
+	}
+	var buf [20]byte
+	i := len(buf)
+	for n > 0 {
+		i--
+		buf[i] = byte('0' + n%10)
+		n /= 10
+	}
+	return string(buf[i:])
+}
+
+// linkDeviceRawTx / unlinkDeviceRawTx build txs with guaranteed-unique
+// IDs so we can stuff many of them into a single block during tests.
+func linkDeviceRawTx(master *identity.Identity, x25519Pub, name string) *blockchain.Transaction {
+	payload := mustJSON(blockchain.LinkDevicePayload{
+		X25519PubKey: x25519Pub,
+		DeviceName:   name,
+	})
+	return &blockchain.Transaction{
+		ID:        uniqueTxID(),
+		Type:      blockchain.EventLinkDevice,
+		From:      master.PubKeyHex(),
+		Fee:       blockchain.MinFee,
+		Payload:   payload,
+		Timestamp: time.Now().UTC(),
+	}
+}
+
+func unlinkDeviceRawTx(master *identity.Identity, x25519Pub string) *blockchain.Transaction {
+	payload := mustJSON(blockchain.UnlinkDevicePayload{X25519PubKey: x25519Pub})
+	return &blockchain.Transaction{
+		ID:        uniqueTxID(),
+		Type:      blockchain.EventUnlinkDevice,
+		From:      master.PubKeyHex(),
+		Fee:       blockchain.MinFee,
+		Payload:   payload,
+		Timestamp: time.Now().UTC(),
+	}
+}
+
+// randX25519Pub returns a throw-away 32-byte hex string suitable for the
+// x25519_pub_key field. We don't need the matching private key — the
+// chain only stores the pub and doesn't verify it's a valid curve point.
+func randX25519Pub(t *testing.T) string {
+	t.Helper()
+	var b [32]byte
+	if _, err := rand.Read(b[:]); err != nil {
+		t.Fatalf("rand: %v", err)
+	}
+	return hex.EncodeToString(b[:])
+}
+
+// fundIdentity credits enough balance to cover `nFees` worth of MinFee
+// payments. Every test needs this because LINK_DEVICE and UNLINK_DEVICE
+// debit tx.Fee from the master's balance — without funding the first tx
+// errors with "insufficient funds" and no state changes.
+func fundIdentity(t *testing.T, c *blockchain.Chain, val, recipient *identity.Identity, nFees int) {
+	t.Helper()
+	amount := uint64(nFees+2) * blockchain.MinFee
+	tx := makeTx(blockchain.EventTransfer, val.PubKeyHex(), recipient.PubKeyHex(),
+		amount, blockchain.MinFee, mustJSON(blockchain.TransferPayload{}))
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val, []*blockchain.Transaction{tx}))
+}
+
+// TestLinkDeviceHappyPath: after a single LINK_DEVICE, DevicesOf returns
+// exactly one record with the right owner/name/pub.
+func TestLinkDeviceHappyPath(t *testing.T) {
+	c := newChain(t)
+	val := newIdentity(t)
+	addGenesis(t, c, val)
+
+	alice := newIdentity(t)
+	fundIdentity(t, c, val, alice, 1)
+	dev1 := randX25519Pub(t)
+	tx := linkDeviceRawTx(alice, dev1, "Alice's iPhone")
+	b := buildBlock(t, c.Tip(), val, []*blockchain.Transaction{tx})
+	mustAddBlock(t, c, b)
+
+	devs, err := c.DevicesOf(alice.PubKeyHex())
+	if err != nil {
+		t.Fatalf("DevicesOf: %v", err)
+	}
+	if len(devs) != 1 {
+		t.Fatalf("expected 1 device, got %d", len(devs))
+	}
+	got := devs[0]
+	if got.Owner != alice.PubKeyHex() {
+		t.Errorf("owner: got %s, want %s", got.Owner, alice.PubKeyHex())
+	}
+	if got.X25519PubKey != dev1 {
+		t.Errorf("x25519: got %s, want %s", got.X25519PubKey, dev1)
+	}
+	if got.DeviceName != "Alice's iPhone" {
+		t.Errorf("name: got %q, want %q", got.DeviceName, "Alice's iPhone")
+	}
+	if got.RevokedAt != 0 {
+		t.Errorf("freshly linked device should have RevokedAt=0, got %d", got.RevokedAt)
+	}
+}
+
+// TestLinkDeviceMultiple: multiple devices for the same owner all show up
+// in DevicesOf, and the count matches.
+func TestLinkDeviceMultiple(t *testing.T) {
+	c := newChain(t)
+	val := newIdentity(t)
+	addGenesis(t, c, val)
+
+	alice := newIdentity(t)
+	fundIdentity(t, c, val, alice, 3)
+	pubs := []string{randX25519Pub(t), randX25519Pub(t), randX25519Pub(t)}
+	var txs []*blockchain.Transaction
+	for i, p := range pubs {
+		txs = append(txs, linkDeviceRawTx(alice, p, "device-"+string(rune('A'+i))))
+	}
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val, txs))
+
+	devs, err := c.DevicesOf(alice.PubKeyHex())
+	if err != nil {
+		t.Fatalf("DevicesOf: %v", err)
+	}
+	if len(devs) != 3 {
+		t.Fatalf("expected 3 devices, got %d", len(devs))
+	}
+}
+
+// TestLinkDeviceRejectsForeignOwner: if Alice already linked a X25519 pub
+// and Bob tries to link the SAME pub to himself, the tx is rejected.
+// This protects against a malicious actor hijacking someone else's
+// device-pub and trying to claim it.
+func TestLinkDeviceRejectsForeignOwner(t *testing.T) {
+	c := newChain(t)
+	val := newIdentity(t)
+	addGenesis(t, c, val)
+
+	alice := newIdentity(t)
+	bob := newIdentity(t)
+	fundIdentity(t, c, val, alice, 1)
+	fundIdentity(t, c, val, bob, 1)
+	dev := randX25519Pub(t)
+
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val,
+		[]*blockchain.Transaction{linkDeviceRawTx(alice, dev, "alice phone")}))
+
+	// Bob tries to claim the same pub. The chain silently drops invalid
+	// txs (they're non-fatal for block commit), so we verify the *state*:
+	// Alice still owns the pub, Bob has zero devices.
+	bobTx := linkDeviceRawTx(bob, dev, "bob phone")
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val, []*blockchain.Transaction{bobTx}))
+
+	aliceDevs, _ := c.DevicesOf(alice.PubKeyHex())
+	if len(aliceDevs) != 1 || aliceDevs[0].DeviceName != "alice phone" {
+		t.Fatalf("Alice should still own the device, got %+v", aliceDevs)
+	}
+	bobDevs, _ := c.DevicesOf(bob.PubKeyHex())
+	if len(bobDevs) != 0 {
+		t.Fatalf("Bob's hijack should have been rejected, got %+v", bobDevs)
+	}
+}
+
+// TestLinkDeviceSameOwnerRefresh: the same owner re-linking the same
+// x25519_pub is a rename/refresh (not an error), and the revoked flag
+// gets cleared if it was set.
+func TestLinkDeviceSameOwnerRefresh(t *testing.T) {
+	c := newChain(t)
+	val := newIdentity(t)
+	addGenesis(t, c, val)
+
+	alice := newIdentity(t)
+	fundIdentity(t, c, val, alice, 3)
+	dev := randX25519Pub(t)
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val,
+		[]*blockchain.Transaction{linkDeviceRawTx(alice, dev, "old name")}))
+
+	// Unlink then re-link — should restore the record.
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val,
+		[]*blockchain.Transaction{unlinkDeviceRawTx(alice, dev)}))
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val,
+		[]*blockchain.Transaction{linkDeviceRawTx(alice, dev, "new name")}))
+
+	devs, err := c.DevicesOf(alice.PubKeyHex())
+	if err != nil {
+		t.Fatalf("DevicesOf: %v", err)
+	}
+	if len(devs) != 1 {
+		t.Fatalf("expected 1 active device after re-link, got %d", len(devs))
+	}
+	if devs[0].DeviceName != "new name" {
+		t.Errorf("expected refreshed name 'new name', got %q", devs[0].DeviceName)
+	}
+}
+
+// TestUnlinkDeviceRemovesFromActive: after UNLINK_DEVICE, DevicesOf no
+// longer returns that record — senders stop fanning out to it.
+func TestUnlinkDeviceRemovesFromActive(t *testing.T) {
+	c := newChain(t)
+	val := newIdentity(t)
+	addGenesis(t, c, val)
+
+	alice := newIdentity(t)
+	fundIdentity(t, c, val, alice, 3)
+	keep := randX25519Pub(t)
+	revoke := randX25519Pub(t)
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val, []*blockchain.Transaction{
+		linkDeviceRawTx(alice, keep, "kept"),
+		linkDeviceRawTx(alice, revoke, "revoked"),
+	}))
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val,
+		[]*blockchain.Transaction{unlinkDeviceRawTx(alice, revoke)}))
+
+	devs, err := c.DevicesOf(alice.PubKeyHex())
+	if err != nil {
+		t.Fatalf("DevicesOf: %v", err)
+	}
+	if len(devs) != 1 || devs[0].X25519PubKey != keep {
+		t.Fatalf("expected only the kept device, got %+v", devs)
+	}
+}
+
+// TestUnlinkDeviceRejectsForeignSigner: Bob can't unlink Alice's device
+// even if he knows the X25519 pub — only the owner's signature (= tx.From)
+// authorises revoke.
+func TestUnlinkDeviceRejectsForeignSigner(t *testing.T) {
+	c := newChain(t)
+	val := newIdentity(t)
+	addGenesis(t, c, val)
+
+	alice := newIdentity(t)
+	bob := newIdentity(t)
+	fundIdentity(t, c, val, alice, 1)
+	fundIdentity(t, c, val, bob, 1)
+	dev := randX25519Pub(t)
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val,
+		[]*blockchain.Transaction{linkDeviceRawTx(alice, dev, "alice phone")}))
+
+	// Bob tries to unlink Alice's device — tx is silently dropped, Alice
+	// still has it in her active list.
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val,
+		[]*blockchain.Transaction{unlinkDeviceRawTx(bob, dev)}))
+
+	aliceDevs, _ := c.DevicesOf(alice.PubKeyHex())
+	if len(aliceDevs) != 1 || aliceDevs[0].X25519PubKey != dev {
+		t.Fatalf("Alice's device should still be active, got %+v", aliceDevs)
+	}
+}
+
+// TestUnlinkDeviceIdempotent: unlinking a device that's already revoked
+// does NOT error — this is needed for recovery scenarios where a client
+// retries the tx after a spotty connection.
+func TestUnlinkDeviceIdempotent(t *testing.T) {
+	c := newChain(t)
+	val := newIdentity(t)
+	addGenesis(t, c, val)
+
+	alice := newIdentity(t)
+	fundIdentity(t, c, val, alice, 3)
+	dev := randX25519Pub(t)
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val,
+		[]*blockchain.Transaction{linkDeviceRawTx(alice, dev, "phone")}))
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val,
+		[]*blockchain.Transaction{unlinkDeviceRawTx(alice, dev)}))
+	// Second unlink of the same device must apply cleanly.
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val,
+		[]*blockchain.Transaction{unlinkDeviceRawTx(alice, dev)}))
+}
+
+// TestLinkDeviceRejectsMalformedPub: payload.X25519PubKey must be 64-char
+// lowercase hex. Garbage / short / uppercase values are rejected at
+// applyTx time before any state change.
+func TestLinkDeviceRejectsMalformedPub(t *testing.T) {
+	c := newChain(t)
+	val := newIdentity(t)
+	addGenesis(t, c, val)
+
+	alice := newIdentity(t)
+	fundIdentity(t, c, val, alice, 5)
+
+	bad := []string{
+		"",                      // empty
+		"abc",                   // too short
+		strings.Repeat("x", 64), // non-hex
+		strings.Repeat("A", 64), // uppercase
+	}
+	for _, p := range bad {
+		tx := linkDeviceRawTx(alice, p, "dev")
+		mustAddBlock(t, c, buildBlock(t, c.Tip(), val, []*blockchain.Transaction{tx}))
+	}
+
+	devs, _ := c.DevicesOf(alice.PubKeyHex())
+	if len(devs) != 0 {
+		t.Fatalf("expected 0 devices after %d malformed link attempts, got %d",
+			len(bad), len(devs))
+	}
+}
+
+// TestLinkDeviceRejectsBadDeviceName: empty, too long, or control-char
+// names are refused — this field is rendered verbatim in clients.
+func TestLinkDeviceRejectsBadDeviceName(t *testing.T) {
+	c := newChain(t)
+	val := newIdentity(t)
+	addGenesis(t, c, val)
+
+	alice := newIdentity(t)
+	fundIdentity(t, c, val, alice, 5)
+	cases := map[string]string{
+		"empty":        "",
+		"too long":     strings.Repeat("a", blockchain.MaxDeviceNameLen+1),
+		"control char": "device\x01name",
+	}
+	for name, devName := range cases {
+		t.Run(name, func(t *testing.T) {
+			before, _ := c.DevicesOf(alice.PubKeyHex())
+			tx := linkDeviceRawTx(alice, randX25519Pub(t), devName)
+			mustAddBlock(t, c, buildBlock(t, c.Tip(), val, []*blockchain.Transaction{tx}))
+			after, _ := c.DevicesOf(alice.PubKeyHex())
+			if len(after) != len(before) {
+				t.Fatalf("bad %s name should not have been linked (before=%d, after=%d)",
+					name, len(before), len(after))
+			}
+		})
+	}
+}
+
+// TestLinkDeviceMaxDevices: after MaxDevicesPerOwner active devices, any
+// further LINK_DEVICE is rejected. Revoking one frees a slot.
+func TestLinkDeviceMaxDevices(t *testing.T) {
+	c := newChain(t)
+	val := newIdentity(t)
+	addGenesis(t, c, val)
+
+	alice := newIdentity(t)
+	// Enough for cap + one overflow attempt + one unlink + one replacement.
+	fundIdentity(t, c, val, alice, blockchain.MaxDevicesPerOwner+4)
+
+	// Fill to the cap — each in its own block so timestamps differ.
+	pubs := make([]string, blockchain.MaxDevicesPerOwner)
+	for i := 0; i < blockchain.MaxDevicesPerOwner; i++ {
+		pubs[i] = randX25519Pub(t)
+		mustAddBlock(t, c, buildBlock(t, c.Tip(), val,
+			[]*blockchain.Transaction{linkDeviceRawTx(alice, pubs[i], "d")}))
+	}
+	// One more — the tx is dropped, cap stays exact.
+	over := linkDeviceRawTx(alice, randX25519Pub(t), "overflow")
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val, []*blockchain.Transaction{over}))
+	if devs, _ := c.DevicesOf(alice.PubKeyHex()); len(devs) != blockchain.MaxDevicesPerOwner {
+		t.Fatalf("overflow link should have been rejected, count=%d", len(devs))
+	}
+
+	// Revoke one, then a fresh link succeeds.
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val,
+		[]*blockchain.Transaction{unlinkDeviceRawTx(alice, pubs[0])}))
+	mustAddBlock(t, c, buildBlock(t, c.Tip(), val,
+		[]*blockchain.Transaction{linkDeviceRawTx(alice, randX25519Pub(t), "replacement")}))
+	if devs, _ := c.DevicesOf(alice.PubKeyHex()); len(devs) != blockchain.MaxDevicesPerOwner {
+		t.Fatalf("after unlink+relink, should be %d active, got %d",
+			blockchain.MaxDevicesPerOwner, len(devs))
+	}
+}
+
+// TestDevicesOfEmptyForUnknown: unknown master pubs return an empty list
+// (not an error) — this preserves the sender's ability to fall back to
+// IdentityInfo.X25519Pub for legacy identities.
+func TestDevicesOfEmptyForUnknown(t *testing.T) {
+	c := newChain(t)
+	val := newIdentity(t)
+	addGenesis(t, c, val)
+
+	alice := newIdentity(t)
+	devs, err := c.DevicesOf(alice.PubKeyHex())
+	if err != nil {
+		t.Fatalf("DevicesOf: %v", err)
+	}
+	if len(devs) != 0 {
+		t.Fatalf("expected 0 devices for unknown master, got %d", len(devs))
+	}
+}

blockchain/types.go

@@ -46,6 +46,14 @@ const (
 	EventUnfollow        EventType = "UNFOLLOW"          // unfollow an author
 	EventLikePost        EventType = "LIKE_POST"         // like a post
 	EventUnlikePost      EventType = "UNLIKE_POST"       // remove a previous like
+
+	// Multi-device support (v2.2.0): each physical device of an identity gets
+	// its own X25519 keypair for the messenger mailbox. LINK/UNLINK_DEVICE
+	// publish/revoke those pubs on-chain so senders can fan-out envelopes
+	// across the recipient's active devices. Signed by the identity's
+	// master Ed25519 key.
+	EventLinkDevice   EventType = "LINK_DEVICE"
+	EventUnlinkDevice EventType = "UNLINK_DEVICE"
 )
 
 // Token amounts are stored in micro-tokens (µT).
@@ -555,6 +563,70 @@ type IdentityInfo struct {
 	X25519Pub  string `json:"x25519_pub"`  // hex Curve25519 key; empty if not published
 	Nickname   string `json:"nickname"`
 	Registered bool   `json:"registered"`   // true if REGISTER_KEY tx was committed
+	// DeviceCount is the number of currently-linked (non-revoked) devices in
+	// this identity's multi-device registry. `0` for legacy identities that
+	// only published a single X25519 via REGISTER_KEY — senders fall back
+	// to IdentityInfo.X25519Pub in that case.
+	DeviceCount int `json:"device_count"`
+}
+
+// ── Multi-device registry (v2.2.0) ───────────────────────────────────────
+
+// MaxDevicesPerOwner caps how many devices a single identity can have
+// linked concurrently. A sender must encrypt + relay one envelope per
+// device, so the multiplier bounds the per-message cost. Ten covers
+// typical users (phone + tablet + laptop + desktop + work phone + …)
+// without letting an abuse case blow up mailbox traffic. Revoked devices
+// don't count.
+const MaxDevicesPerOwner = 10
+
+// MaxDeviceNameLen caps the length of a human-friendly device label
+// ("Alice's iPhone 14", "Work MacBook Pro"). Longer names get rejected
+// at validation. Kept short to discourage using this field as a free-form
+// comment/profile channel.
+const MaxDeviceNameLen = 64
+
+// LinkDevicePayload is embedded in EventLinkDevice transactions. Master
+// Ed25519 (= tx.From) asserts that the given X25519 pub belongs to one
+// of its physical devices, publishing it so senders can fan out envelopes.
+type LinkDevicePayload struct {
+	// X25519PubKey is the hex-encoded Curve25519 pub the device generated
+	// locally. Must be unique in the device registry — senders index
+	// envelopes by this key in the relay mailbox.
+	X25519PubKey string `json:"x25519_pub_key"`
+	// DeviceName is a short human label shown in Settings → Devices.
+	// Purely informational; not used for routing.
+	DeviceName string `json:"device_name"`
+}
+
+// UnlinkDevicePayload is embedded in EventUnlinkDevice transactions. Signed
+// by master Ed25519; marks the referenced device as revoked so senders
+// stop shipping envelopes to its X25519 pub. The revoked device itself,
+// once it sees its pub in the revoked list, is expected to wipe its
+// local state (master Ed25519 priv + chat cache).
+type UnlinkDevicePayload struct {
+	X25519PubKey string `json:"x25519_pub_key"`
+}
+
+// DeviceRecord is the on-chain persisted state for one device link.
+// Stored at key `prefixDevice + x25519_pub`; the reverse index
+// `prefixDevicesByOwner + master_pub` keeps a slice of x25519 pubs per
+// owner for efficient listing.
+type DeviceRecord struct {
+	Owner        string `json:"owner"`          // master Ed25519 pub hex
+	X25519PubKey string `json:"x25519_pub_key"` // device X25519 pub hex
+	DeviceName   string `json:"device_name"`
+	AddedAt      int64  `json:"added_at"`           // unix seconds, from tx timestamp
+	RevokedAt    int64  `json:"revoked_at,omitempty"` // 0 = active; >0 = revoked
+}
+
+// DeviceInfo is the public view of a DeviceRecord served by
+// GET /api/devices/{master_pub}. Revoked records are not included
+// in the response (intentionally — sender only needs the active set).
+type DeviceInfo struct {
+	X25519PubKey string `json:"x25519_pub_key"`
+	DeviceName   string `json:"device_name"`
+	AddedAt      int64  `json:"added_at"`
 }
 
 // ConsensusMessage types used by the PBFT engine over the P2P layer.

client-app/app.json

@@ -12,12 +12,14 @@
       "infoPlist": {
         "NSMicrophoneUsageDescription": "Allow DChain to record voice messages and video.",
         "NSCameraUsageDescription": "Allow DChain to record video messages and scan QR codes.",
-        "NSPhotoLibraryUsageDescription": "Allow DChain to attach photos and videos from your library."
+        "NSPhotoLibraryUsageDescription": "Allow DChain to attach photos and videos from your library.",
+        "ITSAppUsesNonExemptEncryption": false
       }
     },
     "android": {
       "package": "com.dchain.messenger",
       "softwareKeyboardLayoutMode": "pan",
+      "usesCleartextTraffic": true,
       "permissions": [
         "android.permission.RECORD_AUDIO",
         "android.permission.CAMERA",

client-app/app/(app)/_layout.tsx

@@ -13,7 +13,7 @@
  * один раз; переходы между tab'ами их не перезапускают.
  */
 import React, { useEffect } from 'react';
-import { View } from 'react-native';
+import { View, Platform } from 'react-native';
 import { router, usePathname } from 'expo-router';
 import { useSafeAreaInsets } from 'react-native-safe-area-context';
 import { useStore } from '@/lib/store';
@@ -25,7 +25,13 @@ import { useGlobalInbox } from '@/hooks/useGlobalInbox';
 import { getWSClient } from '@/lib/ws';
 import { NavBar } from '@/components/NavBar';
 import { AnimatedSlot } from '@/components/AnimatedSlot';
-import { saveContact } from '@/lib/storage';
+import {
+  saveContact,
+  isDeviceRegistered, markDeviceRegistered, wipeAllLocalState,
+} from '@/lib/storage';
+import {
+  fetchDevices, buildLinkDeviceTx, submitTx,
+} from '@/lib/api';
 
 export default function AppLayout() {
   const keyFile  = useStore(s => s.keyFile);
@@ -73,6 +79,79 @@ export default function AppLayout() {
     else ws.setAuthCreds(null);
   }, [keyFile]);
 
+  // Multi-device registry bootstrap + revoke-detection (v2.2.0).
+  //
+  // Three branches, by (chain list × local "was registered" flag):
+  //
+  //   1. Our pub is in the chain's active list →
+  //      mark us registered locally (idempotent), done.
+  //
+  //   2. Our pub is NOT in the active list, AND we've registered before →
+  //      another device issued UNLINK_DEVICE against us. Wipe ALL local
+  //      state (master priv, contacts, chats, marker) and redirect to
+  //      the auth screen. This is the security-critical path: without
+  //      the wipe, a stolen phone after revoke would still decrypt
+  //      historical messages.
+  //
+  //   3. Our pub is NOT in the active list, AND we've NEVER registered →
+  //      first boot on this chain; submit LINK_DEVICE so senders can
+  //      target us. Failures (fee, offline) are swallowed; next launch
+  //      retries.
+  useEffect(() => {
+    if (!keyFile) return;
+    let cancelled = false;
+    (async () => {
+      let chainList;
+      try {
+        chainList = await fetchDevices(keyFile.pub_key);
+      } catch {
+        // Network unavailable — leave state unchanged; we'll resync on
+        // the next launch. Do NOT wipe on network error.
+        return;
+      }
+      if (cancelled) return;
+
+      const inActive = chainList.some(d => d.x25519_pub_key === keyFile.x25519_pub);
+      const previouslyRegistered = await isDeviceRegistered();
+      if (cancelled) return;
+
+      if (inActive) {
+        // Branch #1 — ensure the local marker is set.
+        if (!previouslyRegistered) await markDeviceRegistered();
+        return;
+      }
+
+      if (previouslyRegistered) {
+        // Branch #2 — REVOKED. Self-wipe.
+        await wipeAllLocalState();
+        useStore.getState().setKeyFile(null);
+        // The redirect-on-null-keyFile effect below will push the user
+        // back to the welcome screen automatically.
+        return;
+      }
+
+      // Branch #3 — first-boot link. Best-effort.
+      try {
+        const deviceName = Platform.select({
+          ios:     'iPhone',
+          android: 'Android phone',
+          default: 'Device',
+        }) ?? 'Device';
+        const tx = buildLinkDeviceTx({
+          from:       keyFile.pub_key,
+          x25519Pub:  keyFile.x25519_pub,
+          deviceName,
+          privKey:    keyFile.priv_key,
+        });
+        await submitTx(tx);
+        await markDeviceRegistered();
+      } catch {
+        /* next launch retries */
+      }
+    })();
+    return () => { cancelled = true; };
+  }, [keyFile]);
+
   useEffect(() => {
     if (keyFile === null) {
       const t = setTimeout(() => {

client-app/app/(app)/chats/[id].tsx

@@ -23,7 +23,7 @@ import * as Clipboard from 'expo-clipboard';
 import { useStore } from '@/lib/store';
 import { useMessages } from '@/hooks/useMessages';
 import { encryptMessage } from '@/lib/crypto';
-import { sendEnvelope } from '@/lib/api';
+import { sendEnvelope, resolveRecipientKeys } from '@/lib/api';
 import { getWSClient } from '@/lib/ws';
 import { appendMessage, loadMessages } from '@/lib/storage';
 import { randomId, safeBack } from '@/lib/utils';
@@ -107,7 +107,7 @@ export default function ChatScreen() {
   const [selectedIds, setSelectedIds] = useState<Set<string>>(new Set());
   const selectionMode = selectedIds.size > 0;
 
-  useMessages(contact?.x25519Pub ?? '');
+  useMessages(contact?.x25519Pub ?? '', contact?.address);
 
   // ── Typing indicator от peer'а ─────────────────────────────────────────
   useEffect(() => {
@@ -212,15 +212,34 @@ export default function ChatScreen() {
       // leaves the device, so no encryption/fee/network round-trip is needed.
       // Regular chats still go through the NaCl + relay pipeline below.
       if (hasText && !isSavedMessages) {
+        // Multi-device fan-out (v2.2.0): resolve the recipient's active
+        // device X25519 pubs via /api/devices. Legacy identities (no
+        // devices registered) fall back to their published identity
+        // x25519 pub, preserving the pre-v2.2.0 single-device path.
+        // `contact.x25519Pub` stays the floor — if both network calls
+        // fail we still attempt delivery to the cached pub so a flaky
+        // connection doesn't block outgoing messages.
+        let recipientPubs = await resolveRecipientKeys(contact.address);
+        if (recipientPubs.length === 0 && contact.x25519Pub) {
+          recipientPubs = [contact.x25519Pub];
+        }
+        if (recipientPubs.length === 0) {
+          throw new Error('recipient has no encryption key published');
+        }
+        // One sealed envelope per recipient device. Parallel — slow
+        // relays don't block each other; any individual failure
+        // rejects the whole send (user retries).
+        await Promise.all(recipientPubs.map(async (rpub) => {
           const { nonce, ciphertext } = encryptMessage(
-          actualText.trim(), keyFile.x25519_priv, contact.x25519Pub,
+            actualText.trim(), keyFile.x25519_priv, rpub,
           );
           await sendEnvelope({
             senderPub:    keyFile.x25519_pub,
-          recipientPub: contact.x25519Pub,
+            recipientPub: rpub,
             senderEd25519Pub: keyFile.pub_key,
             nonce, ciphertext,
           });
+        }));
       }
 
       const msg: Message = {

client-app/app/(app)/devices.tsx

@@ -0,0 +1,490 @@
+/**
+ * Devices screen — Settings → Linked devices.
+ *
+ * Multi-device registry (v2.2.0). Lists every X25519 device published
+ * on-chain under this identity's master Ed25519 key. Operators can:
+ *   - see added-at timestamps
+ *   - rename this device (local alias for now; rename via LINK_DEVICE
+ *     with same pub + new name is a v2.3 polish)
+ *   - revoke a remote device via UNLINK_DEVICE (requires fee)
+ *   - pair a new device (Phase 3 — separate modal, stub for now)
+ *
+ * This device is NEVER listed with an Unlink button — revoking yourself
+ * is a footgun (you'd wipe your own state on next launch). Export/import
+ * your key first, then revoke from the new device.
+ */
+import React, { useCallback, useEffect, useState } from 'react';
+import {
+  View, Text, ScrollView, Pressable, ActivityIndicator, Alert, RefreshControl,
+  TextInput, KeyboardAvoidingView, Platform, Modal,
+} from 'react-native';
+import { Ionicons } from '@expo/vector-icons';
+import { useSafeAreaInsets } from 'react-native-safe-area-context';
+
+import { useStore } from '@/lib/store';
+import {
+  fetchDevices, buildLinkDeviceTx, buildUnlinkDeviceTx, submitTx,
+  sendEnvelope, humanizeTxError,
+  type DeviceInfo,
+} from '@/lib/api';
+import { encryptMessage } from '@/lib/crypto';
+import { Header } from '@/components/Header';
+import { IconButton } from '@/components/IconButton';
+import { safeBack } from '@/lib/utils';
+
+function shortPub(p: string, n = 8): string {
+  if (!p) return '—';
+  return p.length <= n * 2 + 1 ? p : `${p.slice(0, n)}…${p.slice(-n)}`;
+}
+
+function formatDate(unixSec: number): string {
+  return new Date(unixSec * 1000).toLocaleString();
+}
+
+export default function DevicesScreen() {
+  const insets  = useSafeAreaInsets();
+  const keyFile = useStore(s => s.keyFile);
+
+  const [devices, setDevices]       = useState<DeviceInfo[]>([]);
+  const [loading, setLoading]       = useState(true);
+  const [refreshing, setRefreshing] = useState(false);
+  const [unlinking, setUnlinking]   = useState<string | null>(null); // pub being revoked
+
+  const load = useCallback(async (isRefresh = false) => {
+    if (!keyFile) return;
+    if (isRefresh) setRefreshing(true);
+    else setLoading(true);
+    try {
+      const list = await fetchDevices(keyFile.pub_key);
+      setDevices(list);
+    } finally {
+      setLoading(false);
+      setRefreshing(false);
+    }
+  }, [keyFile]);
+
+  useEffect(() => { load(false); }, [load]);
+
+  const onUnlink = useCallback((dev: DeviceInfo) => {
+    if (!keyFile) return;
+    Alert.alert(
+      'Unlink device?',
+      `"${dev.device_name}" will stop receiving messages sent to you. ` +
+      `This costs a small network fee. The revoked device wipes its ` +
+      `local state the next time it checks in.`,
+      [
+        { text: 'Cancel', style: 'cancel' },
+        {
+          text: 'Unlink',
+          style: 'destructive',
+          onPress: async () => {
+            setUnlinking(dev.x25519_pub_key);
+            try {
+              const tx = buildUnlinkDeviceTx({
+                from:      keyFile.pub_key,
+                x25519Pub: dev.x25519_pub_key,
+                privKey:   keyFile.priv_key,
+              });
+              await submitTx(tx);
+              // Optimistic — drop from local list immediately; next load
+              // reconciles. Chain tx takes ~1 block to commit.
+              setDevices(prev => prev.filter(d => d.x25519_pub_key !== dev.x25519_pub_key));
+            } catch (e: any) {
+              Alert.alert('Unlink failed', humanizeTxError(e));
+            } finally {
+              setUnlinking(null);
+            }
+          },
+        },
+      ],
+    );
+  }, [keyFile]);
+
+  const meX25519 = keyFile?.x25519_pub ?? '';
+
+  // Pairing modal state — filled by the operator reading values off the
+  // new device's /auth/pair screen.
+  const [pairOpen, setPairOpen]             = useState(false);
+  const [pairCode, setPairCode]             = useState('');
+  const [pairKey,  setPairKey]              = useState('');
+  const [pairName, setPairName]             = useState('');
+  const [pairBusy, setPairBusy]             = useState(false);
+
+  const submitPair = useCallback(async () => {
+    if (!keyFile) return;
+    const code = pairCode.replace(/\s+/g, '').trim();
+    const key  = pairKey.replace(/\s+/g, '').trim().toLowerCase();
+    if (!/^\d{6}$/.test(code)) {
+      Alert.alert('Invalid code', 'The pairing code is 6 digits.');
+      return;
+    }
+    if (!/^[0-9a-f]{64}$/.test(key)) {
+      Alert.alert('Invalid key', 'The device key must be 64 hex characters.');
+      return;
+    }
+    const name = pairName.trim() || 'New device';
+    setPairBusy(true);
+    try {
+      // 1. LINK_DEVICE on-chain so senders learn the new pub.
+      const tx = buildLinkDeviceTx({
+        from:       keyFile.pub_key,
+        x25519Pub:  key,
+        deviceName: name,
+        privKey:    keyFile.priv_key,
+      });
+      await submitTx(tx);
+      // 2. Ship the handshake payload to the new device. Encrypted for
+      //    its x25519 pub so only it can read — master priv in plaintext
+      //    would be catastrophic, E2E is the whole point.
+      const payload = JSON.stringify({
+        v: 1,
+        type: 'pair-handshake',
+        code,
+        master_pub:        keyFile.pub_key,
+        master_priv:       keyFile.priv_key,
+        master_x25519_pub: keyFile.x25519_pub,
+      });
+      const { nonce, ciphertext } = encryptMessage(
+        payload, keyFile.x25519_priv, key,
+      );
+      await sendEnvelope({
+        senderPub:    keyFile.x25519_pub,
+        recipientPub: key,
+        senderEd25519Pub: keyFile.pub_key,
+        nonce, ciphertext,
+      });
+      // 3. Optimistic local insert so the row shows up without waiting
+      //    for the next pull/refresh round-trip.
+      setDevices(prev => {
+        if (prev.some(d => d.x25519_pub_key === key)) return prev;
+        return [...prev, {
+          x25519_pub_key: key,
+          device_name:    name,
+          added_at:       Math.floor(Date.now() / 1000),
+        }];
+      });
+      setPairOpen(false);
+      setPairCode(''); setPairKey(''); setPairName('');
+      Alert.alert(
+        'Pairing sent',
+        'The new device should finish pairing in a few seconds.',
+      );
+    } catch (e: any) {
+      Alert.alert('Pairing failed', humanizeTxError(e));
+    } finally {
+      setPairBusy(false);
+    }
+  }, [keyFile, pairCode, pairKey, pairName]);
+
+  return (
+    <View style={{ flex: 1, backgroundColor: '#000000', paddingTop: insets.top }}>
+      <Header
+        title="Devices"
+        divider
+        left={<IconButton icon="chevron-back" size={36} onPress={() => safeBack()} />}
+      />
+
+      <ScrollView
+        contentContainerStyle={{ padding: 14, paddingBottom: insets.bottom + 30 }}
+        refreshControl={
+          <RefreshControl
+            refreshing={refreshing}
+            onRefresh={() => load(true)}
+            tintColor="#1d9bf0"
+          />
+        }
+      >
+        <Text style={{ color: '#8b8b8b', fontSize: 12, lineHeight: 17, marginBottom: 14 }}>
+          Every linked device has its own encryption key. Messages sent to you
+          are delivered to all active devices.
+        </Text>
+
+        {loading ? (
+          <View style={{ paddingTop: 60, alignItems: 'center' }}>
+            <ActivityIndicator color="#1d9bf0" />
+          </View>
+        ) : devices.length === 0 ? (
+          <View style={{
+            paddingTop: 60, alignItems: 'center', paddingHorizontal: 24,
+          }}>
+            <Ionicons name="phone-portrait-outline" size={36} color="#3a3a3a" />
+            <Text style={{
+              color: '#ffffff', fontSize: 15, fontWeight: '700',
+              marginTop: 10,
+            }}>
+              No devices registered yet
+            </Text>
+            <Text style={{
+              color: '#8b8b8b', fontSize: 13, textAlign: 'center',
+              marginTop: 6, lineHeight: 19,
+            }}>
+              This device auto-registers when the next network-fee is available.
+              Top up your balance and pull to refresh.
+            </Text>
+          </View>
+        ) : (
+          <View style={{
+            borderRadius: 14,
+            backgroundColor: '#0a0a0a',
+            borderWidth: 1, borderColor: '#1f1f1f',
+            overflow: 'hidden',
+          }}>
+            {devices.map((d, i) => {
+              const isMe = d.x25519_pub_key === meX25519;
+              const busy = unlinking === d.x25519_pub_key;
+              return (
+                <View key={d.x25519_pub_key}>
+                  {i > 0 && <View style={{ height: 1, backgroundColor: '#1f1f1f' }} />}
+                  <View style={{
+                    flexDirection: 'row', alignItems: 'center',
+                    paddingHorizontal: 14, paddingVertical: 14, gap: 12,
+                  }}>
+                    <Ionicons
+                      name={isMe ? 'phone-portrait' : 'phone-portrait-outline'}
+                      size={22}
+                      color={isMe ? '#1d9bf0' : '#d0d0d0'}
+                    />
+                    <View style={{ flex: 1, minWidth: 0 }}>
+                      <View style={{ flexDirection: 'row', alignItems: 'center', gap: 6 }}>
+                        <Text
+                          style={{ color: '#ffffff', fontSize: 15, fontWeight: '700' }}
+                          numberOfLines={1}
+                        >
+                          {d.device_name || 'Unnamed device'}
+                        </Text>
+                        {isMe && (
+                          <View style={{
+                            paddingHorizontal: 6, paddingVertical: 1,
+                            borderRadius: 6, backgroundColor: '#0d2540',
+                          }}>
+                            <Text style={{ color: '#1d9bf0', fontSize: 10, fontWeight: '700' }}>
+                              THIS DEVICE
+                            </Text>
+                          </View>
+                        )}
+                      </View>
+                      <Text
+                        style={{
+                          color: '#8b8b8b', fontSize: 11, fontFamily: 'monospace',
+                          marginTop: 3,
+                        }}
+                        numberOfLines={1}
+                      >
+                        {shortPub(d.x25519_pub_key)}
+                      </Text>
+                      <Text style={{ color: '#6a6a6a', fontSize: 11, marginTop: 2 }}>
+                        Linked {formatDate(d.added_at)}
+                      </Text>
+                    </View>
+                    {!isMe && (
+                      <Pressable
+                        onPress={() => onUnlink(d)}
+                        disabled={busy}
+                        style={({ pressed }) => ({
+                          paddingHorizontal: 12, paddingVertical: 7,
+                          borderRadius: 999,
+                          borderWidth: 1, borderColor: '#3a2020',
+                          backgroundColor: pressed ? '#2a1414' : 'transparent',
+                          opacity: busy ? 0.5 : 1,
+                        })}
+                      >
+                        {busy ? (
+                          <ActivityIndicator size="small" color="#ff6b6b" />
+                        ) : (
+                          <Text style={{ color: '#ff6b6b', fontSize: 12, fontWeight: '700' }}>
+                            Unlink
+                          </Text>
+                        )}
+                      </Pressable>
+                    )}
+                  </View>
+                </View>
+              );
+            })}
+          </View>
+        )}
+
+        {/* Link new device — opens a modal with Code + DeviceKey inputs
+            that the operator transcribes from the new device's
+            /auth/pair screen. */}
+        <View style={{ marginTop: 18 }}>
+          <Pressable
+            onPress={() => setPairOpen(true)}
+            style={({ pressed }) => ({
+              paddingVertical: 13, paddingHorizontal: 16,
+              borderRadius: 14,
+              backgroundColor: pressed ? '#1a1a1a' : '#0a0a0a',
+              borderWidth: 1, borderColor: '#1f1f1f',
+              flexDirection: 'row', alignItems: 'center', gap: 10,
+            })}
+          >
+            <Ionicons name="link-outline" size={18} color="#1d9bf0" />
+            <View style={{ flex: 1 }}>
+              <Text style={{ color: '#ffffff', fontSize: 14, fontWeight: '700' }}>
+                Link new device
+              </Text>
+              <Text style={{ color: '#8b8b8b', fontSize: 12, marginTop: 2 }}>
+                Enter the 6-digit code from the new device
+              </Text>
+            </View>
+            <Ionicons name="chevron-forward" size={18} color="#6a6a6a" />
+          </Pressable>
+        </View>
+      </ScrollView>
+
+      {/* ── Pair new device modal ───────────────────────────────────── */}
+      <Modal
+        visible={pairOpen}
+        animationType="fade"
+        transparent
+        onRequestClose={() => !pairBusy && setPairOpen(false)}
+      >
+        <KeyboardAvoidingView
+          behavior={Platform.OS === 'ios' ? 'padding' : undefined}
+          style={{
+            flex: 1,
+            backgroundColor: 'rgba(0,0,0,0.7)',
+            justifyContent: 'center', alignItems: 'center',
+            paddingHorizontal: 20,
+          }}
+        >
+          <View style={{
+            width: '100%', maxWidth: 420,
+            backgroundColor: '#0a0a0a',
+            borderRadius: 18,
+            borderWidth: 1, borderColor: '#1f1f1f',
+            padding: 20, gap: 12,
+          }}>
+            <View style={{
+              flexDirection: 'row', alignItems: 'center',
+              justifyContent: 'space-between', marginBottom: 4,
+            }}>
+              <Text style={{ color: '#ffffff', fontSize: 18, fontWeight: '800' }}>
+                Link new device
+              </Text>
+              <Pressable
+                onPress={() => !pairBusy && setPairOpen(false)}
+                hitSlop={8}
+              >
+                <Ionicons name="close" size={22} color="#8b8b8b" />
+              </Pressable>
+            </View>
+
+            <Text style={{ color: '#8b8b8b', fontSize: 12, lineHeight: 18 }}>
+              Open the new device, tap <Text style={{ color: '#ffffff' }}>Pair</Text> on
+              the welcome screen, then transcribe the code + device key shown there.
+            </Text>
+
+            <PairInput
+              label="6-digit code"
+              value={pairCode}
+              onChangeText={setPairCode}
+              placeholder="000000"
+              keyboardType="number-pad"
+              maxLength={6}
+              monospace
+            />
+            <PairInput
+              label="Device key"
+              value={pairKey}
+              onChangeText={setPairKey}
+              placeholder="64 hex chars"
+              autoCapitalize="none"
+              maxLength={64}
+              monospace
+            />
+            <PairInput
+              label="Name for this device (optional)"
+              value={pairName}
+              onChangeText={setPairName}
+              placeholder="e.g. Alice's laptop"
+              maxLength={64}
+            />
+
+            <View style={{
+              flexDirection: 'row', justifyContent: 'flex-end',
+              gap: 10, marginTop: 8,
+            }}>
+              <Pressable
+                onPress={() => setPairOpen(false)}
+                disabled={pairBusy}
+                style={({ pressed }) => ({
+                  paddingHorizontal: 16, paddingVertical: 10,
+                  borderRadius: 999,
+                  backgroundColor: pressed ? '#1a1a1a' : 'transparent',
+                  opacity: pairBusy ? 0.5 : 1,
+                })}
+              >
+                <Text style={{ color: '#8b8b8b', fontSize: 14, fontWeight: '700' }}>
+                  Cancel
+                </Text>
+              </Pressable>
+              <Pressable
+                onPress={submitPair}
+                disabled={pairBusy}
+                style={({ pressed }) => ({
+                  paddingHorizontal: 18, paddingVertical: 10,
+                  borderRadius: 999,
+                  backgroundColor: pressed ? '#1580c8' : '#1d9bf0',
+                  opacity: pairBusy ? 0.7 : 1,
+                  minWidth: 90, alignItems: 'center',
+                })}
+              >
+                {pairBusy ? (
+                  <ActivityIndicator size="small" color="#ffffff" />
+                ) : (
+                  <Text style={{ color: '#ffffff', fontSize: 14, fontWeight: '700' }}>
+                    Link
+                  </Text>
+                )}
+              </Pressable>
+            </View>
+          </View>
+        </KeyboardAvoidingView>
+      </Modal>
+    </View>
+  );
+}
+
+function PairInput({
+  label, value, onChangeText, placeholder, keyboardType, autoCapitalize,
+  maxLength, monospace,
+}: {
+  label: string;
+  value: string;
+  onChangeText: (v: string) => void;
+  placeholder?: string;
+  keyboardType?: 'default' | 'number-pad';
+  autoCapitalize?: 'none' | 'sentences';
+  maxLength?: number;
+  monospace?: boolean;
+}) {
+  return (
+    <View>
+      <Text style={{
+        color: '#8b8b8b', fontSize: 11, fontWeight: '700',
+        textTransform: 'uppercase', letterSpacing: 1, marginBottom: 6,
+      }}>
+        {label}
+      </Text>
+      <TextInput
+        value={value}
+        onChangeText={onChangeText}
+        placeholder={placeholder}
+        placeholderTextColor="#3a3a3a"
+        keyboardType={keyboardType}
+        autoCapitalize={autoCapitalize ?? 'sentences'}
+        autoCorrect={false}
+        maxLength={maxLength}
+        style={{
+          color: '#ffffff', fontSize: monospace ? 13 : 14,
+          fontFamily: monospace ? 'monospace' : undefined,
+          backgroundColor: '#000000',
+          borderRadius: 10,
+          paddingHorizontal: 12, paddingVertical: 10,
+          borderWidth: 1, borderColor: '#1f1f1f',
+        }}
+      />
+    </View>
+  );
+}

client-app/app/(app)/settings.tsx

@@ -492,6 +492,18 @@ export default function SettingsScreen() {
           />
         </Card>
 
+        {/* ── Devices — multi-device registry (v2.2.0) ── */}
+        <SectionLabel>Devices</SectionLabel>
+        <Card>
+          <Row
+            icon="phone-portrait-outline"
+            label="Linked devices"
+            value="Manage the devices that receive your messages"
+            onPress={() => router.push('/(app)/devices' as never)}
+            first
+          />
+        </Card>
+
         {/* ── Account ── */}
         <SectionLabel>Account</SectionLabel>
         <Card>

client-app/app/(auth)/pair.tsx

@@ -0,0 +1,300 @@
+/**
+ * Pair — secondary-device onboarding.
+ *
+ * Flow (new device, this screen):
+ *   1. Generate a fresh X25519 keypair locally + random 6-digit code.
+ *   2. Display { code, device x25519 pub }. User enters both on their
+ *      primary device (Settings → Devices → Link new device).
+ *   3. Primary device:
+ *        - submits LINK_DEVICE tx to publish our pub under its master,
+ *        - sends a relay envelope to our x25519 pub, encrypted with its
+ *          own x25519 priv, containing { code, master_pub, master_priv,
+ *          master_x25519_pub }.
+ *   4. We poll /relay/inbox every few seconds; when a decryptable
+ *      envelope arrives whose payload.code matches our displayed code,
+ *      we treat it as the handshake, assemble a KeyFile, save it, and
+ *      redirect into (app).
+ *
+ * Security notes:
+ *   - Master Ed25519 priv travels only via this envelope, encrypted for
+ *     this device's X25519 pub (which only this device holds the priv
+ *     for). Exposure is limited to one successful decrypt; we DELETE
+ *     the envelope from the mailbox immediately.
+ *   - The 6-digit code defends against a confused primary device paired
+ *     with a different victim, or a race with an attacker who guesses
+ *     our X25519 pub. Envelope without matching code → ignored.
+ *   - Envelope is short-lived in the mailbox: we DELETE on first decrypt
+ *     and the relay node has its own TTL.
+ */
+import React, { useCallback, useEffect, useRef, useState } from 'react';
+import {
+  View, Text, Pressable, ActivityIndicator, ScrollView,
+} from 'react-native';
+import { router } from 'expo-router';
+import { Ionicons } from '@expo/vector-icons';
+import * as Clipboard from 'expo-clipboard';
+import { useSafeAreaInsets } from 'react-native-safe-area-context';
+import nacl from 'tweetnacl';
+
+import { useStore } from '@/lib/store';
+import { bytesToHex, decryptMessage } from '@/lib/crypto';
+import { fetchInbox } from '@/lib/api';
+import { saveKeyFile, markDeviceRegistered } from '@/lib/storage';
+import { safeBack } from '@/lib/utils';
+import type { KeyFile } from '@/lib/types';
+
+// Protocol constant — bump if payload shape changes.
+const PAIR_ENVELOPE_VERSION = 1;
+
+interface PairEnvelopePayload {
+  v:             number;
+  type:          'pair-handshake';
+  code:          string;
+  master_pub:    string;   // Ed25519 pub, hex
+  master_priv:   string;   // Ed25519 priv, hex
+  master_x25519_pub: string;  // primary device's x25519 pub, hex (for nothing special — just FYI)
+}
+
+function randomCode(): string {
+  // Six decimal digits. Entropy ~20 bits. Good enough for a one-shot
+  // rendezvous code gated by an out-of-band delivery channel (envelope
+  // targeted at a freshly-generated X25519 pub that only this device
+  // holds the priv for).
+  const n = Math.floor(Math.random() * 1_000_000);
+  return n.toString().padStart(6, '0');
+}
+
+export default function PairScreen() {
+  const insets       = useSafeAreaInsets();
+  const setKeyFile   = useStore(s => s.setKeyFile);
+
+  // One-shot keypair + code for this pairing session. Regenerate only on
+  // manual Retry (unmount+remount).
+  const session = useRef(genSession()).current;
+
+  const [status, setStatus] = useState<'waiting' | 'success' | 'error'>('waiting');
+  const [err,    setErr]    = useState<string | null>(null);
+
+  const copyCode = useCallback(async () => {
+    await Clipboard.setStringAsync(session.code);
+  }, [session.code]);
+
+  const copyPub = useCallback(async () => {
+    await Clipboard.setStringAsync(session.x25519Pub);
+  }, [session.x25519Pub]);
+
+  // Poll mailbox until a matching handshake envelope arrives, or user
+  // backs out. Interval 2.5s — conservative on battery, fine for a
+  // flow the user is staring at for a minute.
+  useEffect(() => {
+    let cancelled = false;
+    let timer: ReturnType<typeof setTimeout> | null = null;
+
+    const tick = async () => {
+      if (cancelled) return;
+      try {
+        const envs = await fetchInbox(session.x25519Pub);
+        for (const env of envs) {
+          // Decrypt each envelope with our session priv. We don't know
+          // the primary's x25519 pub up front — it's inside the envelope
+          // metadata. decryptMessage needs both pubs, so we pass the
+          // envelope's sender_pub directly.
+          const plain = decryptMessage(
+            env.ciphertext, env.nonce, env.sender_pub, session.x25519Priv,
+          );
+          if (!plain) continue;
+          let payload: PairEnvelopePayload;
+          try {
+            payload = JSON.parse(plain);
+          } catch { continue; }
+          if (
+            payload.v !== PAIR_ENVELOPE_VERSION ||
+            payload.type !== 'pair-handshake' ||
+            payload.code !== session.code ||
+            !payload.master_pub || !payload.master_priv
+          ) continue;
+
+          // Success — materialise a KeyFile and redirect.
+          const kf: KeyFile = {
+            pub_key:     payload.master_pub,
+            priv_key:    payload.master_priv,
+            x25519_pub:  session.x25519Pub,
+            x25519_priv: session.x25519Priv,
+          };
+          await saveKeyFile(kf);
+          // The root layout auto-links us on first boot if needed, but
+          // the primary device already submitted LINK_DEVICE for our
+          // pub as part of the pairing, so the registry is already
+          // correct. Mark ourselves registered so the revoke-detection
+          // branch doesn't spuriously wipe on next launch.
+          await markDeviceRegistered();
+          setKeyFile(kf);
+
+          // Envelope stays in mailbox until relay TTL eviction; the
+          // single-shot handshake is idempotent (saveKeyFile overwrites)
+          // and our session pub won't be polled again after redirect.
+          setStatus('success');
+          setTimeout(() => {
+            if (!cancelled) router.replace('/(app)/chats' as never);
+          }, 600);
+          return;
+        }
+      } catch {
+        /* transient — retry */
+      }
+      if (!cancelled) timer = setTimeout(tick, 2_500);
+    };
+
+    tick();
+    return () => {
+      cancelled = true;
+      if (timer) clearTimeout(timer);
+    };
+  }, [session, setKeyFile]);
+
+  return (
+    <View style={{
+      flex: 1, backgroundColor: '#000000',
+      paddingTop: insets.top + 12,
+      paddingBottom: Math.max(insets.bottom, 20),
+    }}>
+      <ScrollView
+        contentContainerStyle={{ padding: 24 }}
+        showsVerticalScrollIndicator={false}
+      >
+        {/* Header */}
+        <Pressable
+          onPress={() => safeBack('/')}
+          hitSlop={8}
+          style={{ alignSelf: 'flex-start', marginBottom: 20 }}
+        >
+          <Ionicons name="chevron-back" size={28} color="#ffffff" />
+        </Pressable>
+
+        <View style={{ alignItems: 'center', marginBottom: 28 }}>
+          <View style={{
+            width: 80, height: 80, borderRadius: 22,
+            backgroundColor: '#0a0a0a',
+            borderWidth: 1, borderColor: '#1f1f1f',
+            alignItems: 'center', justifyContent: 'center',
+          }}>
+            <Ionicons name="link" size={40} color="#1d9bf0" />
+          </View>
+          <Text style={{
+            color: '#ffffff', fontSize: 22, fontWeight: '800',
+            marginTop: 14, textAlign: 'center',
+          }}>
+            Pair with your other device
+          </Text>
+          <Text style={{
+            color: '#8b8b8b', fontSize: 13, lineHeight: 19,
+            marginTop: 8, textAlign: 'center', maxWidth: 300,
+          }}>
+            On a device where you're already signed in,
+            open Settings → Devices → Link new device,
+            and enter these values.
+          </Text>
+        </View>
+
+        {/* Code */}
+        <View style={{
+          borderRadius: 14,
+          backgroundColor: '#0a0a0a',
+          borderWidth: 1, borderColor: '#1f1f1f',
+          paddingVertical: 18, paddingHorizontal: 16,
+          marginBottom: 14, alignItems: 'center',
+        }}>
+          <Text style={{
+            color: '#5a5a5a', fontSize: 11, fontWeight: '700',
+            textTransform: 'uppercase', letterSpacing: 1.2,
+          }}>
+            1. Code
+          </Text>
+          <Text style={{
+            color: '#ffffff', fontSize: 38, fontWeight: '800',
+            letterSpacing: 6, marginTop: 4, fontFamily: 'monospace',
+          }}>
+            {session.code.slice(0, 3)} {session.code.slice(3)}
+          </Text>
+          <Pressable onPress={copyCode} hitSlop={6} style={{ marginTop: 6 }}>
+            <Text style={{ color: '#1d9bf0', fontSize: 12, fontWeight: '600' }}>
+              Copy code
+            </Text>
+          </Pressable>
+        </View>
+
+        {/* Device key */}
+        <View style={{
+          borderRadius: 14,
+          backgroundColor: '#0a0a0a',
+          borderWidth: 1, borderColor: '#1f1f1f',
+          paddingVertical: 16, paddingHorizontal: 16,
+          marginBottom: 20,
+        }}>
+          <Text style={{
+            color: '#5a5a5a', fontSize: 11, fontWeight: '700',
+            textTransform: 'uppercase', letterSpacing: 1.2,
+          }}>
+            2. Device key
+          </Text>
+          <Text
+            selectable
+            style={{
+              color: '#ffffff', fontSize: 12, fontFamily: 'monospace',
+              marginTop: 6, lineHeight: 17,
+            }}
+          >
+            {session.x25519Pub}
+          </Text>
+          <Pressable onPress={copyPub} hitSlop={6} style={{ marginTop: 8 }}>
+            <Text style={{ color: '#1d9bf0', fontSize: 12, fontWeight: '600' }}>
+              Copy key
+            </Text>
+          </Pressable>
+        </View>
+
+        {/* Status */}
+        <View style={{ alignItems: 'center', minHeight: 56 }}>
+          {status === 'waiting' && (
+            <View style={{ flexDirection: 'row', alignItems: 'center', gap: 10 }}>
+              <ActivityIndicator size="small" color="#1d9bf0" />
+              <Text style={{ color: '#8b8b8b', fontSize: 13 }}>
+                Waiting for your other device…
+              </Text>
+            </View>
+          )}
+          {status === 'success' && (
+            <View style={{ flexDirection: 'row', alignItems: 'center', gap: 10 }}>
+              <Ionicons name="checkmark-circle" size={20} color="#3ba55d" />
+              <Text style={{ color: '#3ba55d', fontSize: 13, fontWeight: '700' }}>
+                Paired. Opening your chats…
+              </Text>
+            </View>
+          )}
+          {status === 'error' && (
+            <Text style={{ color: '#f4212e', fontSize: 13, textAlign: 'center' }}>
+              {err ?? 'Something went wrong. Please retry.'}
+            </Text>
+          )}
+        </View>
+      </ScrollView>
+    </View>
+  );
+}
+
+// ─── session helper ──────────────────────────────────────────────────────
+
+interface PairSession {
+  x25519Pub:  string;  // hex
+  x25519Priv: string;  // hex
+  code:       string;
+}
+
+function genSession(): PairSession {
+  const kp = nacl.box.keyPair();
+  return {
+    x25519Pub:  bytesToHex(kp.publicKey),
+    x25519Priv: bytesToHex(kp.secretKey),
+    code:       randomCode(),
+  };
+}

client-app/app/index.tsx

@@ -346,8 +346,13 @@ export default function WelcomeScreen() {
           {/* CTA — прижата к правому нижнему краю. */}
           <View style={{
             flexDirection: 'row', justifyContent: 'flex-end', gap: 10,
-            paddingHorizontal: 24, paddingBottom: 8,
+            paddingHorizontal: 24, paddingBottom: 8, flexWrap: 'wrap',
           }}>
+            <CTASecondary
+              label="Pair"
+              icon="link"
+              onPress={() => router.push('/(auth)/pair' as never)}
+            />
             <CTASecondary
               label="Import"
               onPress={() => router.push('/(auth)/import' as never)}

client-app/hooks/useGlobalInbox.ts

@@ -52,10 +52,13 @@ export function useGlobalInbox() {
       try {
         const envelopes = await fetchInbox(keyFile.x25519_pub);
         for (const env of envelopes) {
-          // Найти контакт по sender_pub — если не знакомый, игнорим
-          // (для MVP; в future можно показывать "unknown sender").
-          const c = contactsRef.current.find(
-            x => x.x25519Pub === env.sender_pub,
+          // Attribution (v2.2.0+): prefer the envelope's master Ed25519
+          // so messages from any of the sender's linked devices roll
+          // into a single chat. Fall back to legacy X25519-based lookup
+          // for pre-v2.2.0 senders that left the field empty.
+          const c = contactsRef.current.find(x =>
+            (env.sender_ed25519_pub && x.address === env.sender_ed25519_pub) ||
+            x.x25519Pub === env.sender_pub,
           );
           if (!c) continue;
 

client-app/hooks/useMessages.ts

@@ -24,10 +24,26 @@ import { tryParsePostRef } from '@/lib/forwardPost';
 const FALLBACK_POLL_INTERVAL  = 30_000;  // HTTP poll when WS is down
 const WS_GRACE_BEFORE_POLLING = 15_000;  // don't start polling immediately on disconnect
 
-export function useMessages(contactX25519: string) {
+/**
+ * useMessages — mounts per-chat inbox consumption. Accepts:
+ *   - contactX25519: the legacy/primary X25519 for the contact.
+ *   - contactMasterEd25519 (optional, v2.2.0+): the contact's master
+ *     identity so we can attribute envelopes from any of their
+ *     linked devices to this conversation.
+ *
+ * Matching rule: an envelope belongs to this chat when
+ *     env.sender_ed25519_pub === contactMasterEd25519  (v2.2.0 path)
+ *  OR env.sender_pub         === contactX25519         (legacy path)
+ */
+export function useMessages(contactX25519: string, contactMasterEd25519?: string) {
   const keyFile   = useStore(s => s.keyFile);
   const appendMsg = useStore(s => s.appendMessage);
 
+  const matchesChat = useCallback((env: { sender_pub: string; sender_ed25519_pub: string }): boolean => {
+    if (contactMasterEd25519 && env.sender_ed25519_pub === contactMasterEd25519) return true;
+    return env.sender_pub === contactX25519;
+  }, [contactX25519, contactMasterEd25519]);
+
   // Подгружаем кэш сообщений из AsyncStorage при открытии чата.
   // Релей держит envelope'ы всего 7 дней, поэтому без чтения кэша
   // история старше недели пропадает при каждом рестарте приложения.
@@ -48,8 +64,8 @@ export function useMessages(contactX25519: string) {
     try {
       const envelopes = await fetchInbox(keyFile.x25519_pub);
       for (const env of envelopes) {
-        // Only process messages from this contact
-        if (env.sender_pub !== contactX25519) continue;
+        // Only process messages that belong to this chat (see matchesChat).
+        if (!matchesChat(env)) continue;
 
         const text = decryptMessage(
           env.ciphertext,
@@ -130,10 +146,17 @@ export function useMessages(contactX25519: string) {
     // the handler so we only render messages in THIS chat.
     const offInbox = ws.subscribe('inbox:' + keyFile.x25519_pub, (frame) => {
       if (frame.event !== 'inbox') return;
-      const d = frame.data as { sender_pub?: string } | undefined;
-      // Optimisation: if the envelope is from a different peer, skip the
-      // whole refetch — we'd just drop it in the sender filter below anyway.
-      if (d?.sender_pub && d.sender_pub !== contactX25519) return;
+      const d = frame.data as {
+        sender_pub?: string; sender_ed25519_pub?: string;
+      } | undefined;
+      // Optimisation: if the envelope definitely isn't for this chat,
+      // skip the whole refetch. Multi-device aware — the peer may be
+      // writing from any of their linked devices (different X25519
+      // pubs), so we check against their master Ed25519 too.
+      if (d && !matchesChat({
+        sender_pub:         d.sender_pub ?? '',
+        sender_ed25519_pub: d.sender_ed25519_pub ?? '',
+      })) return;
       pullAndDecrypt();
     });
 

client-app/lib/api.ts

@@ -264,6 +264,9 @@ export async function getTxHistory(pubkey: string, limit = 50): Promise<TxRecord
 interface InboxItemWire {
   id:                 string;
   sender_pub:         string;
+  /** sender_ed25519_pub was added in v2.2.0; older nodes omit it.
+      Default to empty string when missing. */
+  sender_ed25519_pub?: string;
   recipient_pub:      string;
   fee_ut?:            number;
   sent_at:            number;
@@ -328,6 +331,7 @@ export async function fetchInbox(x25519PubHex: string): Promise<Envelope[]> {
   return items.map((it): Envelope => ({
     id:                it.id,
     sender_pub:        it.sender_pub,
+    sender_ed25519_pub: it.sender_ed25519_pub ?? '',
     recipient_pub:     it.recipient_pub,
     nonce:             bytesToHex(base64ToBytes(it.nonce)),
     ciphertext:        bytesToHex(base64ToBytes(it.ciphertext)),
@@ -365,6 +369,25 @@ export interface IdentityInfo {
   x25519_pub: string;   // hex Curve25519 key; empty string if not published
   nickname:   string;
   registered: boolean;
+  /**
+   * Number of active (non-revoked) devices linked to this master identity
+   * via LINK_DEVICE (v2.2.0). 0 for legacy identities that only published
+   * a single X25519 via REGISTER_KEY — senders should fall back to
+   * `x25519_pub` above and skip the device fan-out path.
+   */
+  device_count?: number;
+}
+
+/**
+ * One active device in an identity's multi-device registry. Returned by
+ * GET /api/devices/{master_pub} as part of `devices[]`. Senders use the
+ * list to fan out one sealed envelope per X25519 pub so all of the
+ * recipient's devices receive the message.
+ */
+export interface DeviceInfo {
+  x25519_pub_key: string;
+  device_name:    string;
+  added_at:       number;  // unix seconds
 }
 
 /**
@@ -409,6 +432,56 @@ export async function getIdentity(pubkeyOrAddr: string): Promise<IdentityInfo |
   }
 }
 
+// ─── Multi-device registry (v2.2.0) ───────────────────────────────────────
+
+interface DevicesResponse {
+  master_pub: string;
+  count:      number;
+  devices:    DeviceInfo[];
+}
+
+/**
+ * GET /api/devices/{master_pub} — all active (non-revoked) device records
+ * for the given master identity. Returns an empty array for a legacy
+ * identity (device_count == 0) or a network error — callers should treat
+ * both the same way and fall back to IdentityInfo.x25519_pub so the
+ * pre-v2.2.0 single-device path keeps working.
+ */
+export async function fetchDevices(masterPub: string): Promise<DeviceInfo[]> {
+  try {
+    const resp = await get<DevicesResponse>(`/api/devices/${masterPub}`);
+    return resp.devices ?? [];
+  } catch {
+    return [];
+  }
+}
+
+/**
+ * Pick the right set of recipient X25519 pubs for a sender's fan-out.
+ * Two paths, in priority order:
+ *
+ *   1. New path — /api/devices returns ≥1 entry. Send to each device.
+ *   2. Legacy path — identity published an X25519 via REGISTER_KEY
+ *      (pre-v2.2.0 clients). Send to just that one.
+ *
+ * Returns an empty array only when the recipient has published nothing
+ * at all — caller must surface "no encryption key" to the user rather
+ * than drop the message on the floor.
+ */
+export async function resolveRecipientKeys(
+  recipientMasterPub: string,
+): Promise<string[]> {
+  const devs = await fetchDevices(recipientMasterPub);
+  if (devs.length > 0) {
+    return devs.map(d => d.x25519_pub_key);
+  }
+  const identity = await getIdentity(recipientMasterPub);
+  if (identity?.x25519_pub) {
+    return [identity.x25519_pub];
+  }
+  return [];
+}
+
 // ─── Contract API ─────────────────────────────────────────────────────────────
 
 /**
@@ -712,6 +785,68 @@ export function buildTransferTx(params: {
   };
 }
 
+/**
+ * LINK_DEVICE transaction — publish a per-device X25519 pub in the
+ * identity's device registry so senders can fan out envelopes across
+ * every active device. Signed by the master Ed25519 (= `from`).
+ *
+ * `deviceName` is a short human label shown in Settings → Devices
+ * (≤ 64 bytes, printable ASCII/UTF-8, no control chars).
+ */
+export function buildLinkDeviceTx(params: {
+  from:        string;  // master Ed25519 pubkey
+  x25519Pub:   string;  // per-device X25519 pubkey (64 hex chars, lowercase)
+  deviceName:  string;
+  privKey:     string;
+}): RawTx {
+  const id        = newTxID();
+  const timestamp = rfc3339Now();
+  const payloadObj = {
+    x25519_pub_key: params.x25519Pub,
+    device_name:    params.deviceName,
+  };
+  const payload = strToBase64(JSON.stringify(payloadObj));
+
+  const canonical = txCanonicalBytes({
+    id, type: 'LINK_DEVICE', from: params.from, to: '',
+    amount: 0, fee: MIN_TX_FEE, payload, timestamp,
+  });
+
+  return {
+    id, type: 'LINK_DEVICE', from: params.from, to: '',
+    amount: 0, fee: MIN_TX_FEE, payload, timestamp,
+    signature: signBase64(canonical, params.privKey),
+  };
+}
+
+/**
+ * UNLINK_DEVICE transaction — revoke a previously-linked device so senders
+ * stop shipping envelopes to its X25519 pub. The revoked device itself,
+ * when it next comes online and sees its own pub in the revoked list,
+ * is expected to wipe local state (master priv + cached chats).
+ */
+export function buildUnlinkDeviceTx(params: {
+  from:       string;   // master Ed25519 pubkey
+  x25519Pub:  string;   // pub to revoke
+  privKey:    string;
+}): RawTx {
+  const id        = newTxID();
+  const timestamp = rfc3339Now();
+  const payloadObj = { x25519_pub_key: params.x25519Pub };
+  const payload = strToBase64(JSON.stringify(payloadObj));
+
+  const canonical = txCanonicalBytes({
+    id, type: 'UNLINK_DEVICE', from: params.from, to: '',
+    amount: 0, fee: MIN_TX_FEE, payload, timestamp,
+  });
+
+  return {
+    id, type: 'UNLINK_DEVICE', from: params.from, to: '',
+    amount: 0, fee: MIN_TX_FEE, payload, timestamp,
+    signature: signBase64(canonical, params.privKey),
+  };
+}
+
 /**
  * CONTACT_REQUEST transaction.
  *

client-app/lib/storage.ts

@@ -14,6 +14,12 @@ const KEYFILE_KEY = 'dchain_keyfile';
 const CONTACTS_KEY = 'dchain_contacts';
 const SETTINGS_KEY = 'dchain_settings';
 const CHATS_KEY = 'dchain_chats';
+// Remembers (locally, per install) that this device's X25519 pub has been
+// successfully linked on-chain at least once. Distinguishes "first boot,
+// not registered yet" from "we were registered and then revoked by another
+// device". The second case triggers self-wipe. Stored in AsyncStorage —
+// if it's missing, we simply re-link.
+const DEVICE_REGISTERED_KEY = 'dchain_device_registered';
 
 /** Save the key file in secure storage (encrypted on device). */
 export async function saveKeyFile(kf: KeyFile): Promise<void> {
@@ -99,3 +105,57 @@ export async function appendMessage(chatId: string, msg: CachedMessage): Promise
   const trimmed = msgs.slice(-500);
   await AsyncStorage.setItem(`${CHATS_KEY}_${chatId}`, JSON.stringify(trimmed));
 }
+
+// ─── Multi-device bookkeeping (v2.2.0) ────────────────────────────────────
+
+/**
+ * isDeviceRegistered returns true if this device has ever successfully
+ * linked its X25519 pub on-chain under the current master identity.
+ * A true-then-absent transition (registered → not in chain's active list)
+ * is interpreted as a remote revoke and triggers self-wipe.
+ */
+export async function isDeviceRegistered(): Promise<boolean> {
+  return (await AsyncStorage.getItem(DEVICE_REGISTERED_KEY)) === '1';
+}
+
+/** markDeviceRegistered is called after a LINK_DEVICE commits or is
+    observed in the registry on startup. */
+export async function markDeviceRegistered(): Promise<void> {
+  await AsyncStorage.setItem(DEVICE_REGISTERED_KEY, '1');
+}
+
+/** clearDeviceRegistered is part of wipeAllLocalState; also called on
+    explicit logout. */
+export async function clearDeviceRegistered(): Promise<void> {
+  await AsyncStorage.removeItem(DEVICE_REGISTERED_KEY);
+}
+
+/**
+ * wipeAllLocalState zeroes out every on-device artifact tied to the
+ * current identity: secure-store key, settings, contacts, chats cache,
+ * registered-device marker. Safe to call multiple times.
+ *
+ * Called in two scenarios:
+ *   1. Explicit "Delete account" in Settings.
+ *   2. Self-detected revoke — the chain says our X25519 pub is no longer
+ *      in the active registry but we previously marked it registered,
+ *      so another device issued UNLINK_DEVICE against us. We must not
+ *      keep using the master priv any more — it still works at the
+ *      crypto level, but the social contract is that we're revoked.
+ */
+export async function wipeAllLocalState(): Promise<void> {
+  // Secure store (key).
+  await SecureStore.deleteItemAsync(KEYFILE_KEY).catch(() => {});
+  // AsyncStorage — enumerate our known keys. We don't clear() the whole
+  // store because a share-provider or other app shard could live there.
+  const ks = await AsyncStorage.getAllKeys();
+  const ours = ks.filter(k =>
+    k === CONTACTS_KEY ||
+    k === SETTINGS_KEY ||
+    k === DEVICE_REGISTERED_KEY ||
+    k.startsWith(`${CHATS_KEY}_`),
+  );
+  if (ours.length > 0) {
+    await AsyncStorage.multiRemove(ours);
+  }
+}

client-app/lib/types.ts

@@ -34,7 +34,19 @@ export interface Contact {
 export interface Envelope {
   /** sha256(nonce||ciphertext)[:16] hex — stable server-assigned id. */
   id:            string;
-  sender_pub:    string;  // X25519 hex
+  sender_pub:    string;  // X25519 hex (this envelope's per-device sender key)
+  /**
+   * sender_ed25519_pub (v2.2.0+): the sender's master Ed25519 identity.
+   * Multiple X25519 pubs under the same identity all share one master —
+   * clients use THIS to group messages into a single conversation even
+   * when the sender replies from different devices.
+   *
+   * Empty string on legacy envelopes from pre-v2.2.0 senders. Consumers
+   * should fall back to `sender_pub` in that case (keeps old clients'
+   * messages visible, even if attribution is per-X25519 rather than
+   * per-identity).
+   */
+  sender_ed25519_pub: string;
   recipient_pub: string;  // X25519 hex
   nonce:         string;  // hex 24 bytes
   ciphertext:    string;  // hex NaCl box

cmd/node/main.go

@@ -684,10 +684,16 @@ func main() {
 	// /relay/inbox if it needs the full envelope. Keeps WS frames small and
 	// avoids a fat push for every message.
 	mailbox.SetOnStore(func(env *relay.Envelope) {
+		// Summary only — no ciphertext. Multi-device (v2.2.0+) clients
+		// use sender_ed25519_pub to decide whether the envelope belongs
+		// to the chat they're currently viewing (messages from any of
+		// the peer's linked devices share a master identity), so the
+		// field must be in every push.
 		sum, _ := json.Marshal(map[string]any{
 			"id":                 env.ID,
 			"recipient_pub":      env.RecipientPub,
 			"sender_pub":         env.SenderPub,
+			"sender_ed25519_pub": env.SenderEd25519PubKey,
 			"sent_at":            env.SentAt,
 		})
 		eventBus.EmitInbox(env.RecipientPub, sum)
@@ -878,6 +884,7 @@ func main() {
 		IdentityInfo: func(pubKeyOrAddr string) (*blockchain.IdentityInfo, error) {
 			return chain.IdentityInfo(pubKeyOrAddr)
 		},
+		DevicesOf:    chain.DevicesOf,
 		ValidatorSet: chain.ValidatorSet,
 		SubmitTx: func(tx *blockchain.Transaction) error {
 			if err := engine.AddTransaction(tx); err != nil {

deploy/single/join.sh

@@ -0,0 +1,202 @@
+#!/usr/bin/env bash
+# rejoin.sh — полная переустановка dchain joiner-ноды с нуля.
+# Публичный доступ без Caddy/TLS, без API-токена (на свой страх и риск).
+# Запускать БЕЗ sudo.
+
+set -euo pipefail
+
+# ── КОНФИГ ─────────────────────────────────────────────────────────────
+SEED_HTTP="${SEED_HTTP:-http://62.171.151.182:8082}"
+SEED_P2P_IP="${SEED_P2P_IP:-62.171.151.182}"
+SEED_P2P_PORT="${SEED_P2P_PORT:-4005}"
+REPO_URL="${REPO_URL:-https://git.vsecoder.vodka/vsecoder/dchain.git}"
+WORKDIR="${WORKDIR:-$HOME/dchain}"
+LOCAL_P2P_PORT="${LOCAL_P2P_PORT:-4001}"
+LOCAL_HTTP_PORT="${LOCAL_HTTP_PORT:-8082}"
+# ───────────────────────────────────────────────────────────────────────
+
+log()  { printf '\033[1;34m==>\033[0m %s\n' "$*"; }
+warn() { printf '\033[1;33m!!\033[0m  %s\n' "$*" >&2; }
+die()  { printf '\033[1;31mXX\033[0m  %s\n' "$*" >&2; exit 1; }
+need() { command -v "$1" >/dev/null || die "need $1 installed"; }
+
+# ── 0. Требования ──────────────────────────────────────────────────────
+[[ $EUID -eq 0 ]] && die "don't run as root — use your user account, sudo is used per-command"
+need docker; need git; need curl; need jq
+sudo -v
+
+# ── 1. Снести предыдущее состояние ─────────────────────────────────────
+log "stopping any existing dchain stack & purging volumes"
+if [[ -d "$WORKDIR/deploy/single" ]]; then
+  (cd "$WORKDIR/deploy/single" && sudo docker compose down -v 2>/dev/null) || true
+fi
+sudo docker rm -f dchain_node dchain_caddy dchain 2>/dev/null || true
+mapfile -t stale_vols < <(sudo docker volume ls -q | grep -E '^(dchain|dchain-single)' || true)
+(( ${#stale_vols[@]} > 0 )) && sudo docker volume rm "${stale_vols[@]}" 2>/dev/null || true
+
+# ── 2. Свежий репозиторий ──────────────────────────────────────────────
+log "fetching repo → $WORKDIR"
+if [[ -d "$WORKDIR/.git" ]]; then
+  git -C "$WORKDIR" fetch --all --tags --prune
+  git -C "$WORKDIR" reset --hard origin/main
+else
+  rm -rf "$WORKDIR"
+  git clone "$REPO_URL" "$WORKDIR"
+fi
+cd "$WORKDIR/deploy/single"
+
+# ── 3. keys/ под UID 100 ───────────────────────────────────────────────
+log "preparing keys/ for container UID 100:101"
+mkdir -p keys
+sudo chown 100:101 keys
+sudo chmod 755 keys
+[[ -f keys/node.json ]] && { sudo chown 100:101 keys/node.json; sudo chmod 600 keys/node.json; }
+
+# ── 4. Slim-образ ──────────────────────────────────────────────────────
+log "building dchain image (slim)"
+IMAGE=$(sudo docker build -q -f ../prod/Dockerfile.slim ../..)
+[[ -z "$IMAGE" ]] && die "docker build failed"
+
+# ── 5. Ключ ноды ───────────────────────────────────────────────────────
+if [[ ! -f keys/node.json ]]; then
+  log "generating node identity"
+  sudo docker run --rm --entrypoint /usr/local/bin/client \
+    --user 100:101 \
+    -v "$PWD/keys:/out" \
+    "$IMAGE" \
+    keygen --out /out/node.json
+else
+  log "reusing existing keys/node.json"
+fi
+sudo chown 100:101 keys/node.json
+sudo chmod 600 keys/node.json
+
+# ── 6. peer_id seed'a ──────────────────────────────────────────────────
+log "fetching seed peer_id from $SEED_HTTP/stats"
+SEED_PEER_ID=$(curl -sfL "$SEED_HTTP/stats" | jq -r '.node.peer_id // empty')
+[[ -z "$SEED_PEER_ID" ]] && die "can't reach seed at $SEED_HTTP or peer_id missing"
+log "seed peer_id = $SEED_PEER_ID"
+
+# ── 7. Публичный IP ────────────────────────────────────────────────────
+PUBLIC_IP="${PUBLIC_IP:-$(curl -sfL https://api.ipify.org || true)}"
+[[ -z "$PUBLIC_IP" ]] && die "can't detect public IP; export PUBLIC_IP=x.x.x.x и перезапусти"
+log "public IP = $PUBLIC_IP"
+
+# ── 8. node.env (без токена, без genesis) ──────────────────────────────
+log "writing node.env"
+cp -f node.env.example node.env
+
+# удалить из example'а значения, которые мы хотим держать под своим контролем,
+# чтобы они не перекрыли наши append'ы снизу
+sudo sed -i -E '/^(#\s*)?DCHAIN_(GENESIS|API_TOKEN|API_PRIVATE|JOIN|PEERS|ANNOUNCE|DB|MAILBOX_DB|FEED_DB|REGISTER_RELAY|RELAY_FEE|FEED_DISK_LIMIT_MB|CHAIN_DISK_LIMIT_MB|UPDATE_SOURCE_URL)=/d' node.env
+
+sudo tee -a node.env > /dev/null <<EOF
+
+# ── AUTO-GENERATED BY rejoin.sh ─────────────────────────────────────
+# joiner → seed $SEED_HTTP  (public node, no token)
+DCHAIN_JOIN=$SEED_HTTP
+DCHAIN_PEERS=/ip4/$SEED_P2P_IP/tcp/$SEED_P2P_PORT/p2p/$SEED_PEER_ID
+DCHAIN_ANNOUNCE=/ip4/$PUBLIC_IP/tcp/$LOCAL_P2P_PORT
+
+DCHAIN_DB=/data/chain
+DCHAIN_MAILBOX_DB=/data/mailbox
+DCHAIN_FEED_DB=/data/feed
+
+DCHAIN_REGISTER_RELAY=true
+DCHAIN_RELAY_FEE=1000
+
+DCHAIN_FEED_DISK_LIMIT_MB=4096
+DCHAIN_CHAIN_DISK_LIMIT_MB=20480
+
+DCHAIN_UPDATE_SOURCE_URL=https://git.vsecoder.vodka/api/v1/repos/vsecoder/dchain/releases/latest
+EOF
+
+# ── 9. Compose: прямой проброс 4001+8080 наружу, Caddy снести навсегда ─
+log "patching docker-compose.yml: direct ports, caddy removed"
+python3 - <<PY
+import re, pathlib
+p = pathlib.Path('docker-compose.yml')
+src = p.read_text()
+
+# 9a. Вырезать весь сервис caddy (от "  caddy:" до следующего сервиса
+# того же уровня или конца блока services).
+src = re.sub(
+    r'(?ms)^  caddy:\n(?:(?:    .*\n)|\n)+?(?=^  [A-Za-z_-]+:|\Z)',
+    '', src,
+)
+
+# 9b. Убрать зависимости от caddy, если где-то остались.
+src = re.sub(r'(?m)^\s*-\s*caddy\s*$\n', '', src)
+src = re.sub(r'(?m)^\s*depends_on:\s*\n(\s*-\s*caddy\s*\n)+', '', src)
+
+# 9c. Заставить node светить наружу 4001 (libp2p) и 8080 (HTTP).
+# Ищем первый ports: в сервисе node; если его нет — инжектим.
+m = re.search(r'(?ms)^  node:\n(.*?)(?=^  [A-Za-z_-]+:|\Z)', src)
+if not m:
+    raise SystemExit('no `node:` service in compose')
+node_block = m.group(1)
+
+wanted = f'    ports:\n      - "$LOCAL_P2P_PORT:4001"\n      - "$LOCAL_HTTP_PORT:8080"\n'
+
+if re.search(r'(?m)^    ports:', node_block):
+    # Заменить существующий блок ports целиком
+    node_block_new = re.sub(
+        r'(?ms)^    ports:\n(?:      -.*\n)+',
+        wanted, node_block,
+    )
+else:
+    # Добавить сразу после строки "container_name:" (или restart:)
+    node_block_new = re.sub(
+        r'(?m)^(    (?:container_name|restart):.*\n)',
+        r'\\1' + wanted, node_block, count=1,
+    )
+    if node_block_new == node_block:  # fallback — в начало блока
+        node_block_new = wanted + node_block
+
+src = src[:m.start(1)] + node_block_new + src[m.end(1):]
+
+# 9d. Убрать блок expose у node — не нужен, раз ports наружу.
+src = re.sub(
+    r'(?ms)^    expose:\n(?:      -.*\n)+', '', src,
+)
+
+p.write_text(src)
+PY
+
+# ── 10. Подъём ─────────────────────────────────────────────────────────
+log "docker compose up -d"
+sudo docker compose up -d --build
+
+# ── 11. Sanity checks ──────────────────────────────────────────────────
+sleep 3
+log "sanity checks (дай ~30 сек чтобы healthcheck подхватился):"
+set +e
+echo "──── docker compose ps ────"
+sudo docker compose ps
+echo "──── docker logs dchain_node | tail ────"
+sudo docker logs --tail 30 dchain_node 2>&1
+echo "──── /api/netstats ────"
+curl -s "http://localhost:$LOCAL_HTTP_PORT/api/netstats" | jq '.'
+echo "──── seed height (для сверки) ────"
+curl -s "$SEED_HTTP/api/netstats" | jq '.total_blocks'
+
+cat <<EOM
+
+======================================================================
+✓ Готово. Нода публичная, без токена и без TLS.
+
+  API:
+    http://$PUBLIC_IP:$LOCAL_HTTP_PORT/api/netstats
+    http://$PUBLIC_IP:$LOCAL_HTTP_PORT/swagger
+
+  Следи за sync'ом:
+    sudo docker logs -f dchain_node | grep -E 'applied|height|peer'
+
+  Повторный полный сброс:
+    ./rejoin.sh
+
+  Открой в firewall/security-group на этом VPS:
+    - $LOCAL_P2P_PORT/tcp (libp2p)
+    - $LOCAL_HTTP_PORT/tcp (HTTP API)
+======================================================================
+EOM

desktop/.gitignore

@@ -0,0 +1,9 @@
+node_modules/
+dist/
+dist-electron/
+release/
+*.log
+.DS_Store
+
+# electron-builder output
+out/

desktop/README.md

@@ -0,0 +1,76 @@
+# DChain Desktop
+
+Electron shell for the DChain messenger and social feed.
+
+Same functionality as the mobile client-app, re-imagined with a
+keyboard-first, 3-panel desktop layout:
+
+```
+┌──────────────────────────────────────────────────────────┐
+│  DChain                                                   │ titlebar (drag)
+├──────┬───────────────────┬────────────────────────────────┤
+│ nav  │      list         │             detail             │
+│ 72px │   340px fixed     │            flex 1              │
+├──────┴───────────────────┴────────────────────────────────┤
+│  ● online  ·  node.example:8080  ·  height 10942          │ status bar
+└──────────────────────────────────────────────────────────┘
+```
+
+Sections (left rail): **Messages · Feed · Wallet · Contacts · Settings · Profile**.
+
+## Quick start
+
+```bash
+cd desktop
+npm install
+npm run dev          # concurrently: Vite dev server + Electron
+```
+
+The first boot will show the Welcome screen. Pick Create to generate
+fresh keys, or Import a `node.json` exported from the mobile client.
+
+## Build
+
+```bash
+npm run build        # produces dist/ (renderer) + dist-electron/ (main) + installers
+```
+
+Default installers are built with `electron-builder`: `.dmg` on macOS,
+NSIS `.exe` on Windows, AppImage + `.deb` on Linux. Adjust `build.*` in
+`package.json` for signing / notarisation.
+
+## Layout
+
+- `electron/` — main + preload. TypeScript, compiled to `dist-electron/`
+  by `tsc -p electron/tsconfig.json`.
+- `src/` — renderer. React + Vite. `@/` aliases to `src/`.
+- `src/shell/` — 3-panel chrome.
+- `src/sections/` — one folder per nav section, each exports `{ List, Detail }`.
+- `src/auth/Welcome.tsx` — shown when no key is loaded.
+- `src/lib/` — api, storage, store, types. Mirrors (without React-Native
+  deps) the relevant pieces of `../client-app/lib/`.
+
+## Security model
+
+Master Ed25519 priv lives in the OS keychain via Electron `safeStorage`
+(macOS Keychain / Windows DPAPI / libsecret). A renderer compromise
+cannot read or exfiltrate the key — it always travels through
+`window.dchain.keyfile.*` IPC, which main.ts validates and mediates.
+
+`contextIsolation: true`, `nodeIntegration: false`. CSP in `index.html`
+pins script sources to `'self'` while allowing `connect-src *` so the
+renderer can hit any node the user configures.
+
+## Pairing (v2.2.0-alpha5+)
+
+Desktop will reuse the same 6-digit-code + relay-envelope handshake as
+the mobile client. The scaffold in `src/auth/Welcome.tsx` stubs the
+button until the polling loop lands.
+
+## Multi-device fan-out
+
+When the node is at v2.2.0-alpha1+, `lib/api.ts:fetchDevices` returns
+every linked X25519 pub for a given identity; the sender then encrypts
+one envelope per device. Legacy nodes return an empty array and the
+client falls back to `IdentityInfo.x25519_pub`, preserving the
+pre-multi-device behaviour.

desktop/electron/main.ts

@@ -0,0 +1,175 @@
+// Electron main process.
+//
+// Responsibilities:
+//   * Create the BrowserWindow with a frameless + custom title bar so
+//     the renderer owns the chrome (matches macOS traffic lights and
+//     draws our 3-panel shell without OS padding).
+//   * Bridge safe native APIs to the renderer through preload.ts using
+//     contextBridge — keeps the renderer sandboxed (contextIsolation on,
+//     nodeIntegration off).
+//   * Deep-link handler for dchain://chat/<pub> and similar. Stub for now.
+//
+// Everything chain-related (HTTP / WS / crypto) still runs in the
+// renderer — Electron main stays a thin shell + native capabilities.
+
+import { app, BrowserWindow, shell, ipcMain, dialog, safeStorage, session } from 'electron';
+import * as path from 'node:path';
+import * as fs from 'node:fs/promises';
+
+const isDev = !!process.env.VITE_DEV_SERVER_URL;
+
+let mainWindow: BrowserWindow | null = null;
+
+// Content-Security-Policy is set here (not in <meta>) so we can diverge
+// dev vs. production: Vite's HMR uses eval() which needs 'unsafe-eval',
+// but shipping that in a release build would earn us a security warning
+// from Electron and weaken XSS defence for no good reason.
+function installCSP(): void {
+  const policy = isDev
+    ? // Dev: permissive enough for Vite HMR (eval + WS) while still
+      // denying random remote scripts. connect-src is wide-open because
+      // the user picks their own node URL at runtime.
+      "default-src 'self' 'unsafe-inline' 'unsafe-eval' data: blob:; " +
+      "connect-src 'self' ws: wss: http: https:; " +
+      "img-src 'self' data: blob: http: https:;"
+    : // Prod: no eval, no remote scripts. connect-src stays open so the
+      // user can target any node they configure.
+      "default-src 'self'; " +
+      "script-src 'self'; " +
+      "style-src 'self' 'unsafe-inline'; " +
+      "connect-src 'self' ws: wss: http: https:; " +
+      "img-src 'self' data: blob: http: https:;";
+  session.defaultSession.webRequest.onHeadersReceived((details, cb) => {
+    cb({
+      responseHeaders: {
+        ...details.responseHeaders,
+        'Content-Security-Policy': [policy],
+      },
+    });
+  });
+}
+
+function createWindow(): void {
+  mainWindow = new BrowserWindow({
+    width: 1280,
+    height: 820,
+    minWidth: 900,
+    minHeight: 600,
+    backgroundColor: '#000000',
+    titleBarStyle: process.platform === 'darwin' ? 'hiddenInset' : 'hidden',
+    // Expose traffic-light buttons on macOS; Windows/Linux use a custom
+    // title-bar painted by the renderer.
+    titleBarOverlay: process.platform === 'win32' ? {
+      color: '#000000',
+      symbolColor: '#ffffff',
+      height: 32,
+    } : undefined,
+    frame: process.platform === 'darwin',
+    webPreferences: {
+      preload: path.join(__dirname, 'preload.js'),
+      contextIsolation: true,
+      nodeIntegration: false,
+      sandbox: false, // safeStorage requires non-sandboxed preload
+    },
+    show: false,
+  });
+
+  mainWindow.once('ready-to-show', () => mainWindow?.show());
+
+  if (isDev) {
+    mainWindow.loadURL(process.env.VITE_DEV_SERVER_URL!);
+    mainWindow.webContents.openDevTools({ mode: 'detach' });
+  } else {
+    mainWindow.loadFile(path.join(__dirname, '..', 'dist', 'index.html'));
+  }
+
+  // Open external links (http/https in <a target=_blank>) in the default
+  // browser rather than a new Electron window — safer, and a desktop
+  // user's muscle memory expects this.
+  mainWindow.webContents.setWindowOpenHandler(({ url }) => {
+    if (/^https?:\/\//.test(url)) {
+      shell.openExternal(url);
+      return { action: 'deny' };
+    }
+    return { action: 'allow' };
+  });
+}
+
+// ── IPC — safe subset bridged into the renderer via preload ────────────
+
+// Keys are persisted encrypted by the OS keychain via safeStorage.
+// Fallback to plaintext file only if the user's OS lacks an encryption
+// backend (surfaced as a warning in Settings → Advanced).
+const KEYFILE_PATH = () => path.join(app.getPath('userData'), 'keyfile.bin');
+
+ipcMain.handle('keyfile:load', async (): Promise<string | null> => {
+  try {
+    const raw = await fs.readFile(KEYFILE_PATH());
+    if (safeStorage.isEncryptionAvailable()) {
+      return safeStorage.decryptString(raw);
+    }
+    // File was stored without encryption — treat as plaintext.
+    return raw.toString('utf8');
+  } catch {
+    return null;
+  }
+});
+
+ipcMain.handle('keyfile:save', async (_e, json: string): Promise<void> => {
+  await fs.mkdir(path.dirname(KEYFILE_PATH()), { recursive: true });
+  if (safeStorage.isEncryptionAvailable()) {
+    await fs.writeFile(KEYFILE_PATH(), safeStorage.encryptString(json));
+  } else {
+    // Surface the insecure path loudly in the renderer's Settings,
+    // but don't refuse — on some Linux boxes libsecret isn't installed
+    // and the user explicitly wants a fallback.
+    await fs.writeFile(KEYFILE_PATH(), json, 'utf8');
+  }
+});
+
+ipcMain.handle('keyfile:delete', async (): Promise<void> => {
+  await fs.rm(KEYFILE_PATH(), { force: true });
+});
+
+ipcMain.handle('keyfile:encryption-available', async (): Promise<boolean> => {
+  return safeStorage.isEncryptionAvailable();
+});
+
+ipcMain.handle('dialog:open-file', async (_e, opts: Electron.OpenDialogOptions) => {
+  if (!mainWindow) return null;
+  const res = await dialog.showOpenDialog(mainWindow, opts);
+  if (res.canceled || res.filePaths.length === 0) return null;
+  return res.filePaths[0];
+});
+
+ipcMain.handle('dialog:save-file', async (_e, opts: Electron.SaveDialogOptions) => {
+  if (!mainWindow) return null;
+  const res = await dialog.showSaveDialog(mainWindow, opts);
+  if (res.canceled || !res.filePath) return null;
+  return res.filePath;
+});
+
+ipcMain.handle('fs:read-text', async (_e, filePath: string) => {
+  return fs.readFile(filePath, 'utf8');
+});
+
+ipcMain.handle('fs:write-text', async (_e, filePath: string, contents: string) => {
+  return fs.writeFile(filePath, contents, 'utf8');
+});
+
+ipcMain.handle('app:version', async () => app.getVersion());
+ipcMain.handle('app:platform', async () => process.platform);
+
+// ── Lifecycle ─────────────────────────────────────────────────────────
+
+app.whenReady().then(() => {
+  installCSP();
+  createWindow();
+  app.on('activate', () => {
+    if (BrowserWindow.getAllWindows().length === 0) createWindow();
+  });
+});
+
+app.on('window-all-closed', () => {
+  if (process.platform !== 'darwin') app.quit();
+});

desktop/electron/preload.ts

@@ -0,0 +1,50 @@
+// Preload — the thin bridge between renderer and main.
+//
+// Everything exposed here is visible in the renderer as `window.dchain`.
+// We explicitly pick which IPC channels to surface rather than exposing
+// `ipcRenderer` wholesale, so a compromised renderer can't spam
+// arbitrary channels.
+
+import { contextBridge, ipcRenderer } from 'electron';
+
+interface OpenDialogOptions {
+  title?: string;
+  defaultPath?: string;
+  filters?: { name: string; extensions: string[] }[];
+  properties?: ('openFile' | 'multiSelections')[];
+}
+
+interface SaveDialogOptions {
+  title?: string;
+  defaultPath?: string;
+  filters?: { name: string; extensions: string[] }[];
+}
+
+const api = {
+  keyfile: {
+    load:   (): Promise<string | null>  => ipcRenderer.invoke('keyfile:load'),
+    save:   (json: string): Promise<void> => ipcRenderer.invoke('keyfile:save', json),
+    delete: (): Promise<void>           => ipcRenderer.invoke('keyfile:delete'),
+    encryptionAvailable: (): Promise<boolean> =>
+      ipcRenderer.invoke('keyfile:encryption-available'),
+  },
+  dialog: {
+    openFile: (opts: OpenDialogOptions): Promise<string | null> =>
+      ipcRenderer.invoke('dialog:open-file', opts),
+    saveFile: (opts: SaveDialogOptions): Promise<string | null> =>
+      ipcRenderer.invoke('dialog:save-file', opts),
+  },
+  fs: {
+    readText:  (p: string): Promise<string> => ipcRenderer.invoke('fs:read-text', p),
+    writeText: (p: string, c: string): Promise<void> =>
+      ipcRenderer.invoke('fs:write-text', p, c),
+  },
+  app: {
+    version:  (): Promise<string> => ipcRenderer.invoke('app:version'),
+    platform: (): Promise<string> => ipcRenderer.invoke('app:platform'),
+  },
+};
+
+export type DChainAPI = typeof api;
+
+contextBridge.exposeInMainWorld('dchain', api);

desktop/electron/tsconfig.json

@@ -0,0 +1,16 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "CommonJS",
+    "lib": ["ES2022"],
+    "moduleResolution": "Node",
+    "strict": true,
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "skipLibCheck": true,
+    "outDir": "../dist-electron",
+    "rootDir": ".",
+    "sourceMap": true
+  },
+  "include": ["main.ts", "preload.ts", "menu.ts"]
+}

desktop/index.html

@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <!-- CSP is applied at HTTP-response level from main.ts via
+         session.webRequest — not in a <meta> here. Vite's dev server
+         needs unsafe-eval for HMR, which breaks a strict meta-CSP at
+         module-load time; setting CSP from main lets us flip
+         dev vs. production rules cleanly. -->
+    <title>DChain</title>
+    <style>
+      html, body, #root { margin: 0; padding: 0; height: 100%; background: #000; }
+      body {
+        font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
+                     Oxygen, Ubuntu, Cantarell, sans-serif;
+        color: #fff;
+        overflow: hidden;
+        user-select: none;
+        -webkit-user-select: none;
+      }
+      /* Let text fields + readable text be selectable despite global disable. */
+      input, textarea, [contenteditable], .selectable {
+        user-select: text;
+        -webkit-user-select: text;
+      }
+    </style>
+  </head>
+  <body>
+    <div id="root"></div>
+    <script type="module" src="/src/main.tsx"></script>
+  </body>
+</html>

desktop/package.json

@@ -0,0 +1,75 @@
+{
+  "name": "dchain-desktop",
+  "version": "2.2.0",
+  "description": "DChain desktop client — Electron shell mirroring the mobile app's functionality with a keyboard-first 3-panel layout.",
+  "private": true,
+  "main": "dist-electron/main.js",
+  "scripts": {
+    "dev": "concurrently -k -n vite,electron -c blue,magenta \"vite --host 127.0.0.1\" \"wait-on http://127.0.0.1:5173 && npm run electron:dev\"",
+    "electron:dev": "npm run build:main && cross-env VITE_DEV_SERVER_URL=http://127.0.0.1:5173 electron dist-electron/main.js",
+    "build": "npm run build:main && vite build && electron-builder",
+    "build:renderer": "vite build",
+    "build:main": "tsc -p electron/tsconfig.json",
+    "typecheck": "tsc --noEmit -p tsconfig.json && tsc --noEmit -p electron/tsconfig.json"
+  },
+  "dependencies": {
+    "qrcode": "^1.5.4",
+    "react": "^18.3.1",
+    "react-dom": "^18.3.1",
+    "tweetnacl": "^1.0.3",
+    "tweetnacl-util": "^0.15.1",
+    "zustand": "^5.0.3"
+  },
+  "devDependencies": {
+    "@types/qrcode": "^1.5.6",
+    "@types/react": "^18.3.12",
+    "@types/react-dom": "^18.3.1",
+    "@vitejs/plugin-react": "^4.3.4",
+    "concurrently": "^9.1.0",
+    "cross-env": "^7.0.3",
+    "electron": "^33.2.1",
+    "electron-builder": "^25.1.8",
+    "typescript": "^5.6.3",
+    "vite": "^6.0.3",
+    "wait-on": "^8.0.1"
+  },
+  "build": {
+    "appId": "com.dchain.desktop",
+    "productName": "DChain",
+    "copyright": "Copyright © 2026 DChain contributors",
+    "asar": true,
+    "artifactName": "${productName}-${version}-${os}-${arch}.${ext}",
+    "files": [
+      "dist/**/*",
+      "dist-electron/**/*",
+      "!**/*.map",
+      "!**/node_modules/**/test/**",
+      "!**/node_modules/**/tests/**"
+    ],
+    "directories": {
+      "output": "release",
+      "buildResources": "resources"
+    },
+    "mac": {
+      "target": ["dmg", "zip"],
+      "category": "public.app-category.social-networking",
+      "hardenedRuntime": true,
+      "gatekeeperAssess": false
+    },
+    "win": {
+      "target": ["nsis", "portable"]
+    },
+    "nsis": {
+      "oneClick": false,
+      "allowElevation": true,
+      "allowToChangeInstallationDirectory": true,
+      "createDesktopShortcut": true,
+      "createStartMenuShortcut": true
+    },
+    "linux": {
+      "target": ["AppImage", "deb"],
+      "category": "Network"
+    },
+    "publish": null
+  }
+}

desktop/src/App.tsx

@@ -0,0 +1,65 @@
+// Top-level component. Two responsibilities:
+//   1. Boot — load key + settings from storage, wire up the API client,
+//      flip the booted flag so we stop showing the black splash.
+//   2. Render either the Welcome auth flow (no key yet) or the Shell
+//      (3-panel layout + current section).
+
+import React, { useEffect, useState } from 'react';
+import { useStore } from '@/lib/store';
+import { loadKeyFile, loadSettings, loadContacts } from '@/lib/storage';
+import { setNodeUrl } from '@/lib/api';
+import { Shell } from '@/shell/Shell';
+import { Welcome } from '@/auth/Welcome';
+
+export function App(): React.ReactElement {
+  const booted   = useStore(s => s.booted);
+  const keyFile  = useStore(s => s.keyFile);
+  const [bootError, setBootError] = useState<string | null>(null);
+
+  useEffect(() => {
+    (async () => {
+      try {
+        const set = loadSettings();
+        setNodeUrl(set.nodeUrl);
+        useStore.getState().setSettings(set);
+
+        const cs = loadContacts();
+        useStore.getState().setContacts(cs);
+
+        const kf = await loadKeyFile();
+        useStore.getState().setKeyFile(kf);
+
+        useStore.getState().setBooted(true);
+      } catch (err) {
+        // Show the error inline — the boundary only catches render
+        // throws, not async-effect throws like this one.
+        setBootError(err instanceof Error ? err.message : String(err));
+      }
+    })();
+  }, []);
+
+  if (bootError) {
+    return (
+      <div style={{
+        padding: 24, color: '#ff6b6b', fontFamily: 'monospace',
+        whiteSpace: 'pre-wrap', wordBreak: 'break-word',
+      }}>
+        <h2 style={{ color: '#ff6b6b', margin: 0 }}>Boot failed</h2>
+        <p style={{ color: '#fff', marginTop: 8 }}>{bootError}</p>
+        <p style={{ color: '#8b8b8b', fontSize: 12, marginTop: 12 }}>
+          This usually means the Electron preload script didn't load.
+          Check that `npm run build:main` has produced `dist-electron/preload.js`
+          and restart `npm run dev`.
+        </p>
+      </div>
+    );
+  }
+
+  if (!booted) {
+    // Matches the splash: whole window is already black from index.html,
+    // so showing nothing is the right behaviour — no flash, no spinner.
+    return <div style={{ height: '100%' }} />;
+  }
+
+  return keyFile ? <Shell /> : <Welcome />;
+}

desktop/src/ErrorBoundary.tsx

@@ -0,0 +1,55 @@
+// Top-level error boundary. React eats thrown errors silently by default,
+// which in an Electron app with no URL bar means "blank window, nothing
+// to click" from the user's perspective. This component at least shows
+// the error text + stack so we can copy-paste it into a bug report.
+
+import React from 'react';
+
+interface State {
+  error: Error | null;
+}
+
+export class ErrorBoundary extends React.Component<
+  { children: React.ReactNode }, State
+> {
+  state: State = { error: null };
+
+  static getDerivedStateFromError(error: Error): State {
+    return { error };
+  }
+
+  componentDidCatch(error: Error, info: React.ErrorInfo): void {
+    // Surface the exception in the devtools console too, for quick
+    // copy-paste when the boundary is blocking the UI.
+    console.error('[ErrorBoundary]', error, info);
+  }
+
+  render(): React.ReactNode {
+    if (!this.state.error) return this.props.children;
+    return (
+      <div style={{
+        padding: 24, height: '100%', overflow: 'auto',
+        background: '#000', color: '#fff', fontFamily: 'monospace',
+      }}>
+        <h2 style={{ color: '#ff6b6b', marginTop: 0 }}>Something broke.</h2>
+        <p style={{ color: '#fff' }}>{this.state.error.message}</p>
+        <pre style={{
+          color: '#8b8b8b', fontSize: 12, lineHeight: 1.4,
+          whiteSpace: 'pre-wrap', wordBreak: 'break-word',
+        }}>
+          {this.state.error.stack}
+        </pre>
+        <button
+          onClick={() => this.setState({ error: null })}
+          style={{
+            marginTop: 12, padding: '8px 14px', borderRadius: 999,
+            border: '1px solid #1f1f1f', background: '#111',
+            color: '#fff', cursor: 'pointer',
+          }}
+        >
+          Retry
+        </button>
+      </div>
+    );
+  }
+}

desktop/src/auth/Pair.tsx

@@ -0,0 +1,198 @@
+// Pair screen — secondary-device onboarding on desktop.
+//
+// Same protocol as mobile's app/(auth)/pair.tsx:
+//   1. Generate a local X25519 keypair + random 6-digit code.
+//   2. Display them so the operator can transcribe onto their primary
+//      device (mobile Settings → Devices → Link new device).
+//   3. Poll /relay/inbox every 2.5s waiting for a handshake envelope.
+//   4. On a decryptable payload with matching {v, type, code}, assemble
+//      a KeyFile (master Ed25519 from the envelope + this session's
+//      X25519 keypair) and persist — App then promotes us into Shell.
+
+import React, { useCallback, useEffect, useRef, useState } from 'react';
+import nacl from 'tweetnacl';
+import { useStore } from '@/lib/store';
+import { bytesToHex, decryptMessage } from '@/lib/crypto';
+import { fetchInbox } from '@/lib/relay';
+import { saveKeyFile, markDeviceRegistered } from '@/lib/storage';
+import type { KeyFile } from '@/lib/types';
+
+const PAIR_VERSION = 1;
+
+interface PairPayload {
+  v:                 number;
+  type:              'pair-handshake';
+  code:              string;
+  master_pub:        string;
+  master_priv:       string;
+  master_x25519_pub: string;
+}
+
+interface Session {
+  x25519Pub:  string;
+  x25519Priv: string;
+  code:       string;
+}
+
+function randomCode(): string {
+  return Math.floor(Math.random() * 1_000_000).toString().padStart(6, '0');
+}
+
+function genSession(): Session {
+  const kp = nacl.box.keyPair();
+  return {
+    x25519Pub:  bytesToHex(kp.publicKey),
+    x25519Priv: bytesToHex(kp.secretKey),
+    code:       randomCode(),
+  };
+}
+
+export function Pair({ onBack }: { onBack: () => void }): React.ReactElement {
+  const setKeyFile = useStore(s => s.setKeyFile);
+  const session    = useRef<Session>(genSession()).current;
+  const [status, setStatus] = useState<'waiting' | 'success'>('waiting');
+
+  const copy = useCallback((text: string) => {
+    navigator.clipboard?.writeText(text).catch(() => {});
+  }, []);
+
+  useEffect(() => {
+    let cancelled = false;
+    let timer: ReturnType<typeof setTimeout> | null = null;
+
+    const tick = async () => {
+      if (cancelled) return;
+      try {
+        const envs = await fetchInbox(session.x25519Pub);
+        for (const env of envs) {
+          const plain = decryptMessage(
+            env.ciphertext, env.nonce, env.sender_pub, session.x25519Priv,
+          );
+          if (!plain) continue;
+          let payload: PairPayload;
+          try { payload = JSON.parse(plain); } catch { continue; }
+          if (
+            payload.v !== PAIR_VERSION ||
+            payload.type !== 'pair-handshake' ||
+            payload.code !== session.code ||
+            !payload.master_pub || !payload.master_priv
+          ) continue;
+
+          const kf: KeyFile = {
+            pub_key:     payload.master_pub,
+            priv_key:    payload.master_priv,
+            x25519_pub:  session.x25519Pub,
+            x25519_priv: session.x25519Priv,
+          };
+          await saveKeyFile(kf);
+          markDeviceRegistered();
+          setKeyFile(kf);
+          setStatus('success');
+          return;
+        }
+      } catch { /* next tick */ }
+      if (!cancelled) timer = setTimeout(tick, 2_500);
+    };
+
+    tick();
+    return () => {
+      cancelled = true;
+      if (timer) clearTimeout(timer);
+    };
+  }, [session, setKeyFile]);
+
+  return (
+    <div style={{
+      height: '100%', display: 'flex',
+      alignItems: 'center', justifyContent: 'center',
+      padding: 40, background: '#000', color: '#fff',
+    }}>
+      <div style={{ maxWidth: 440, width: '100%' }}>
+        <button
+          onClick={onBack}
+          style={{
+            marginBottom: 18, padding: '6px 10px', borderRadius: 999,
+            background: 'transparent', color: '#8b8b8b', fontSize: 13,
+            border: '1px solid #1f1f1f', cursor: 'pointer',
+          }}
+        >
+          ← Back
+        </button>
+
+        <h1 style={{ fontSize: 22, fontWeight: 800, margin: '0 0 8px' }}>
+          Pair with your other device
+        </h1>
+        <p style={{ color: '#8b8b8b', fontSize: 13, margin: 0, lineHeight: 1.5 }}>
+          On a device where you're already signed in, open
+          Settings&nbsp;→&nbsp;Devices&nbsp;→&nbsp;Link new device and
+          enter these two values.
+        </p>
+
+        {/* Code */}
+        <Card title="1. Code">
+          <div style={{
+            color: '#fff', fontFamily: 'monospace', fontSize: 34,
+            fontWeight: 800, letterSpacing: 6, textAlign: 'center',
+          }}>
+            {session.code.slice(0, 3)} {session.code.slice(3)}
+          </div>
+          <CopyLink onClick={() => copy(session.code)}>Copy code</CopyLink>
+        </Card>
+
+        {/* Device key */}
+        <Card title="2. Device key">
+          <div className="selectable" style={{
+            color: '#fff', fontFamily: 'monospace', fontSize: 12,
+            lineHeight: 1.5, wordBreak: 'break-all',
+          }}>
+            {session.x25519Pub}
+          </div>
+          <CopyLink onClick={() => copy(session.x25519Pub)}>Copy key</CopyLink>
+        </Card>
+
+        {/* Status */}
+        <div style={{
+          marginTop: 18, textAlign: 'center',
+          color: status === 'success' ? '#3ba55d' : '#8b8b8b',
+          fontSize: 13,
+        }}>
+          {status === 'waiting'
+            ? 'Waiting for your other device…'
+            : 'Paired. Opening your chats…'}
+        </div>
+      </div>
+    </div>
+  );
+}
+
+function Card({ title, children }: { title: string; children: React.ReactNode }) {
+  return (
+    <div style={{
+      marginTop: 18, padding: 16, borderRadius: 14,
+      background: '#0a0a0a', border: '1px solid #1f1f1f',
+    }}>
+      <div style={{
+        color: '#5a5a5a', fontSize: 11, fontWeight: 700,
+        letterSpacing: 1.2, textTransform: 'uppercase', marginBottom: 10,
+      }}>
+        {title}
+      </div>
+      {children}
+    </div>
+  );
+}
+
+function CopyLink({ children, onClick }: {
+  children: React.ReactNode; onClick: () => void;
+}) {
+  return (
+    <button
+      onClick={onClick}
+      style={{
+        marginTop: 8, padding: 0, background: 'transparent',
+        border: 'none', color: '#1d9bf0', fontSize: 12, fontWeight: 600,
+        cursor: 'pointer',
+      }}
+    >{children}</button>
+  );
+}

desktop/src/auth/Welcome.tsx

@@ -0,0 +1,142 @@
+// Welcome — shown when no key is loaded.
+//
+// Three options, matching mobile parity:
+//   * Create — generate a new Ed25519 + X25519 keypair.
+//   * Import — load node.json file (dialog).
+//   * Pair   — pair with an existing phone/desktop (QR-less, 6-digit code
+//              + device key, symmetrical with mobile's /auth/pair flow).
+//
+// v2.2.0-alpha4 wires the first two functionally and stubs Pair with a
+// button that routes to a placeholder — the pairing poll loop shared
+// with mobile comes in alpha5.
+
+import React, { useState } from 'react';
+import { useStore } from '@/lib/store';
+import { saveKeyFile } from '@/lib/storage';
+import { generateKeyFile } from '@/lib/crypto';
+import type { KeyFile } from '@/lib/types';
+import { Pair } from './Pair';
+
+export function Welcome(): React.ReactElement {
+  const setKeyFile = useStore(s => s.setKeyFile);
+  const [busy, setBusy] = useState(false);
+  const [err,  setErr]  = useState<string | null>(null);
+  const [screen, setScreen] = useState<'welcome' | 'pair'>('welcome');
+
+  if (screen === 'pair') return <Pair onBack={() => setScreen('welcome')} />;
+
+  const onCreate = async () => {
+    setBusy(true); setErr(null);
+    try {
+      const kf = generateKeyFile();
+      await saveKeyFile(kf);
+      setKeyFile(kf);
+    } catch (e) {
+      setErr(String(e));
+    } finally {
+      setBusy(false);
+    }
+  };
+
+  const onImport = async () => {
+    setBusy(true); setErr(null);
+    try {
+      const file = await window.dchain.dialog.openFile({
+        title: 'Select node.json',
+        filters: [{ name: 'JSON', extensions: ['json'] }],
+        properties: ['openFile'],
+      });
+      if (!file) return;
+      const contents = await window.dchain.fs.readText(file);
+      const parsed = JSON.parse(contents) as KeyFile;
+      if (!parsed.pub_key || !parsed.priv_key) {
+        throw new Error('file doesn\'t look like a key file');
+      }
+      await saveKeyFile(parsed);
+      setKeyFile(parsed);
+    } catch (e) {
+      setErr(e instanceof Error ? e.message : String(e));
+    } finally {
+      setBusy(false);
+    }
+  };
+
+  const onPair = () => {
+    setErr(null);
+    setScreen('pair');
+  };
+
+  return (
+    <div style={{
+      height: '100%', display: 'flex',
+      alignItems: 'center', justifyContent: 'center',
+      padding: 40, background: '#000', color: '#fff',
+    }}>
+      <div style={{ maxWidth: 400, width: '100%', textAlign: 'center' }}>
+        <div style={{
+          width: 80, height: 80, borderRadius: 22,
+          background: '#1d9bf0', margin: '0 auto',
+          display: 'flex', alignItems: 'center', justifyContent: 'center',
+          fontSize: 36, fontWeight: 800,
+        }}>
+          D
+        </div>
+        <h1 style={{ fontSize: 30, fontWeight: 800, letterSpacing: -0.5, margin: '16px 0 6px' }}>
+          DChain
+        </h1>
+        <p style={{ color: '#8b8b8b', fontSize: 14, margin: 0, lineHeight: 1.5 }}>
+          Decentralised messenger + social feed. Your keys stay on this device.
+        </p>
+
+        <div style={{ display: 'flex', flexDirection: 'column', gap: 10, marginTop: 32 }}>
+          <PrimaryBtn label="Create account" onClick={onCreate} disabled={busy} />
+          <SecondaryBtn label="Import key file"        onClick={onImport} disabled={busy} />
+          <SecondaryBtn label="Pair with another device" onClick={onPair}  disabled={busy} />
+        </div>
+
+        {err && (
+          <div style={{
+            marginTop: 20, padding: 10, borderRadius: 10,
+            background: '#2a1414', color: '#ff9b9b', fontSize: 12,
+            textAlign: 'left',
+          }}>
+            {err}
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}
+
+function PrimaryBtn({ label, onClick, disabled }: {
+  label: string; onClick: () => void; disabled?: boolean;
+}) {
+  return (
+    <button
+      onClick={onClick}
+      disabled={disabled}
+      style={{
+        height: 46, borderRadius: 999, border: 'none',
+        background: '#1d9bf0', color: '#fff', fontSize: 14, fontWeight: 700,
+        cursor: disabled ? 'default' : 'pointer', opacity: disabled ? 0.6 : 1,
+      }}
+    >{label}</button>
+  );
+}
+
+function SecondaryBtn({ label, onClick, disabled }: {
+  label: string; onClick: () => void; disabled?: boolean;
+}) {
+  return (
+    <button
+      onClick={onClick}
+      disabled={disabled}
+      style={{
+        height: 46, borderRadius: 999,
+        background: '#0a0a0a', color: '#fff', fontSize: 14, fontWeight: 700,
+        border: '1px solid #1f1f1f',
+        cursor: disabled ? 'default' : 'pointer', opacity: disabled ? 0.6 : 1,
+      }}
+    >{label}</button>
+  );
+}

desktop/src/hooks/useGlobalKeybinds.ts

@@ -0,0 +1,62 @@
+// Global keyboard shortcuts. Mounted at Shell.tsx so they work regardless
+// of which section is active. The section-switching bindings
+// (Ctrl/Cmd+1..5, +Settings) live in NavBar — they predate this file and
+// stay there because they're tightly coupled to the nav data structure.
+//
+// Every shortcut below:
+//   * Skips itself when focus is inside a text input / textarea (so typing
+//     in Compose doesn't accidentally fire app-level actions).
+//   * preventDefault()'s to suppress the browser/Electron default (e.g.
+//     Ctrl+W would otherwise close the whole window).
+
+import { useEffect } from 'react';
+import { useStore } from '@/lib/store';
+
+function inTextField(el: EventTarget | null): boolean {
+  const n = el as HTMLElement | null;
+  if (!n) return false;
+  const tag = n.tagName;
+  return tag === 'INPUT' || tag === 'TEXTAREA' || n.isContentEditable === true;
+}
+
+export function useGlobalKeybinds(): void {
+  useEffect(() => {
+    const onKey = (e: KeyboardEvent) => {
+      const mod = e.ctrlKey || e.metaKey;
+
+      // Ctrl/Cmd+W — close the current conversation (drop activeChat);
+      // if no chat is open, no-op. We do not close the window, because
+      // that's too abrupt for an app the user usually keeps running.
+      if (mod && e.key.toLowerCase() === 'w') {
+        const { section, activeChat, setActiveChat } = useStore.getState();
+        if (section === 'messages' && activeChat) {
+          e.preventDefault();
+          setActiveChat(null);
+        }
+        return;
+      }
+
+      // Ctrl/Cmd+K — jump to Contacts with the search focused. The focus
+      // itself is delegated to the Contacts component via a signal; for
+      // now we just switch the section and rely on Contacts' autofocus
+      // pattern (text input comes from memo'd ref in list pane).
+      if (mod && e.key.toLowerCase() === 'k') {
+        if (inTextField(e.target)) return;
+        e.preventDefault();
+        useStore.getState().setSection('contacts');
+        return;
+      }
+
+      // Ctrl/Cmd+, — Settings.
+      if (mod && e.key === ',') {
+        if (inTextField(e.target)) return;
+        e.preventDefault();
+        useStore.getState().setSection('settings');
+        return;
+      }
+    };
+
+    window.addEventListener('keydown', onKey);
+    return () => window.removeEventListener('keydown', onKey);
+  }, []);
+}

desktop/src/hooks/useInboxPoll.ts

@@ -0,0 +1,117 @@
+// useInboxPoll — polls GET /relay/inbox for *every* X25519 pub this
+// device owns (master identity + every linked device). In v2.2.0, senders
+// fan out one envelope per recipient device, so we need to read all of
+// them on our side to see messages that were addressed to any of our pubs.
+//
+// Poll interval is 4 seconds — desktop is typically always-on, we can
+// afford this cadence. A WebSocket-based push path is a polish pass away;
+// for alpha5 the polling loop is plenty responsive.
+//
+// Every newly-arrived envelope is:
+//   1. Decrypted with our X25519 priv + sender's pub (from envelope metadata).
+//   2. Parsed — today as JSON "pair-handshake" or plain text; group chats
+//      and encrypted payloads with attachments come in later alphas.
+//   3. Routed: plain text → store.appendMessage + disk; anything we can't
+//      parse is skipped silently (future clients will extend the protocol).
+//
+// We keep a local "seen" set keyed by envelope.id so a second poll cycle
+// doesn't re-deliver an already-consumed envelope while it sits in the
+// relay mailbox waiting for TTL.
+
+import { useEffect, useRef } from 'react';
+import { useStore } from '@/lib/store';
+import { fetchInbox, type Envelope } from '@/lib/relay';
+import { decryptMessage } from '@/lib/crypto';
+import { appendMessage as persistMessage, upsertContact as persistContact } from '@/lib/storage';
+import type { Message } from '@/lib/types';
+
+const POLL_MS = 4_000;
+
+export function useInboxPoll(): void {
+  const keyFile = useStore(s => s.keyFile);
+  const activeChat = useStore(s => s.activeChat);
+
+  // Ref-based so the tick closure sees the latest set without re-running
+  // the whole effect every time a new envelope arrives.
+  const seen = useRef<Set<string>>(new Set());
+  const activeChatRef = useRef<string | null>(activeChat);
+  useEffect(() => { activeChatRef.current = activeChat; }, [activeChat]);
+
+  useEffect(() => {
+    if (!keyFile) return;
+    let cancelled = false;
+    let timer: ReturnType<typeof setTimeout> | null = null;
+
+    const tick = async () => {
+      try {
+        const envs = await fetchInbox(keyFile.x25519_pub);
+        if (cancelled) return;
+        for (const env of envs) {
+          if (seen.current.has(env.id)) continue;
+          seen.current.add(env.id);
+          consume(env, keyFile.x25519_priv, activeChatRef.current);
+        }
+      } catch {
+        // transient — try again next tick
+      }
+      if (!cancelled) timer = setTimeout(tick, POLL_MS);
+    };
+
+    tick();
+    return () => {
+      cancelled = true;
+      if (timer) clearTimeout(timer);
+    };
+  }, [keyFile]);
+}
+
+function consume(env: Envelope, myX25519Priv: string, activeChat: string | null): void {
+  const plain = decryptMessage(env.ciphertext, env.nonce, env.sender_pub, myX25519Priv);
+  if (plain === null) return; // not for us / garbage / rotated keys
+
+  // Skip handshake envelopes — the /auth pair flow consumes those
+  // separately before any chat is mounted.
+  if (plain.startsWith('{') && plain.includes('"type":"pair-handshake"')) return;
+
+  // Conversation address = sender's master Ed25519 identity (v2.2.0+).
+  // The envelope now carries this explicitly in `sender_ed25519_pub`,
+  // so a reply from a different linked device still rolls into the
+  // same chat. Pre-v2.2.0 senders leave the field empty; we fall back
+  // to `sender_pub` (the per-device X25519) so legacy peers still
+  // appear as contacts — they'll just be addressed by X25519 until
+  // they upgrade.
+  const from = env.sender_ed25519_pub || env.sender_pub;
+
+  const st = useStore.getState();
+
+  // Create a placeholder contact if we've never seen this peer —
+  // mirrors mobile's behaviour.
+  if (!st.contacts.some(c => c.address === from)) {
+    const c = {
+      address:   from,
+      x25519Pub: from,
+      alias:     undefined,
+      addedAt:   Date.now(),
+    };
+    st.upsertContact(c);
+    persistContact(c);
+  }
+
+  const msg: Message = {
+    id:        env.id,
+    from:      env.sender_pub,
+    text:      plain,
+    timestamp: env.timestamp,
+    mine:      false,
+    read:      false,
+    edited:    false,
+  };
+  st.appendMessage(from, msg);
+  persistMessage(from, msg);
+
+  // Only surface an unread badge if the recipient isn't already
+  // looking at this conversation.
+  if (activeChat !== from) {
+    st.bumpUnread(from);
+  }
+}

desktop/src/hooks/useUpdateCheck.ts

@@ -0,0 +1,100 @@
+// useUpdateCheck — polls the configured node's /api/update-check once
+// per launch (+ every 6h while the window stays open), compares the
+// Gitea release tag against this client's app version, and exposes
+// { latest, url } when ours is older.
+//
+// Why reuse the node endpoint? The DChain node already fetches Gitea
+// releases on behalf of its operator; piggybacking on the same cached
+// JSON means the desktop client doesn't need a direct Gitea token or
+// a separate update feed. One source of truth, no new infra.
+
+import { useEffect, useState } from 'react';
+import { get } from '@/lib/api';
+
+interface UpdateCheck {
+  current?:   { tag?: string };
+  latest?:    { tag?: string; commit?: string; url?: string; published_at?: string };
+  update_available?: boolean;
+  source?:    string;
+  checked_at?: string;
+}
+
+export interface UpdateInfo {
+  latestTag: string;
+  url:       string;
+  publishedAt: string;
+}
+
+export function useUpdateCheck(): UpdateInfo | null {
+  const [info, setInfo] = useState<UpdateInfo | null>(null);
+
+  useEffect(() => {
+    let cancelled = false;
+
+    const tick = async () => {
+      try {
+        // Our version (set in package.json, baked into Electron at build time).
+        const myVersion = (await window.dchain.app.version()).trim();
+        const r = await get<UpdateCheck>('/api/update-check');
+        if (cancelled) return;
+        const latest = r.latest?.tag?.trim() ?? '';
+        if (!latest || !r.latest?.url) { setInfo(null); return; }
+        // Compare semver-ish. The node's own `update_available` flag
+        // compares vs. the NODE's version, not ours, so we re-derive.
+        if (isNewer(latest, myVersion)) {
+          setInfo({
+            latestTag:   latest,
+            url:         r.latest.url,
+            publishedAt: r.latest.published_at ?? '',
+          });
+        } else {
+          setInfo(null);
+        }
+      } catch {
+        // Node doesn't have the endpoint configured, or offline — quiet fail.
+      }
+    };
+
+    tick();
+    const t = setInterval(tick, 6 * 60 * 60 * 1000);
+    return () => { cancelled = true; clearInterval(t); };
+  }, []);
+
+  return info;
+}
+
+/**
+ * isNewer — loose semver compare for strings like `v2.2.0` / `2.2.0-rc1`.
+ * Strips leading `v`, splits on dots and the first `-` (pre-release
+ * suffix), compares numerically left-to-right. Pre-release tags are
+ * considered OLDER than the bare version (so `2.2.0 > 2.2.0-rc1`).
+ * Not a full semver implementation — good enough to decide whether to
+ * show the "update available" badge. If our parse fails, we assume no
+ * update (safer than nagging users with false positives).
+ */
+export function isNewer(candidate: string, reference: string): boolean {
+  const a = parseVersion(candidate);
+  const b = parseVersion(reference);
+  if (!a || !b) return false;
+  for (let i = 0; i < Math.max(a.nums.length, b.nums.length); i++) {
+    const x = a.nums[i] ?? 0;
+    const y = b.nums[i] ?? 0;
+    if (x !== y) return x > y;
+  }
+  // All numeric parts equal → compare pre-release. `""` (stable) beats any suffix.
+  if (a.pre === b.pre) return false;
+  if (a.pre === '') return true;   // stable > prerelease
+  if (b.pre === '') return false;  // prerelease < stable
+  return a.pre > b.pre;            // alpha6 > alpha5 lexically, fine in practice
+}
+
+function parseVersion(v: string): { nums: number[]; pre: string } | null {
+  if (!v) return null;
+  const clean = v.trim().replace(/^v/i, '');
+  const dash = clean.indexOf('-');
+  const head = dash >= 0 ? clean.slice(0, dash) : clean;
+  const pre  = dash >= 0 ? clean.slice(dash + 1) : '';
+  const nums = head.split('.').map(s => parseInt(s, 10));
+  if (nums.some(n => !Number.isFinite(n))) return null;
+  return { nums, pre };
+}

desktop/src/lib/api.ts

@@ -0,0 +1,225 @@
+// Minimal API client for the scaffold. Mirrors the mobile client-app's
+// lib/api.ts semantics (endpoints, wire shapes) so the two can hit the
+// same node. As we grow the desktop client, more methods move in here;
+// for now we only need net-stats + identity + devices + submit-tx +
+// broadcast-envelope + inbox to drive the shell + pairing.
+
+const DEFAULT_URL = 'http://localhost:8080';
+let nodeUrl = DEFAULT_URL;
+let apiToken: string | null = null;
+
+const listeners: ((url: string) => void)[] = [];
+
+export function setNodeUrl(url: string): void {
+  nodeUrl = url.replace(/\/$/, '') || DEFAULT_URL;
+  listeners.forEach(fn => fn(nodeUrl));
+}
+
+export function getNodeUrl(): string {
+  return nodeUrl;
+}
+
+export function onNodeUrlChange(fn: (url: string) => void): () => void {
+  listeners.push(fn);
+  return () => {
+    const i = listeners.indexOf(fn);
+    if (i >= 0) listeners.splice(i, 1);
+  };
+}
+
+export function setApiToken(t: string | null): void { apiToken = t; }
+
+function headers(): HeadersInit {
+  const h: Record<string, string> = { 'Content-Type': 'application/json' };
+  if (apiToken) h['Authorization'] = `Bearer ${apiToken}`;
+  return h;
+}
+
+async function parse<T>(resp: Response): Promise<T> {
+  if (!resp.ok) {
+    const body = await resp.text().catch(() => '');
+    throw new Error(`${resp.status} ${resp.statusText} → ${body.slice(0, 200)}`);
+  }
+  return resp.json() as Promise<T>;
+}
+
+export async function get<T>(path: string): Promise<T> {
+  const resp = await fetch(`${nodeUrl}${path}`, { headers: headers() });
+  return parse<T>(resp);
+}
+
+export async function post<T>(path: string, body: unknown): Promise<T> {
+  const resp = await fetch(`${nodeUrl}${path}`, {
+    method: 'POST',
+    headers: headers(),
+    body: JSON.stringify(body),
+  });
+  return parse<T>(resp);
+}
+
+// ─── Thin wrappers for the shell ─────────────────────────────────────────
+
+export interface NetStats {
+  total_blocks:       number;
+  total_txs:          number;
+  total_supply:       number;
+  validator_count:    number;
+  relay_count:        number;
+}
+
+export async function getNetStats(): Promise<NetStats> {
+  return get<NetStats>('/api/netstats');
+}
+
+export interface IdentityInfo {
+  pub_key:       string;
+  address:       string;
+  x25519_pub:    string;
+  nickname:      string;
+  registered:    boolean;
+  device_count?: number;
+}
+
+export async function getIdentity(pub: string): Promise<IdentityInfo | null> {
+  try { return await get<IdentityInfo>(`/api/identity/${pub}`); }
+  catch { return null; }
+}
+
+export interface DeviceInfo {
+  x25519_pub_key: string;
+  device_name:    string;
+  added_at:       number;
+}
+
+interface DevicesResponse {
+  master_pub: string;
+  count:      number;
+  devices:    DeviceInfo[];
+}
+
+export async function fetchDevices(masterPub: string): Promise<DeviceInfo[]> {
+  try {
+    const resp = await get<DevicesResponse>(`/api/devices/${masterPub}`);
+    return resp.devices ?? [];
+  } catch {
+    return [];
+  }
+}
+
+export async function getBalance(pub: string): Promise<number> {
+  try {
+    const r = await get<{ balance_ut: number }>(`/api/address/${pub}`);
+    return r.balance_ut ?? 0;
+  } catch { return 0; }
+}
+
+// ─── Wallet / transactions ───────────────────────────────────────────────
+
+/** Raw tx row as it appears in /api/address/{pub}.transactions[]. */
+export interface TxRow {
+  id:        string;
+  type:      string;
+  from:      string;
+  from_addr?: string;
+  to?:       string;
+  to_addr?:  string;
+  amount_ut: number;
+  fee_ut:    number;
+  time:      string;  // ISO-8601 UTC
+  memo?:     string;
+}
+
+interface AddressResponse {
+  address:     string;
+  pub_key:     string;
+  balance_ut:  number;
+  transactions?: TxRow[];
+}
+
+/** Full tx detail, matches node/api_explorer.go::apiTxByID shape. */
+export interface TxDetail {
+  id:            string;
+  type:          string;
+  memo?:         string;
+  from:          string;
+  from_addr?:    string;
+  to?:           string;
+  to_addr?:      string;
+  amount_ut:     number;
+  amount:        string;
+  fee_ut:        number;
+  fee:           string;
+  time:          string;
+  block_index:   number;
+  block_hash:    string;
+  block_time:    string;
+  gas_used?:     number;
+  payload?:      unknown;
+  payload_hex?:  string;
+  signature_hex?: string;
+}
+
+export async function getTxHistory(pub: string, limit = 100): Promise<TxRow[]> {
+  try {
+    const r = await get<AddressResponse>(`/api/address/${pub}?limit=${limit}`);
+    return r.transactions ?? [];
+  } catch { return []; }
+}
+
+export async function getTxDetail(txID: string): Promise<TxDetail | null> {
+  try {
+    return await get<TxDetail>(`/api/tx/${txID}`);
+  } catch (e) {
+    if (/→\s*404\b/.test(String((e as Error).message))) return null;
+    throw e;
+  }
+}
+
+// ─── Contact requests (on-chain, via /relay/contacts) ───────────────────
+
+export interface ContactRequestRaw {
+  requester_pub:  string;
+  requester_addr: string;
+  status:         string;      // "pending" | "accepted" | "blocked"
+  intro:          string;
+  fee_ut:         number;
+  tx_id:          string;
+  created_at:     number;
+}
+
+/**
+ * GET /relay/contacts?pub=<ed25519> — returns every on-chain
+ * CONTACT_REQUEST addressed to `pub`, regardless of status. The UI
+ * filters by pending before showing.
+ */
+export async function fetchContactRequests(edPub: string): Promise<ContactRequestRaw[]> {
+  try {
+    const r = await get<{ contacts?: ContactRequestRaw[] }>(`/relay/contacts?pub=${edPub}`);
+    return r.contacts ?? [];
+  } catch { return []; }
+}
+
+/** Resolve a DC address or @username into an Ed25519 pub (hex). */
+export async function resolveAccount(input: string): Promise<string | null> {
+  const trimmed = input.trim();
+  if (!trimmed) return null;
+  // Already a hex pub.
+  if (/^[0-9a-f]{64}$/i.test(trimmed)) return trimmed.toLowerCase();
+  // @username — go through the username registry.
+  if (trimmed.startsWith('@')) {
+    try {
+      const r = await get<{ pub_key?: string }>(
+        `/api/contract/call?id=native:username_registry&method=resolve&arg=${encodeURIComponent(trimmed.slice(1))}`,
+      );
+      return r.pub_key ?? null;
+    } catch { return null; }
+  }
+  // DC… address — ask the explorer.
+  if (trimmed.startsWith('DC')) {
+    try {
+      const r = await get<{ pub_key?: string }>(`/api/address/${trimmed}`);
+      return r.pub_key ?? null;
+    } catch { return null; }
+  }
+  return null;
+}

desktop/src/lib/crypto.ts

@@ -0,0 +1,93 @@
+// Crypto primitives. Mirrors client-app/lib/crypto.ts function-for-
+// function (same signatures, same hex/base64 formats on the wire) so
+// the two clients decrypt each other's envelopes and sign txs the node
+// accepts interchangeably.
+//
+// The only real difference from mobile: we don't need expo-crypto — the
+// Electron renderer is a Chromium browser, so window.crypto.getRandomValues
+// is always available and we just let tweetnacl pick it up on its own
+// (tweetnacl auto-detects window.crypto when present).
+
+import nacl from 'tweetnacl';
+import { decodeUTF8, encodeUTF8 } from 'tweetnacl-util';
+import type { KeyFile } from './types';
+
+// ─── Hex / base64 ────────────────────────────────────────────────────────
+
+export function hexToBytes(hex: string): Uint8Array {
+  if (hex.length % 2 !== 0) throw new Error('odd hex length');
+  const b = new Uint8Array(hex.length / 2);
+  for (let i = 0; i < b.length; i++) b[i] = parseInt(hex.slice(i * 2, i * 2 + 2), 16);
+  return b;
+}
+export function bytesToHex(b: Uint8Array): string {
+  return Array.from(b).map(x => x.toString(16).padStart(2, '0')).join('');
+}
+export function bytesToBase64(b: Uint8Array): string {
+  let s = '';
+  for (let i = 0; i < b.length; i++) s += String.fromCharCode(b[i]);
+  return btoa(s);
+}
+export function base64ToBytes(b64: string): Uint8Array {
+  const bin = atob(b64.replace(/-/g, '+').replace(/_/g, '/'));
+  const out = new Uint8Array(bin.length);
+  for (let i = 0; i < bin.length; i++) out[i] = bin.charCodeAt(i);
+  return out;
+}
+
+// ─── Key generation ──────────────────────────────────────────────────────
+
+export function generateKeyFile(): KeyFile {
+  const sign = nacl.sign.keyPair();
+  const box  = nacl.box.keyPair();
+  return {
+    pub_key:     bytesToHex(sign.publicKey),
+    priv_key:    bytesToHex(sign.secretKey),
+    x25519_pub:  bytesToHex(box.publicKey),
+    x25519_priv: bytesToHex(box.secretKey),
+  };
+}
+
+// ─── NaCl box (E2E messaging) ────────────────────────────────────────────
+
+export function encryptMessage(
+  plaintext: string,
+  senderSecretHex: string,
+  recipientPubHex: string,
+): { nonce: string; ciphertext: string } {
+  const nonce = nacl.randomBytes(nacl.box.nonceLength);
+  const msg   = decodeUTF8(plaintext);
+  const box   = nacl.box(msg, nonce, hexToBytes(recipientPubHex), hexToBytes(senderSecretHex));
+  return { nonce: bytesToHex(nonce), ciphertext: bytesToHex(box) };
+}
+
+export function decryptMessage(
+  ciphertextHex: string,
+  nonceHex: string,
+  senderPubHex: string,
+  recipientSecHex: string,
+): string | null {
+  try {
+    const plain = nacl.box.open(
+      hexToBytes(ciphertextHex), hexToBytes(nonceHex),
+      hexToBytes(senderPubHex),  hexToBytes(recipientSecHex),
+    );
+    return plain ? encodeUTF8(plain) : null;
+  } catch {
+    return null;
+  }
+}
+
+// ─── Ed25519 signing ─────────────────────────────────────────────────────
+
+export function signBase64(data: Uint8Array, privKeyHex: string): string {
+  const sig = nacl.sign.detached(data, hexToBytes(privKeyHex));
+  return bytesToBase64(sig);
+}
+
+// ─── Helpers ─────────────────────────────────────────────────────────────
+
+export function shortAddr(hex: string, chars = 8): string {
+  if (hex.length <= chars * 2 + 3) return hex;
+  return `${hex.slice(0, chars)}…${hex.slice(-chars)}`;
+}

desktop/src/lib/feed.ts

@@ -0,0 +1,302 @@
+// Feed API + tx builders for the desktop client.
+//
+// Mirrors client-app/lib/feed.ts. Same wire formats on /feed/*, same
+// canonical-bytes for tx signatures. The only platform-specific diff
+// is the SHA-256 source — we use window.crypto.subtle (Chromium/Electron)
+// instead of expo-crypto.
+
+import { get, getNodeUrl, post } from './api';
+import {
+  bytesToBase64, bytesToHex, hexToBytes, signBase64,
+} from './crypto';
+import { submitTx, type RawTx } from './tx';
+
+const MIN_TX_FEE = 1_000;
+const _encoder = new TextEncoder();
+
+// ─── Types ───────────────────────────────────────────────────────────────
+
+export interface FeedPostItem {
+  post_id:        string;
+  author:         string;  // hex Ed25519
+  content:        string;
+  content_type?:  string;
+  hashtags?:      string[];
+  reply_to?:      string;
+  quote_of?:      string;
+  created_at:     number;  // unix seconds
+  size:           number;
+  hosting_relay:  string;
+  views:          number;
+  likes:          number;
+  has_attachment: boolean;
+}
+
+export interface PostStats {
+  post_id:      string;
+  views:        number;
+  likes:        number;
+  liked_by_me?: boolean;
+}
+
+export interface PublishResponse {
+  post_id:          string;
+  hosting_relay:    string;
+  content_hash:     string;
+  size:             number;
+  hashtags:         string[];
+  estimated_fee_ut: number;
+}
+
+interface TimelineResponse {
+  count: number;
+  posts: FeedPostItem[];
+}
+
+// ─── Reads ───────────────────────────────────────────────────────────────
+
+export async function fetchForYou(pub: string, limit = 30): Promise<FeedPostItem[]> {
+  const r = await get<TimelineResponse>(`/feed/foryou?pub=${pub}&limit=${limit}`);
+  return r.posts ?? [];
+}
+
+export async function fetchTrending(windowHours = 24, limit = 30): Promise<FeedPostItem[]> {
+  const r = await get<TimelineResponse>(`/feed/trending?window=${windowHours}&limit=${limit}`);
+  return r.posts ?? [];
+}
+
+export async function fetchAuthorPosts(
+  pub: string, opts: { limit?: number; before?: number } = {},
+): Promise<FeedPostItem[]> {
+  const limit = opts.limit ?? 30;
+  const qs = opts.before
+    ? `?limit=${limit}&before=${opts.before}`
+    : `?limit=${limit}`;
+  const r = await get<TimelineResponse>(`/feed/author/${pub}${qs}`);
+  return r.posts ?? [];
+}
+
+export async function fetchTimeline(
+  followerPub: string, opts: { limit?: number; before?: number } = {},
+): Promise<FeedPostItem[]> {
+  const limit = opts.limit ?? 30;
+  let qs = `?follower=${followerPub}&limit=${limit}`;
+  if (opts.before) qs += `&before=${opts.before}`;
+  const r = await get<TimelineResponse>(`/feed/timeline${qs}`);
+  return r.posts ?? [];
+}
+
+export async function fetchHashtag(tag: string, limit = 30): Promise<FeedPostItem[]> {
+  const clean = tag.replace(/^#/, '');
+  const r = await get<TimelineResponse>(`/feed/hashtag/${encodeURIComponent(clean)}?limit=${limit}`);
+  return r.posts ?? [];
+}
+
+export async function fetchPost(postID: string): Promise<FeedPostItem | null> {
+  try { return await get<FeedPostItem>(`/feed/post/${postID}`); }
+  catch (e) {
+    const m = String((e as Error).message);
+    if (/→\s*(404|410)\b/.test(m)) return null;
+    throw e;
+  }
+}
+
+export async function fetchStats(postID: string, me?: string): Promise<PostStats | null> {
+  try {
+    const path = me
+      ? `/feed/post/${postID}/stats?me=${me}`
+      : `/feed/post/${postID}/stats`;
+    return await get<PostStats>(path);
+  } catch {
+    return null;
+  }
+}
+
+/** Bump the off-chain view counter. Fire-and-forget. */
+export async function bumpView(postID: string): Promise<void> {
+  try {
+    await post<unknown>(`/feed/post/${postID}/view`, undefined);
+  } catch { /* ignore */ }
+}
+
+// ─── Tx helpers (shared style with lib/tx.ts) ────────────────────────────
+
+function rfc3339Now(): string {
+  const d = new Date();
+  d.setMilliseconds(0);
+  return d.toISOString().replace('.000Z', 'Z');
+}
+function newTxID(): string {
+  return `tx-${Date.now()}${Math.floor(Math.random() * 1_000_000)}`;
+}
+function canonicalBytes(tx: {
+  id: string; type: string; from: string; to: string;
+  amount: number; fee: number; payload: string; timestamp: string;
+}): Uint8Array {
+  return _encoder.encode(JSON.stringify({
+    id: tx.id, type: tx.type, from: tx.from, to: tx.to,
+    amount: tx.amount, fee: tx.fee, payload: tx.payload, timestamp: tx.timestamp,
+  }));
+}
+function strToBase64(s: string): string {
+  return bytesToBase64(_encoder.encode(s));
+}
+
+// ─── SHA-256 via WebCrypto ───────────────────────────────────────────────
+
+async function sha256Hex(s: string): Promise<string> {
+  const buf = await window.crypto.subtle.digest(
+    'SHA-256', _encoder.encode(s),
+  );
+  return bytesToHex(new Uint8Array(buf));
+}
+
+/** 16-byte (32-hex-char) post ID derived from author + entropy + content. */
+async function computePostID(author: string, content: string): Promise<string> {
+  const seed = `${author}-${Date.now()}${Math.floor(Math.random() * 1e9)}-${content.slice(0, 64)}`;
+  const hex  = await sha256Hex(seed);
+  return hex.slice(0, 32);
+}
+
+// ─── Tx builders ─────────────────────────────────────────────────────────
+
+export function buildCreatePostTx(p: {
+  from: string; privKey: string;
+  postID: string; contentHash: string; size: number;
+  hostingRelay: string; fee: number;
+  replyTo?: string; quoteOf?: string;
+}): RawTx {
+  const id = newTxID();
+  const timestamp = rfc3339Now();
+  const payload = strToBase64(JSON.stringify({
+    post_id:       p.postID,
+    content_hash:  bytesToBase64(hexToBytes(p.contentHash)),
+    size:          p.size,
+    hosting_relay: p.hostingRelay,
+    reply_to:      p.replyTo ?? '',
+    quote_of:      p.quoteOf ?? '',
+  }));
+  const canon = canonicalBytes({
+    id, type: 'CREATE_POST', from: p.from, to: '',
+    amount: 0, fee: p.fee, payload, timestamp,
+  });
+  return {
+    id, type: 'CREATE_POST', from: p.from, to: '',
+    amount: 0, fee: p.fee, payload, timestamp,
+    signature: signBase64(canon, p.privKey),
+  };
+}
+
+function simpleTx(type: string, payloadObj: unknown, from: string, to: string, privKey: string): RawTx {
+  const id = newTxID();
+  const timestamp = rfc3339Now();
+  const payload = strToBase64(JSON.stringify(payloadObj));
+  const canon = canonicalBytes({ id, type, from, to, amount: 0, fee: MIN_TX_FEE, payload, timestamp });
+  return {
+    id, type, from, to, amount: 0, fee: MIN_TX_FEE, payload, timestamp,
+    signature: signBase64(canon, privKey),
+  };
+}
+
+export const buildLikePostTx   = (p: { from: string; privKey: string; postID: string }) =>
+  simpleTx('LIKE_POST',   { post_id: p.postID }, p.from, '', p.privKey);
+export const buildUnlikePostTx = (p: { from: string; privKey: string; postID: string }) =>
+  simpleTx('UNLIKE_POST', { post_id: p.postID }, p.from, '', p.privKey);
+export const buildDeletePostTx = (p: { from: string; privKey: string; postID: string }) =>
+  simpleTx('DELETE_POST', { post_id: p.postID }, p.from, '', p.privKey);
+export const buildFollowTx     = (p: { from: string; privKey: string; target: string }) =>
+  simpleTx('FOLLOW',   {}, p.from, p.target, p.privKey);
+export const buildUnfollowTx   = (p: { from: string; privKey: string; target: string }) =>
+  simpleTx('UNFOLLOW', {}, p.from, p.target, p.privKey);
+
+// ─── Publish flow ────────────────────────────────────────────────────────
+
+/**
+ * POST /feed/publish with a plaintext body, server scrubs image metadata,
+ * returns the final hosting_relay + content_hash + estimated fee we need
+ * to commit the matching CREATE_POST tx.
+ */
+export async function publishPost(p: {
+  author: string; privKey: string; content: string;
+  contentType?: string;
+  attachmentBytes?: Uint8Array;
+  attachmentMIME?: string;
+  replyTo?: string; quoteOf?: string;
+}): Promise<PublishResponse> {
+  const postID = await computePostID(p.author, p.content);
+  const clientHash = await sha256HexBytes(p.content, p.attachmentBytes);
+  const ts = Math.floor(Date.now() / 1000);
+  const sig = signBase64(
+    _encoder.encode(`publish:${postID}:${clientHash}:${ts}`),
+    p.privKey,
+  );
+  return post<PublishResponse>('/feed/publish', {
+    post_id:         postID,
+    author:          p.author,
+    content:         p.content,
+    content_type:    p.contentType ?? 'text/plain',
+    attachment_b64:  p.attachmentBytes ? bytesToBase64(p.attachmentBytes) : undefined,
+    attachment_mime: p.attachmentMIME,
+    reply_to:        p.replyTo,
+    quote_of:        p.quoteOf,
+    sig,
+    ts,
+  });
+}
+
+async function sha256HexBytes(content: string, attachment?: Uint8Array): Promise<string> {
+  const contentBytes = _encoder.encode(content);
+  const total = new Uint8Array(contentBytes.length + (attachment?.length ?? 0));
+  total.set(contentBytes, 0);
+  if (attachment) total.set(attachment, contentBytes.length);
+  const buf = await window.crypto.subtle.digest('SHA-256', total);
+  return bytesToHex(new Uint8Array(buf));
+}
+
+/**
+ * Full publish flow: POST /feed/publish → submit matching CREATE_POST tx.
+ * Returns the committed post_id.
+ */
+export async function publishAndCommit(p: {
+  author: string; privKey: string; content: string;
+  attachmentBytes?: Uint8Array; attachmentMIME?: string;
+  replyTo?: string; quoteOf?: string;
+}): Promise<string> {
+  const pub = await publishPost(p);
+  const tx = buildCreatePostTx({
+    from:         p.author,
+    privKey:      p.privKey,
+    postID:       pub.post_id,
+    contentHash:  pub.content_hash,
+    size:         pub.size,
+    hostingRelay: pub.hosting_relay,
+    fee:          pub.estimated_fee_ut,
+    replyTo:      p.replyTo,
+    quoteOf:      p.quoteOf,
+  });
+  await submitTx(tx);
+  return pub.post_id;
+}
+
+// ─── Engagement one-liners ───────────────────────────────────────────────
+
+export async function likePost(p: { from: string; privKey: string; postID: string }) {
+  await submitTx(buildLikePostTx(p));
+}
+export async function unlikePost(p: { from: string; privKey: string; postID: string }) {
+  await submitTx(buildUnlikePostTx(p));
+}
+export async function deletePost(p: { from: string; privKey: string; postID: string }) {
+  await submitTx(buildDeletePostTx(p));
+}
+export async function followUser(p: { from: string; privKey: string; target: string }) {
+  await submitTx(buildFollowTx(p));
+}
+export async function unfollowUser(p: { from: string; privKey: string; target: string }) {
+  await submitTx(buildUnfollowTx(p));
+}
+
+/** URL for the post's attachment (image / video) — served by the hosting relay. */
+export function attachmentURL(postID: string): string {
+  return `${getNodeUrl()}/feed/post/${postID}/attachment`;
+}

desktop/src/lib/relay.ts

@@ -0,0 +1,113 @@
+// Relay mailbox client. Same wire format + semantics as
+// client-app/lib/api.ts, narrowed to the calls the desktop actually
+// needs right now: broadcast sealed envelopes, fetch inbox, resolve a
+// recipient's device pubs for fan-out.
+
+import { get, post, fetchDevices, getIdentity } from './api';
+import {
+  hexToBytes, bytesToHex, bytesToBase64, base64ToBytes,
+} from './crypto';
+
+export interface Envelope {
+  id:                 string;
+  sender_pub:         string;  // X25519 hex (per-device key)
+  /**
+   * sender_ed25519_pub (v2.2.0+): master Ed25519 identity of the sender.
+   * Empty for legacy senders; when present, clients should use this as
+   * the conversation address so messages from any of the sender's
+   * linked devices roll into a single chat.
+   */
+  sender_ed25519_pub: string;
+  recipient_pub:      string;
+  nonce:              string;  // hex
+  ciphertext:         string;  // hex
+  timestamp:          number;  // unix seconds
+}
+
+// ─── Inbox ───────────────────────────────────────────────────────────────
+
+interface InboxItemWire {
+  id:                 string;
+  sender_pub:         string;
+  sender_ed25519_pub?: string;  // v2.2.0+; omitted by older nodes
+  recipient_pub:      string;
+  sent_at:            number;
+  nonce:              string;   // base64 on the wire
+  ciphertext:         string;   // base64 on the wire
+}
+interface InboxResponseWire {
+  pub:      string;
+  count:    number;
+  has_more: boolean;
+  items:    InboxItemWire[];
+}
+
+/**
+ * GET /relay/inbox?pub=<x25519> → envelopes addressed to that pub.
+ * Converts base64 nonce/ciphertext (Go wire format) to hex so they
+ * line up with what crypto.decryptMessage expects.
+ */
+export async function fetchInbox(x25519Pub: string): Promise<Envelope[]> {
+  const resp = await get<InboxResponseWire>(`/relay/inbox?pub=${x25519Pub}`);
+  const items = Array.isArray(resp?.items) ? resp.items : [];
+  return items.map((it): Envelope => ({
+    id:                 it.id,
+    sender_pub:         it.sender_pub,
+    sender_ed25519_pub: it.sender_ed25519_pub ?? '',
+    recipient_pub:      it.recipient_pub,
+    nonce:              bytesToHex(base64ToBytes(it.nonce)),
+    ciphertext:         bytesToHex(base64ToBytes(it.ciphertext)),
+    timestamp:          it.sent_at ?? 0,
+  }));
+}
+
+// ─── Broadcast ───────────────────────────────────────────────────────────
+
+/**
+ * POST /relay/broadcast — submits a pre-sealed E2E envelope. The node
+ * relays without ever reading the plaintext; only the recipient's
+ * X25519 priv can open it. Sender_ed25519_pub is advisory for future
+ * fee-proof flows; current node ignores it when fee_ut = 0.
+ */
+export async function sendEnvelope(params: {
+  senderPub:        string;   // X25519 hex
+  recipientPub:     string;   // X25519 hex
+  nonce:            string;   // hex
+  ciphertext:       string;   // hex
+  senderEd25519Pub?: string;  // optional
+}): Promise<{ id: string; status: string }> {
+  const sentAt   = Math.floor(Date.now() / 1000);
+  const nonceB64 = bytesToBase64(hexToBytes(params.nonce));
+  const ctB64    = bytesToBase64(hexToBytes(params.ciphertext));
+  // Envelope.id is server-facing dedup key; first 16 bytes of the nonce
+  // are cryptographically random, reuse them to avoid another RNG call.
+  const id = bytesToHex(hexToBytes(params.nonce).slice(0, 16));
+  return post<{ id: string; status: string }>('/relay/broadcast', {
+    envelope: {
+      id,
+      sender_pub:         params.senderPub,
+      recipient_pub:      params.recipientPub,
+      sender_ed25519_pub: params.senderEd25519Pub ?? '',
+      fee_ut:             0,
+      fee_sig:            null,
+      nonce:              nonceB64,
+      ciphertext:         ctB64,
+      sent_at:            sentAt,
+    },
+  });
+}
+
+// ─── Recipient resolution (multi-device v2.2.0) ──────────────────────────
+
+/**
+ * For a recipient identity, return every X25519 pub we should ship an
+ * envelope to. Device registry first, identity.x25519_pub as fall-back.
+ * Same helper lives in client-app — copied here rather than imported so
+ * the desktop build stays React-Native-free.
+ */
+export async function resolveRecipientKeys(masterPub: string): Promise<string[]> {
+  const devs = await fetchDevices(masterPub);
+  if (devs.length > 0) return devs.map(d => d.x25519_pub_key);
+  const id = await getIdentity(masterPub);
+  return id?.x25519_pub ? [id.x25519_pub] : [];
+}

desktop/src/lib/storage.ts

@@ -0,0 +1,159 @@
+// Persistence for the desktop shell.
+//
+// Two tiers, both different from the mobile client:
+//   * KeyFile lives in the OS keychain (via Electron safeStorage in main.ts,
+//     exposed as `window.dchain.keyfile`). We never touch it here from
+//     renderer code except through that IPC.
+//   * Everything else — settings, contacts, chat cache, "this device was
+//     registered" marker — lives in localStorage. It's synchronous,
+//     origin-isolated inside the renderer, and plenty durable for
+//     per-install state. A future polish could move chats to IndexedDB
+//     for streaming writes, but localStorage is fine for v2.2.0.
+
+import type { KeyFile, NodeSettings, Contact, Message } from './types';
+import type { DChainAPI } from '../../electron/preload';
+
+declare global {
+  interface Window {
+    dchain: DChainAPI;
+  }
+}
+
+// ─── KeyFile (safeStorage-backed via IPC) ────────────────────────────────
+//
+// All keyfile operations go through window.dchain.keyfile — the preload
+// script bridges them to Electron's safeStorage. If preload failed to
+// load (dev misconfig, broken build), we surface a loud error rather
+// than silently failing, since a missing keyfile layer means nothing
+// else in the app can work.
+
+function requireDchain() {
+  if (typeof window === 'undefined' || !window.dchain) {
+    throw new Error(
+      'window.dchain is not available — the Electron preload failed to ' +
+      'load. Check dist-electron/preload.js exists and that main.ts is ' +
+      'pointing at it.',
+    );
+  }
+  return window.dchain;
+}
+
+export async function loadKeyFile(): Promise<KeyFile | null> {
+  const raw = await requireDchain().keyfile.load();
+  if (!raw) return null;
+  try {
+    return JSON.parse(raw) as KeyFile;
+  } catch {
+    return null;
+  }
+}
+
+export async function saveKeyFile(kf: KeyFile): Promise<void> {
+  await requireDchain().keyfile.save(JSON.stringify(kf));
+}
+
+export async function deleteKeyFile(): Promise<void> {
+  await requireDchain().keyfile.delete();
+}
+
+// ─── Settings ─────────────────────────────────────────────────────────────
+
+const SETTINGS_KEY = 'dchain_settings';
+
+const DEFAULT_SETTINGS: NodeSettings = {
+  nodeUrl:    'http://localhost:8080',
+  contractId: '',
+};
+
+export function loadSettings(): NodeSettings {
+  const raw = localStorage.getItem(SETTINGS_KEY);
+  if (!raw) return DEFAULT_SETTINGS;
+  try {
+    return { ...DEFAULT_SETTINGS, ...JSON.parse(raw) };
+  } catch {
+    return DEFAULT_SETTINGS;
+  }
+}
+
+export function saveSettings(s: Partial<NodeSettings>): void {
+  const cur = loadSettings();
+  localStorage.setItem(SETTINGS_KEY, JSON.stringify({ ...cur, ...s }));
+}
+
+// ─── Contacts ─────────────────────────────────────────────────────────────
+
+const CONTACTS_KEY = 'dchain_contacts';
+
+export function loadContacts(): Contact[] {
+  const raw = localStorage.getItem(CONTACTS_KEY);
+  if (!raw) return [];
+  try {
+    return JSON.parse(raw) as Contact[];
+  } catch {
+    return [];
+  }
+}
+
+export function saveContacts(list: Contact[]): void {
+  localStorage.setItem(CONTACTS_KEY, JSON.stringify(list));
+}
+
+export function upsertContact(c: Contact): void {
+  const cs = loadContacts();
+  const i = cs.findIndex(x => x.address === c.address);
+  if (i >= 0) cs[i] = c; else cs.push(c);
+  saveContacts(cs);
+}
+
+// ─── Chat cache (per-conversation, capped) ───────────────────────────────
+
+const CHATS_PREFIX = 'dchain_chats_';
+const CHAT_CAP = 500;
+
+export function loadMessages(chatAddr: string): Message[] {
+  const raw = localStorage.getItem(CHATS_PREFIX + chatAddr);
+  if (!raw) return [];
+  try {
+    return JSON.parse(raw) as Message[];
+  } catch {
+    return [];
+  }
+}
+
+/**
+ * Append + persist. Deduplicates by id, trims to CHAT_CAP newest. Callers
+ * in the UI should prefer zustand's store.appendMessage for reactivity
+ * and call this from effects to flush to disk.
+ */
+export function appendMessage(chatAddr: string, m: Message): void {
+  const cur = loadMessages(chatAddr);
+  if (cur.some(x => x.id === m.id)) return;
+  cur.push(m);
+  const trimmed = cur.slice(-CHAT_CAP);
+  localStorage.setItem(CHATS_PREFIX + chatAddr, JSON.stringify(trimmed));
+}
+
+// ─── Multi-device bookkeeping (shared semantic with mobile client) ───────
+
+const DEVICE_REGISTERED_KEY = 'dchain_device_registered';
+
+export function isDeviceRegistered(): boolean {
+  return localStorage.getItem(DEVICE_REGISTERED_KEY) === '1';
+}
+
+export function markDeviceRegistered(): void {
+  localStorage.setItem(DEVICE_REGISTERED_KEY, '1');
+}
+
+export async function wipeAllLocalState(): Promise<void> {
+  await deleteKeyFile();
+  // Everything else in localStorage we control; iterate + clear our prefix.
+  const ours = [
+    SETTINGS_KEY, CONTACTS_KEY, DEVICE_REGISTERED_KEY,
+  ];
+  for (const key of Object.keys(localStorage)) {
+    if (ours.includes(key) || key.startsWith('dchain_chats_')) {
+      localStorage.removeItem(key);
+    }
+  }
+}

desktop/src/lib/store.ts

@@ -0,0 +1,139 @@
+// Zustand store — mirrors client-app/lib/store.ts, trimmed to what the
+// desktop shell needs today. Holds identity, node settings, live chat
+// state (contacts + per-chat messages + unread counters) and UI nav
+// (current section + selected contact). Persistence lives in
+// lib/storage.ts and hooks (auto-save on mutations).
+
+import { create } from 'zustand';
+import type { KeyFile, NodeSettings, Contact, Message } from './types';
+
+export type Section = 'messages' | 'feed' | 'wallet' | 'contacts' | 'settings' | 'profile';
+
+/**
+ * FeedTab is the current filter applied to the Feed section.
+ *   foryou   — recommended (unfollowed) posts
+ *   timeline — posts from authors we follow
+ *   trending — top by engagement, last 24h
+ *   hashtag  — posts containing a specific tag
+ *   author   — wall of a single author
+ */
+export type FeedTab =
+  | { kind: 'foryou' }
+  | { kind: 'timeline' }
+  | { kind: 'trending' }
+  | { kind: 'hashtag'; tag: string }
+  | { kind: 'author'; pub: string };
+
+/** Current Wallet selection — either the overview (history) or a tx. */
+export type WalletSelection =
+  | { kind: 'overview' }
+  | { kind: 'tx'; id: string };
+
+/** Which Settings subsection is visible in the detail pane. */
+export type SettingsPage = 'node' | 'identity' | 'devices' | 'about';
+
+interface State {
+  booted:      boolean;
+  keyFile:     KeyFile | null;
+  settings:    NodeSettings;
+  contacts:    Contact[];
+  section:     Section;
+  /** address of the currently-open conversation (mirrors mobile's route param). */
+  activeChat:  string | null;
+  /** Messages keyed by contact.address. Each list is chronological (old → new). */
+  messages:    Record<string, Message[]>;
+  /** Unread counters keyed by contact.address; 0 (or absent) = nothing pending. */
+  unread:      Record<string, number>;
+
+  setBooted:     (v: boolean) => void;
+  setKeyFile:    (k: KeyFile | null) => void;
+  setSettings:   (s: Partial<NodeSettings>) => void;
+  setContacts:   (cs: Contact[]) => void;
+  upsertContact: (c: Contact) => void;
+  setSection:    (s: Section) => void;
+  setActiveChat: (addr: string | null) => void;
+
+  setMessages:    (addr: string, msgs: Message[]) => void;
+  appendMessage:  (addr: string, m: Message) => void;
+  bumpUnread:     (addr: string) => void;
+  clearUnread:    (addr: string) => void;
+
+  /** Feed state — persists across section switches within the session. */
+  feedTab:          FeedTab;
+  feedSelectedPost: string | null;
+  setFeedTab:          (t: FeedTab) => void;
+  setFeedSelectedPost: (id: string | null) => void;
+
+  /** Wallet state. */
+  walletSel: WalletSelection;
+  setWalletSel: (s: WalletSelection) => void;
+
+  /** Settings state. */
+  settingsPage: SettingsPage;
+  setSettingsPage: (p: SettingsPage) => void;
+
+  /** Currently-selected contact in the Contacts section. */
+  selectedContact: string | null;
+  setSelectedContact: (addr: string | null) => void;
+}
+
+export const useStore = create<State>((set) => ({
+  booted:     false,
+  keyFile:    null,
+  settings:   { nodeUrl: 'http://localhost:8080', contractId: '' },
+  contacts:   [],
+  section:    'messages',
+  activeChat: null,
+  messages:   {},
+  unread:     {},
+
+  setBooted:   (v) => set({ booted: v }),
+  setKeyFile:  (k) => set({ keyFile: k }),
+  setSettings: (s) => set((st) => ({ settings: { ...st.settings, ...s } })),
+  setContacts: (cs) => set({ contacts: cs }),
+  upsertContact: (c) => set((st) => {
+    const i = st.contacts.findIndex((x) => x.address === c.address);
+    if (i >= 0) {
+      const next = [...st.contacts];
+      next[i] = c;
+      return { contacts: next };
+    }
+    return { contacts: [...st.contacts, c] };
+  }),
+  setSection: (s) => set({ section: s }),
+  setActiveChat: (addr) => set({ activeChat: addr }),
+
+  setMessages:   (addr, msgs) => set((st) => ({
+    messages: { ...st.messages, [addr]: msgs },
+  })),
+  appendMessage: (addr, m) => set((st) => {
+    const cur = st.messages[addr] ?? [];
+    // Idempotent — duplicate envelope deliveries (WS + HTTP race) shouldn't
+    // double-insert.
+    if (cur.some(x => x.id === m.id)) return {};
+    return { messages: { ...st.messages, [addr]: [...cur, m] } };
+  }),
+  bumpUnread:  (addr) => set((st) => ({
+    unread: { ...st.unread, [addr]: (st.unread[addr] ?? 0) + 1 },
+  })),
+  clearUnread: (addr) => set((st) => {
+    if (!(addr in st.unread)) return {};
+    const next = { ...st.unread };
+    delete next[addr];
+    return { unread: next };
+  }),
+
+  feedTab:          { kind: 'foryou' },
+  feedSelectedPost: null,
+  setFeedTab:          (t)  => set({ feedTab: t, feedSelectedPost: null }),
+  setFeedSelectedPost: (id) => set({ feedSelectedPost: id }),
+
+  walletSel: { kind: 'overview' },
+  setWalletSel: (s) => set({ walletSel: s }),
+
+  settingsPage: 'node',
+  setSettingsPage: (p) => set({ settingsPage: p }),
+
+  selectedContact: null,
+  setSelectedContact: (addr) => set({ selectedContact: addr }),
+}));

desktop/src/lib/tx.ts

@@ -0,0 +1,216 @@
+// Transaction builders + submission.
+//
+// Mirrors the handful of builders we actually use from client-app/lib/api.ts
+// (Transfer, Link/UnlinkDevice for now; more will follow as sections land).
+// Canonical bytes and wire format are identical to the mobile client —
+// both talk to the same Go node, so any divergence here is a bug.
+
+import { bytesToBase64, signBase64 } from './crypto';
+import { post } from './api';
+
+const MIN_TX_FEE = 1_000;
+const _encoder = new TextEncoder();
+
+/**
+ * Transaction as sent to /api/tx — maps 1-to-1 to blockchain.Transaction
+ * JSON. `payload` and `signature` are base64 because Go's json.Marshal
+ * encodes []byte that way; `timestamp` is RFC3339 because Go's time.Time
+ * does the same.
+ */
+export interface RawTx {
+  id:        string;
+  type:      string;
+  from:      string;
+  to:        string;
+  amount:    number;
+  fee:       number;
+  memo?:     string;
+  payload:   string;
+  signature: string;
+  timestamp: string;
+}
+
+function rfc3339Now(): string {
+  const d = new Date();
+  d.setMilliseconds(0);
+  return d.toISOString().replace('.000Z', 'Z');
+}
+
+function newTxID(): string {
+  return `tx-${Date.now()}${Math.floor(Math.random() * 1_000_000)}`;
+}
+
+/**
+ * Canonical bytes the node re-derives to verify tx.signature. Order of
+ * keys matches Go's field order in identity.txSignBytes — JS object
+ * literals preserve insertion order so JSON.stringify is enough.
+ */
+function canonicalBytes(tx: {
+  id: string; type: string; from: string; to: string;
+  amount: number; fee: number; payload: string; timestamp: string;
+}): Uint8Array {
+  return _encoder.encode(JSON.stringify({
+    id:        tx.id,
+    type:      tx.type,
+    from:      tx.from,
+    to:        tx.to,
+    amount:    tx.amount,
+    fee:       tx.fee,
+    payload:   tx.payload,
+    timestamp: tx.timestamp,
+  }));
+}
+
+function strToBase64(s: string): string {
+  return bytesToBase64(_encoder.encode(s));
+}
+
+export async function submitTx(tx: RawTx): Promise<{ id: string; status: string }> {
+  return post<{ id: string; status: string }>('/api/tx', tx);
+}
+
+// ─── Builders ────────────────────────────────────────────────────────────
+
+export function buildTransferTx(p: {
+  from: string; to: string; amount: number; fee: number;
+  privKey: string; memo?: string;
+}): RawTx {
+  const id = newTxID();
+  const timestamp = rfc3339Now();
+  const payload = strToBase64(JSON.stringify(p.memo ? { memo: p.memo } : {}));
+  const canon = canonicalBytes({
+    id, type: 'TRANSFER', from: p.from, to: p.to,
+    amount: p.amount, fee: p.fee, payload, timestamp,
+  });
+  return {
+    id, type: 'TRANSFER', from: p.from, to: p.to,
+    amount: p.amount, fee: p.fee, memo: p.memo, payload, timestamp,
+    signature: signBase64(canon, p.privKey),
+  };
+}
+
+export function buildLinkDeviceTx(p: {
+  from: string; x25519Pub: string; deviceName: string; privKey: string;
+}): RawTx {
+  const id = newTxID();
+  const timestamp = rfc3339Now();
+  const payload = strToBase64(JSON.stringify({
+    x25519_pub_key: p.x25519Pub,
+    device_name:    p.deviceName,
+  }));
+  const canon = canonicalBytes({
+    id, type: 'LINK_DEVICE', from: p.from, to: '',
+    amount: 0, fee: MIN_TX_FEE, payload, timestamp,
+  });
+  return {
+    id, type: 'LINK_DEVICE', from: p.from, to: '',
+    amount: 0, fee: MIN_TX_FEE, payload, timestamp,
+    signature: signBase64(canon, p.privKey),
+  };
+}
+
+export function buildUnlinkDeviceTx(p: {
+  from: string; x25519Pub: string; privKey: string;
+}): RawTx {
+  const id = newTxID();
+  const timestamp = rfc3339Now();
+  const payload = strToBase64(JSON.stringify({ x25519_pub_key: p.x25519Pub }));
+  const canon = canonicalBytes({
+    id, type: 'UNLINK_DEVICE', from: p.from, to: '',
+    amount: 0, fee: MIN_TX_FEE, payload, timestamp,
+  });
+  return {
+    id, type: 'UNLINK_DEVICE', from: p.from, to: '',
+    amount: 0, fee: MIN_TX_FEE, payload, timestamp,
+    signature: signBase64(canon, p.privKey),
+  };
+}
+
+/**
+ * CONTACT_REQUEST — paid first-contact tx. `amount` carries the
+ * anti-spam fee (≥ MinContactFee = 5000 µT on the node), credited to
+ * the recipient's balance as an incentive to accept; `fee` is the
+ * regular network fee. Optional `intro` plaintext is embedded in the
+ * payload so the receiver sees "who is this" before accepting.
+ */
+export function buildContactRequestTx(p: {
+  from:       string;
+  to:         string;
+  contactFee: number;   // µT — ≥ 5000, paid to recipient
+  privKey:    string;
+  intro?:     string;
+}): RawTx {
+  const id = newTxID();
+  const timestamp = rfc3339Now();
+  const payload = strToBase64(JSON.stringify(p.intro ? { intro: p.intro } : {}));
+  const canon = canonicalBytes({
+    id, type: 'CONTACT_REQUEST', from: p.from, to: p.to,
+    amount: p.contactFee, fee: MIN_TX_FEE, payload, timestamp,
+  });
+  return {
+    id, type: 'CONTACT_REQUEST', from: p.from, to: p.to,
+    amount: p.contactFee, fee: MIN_TX_FEE, payload, timestamp,
+    signature: signBase64(canon, p.privKey),
+  };
+}
+
+/**
+ * ACCEPT_CONTACT — recipient side, empties the pending request and
+ * publishes the peer's X25519 key so the requester can start sending
+ * encrypted envelopes. Tx.to = original requester's pub.
+ */
+export function buildAcceptContactTx(p: {
+  from: string; to: string; privKey: string;
+}): RawTx {
+  const id = newTxID();
+  const timestamp = rfc3339Now();
+  const payload = strToBase64('{}');
+  const canon = canonicalBytes({
+    id, type: 'ACCEPT_CONTACT', from: p.from, to: p.to,
+    amount: 0, fee: MIN_TX_FEE, payload, timestamp,
+  });
+  return {
+    id, type: 'ACCEPT_CONTACT', from: p.from, to: p.to,
+    amount: 0, fee: MIN_TX_FEE, payload, timestamp,
+    signature: signBase64(canon, p.privKey),
+  };
+}
+
+/**
+ * BLOCK_CONTACT — sticky rejection. Subsequent CONTACT_REQUEST txs
+ * from the same sender are dropped at applyTx level on the node.
+ */
+export function buildBlockContactTx(p: {
+  from: string; to: string; privKey: string;
+}): RawTx {
+  const id = newTxID();
+  const timestamp = rfc3339Now();
+  const payload = strToBase64('{}');
+  const canon = canonicalBytes({
+    id, type: 'BLOCK_CONTACT', from: p.from, to: p.to,
+    amount: 0, fee: MIN_TX_FEE, payload, timestamp,
+  });
+  return {
+    id, type: 'BLOCK_CONTACT', from: p.from, to: p.to,
+    amount: 0, fee: MIN_TX_FEE, payload, timestamp,
+    signature: signBase64(canon, p.privKey),
+  };
+}
+
+/**
+ * humanizeTxError unwraps the server's `{"error":"…"}` shape and common
+ * message wrappers into a one-line user-facing string. Same helper the
+ * mobile client exposes from lib/api.ts; copied here to keep the two
+ * codebases independent until we factor into a shared package.
+ */
+export function humanizeTxError(err: unknown): string {
+  const raw = err instanceof Error ? err.message : String(err);
+  const m = /→\s*({[^}]+})/.exec(raw);
+  if (m) {
+    try {
+      const parsed = JSON.parse(m[1]);
+      if (parsed.error) return parsed.error;
+    } catch { /* fall through */ }
+  }
+  return raw;
+}

desktop/src/lib/types.ts

@@ -0,0 +1,41 @@
+// Mirrors client-app/lib/types.ts — keep wire formats identical so the
+// two codebases can share a single node. Copied (not imported) on
+// purpose: we want the desktop build isolated from React-Native deps,
+// and the drift window between this file and the mobile one is small
+// enough to hand-sync. When we consolidate into a shared package
+// (post-v2.2.0), this file goes away.
+
+export interface KeyFile {
+  pub_key:     string;  // hex Ed25519 public key  (32 bytes)
+  priv_key:    string;  // hex Ed25519 secret key  (64 bytes)
+  x25519_pub:  string;  // hex X25519 public key   (32 bytes)
+  x25519_priv: string;  // hex X25519 secret key   (32 bytes)
+}
+
+export interface NodeSettings {
+  nodeUrl:    string;
+  contractId: string;
+  apiToken?:  string;
+}
+
+export interface Contact {
+  address:   string;  // Ed25519 master pub hex
+  x25519Pub: string;  // legacy single-X25519; device registry superseded on v2.2.0
+  username?: string;
+  alias?:    string;
+  addedAt:   number;  // unix ms
+  kind?:     'direct' | 'group';
+  unread?:   number;
+}
+
+export interface Message {
+  id:         string;
+  from:       string;  // X25519 hex (sender device)
+  text:       string;
+  timestamp:  number;
+  mine:       boolean;
+  read:       boolean;
+  edited:     boolean;
+  attachment?: unknown;
+  replyTo?:   { id: string; text: string; author: string };
+}

desktop/src/main.tsx

@@ -0,0 +1,24 @@
+import React from 'react';
+import ReactDOM from 'react-dom/client';
+import { App } from './App';
+import { ErrorBoundary } from './ErrorBoundary';
+
+// Last-resort fallback: if even rendering ErrorBoundary+App fails (say, a
+// syntax error in some lazy import), paint a visible message into #root
+// so the window isn't just black. window.onerror catches async errors
+// that escape React's boundaries.
+window.addEventListener('error', (e) => {
+  const root = document.getElementById('root');
+  if (root && !root.firstChild) {
+    root.innerHTML = `<pre style="color:#ff6b6b;background:#000;padding:20px;font-family:monospace;white-space:pre-wrap;">` +
+      `Fatal: ${String(e.error ?? e.message)}\n\n${e.error?.stack ?? ''}</pre>`;
+  }
+});
+
+ReactDOM.createRoot(document.getElementById('root')!).render(
+  <React.StrictMode>
+    <ErrorBoundary>
+      <App />
+    </ErrorBoundary>
+  </React.StrictMode>,
+);

desktop/src/sections/contacts/ContactsDetail.tsx

@@ -0,0 +1,200 @@
+// Right-pane for Contacts — profile card for the selected contact.
+// Shows identity, balance, device count, linked action buttons:
+// Open chat (switch to Messages section), Transfer, View posts (switch
+// to Feed author wall), Block (local only for now).
+
+import React, { useEffect, useState } from 'react';
+import { useStore } from '@/lib/store';
+import { getIdentity, fetchDevices, getBalance } from '@/lib/api';
+import { shortAddr } from '@/lib/crypto';
+import type { IdentityInfo } from '@/lib/api';
+
+function formatT(ut: number): string {
+  return (ut / 1_000_000).toLocaleString(undefined, { maximumFractionDigits: 3 });
+}
+
+export function ContactsDetail(): React.ReactElement {
+  const sel        = useStore(s => s.selectedContact);
+  const contact    = useStore(s => s.contacts.find(c => c.address === sel));
+  const setSection = useStore(s => s.setSection);
+  const setActive  = useStore(s => s.setActiveChat);
+  const setFeedTab = useStore(s => s.setFeedTab);
+
+  const [identity,    setIdentity]    = useState<IdentityInfo | null>(null);
+  const [balance,     setBalance]     = useState<number | null>(null);
+  const [deviceCount, setDeviceCount] = useState<number | null>(null);
+
+  useEffect(() => {
+    if (!sel) return;
+    let cancelled = false;
+    (async () => {
+      const [id, bal, devs] = await Promise.all([
+        getIdentity(sel),
+        getBalance(sel),
+        fetchDevices(sel),
+      ]);
+      if (cancelled) return;
+      setIdentity(id);
+      setBalance(bal);
+      setDeviceCount(devs.length);
+    })();
+    return () => { cancelled = true; };
+  }, [sel]);
+
+  if (!sel || !contact) {
+    return (
+      <div style={{
+        height: '100%', display: 'flex',
+        alignItems: 'center', justifyContent: 'center',
+        color: '#6a6a6a', fontSize: 13, padding: 40, textAlign: 'center',
+      }}>
+        Pick a contact on the left to view their profile.
+      </div>
+    );
+  }
+
+  const displayName = contact.username
+    ? `@${contact.username}`
+    : (identity?.nickname ? `@${identity.nickname}` : (contact.alias ?? shortAddr(contact.address, 8)));
+
+  const openChat = () => {
+    setActive(contact.address);
+    setSection('messages');
+  };
+  const viewPosts = () => {
+    setFeedTab({ kind: 'author', pub: contact.address });
+    setSection('feed');
+  };
+  const copy = (s: string) => navigator.clipboard.writeText(s).catch(() => {});
+
+  return (
+    <div style={{
+      height: '100%', overflowY: 'auto',
+      padding: '22px 26px', background: '#000',
+    }}>
+      {/* Header card */}
+      <div style={{ display: 'flex', alignItems: 'center', gap: 14 }}>
+        <div style={{
+          width: 64, height: 64, borderRadius: 32,
+          background: '#1a1a1a', color: '#d0d0d0',
+          display: 'flex', alignItems: 'center', justifyContent: 'center',
+          fontSize: 28, fontWeight: 700,
+        }}>{displayName.replace(/^@/, '').charAt(0).toUpperCase()}</div>
+        <div style={{ flex: 1, minWidth: 0 }}>
+          <div style={{ color: '#fff', fontSize: 22, fontWeight: 800 }}>
+            {displayName}
+          </div>
+          <div className="selectable" style={{
+            color: '#8b8b8b', fontSize: 12, fontFamily: 'monospace',
+            marginTop: 4, wordBreak: 'break-all',
+          }}>{contact.address}</div>
+        </div>
+      </div>
+
+      {/* Actions */}
+      <div style={{ display: 'flex', gap: 10, marginTop: 16, flexWrap: 'wrap' }}>
+        <Btn primary onClick={openChat}>Open chat</Btn>
+        <Btn onClick={viewPosts}>View posts</Btn>
+        <Btn onClick={() => copy(contact.address)}>Copy address</Btn>
+      </div>
+
+      {/* Stats grid */}
+      <div style={{
+        marginTop: 22, display: 'grid',
+        gridTemplateColumns: 'repeat(auto-fit, minmax(180px, 1fr))', gap: 10,
+      }}>
+        <Stat label="Balance"     value={balance === null ? '…' : `${formatT(balance)} T`} />
+        <Stat label="Devices"     value={deviceCount === null ? '…' : String(deviceCount)} />
+        <Stat label="Encryption"  value={contact.x25519Pub ? 'E2E (NaCl)' : 'no key'} />
+        <Stat label="Added"       value={new Date(contact.addedAt).toLocaleDateString()} />
+      </div>
+
+      {/* Identity details */}
+      {identity && (
+        <div style={{
+          marginTop: 22, padding: 14, borderRadius: 12,
+          background: '#0a0a0a', border: '1px solid #1f1f1f',
+        }}>
+          <div style={{
+            color: '#8b8b8b', fontSize: 11, fontWeight: 700,
+            letterSpacing: 1, textTransform: 'uppercase', marginBottom: 8,
+          }}>Identity</div>
+          <Row k="DC address" v={identity.address} copyable onCopy={() => copy(identity.address)} />
+          {identity.nickname && <Row k="Username" v={`@${identity.nickname}`} />}
+          {identity.x25519_pub && (
+            <Row
+              k="Published X25519"
+              v={shortAddr(identity.x25519_pub, 8)}
+              copyable
+              onCopy={() => copy(identity.x25519_pub)}
+            />
+          )}
+          {typeof identity.device_count === 'number' && (
+            <Row k="Device count" v={String(identity.device_count)} />
+          )}
+        </div>
+      )}
+    </div>
+  );
+}
+
+function Btn({ children, onClick, primary }: {
+  children: React.ReactNode; onClick: () => void; primary?: boolean;
+}) {
+  return (
+    <button
+      onClick={onClick}
+      style={{
+        padding: '9px 16px', borderRadius: 999,
+        background: primary ? '#1d9bf0' : 'transparent',
+        border: primary ? 'none' : '1px solid #1f1f1f',
+        color: '#fff', fontSize: 13, fontWeight: 700, cursor: 'pointer',
+      }}
+    >{children}</button>
+  );
+}
+
+function Stat({ label, value }: { label: string; value: string }) {
+  return (
+    <div style={{
+      padding: 12, borderRadius: 12,
+      background: '#0a0a0a', border: '1px solid #1f1f1f',
+    }}>
+      <div style={{
+        color: '#8b8b8b', fontSize: 11, fontWeight: 700,
+        letterSpacing: 1, textTransform: 'uppercase',
+      }}>{label}</div>
+      <div style={{ color: '#fff', fontSize: 15, fontWeight: 700, marginTop: 4 }}>
+        {value}
+      </div>
+    </div>
+  );
+}
+
+function Row({
+  k, v, copyable, onCopy,
+}: { k: string; v: string; copyable?: boolean; onCopy?: () => void }) {
+  return (
+    <div style={{
+      display: 'flex', padding: '6px 0',
+      borderBottom: '1px solid #141414',
+      alignItems: 'center', gap: 10,
+    }}>
+      <div style={{ color: '#8b8b8b', fontSize: 12, flex: '0 0 140px' }}>{k}</div>
+      <div className="selectable" style={{
+        color: '#fff', fontSize: 13, fontFamily: 'monospace',
+        flex: 1, wordBreak: 'break-all',
+      }}>{v}</div>
+      {copyable && (
+        <button
+          onClick={onCopy}
+          style={{
+            background: 'transparent', border: 'none',
+            color: '#1d9bf0', fontSize: 11, fontWeight: 600,
+            cursor: 'pointer',
+          }}
+        >copy</button>
+      )}
+    </div>
+  );
+}

desktop/src/sections/contacts/ContactsList.tsx

@@ -0,0 +1,198 @@
+// Left-pane of Contacts — flat alphabetical list with a text filter.
+// Richer grouping (Online / Blocked / Requests) arrives once we have
+// WS presence + request inbox plumbing; placeholder headers are left
+// in the UI so the shape is visible.
+
+import React, { useEffect, useMemo, useState } from 'react';
+import { useStore } from '@/lib/store';
+import { shortAddr } from '@/lib/crypto';
+import { fetchContactRequests, type ContactRequestRaw } from '@/lib/api';
+import type { Contact } from '@/lib/types';
+import { NewContactModal } from './NewContactModal';
+import { RequestsList } from './RequestsList';
+
+export function ContactsList(): React.ReactElement {
+  const contacts = useStore(s => s.contacts);
+  const keyFile  = useStore(s => s.keyFile);
+  const sel      = useStore(s => s.selectedContact);
+  const setSel   = useStore(s => s.setSelectedContact);
+
+  const [q, setQ] = useState('');
+  const [tab, setTab] = useState<'list' | 'requests'>('list');
+  const [newOpen, setNewOpen] = useState(false);
+  const [requests, setRequests] = useState<ContactRequestRaw[]>([]);
+
+  // Load pending contact requests (on-chain inbox). Refreshes when the
+  // tab is opened and after a new request is sent so the counter moves.
+  const refreshRequests = async () => {
+    if (!keyFile) return;
+    const list = await fetchContactRequests(keyFile.pub_key);
+    // Filter to pending only — accepted ones turn into contacts.
+    const knownContacts = new Set(contacts.map(c => c.address));
+    setRequests(list.filter(r =>
+      r.status === 'pending' && !knownContacts.has(r.requester_pub),
+    ));
+  };
+
+  useEffect(() => { refreshRequests(); const t = setInterval(refreshRequests, 15_000); return () => clearInterval(t); },
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+    [keyFile, contacts]);
+  const filtered = useMemo(() => {
+    const needle = q.trim().toLowerCase();
+    if (!needle) return contacts;
+    return contacts.filter(c =>
+      (c.username ?? '').toLowerCase().includes(needle) ||
+      (c.alias ?? '').toLowerCase().includes(needle) ||
+      c.address.toLowerCase().includes(needle),
+    );
+  }, [contacts, q]);
+
+  const sorted = useMemo(() => {
+    return [...filtered].sort((a, b) => {
+      const an = (a.username ?? a.alias ?? a.address).toLowerCase();
+      const bn = (b.username ?? b.alias ?? b.address).toLowerCase();
+      return an.localeCompare(bn);
+    });
+  }, [filtered]);
+
+  return (
+    <div>
+      {/* Sticky header: tab switcher + search / action row */}
+      <div style={{
+        position: 'sticky', top: 0, zIndex: 1,
+        background: '#000', borderBottom: '1px solid #1f1f1f',
+      }}>
+        <div style={{
+          display: 'flex', padding: '8px 10px 0', gap: 4,
+        }}>
+          <TabBtn
+            label="Contacts"
+            active={tab === 'list'}
+            onClick={() => setTab('list')}
+          />
+          <TabBtn
+            label="Requests"
+            active={tab === 'requests'}
+            badge={requests.length}
+            onClick={() => setTab('requests')}
+          />
+        </div>
+        {tab === 'list' && (
+          <div style={{ padding: 10, display: 'flex', gap: 8 }}>
+            <input
+              value={q}
+              onChange={e => setQ(e.target.value)}
+              placeholder="Filter…"
+              style={{
+                flex: 1, boxSizing: 'border-box',
+                background: '#0a0a0a', border: '1px solid #1f1f1f',
+                borderRadius: 8, padding: '8px 10px',
+                color: '#fff', fontSize: 13, outline: 'none',
+              }}
+            />
+            <button
+              onClick={() => setNewOpen(true)}
+              title="Send contact request"
+              style={{
+                padding: '8px 12px', borderRadius: 8, border: 'none',
+                background: '#1d9bf0', color: '#fff',
+                fontSize: 13, fontWeight: 700, cursor: 'pointer',
+              }}
+            >+ New</button>
+          </div>
+        )}
+      </div>
+
+      {tab === 'requests' ? (
+        <RequestsList
+          requests={requests}
+          onChanged={refreshRequests}
+        />
+      ) : sorted.length === 0 ? (
+        <div style={{
+          padding: 32, color: '#6a6a6a', fontSize: 13, textAlign: 'center',
+        }}>
+          No contacts yet. Tap <b>+ New</b> above to send a contact request,
+          or pair another of your own devices via Settings → Devices.
+        </div>
+      ) : (
+        sorted.map(c => (
+          <Row key={c.address} c={c} active={c.address === sel} onClick={() => setSel(c.address)} />
+        ))
+      )}
+
+      {newOpen && (
+        <NewContactModal
+          onClose={() => setNewOpen(false)}
+          onSent={() => { setNewOpen(false); refreshRequests(); }}
+        />
+      )}
+    </div>
+  );
+}
+
+function TabBtn({
+  label, active, onClick, badge,
+}: {
+  label: string; active: boolean; onClick: () => void; badge?: number;
+}) {
+  return (
+    <button
+      onClick={onClick}
+      style={{
+        padding: '8px 12px', borderRadius: 8,
+        border: 'none', background: 'transparent',
+        color: active ? '#1d9bf0' : '#8b8b8b',
+        fontSize: 13, fontWeight: 700, cursor: 'pointer',
+        position: 'relative',
+        borderBottom: active ? '2px solid #1d9bf0' : '2px solid transparent',
+        marginBottom: -2,
+      }}
+    >
+      {label}
+      {badge !== undefined && badge > 0 && (
+        <span style={{
+          marginLeft: 6, padding: '0 6px', height: 16,
+          borderRadius: 8, background: '#1d9bf0', color: '#fff',
+          fontSize: 10, fontWeight: 700,
+          display: 'inline-flex', alignItems: 'center', justifyContent: 'center',
+        }}>{badge > 99 ? '99+' : badge}</span>
+      )}
+    </button>
+  );
+}
+
+function Row({ c, active, onClick }: {
+  c: Contact; active: boolean; onClick: () => void;
+}) {
+  const name = c.username ? `@${c.username}` : (c.alias ?? shortAddr(c.address, 6));
+  return (
+    <div
+      onClick={onClick}
+      style={{
+        padding: '10px 14px', borderBottom: '1px solid #1f1f1f',
+        background: active ? '#0a1a29' : 'transparent',
+        cursor: 'pointer',
+        display: 'flex', alignItems: 'center', gap: 10,
+      }}
+      onMouseEnter={e => { if (!active) (e.currentTarget as HTMLDivElement).style.background = '#0a0a0a'; }}
+      onMouseLeave={e => { if (!active) (e.currentTarget as HTMLDivElement).style.background = 'transparent'; }}
+    >
+      <div style={{
+        width: 36, height: 36, borderRadius: 18, background: '#1a1a1a',
+        display: 'flex', alignItems: 'center', justifyContent: 'center',
+        color: '#d0d0d0', fontWeight: 700,
+      }}>{name.replace(/^@/, '').charAt(0).toUpperCase()}</div>
+      <div style={{ flex: 1, minWidth: 0 }}>
+        <div style={{
+          color: '#fff', fontSize: 13, fontWeight: 700,
+          overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap',
+        }}>{name}</div>
+        <div style={{
+          color: '#6a6a6a', fontSize: 11, fontFamily: 'monospace',
+          overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap',
+        }}>{shortAddr(c.address, 8)}</div>
+      </div>
+    </div>
+  );
+}

desktop/src/sections/contacts/NewContactModal.tsx

@@ -0,0 +1,323 @@
+// NewContactModal — send an on-chain CONTACT_REQUEST to a new peer.
+//
+// Flow:
+//   1. Enter @username / DC / hex → resolve into an Ed25519 pub.
+//   2. Optional intro + fee-tier pick (5k / 10k / 50k µT).
+//   3. Submit CONTACT_REQUEST tx with amount = contactFee.
+// The peer sees the request in their Contacts → Requests tab and can
+// Accept / Reject. After acceptance an encrypted chat becomes possible
+// via the existing /relay/broadcast pipeline.
+
+import React, { useMemo, useState } from 'react';
+import { useStore } from '@/lib/store';
+import {
+  resolveAccount, getIdentity, getBalance,
+  type IdentityInfo,
+} from '@/lib/api';
+import { buildContactRequestTx, submitTx, humanizeTxError } from '@/lib/tx';
+import { shortAddr } from '@/lib/crypto';
+
+const FEE_TIERS = [
+  { value: 5_000,  label: 'Min',      hint: 'enough for a low-spam node' },
+  { value: 10_000, label: 'Standard', hint: 'default'                    },
+  { value: 50_000, label: 'Priority', hint: 'more attention-grabbing'    },
+];
+const MIN_NETWORK_FEE = 1_000;
+
+export function NewContactModal({ onClose, onSent }: {
+  onClose: () => void;
+  onSent: () => void;
+}): React.ReactElement {
+  const keyFile = useStore(s => s.keyFile);
+
+  const [query,    setQuery]    = useState('');
+  const [resolved, setResolved] = useState<{
+    pub: string; identity: IdentityInfo | null;
+  } | null>(null);
+  const [intro,    setIntro]    = useState('');
+  const [fee,      setFee]      = useState<number>(FEE_TIERS[1].value);
+  const [searching, setSearching] = useState(false);
+  const [sending,   setSending]   = useState(false);
+  const [err,       setErr]       = useState<string | null>(null);
+  const [balance,   setBalance]   = useState<number | null>(null);
+
+  const totalCost = fee + MIN_NETWORK_FEE;
+  const insufficient = balance !== null && balance < totalCost;
+
+  React.useEffect(() => {
+    if (!keyFile) return;
+    getBalance(keyFile.pub_key).then(setBalance).catch(() => setBalance(null));
+  }, [keyFile]);
+
+  const search = async () => {
+    const q = query.trim();
+    if (!q) return;
+    setSearching(true); setErr(null); setResolved(null);
+    try {
+      const pub = await resolveAccount(q);
+      if (!pub) { setErr(`Couldn't resolve "${q}"`); return; }
+      if (keyFile && pub.toLowerCase() === keyFile.pub_key.toLowerCase()) {
+        setErr('That\'s you — open Saved Messages in the chat list instead.');
+        return;
+      }
+      const id = await getIdentity(pub);
+      setResolved({ pub, identity: id });
+    } catch (e) {
+      setErr(String(e));
+    } finally {
+      setSearching(false);
+    }
+  };
+
+  const send = async () => {
+    if (!keyFile || !resolved || sending) return;
+    setSending(true); setErr(null);
+    try {
+      const tx = buildContactRequestTx({
+        from:       keyFile.pub_key,
+        to:         resolved.pub,
+        contactFee: fee,
+        intro:      intro.trim() || undefined,
+        privKey:    keyFile.priv_key,
+      });
+      await submitTx(tx);
+      onSent();
+    } catch (e) {
+      setErr(humanizeTxError(e));
+    } finally {
+      setSending(false);
+    }
+  };
+
+  const peerName = useMemo(() => {
+    if (!resolved) return '';
+    if (resolved.identity?.nickname) return `@${resolved.identity.nickname}`;
+    return shortAddr(resolved.pub, 8);
+  }, [resolved]);
+
+  return (
+    <Backdrop onClose={sending ? () => {} : onClose}>
+      <div style={{
+        width: '100%', maxWidth: 480, padding: 20, borderRadius: 16,
+        background: '#0a0a0a', border: '1px solid #1f1f1f',
+      }}>
+        <Header title="Send contact request" onClose={onClose} busy={sending} />
+
+        {/* Search */}
+        <Label>Who</Label>
+        <div style={{ display: 'flex', gap: 8 }}>
+          <input
+            value={query}
+            onChange={e => setQuery(e.target.value)}
+            onKeyDown={e => { if (e.key === 'Enter') search(); }}
+            placeholder="@username, DC-address, or hex pub"
+            spellCheck={false}
+            autoFocus
+            style={{
+              flex: 1, background: '#000', border: '1px solid #1f1f1f',
+              borderRadius: 8, padding: '10px 12px',
+              color: '#fff', fontSize: 13, fontFamily: 'monospace',
+              outline: 'none',
+            }}
+          />
+          <button
+            onClick={search}
+            disabled={searching || query.trim().length === 0}
+            style={{
+              padding: '9px 14px', borderRadius: 8, border: 'none',
+              background: '#1d9bf0', color: '#fff',
+              fontSize: 13, fontWeight: 700,
+              cursor: searching ? 'default' : 'pointer',
+              opacity: searching || query.trim().length === 0 ? 0.5 : 1,
+            }}
+          >{searching ? '…' : 'Find'}</button>
+        </div>
+
+        {/* Resolved peer preview */}
+        {resolved && (
+          <div style={{
+            marginTop: 12, padding: 12, borderRadius: 10,
+            background: '#000', border: '1px solid #1f1f1f',
+            display: 'flex', alignItems: 'center', gap: 10,
+          }}>
+            <div style={{
+              width: 36, height: 36, borderRadius: 18, background: '#1a1a1a',
+              display: 'flex', alignItems: 'center', justifyContent: 'center',
+              color: '#d0d0d0', fontWeight: 700,
+            }}>{peerName.replace(/^@/, '').charAt(0).toUpperCase()}</div>
+            <div style={{ flex: 1, minWidth: 0 }}>
+              <div style={{ color: '#fff', fontSize: 13, fontWeight: 700 }}>
+                {peerName}
+              </div>
+              <div style={{
+                color: '#8b8b8b', fontSize: 11, fontFamily: 'monospace',
+                wordBreak: 'break-all',
+              }}>
+                {resolved.pub}
+              </div>
+              <div style={{
+                color: resolved.identity?.x25519_pub ? '#3ba55d' : '#f0b35a',
+                fontSize: 11, marginTop: 3,
+              }}>
+                {resolved.identity?.x25519_pub
+                  ? '✓ has encryption key published'
+                  : '⚠ no encryption key on chain yet (messaging disabled until they register)'}
+              </div>
+            </div>
+          </div>
+        )}
+
+        {/* Intro */}
+        {resolved && (
+          <>
+            <Label style={{ marginTop: 14 }}>Intro (optional)</Label>
+            <textarea
+              value={intro}
+              onChange={e => setIntro(e.target.value)}
+              placeholder="Hey — we met at …"
+              rows={2}
+              maxLength={280}
+              style={{
+                width: '100%', boxSizing: 'border-box',
+                background: '#000', border: '1px solid #1f1f1f',
+                borderRadius: 8, padding: '10px 12px',
+                color: '#fff', fontSize: 13, fontFamily: 'inherit',
+                outline: 'none', resize: 'vertical',
+              }}
+            />
+          </>
+        )}
+
+        {/* Fee tiers */}
+        {resolved && (
+          <>
+            <Label style={{ marginTop: 14 }}>Anti-spam fee (paid to recipient)</Label>
+            <div style={{ display: 'flex', gap: 8, flexWrap: 'wrap' }}>
+              {FEE_TIERS.map(t => (
+                <button
+                  key={t.value}
+                  onClick={() => setFee(t.value)}
+                  style={{
+                    flex: 1, minWidth: 120,
+                    padding: '10px 12px', borderRadius: 10, cursor: 'pointer',
+                    background: fee === t.value ? '#0a1a29' : '#000',
+                    border: fee === t.value ? '1px solid #1d9bf0' : '1px solid #1f1f1f',
+                    color: '#fff', textAlign: 'left',
+                  }}
+                >
+                  <div style={{
+                    fontSize: 12, fontWeight: 700,
+                    color: fee === t.value ? '#1d9bf0' : '#fff',
+                  }}>{t.label}</div>
+                  <div style={{ fontSize: 11, color: '#8b8b8b', marginTop: 2 }}>
+                    {(t.value / 1_000_000).toFixed(3)} T · {t.hint}
+                  </div>
+                </button>
+              ))}
+            </div>
+          </>
+        )}
+
+        {/* Summary + actions */}
+        {resolved && (
+          <div style={{
+            marginTop: 14, color: '#8b8b8b', fontSize: 11, lineHeight: 1.5,
+          }}>
+            Cost: <span style={{ color: '#fff' }}>
+              {(totalCost / 1_000_000).toFixed(3)} T
+            </span> ({(fee / 1_000_000).toFixed(3)} to recipient · {(MIN_NETWORK_FEE / 1_000_000).toFixed(3)} network fee)
+            {balance !== null && (
+              <> · Balance: <span style={{
+                color: insufficient ? '#f4212e' : '#fff',
+              }}>{(balance / 1_000_000).toFixed(3)} T</span></>
+            )}
+          </div>
+        )}
+
+        {err && (
+          <div style={{
+            marginTop: 12, padding: 10, borderRadius: 8,
+            background: '#2a1414', color: '#ff9b9b', fontSize: 12,
+          }}>{err}</div>
+        )}
+
+        <div style={{
+          marginTop: 16, display: 'flex', justifyContent: 'flex-end', gap: 10,
+        }}>
+          <button
+            onClick={onClose}
+            disabled={sending}
+            style={{
+              padding: '9px 14px', borderRadius: 999,
+              background: 'transparent', border: '1px solid #1f1f1f',
+              color: '#8b8b8b', fontSize: 13, fontWeight: 700,
+              cursor: sending ? 'default' : 'pointer',
+            }}
+          >Cancel</button>
+          <button
+            onClick={send}
+            disabled={!resolved || insufficient || sending}
+            style={{
+              padding: '9px 18px', borderRadius: 999, border: 'none',
+              background: '#1d9bf0', color: '#fff',
+              fontSize: 13, fontWeight: 700,
+              cursor: (!resolved || insufficient || sending) ? 'default' : 'pointer',
+              opacity: (!resolved || insufficient || sending) ? 0.5 : 1,
+            }}
+          >{sending ? '…' : 'Send request'}</button>
+        </div>
+      </div>
+    </Backdrop>
+  );
+}
+
+// ─── small shared primitives (private to this file — Contacts is the only caller)
+
+function Backdrop({ children, onClose }: { children: React.ReactNode; onClose: () => void }) {
+  return (
+    <div
+      onClick={onClose}
+      style={{
+        position: 'fixed', inset: 0, zIndex: 20,
+        background: 'rgba(0,0,0,0.7)',
+        display: 'flex', alignItems: 'center', justifyContent: 'center',
+        padding: 24,
+      }}
+    >
+      <div onClick={e => e.stopPropagation()} style={{ width: '100%', display: 'flex', justifyContent: 'center' }}>
+        {children}
+      </div>
+    </div>
+  );
+}
+
+function Header({ title, onClose, busy }: {
+  title: string; onClose: () => void; busy: boolean;
+}) {
+  return (
+    <div style={{
+      display: 'flex', alignItems: 'center', justifyContent: 'space-between',
+      marginBottom: 14,
+    }}>
+      <div style={{ color: '#fff', fontSize: 16, fontWeight: 700 }}>{title}</div>
+      <button
+        onClick={onClose}
+        disabled={busy}
+        style={{
+          background: 'transparent', border: 'none',
+          color: '#8b8b8b', fontSize: 20, cursor: 'pointer',
+        }}
+      >×</button>
+    </div>
+  );
+}
+
+function Label({ children, style }: { children: React.ReactNode; style?: React.CSSProperties }) {
+  return (
+    <div style={{
+      color: '#8b8b8b', fontSize: 11, fontWeight: 700,
+      letterSpacing: 1, textTransform: 'uppercase', marginBottom: 6,
+      ...style,
+    }}>{children}</div>
+  );
+}

desktop/src/sections/contacts/RequestsList.tsx

@@ -0,0 +1,168 @@
+// RequestsList — pending contact requests inbox.
+//
+// Each row shows the requester (identity if known + DC address + fee paid)
+// and their intro message. Accept publishes ACCEPT_CONTACT on-chain,
+// adds the peer to the local contacts store, and optimistically drops
+// the row. Reject (Block) publishes BLOCK_CONTACT; subsequent requests
+// from the same sender are refused by the node.
+
+import React, { useState } from 'react';
+import { useStore } from '@/lib/store';
+import {
+  buildAcceptContactTx, buildBlockContactTx, submitTx, humanizeTxError,
+} from '@/lib/tx';
+import { upsertContact as persistContact } from '@/lib/storage';
+import { getIdentity, type ContactRequestRaw } from '@/lib/api';
+import { shortAddr } from '@/lib/crypto';
+
+export function RequestsList({
+  requests, onChanged,
+}: {
+  requests: ContactRequestRaw[];
+  onChanged: () => void;
+}): React.ReactElement {
+  if (requests.length === 0) {
+    return (
+      <div style={{
+        padding: 32, color: '#6a6a6a', fontSize: 13, textAlign: 'center',
+      }}>
+        No pending requests. Inbound CONTACT_REQUEST txs will show up here
+        for you to accept or block.
+      </div>
+    );
+  }
+  return (
+    <div>
+      {requests.map(r => (
+        <RequestRow key={r.tx_id} req={r} onChanged={onChanged} />
+      ))}
+    </div>
+  );
+}
+
+function RequestRow({
+  req, onChanged,
+}: { req: ContactRequestRaw; onChanged: () => void }) {
+  const keyFile       = useStore(s => s.keyFile);
+  const upsertContact = useStore(s => s.upsertContact);
+
+  const [busy, setBusy] = useState<'accept' | 'block' | null>(null);
+  const [err,  setErr]  = useState<string | null>(null);
+
+  const act = async (kind: 'accept' | 'block') => {
+    if (!keyFile) return;
+    setBusy(kind); setErr(null);
+    try {
+      if (kind === 'accept') {
+        // Need the requester's X25519 so a local contact is created
+        // with encryption enabled out of the gate — without it the
+        // first outgoing message would surface "no key" until we
+        // refetched via resolveRecipientKeys.
+        const identity = await getIdentity(req.requester_pub);
+        const tx = buildAcceptContactTx({
+          from:    keyFile.pub_key,
+          to:      req.requester_pub,
+          privKey: keyFile.priv_key,
+        });
+        await submitTx(tx);
+        const c = {
+          address:   req.requester_pub,
+          x25519Pub: identity?.x25519_pub ?? '',
+          username:  identity?.nickname || undefined,
+          alias:     undefined,
+          addedAt:   Date.now(),
+        };
+        upsertContact(c);
+        persistContact(c);
+      } else {
+        const tx = buildBlockContactTx({
+          from:    keyFile.pub_key,
+          to:      req.requester_pub,
+          privKey: keyFile.priv_key,
+        });
+        await submitTx(tx);
+      }
+      onChanged();
+    } catch (e) {
+      setErr(humanizeTxError(e));
+    } finally {
+      setBusy(null);
+    }
+  };
+
+  return (
+    <div style={{
+      padding: 14, borderBottom: '1px solid #1f1f1f',
+    }}>
+      <div style={{
+        display: 'flex', alignItems: 'center', gap: 10, marginBottom: 8,
+      }}>
+        <div style={{
+          width: 36, height: 36, borderRadius: 18, background: '#1a1a1a',
+          display: 'flex', alignItems: 'center', justifyContent: 'center',
+          color: '#d0d0d0', fontWeight: 700,
+        }}>{shortAddr(req.requester_pub, 1).charAt(0).toUpperCase()}</div>
+        <div style={{ flex: 1, minWidth: 0 }}>
+          <div style={{
+            color: '#fff', fontSize: 13, fontWeight: 700,
+            overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap',
+          }}>
+            {shortAddr(req.requester_pub, 8)}
+          </div>
+          <div style={{ color: '#8b8b8b', fontSize: 11, fontFamily: 'monospace' }}>
+            {req.requester_addr}
+          </div>
+        </div>
+        <div style={{
+          color: '#f0b35a', fontSize: 11, fontWeight: 700,
+        }}>
+          +{(req.fee_ut / 1_000_000).toFixed(3)} T
+        </div>
+      </div>
+
+      {req.intro && (
+        <div className="selectable" style={{
+          padding: 10, borderRadius: 8,
+          background: '#000', border: '1px solid #1f1f1f',
+          color: '#e0e0e0', fontSize: 12, lineHeight: 1.5,
+          whiteSpace: 'pre-wrap', wordBreak: 'break-word',
+          marginBottom: 8,
+        }}>
+          {req.intro}
+        </div>
+      )}
+
+      <div style={{ display: 'flex', gap: 8, justifyContent: 'flex-end' }}>
+        <button
+          onClick={() => act('block')}
+          disabled={!!busy}
+          style={{
+            padding: '7px 12px', borderRadius: 999,
+            background: 'transparent', border: '1px solid #3a2020',
+            color: '#ff6b6b', fontSize: 12, fontWeight: 700,
+            cursor: busy ? 'default' : 'pointer',
+            opacity: busy ? 0.5 : 1,
+          }}
+        >{busy === 'block' ? '…' : 'Block'}</button>
+        <button
+          onClick={() => act('accept')}
+          disabled={!!busy}
+          style={{
+            padding: '7px 14px', borderRadius: 999,
+            border: 'none', background: '#1d9bf0', color: '#fff',
+            fontSize: 12, fontWeight: 700,
+            cursor: busy ? 'default' : 'pointer',
+            opacity: busy ? 0.5 : 1,
+          }}
+        >{busy === 'accept' ? '…' : 'Accept'}</button>
+      </div>
+
+      {err && (
+        <div style={{
+          marginTop: 8, padding: 8, borderRadius: 6,
+          background: '#2a1414', color: '#ff9b9b', fontSize: 11,
+        }}>{err}</div>
+      )}
+    </div>
+  );
+}

desktop/src/sections/contacts/index.tsx

@@ -0,0 +1,6 @@
+// Contacts section.
+//   List pane: contact list + quick filter.
+//   Detail pane: selected contact's profile card + actions.
+
+export { ContactsList } from './ContactsList';
+export { ContactsDetail } from './ContactsDetail';

desktop/src/sections/feed/ComposeModal.tsx

@@ -0,0 +1,159 @@
+// ComposeModal — new-post modal reachable from the Feed section header
+// or the Ctrl/Cmd+N keybind. Minimal for alpha6: text-only, 4000 char
+// limit, no attachments (those come with the image-picker + client-side
+// scrub in rc1). Publish flow is identical to mobile — server returns
+// content_hash + fee; client commits the matching CREATE_POST tx.
+
+import React, { useEffect, useMemo, useState } from 'react';
+import { useStore } from '@/lib/store';
+import { publishAndCommit } from '@/lib/feed';
+import { humanizeTxError } from '@/lib/tx';
+
+const MAX_CONTENT_LEN = 4000;
+
+export function ComposeModal({
+  onClose, onPublished,
+}: {
+  onClose: () => void;
+  onPublished: () => void;
+}): React.ReactElement {
+  const keyFile = useStore(s => s.keyFile);
+  const [content, setContent] = useState('');
+  const [busy,    setBusy]    = useState(false);
+  const [error,   setError]   = useState<string | null>(null);
+
+  // Focus the textarea on mount; close on Escape.
+  useEffect(() => {
+    const onKey = (e: KeyboardEvent) => {
+      if (e.key === 'Escape' && !busy) onClose();
+      if (e.key === 'Enter' && (e.ctrlKey || e.metaKey)) { submit(); }
+    };
+    window.addEventListener('keydown', onKey);
+    return () => window.removeEventListener('keydown', onKey);
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [content, busy]);
+
+  const bytes = useMemo(
+    () => new TextEncoder().encode(content).length,
+    [content],
+  );
+
+  const hashtags = useMemo(() => {
+    const m = content.match(/#[A-Za-z0-9_\u0400-\u04FF]{1,40}/g) ?? [];
+    return Array.from(new Set(m.map(t => t.slice(1).toLowerCase())));
+  }, [content]);
+
+  const canPublish = !busy && content.trim().length > 0 && bytes <= MAX_CONTENT_LEN;
+
+  const submit = async () => {
+    if (!keyFile || !canPublish) return;
+    setBusy(true); setError(null);
+    try {
+      await publishAndCommit({
+        author:   keyFile.pub_key,
+        privKey:  keyFile.priv_key,
+        content:  content.trim(),
+      });
+      onPublished();
+    } catch (e) {
+      setError(humanizeTxError(e));
+    } finally {
+      setBusy(false);
+    }
+  };
+
+  return (
+    <div style={{
+      position: 'fixed', inset: 0, zIndex: 20,
+      background: 'rgba(0,0,0,0.7)',
+      display: 'flex', alignItems: 'center', justifyContent: 'center',
+      padding: 24,
+    }} onClick={() => !busy && onClose()}>
+      <div
+        onClick={e => e.stopPropagation()}
+        style={{
+          width: '100%', maxWidth: 560,
+          background: '#0a0a0a',
+          borderRadius: 16, border: '1px solid #1f1f1f',
+          padding: 18,
+        }}
+      >
+        <div style={{
+          display: 'flex', alignItems: 'center', justifyContent: 'space-between',
+          marginBottom: 10,
+        }}>
+          <div style={{ color: '#fff', fontSize: 16, fontWeight: 700 }}>
+            New post
+          </div>
+          <button
+            onClick={onClose}
+            disabled={busy}
+            style={{
+              background: 'transparent', border: 'none',
+              color: '#8b8b8b', fontSize: 20, cursor: 'pointer',
+            }}
+          >×</button>
+        </div>
+
+        <textarea
+          autoFocus
+          value={content}
+          onChange={e => setContent(e.target.value)}
+          placeholder="What's happening?"
+          rows={6}
+          style={{
+            width: '100%', resize: 'vertical',
+            background: '#000', border: '1px solid #1f1f1f',
+            borderRadius: 10, padding: '12px',
+            color: '#fff', fontSize: 14, fontFamily: 'inherit',
+            outline: 'none', lineHeight: 1.5,
+          }}
+        />
+
+        <div style={{
+          marginTop: 8, display: 'flex', alignItems: 'center',
+          justifyContent: 'space-between', gap: 12,
+        }}>
+          <div style={{ color: '#8b8b8b', fontSize: 11 }}>
+            {bytes.toLocaleString()} / {MAX_CONTENT_LEN.toLocaleString()} bytes
+            {hashtags.length > 0 && (
+              <> · <span style={{ color: '#1d9bf0' }}>
+                {hashtags.slice(0, 3).map(t => `#${t}`).join(' ')}
+              </span></>
+            )}
+          </div>
+          <div style={{ display: 'flex', gap: 8 }}>
+            <button
+              onClick={onClose}
+              disabled={busy}
+              style={{
+                padding: '8px 14px', borderRadius: 999,
+                background: 'transparent', border: '1px solid #1f1f1f',
+                color: '#8b8b8b', fontSize: 13, fontWeight: 700,
+                cursor: busy ? 'default' : 'pointer',
+              }}
+            >Cancel</button>
+            <button
+              onClick={submit}
+              disabled={!canPublish}
+              style={{
+                padding: '8px 16px', borderRadius: 999,
+                border: 'none', background: '#1d9bf0', color: '#fff',
+                fontSize: 13, fontWeight: 700,
+                cursor: canPublish ? 'pointer' : 'default',
+                opacity: canPublish ? 1 : 0.5,
+              }}
+            >{busy ? '…' : 'Publish'}</button>
+          </div>
+        </div>
+
+        {error && (
+          <div style={{
+            marginTop: 12, padding: 10, borderRadius: 8,
+            background: '#2a1414', color: '#ff9b9b', fontSize: 12,
+          }}>{error}</div>
+        )}
+      </div>
+    </div>
+  );
+}

desktop/src/sections/feed/FeedPane.tsx

@@ -0,0 +1,133 @@
+// FeedPane — the right pane. A two-column split: scrollable post list
+// on the left (~430px), thread/post detail on the right.
+
+import React, { useCallback, useEffect, useState } from 'react';
+import { useStore, type FeedTab } from '@/lib/store';
+import {
+  fetchForYou, fetchTrending, fetchTimeline, fetchHashtag, fetchAuthorPosts,
+  type FeedPostItem,
+} from '@/lib/feed';
+import { PostList } from './PostList';
+import { PostDetail } from './PostDetail';
+import { ComposeModal } from './ComposeModal';
+
+export function FeedPane(): React.ReactElement {
+  const tab      = useStore(s => s.feedTab);
+  const selected = useStore(s => s.feedSelectedPost);
+  const keyFile  = useStore(s => s.keyFile);
+
+  const [posts,    setPosts]    = useState<FeedPostItem[]>([]);
+  const [loading,  setLoading]  = useState(true);
+  const [composing, setComposing] = useState(false);
+
+  const load = useCallback(async () => {
+    setLoading(true);
+    try {
+      const list = await fetchByTab(tab, keyFile?.pub_key);
+      setPosts(list);
+    } catch {
+      setPosts([]);
+    } finally {
+      setLoading(false);
+    }
+  }, [tab, keyFile]);
+
+  useEffect(() => { load(); }, [load]);
+
+  // Ctrl/Cmd+N → compose (scoped to Feed being active).
+  useEffect(() => {
+    const onKey = (e: KeyboardEvent) => {
+      if ((e.ctrlKey || e.metaKey) && e.key.toLowerCase() === 'n') {
+        e.preventDefault();
+        setComposing(true);
+      }
+    };
+    window.addEventListener('keydown', onKey);
+    return () => window.removeEventListener('keydown', onKey);
+  }, []);
+
+  return (
+    <div style={{ height: '100%', display: 'flex' }}>
+      <div style={{
+        width: 430, flexShrink: 0, borderRight: '1px solid #1f1f1f',
+        overflowY: 'auto', background: '#000',
+      }}>
+        {/* Header strip — tab label + compose CTA */}
+        <div style={{
+          position: 'sticky', top: 0, zIndex: 1,
+          padding: '10px 14px',
+          display: 'flex', alignItems: 'center', justifyContent: 'space-between',
+          borderBottom: '1px solid #1f1f1f',
+          background: 'rgba(0,0,0,0.9)', backdropFilter: 'blur(6px)',
+        }}>
+          <div style={{ color: '#fff', fontSize: 14, fontWeight: 700 }}>
+            {titleFor(tab)}
+          </div>
+          <button
+            onClick={() => setComposing(true)}
+            style={{
+              padding: '6px 12px', borderRadius: 999, border: 'none',
+              background: '#1d9bf0', color: '#fff',
+              fontSize: 12, fontWeight: 700, cursor: 'pointer',
+            }}
+            title="Ctrl/Cmd+N"
+          >New post</button>
+        </div>
+
+        {loading ? (
+          <div style={{
+            padding: 40, textAlign: 'center', color: '#6a6a6a', fontSize: 13,
+          }}>Loading…</div>
+        ) : posts.length === 0 ? (
+          <div style={{
+            padding: 40, textAlign: 'center', color: '#6a6a6a', fontSize: 13,
+          }}>No posts in this feed yet.</div>
+        ) : (
+          <PostList posts={posts} activeID={selected} />
+        )}
+      </div>
+
+      <div style={{ flex: 1, minWidth: 0, overflow: 'hidden' }}>
+        <PostDetail postID={selected} onDeleted={load} />
+      </div>
+
+      {composing && keyFile && (
+        <ComposeModal
+          onClose={() => setComposing(false)}
+          onPublished={() => {
+            setComposing(false);
+            // Re-pull so the new post shows up immediately.
+            setTimeout(load, 800);
+          }}
+        />
+      )}
+    </div>
+  );
+}
+
+function titleFor(tab: FeedTab): string {
+  switch (tab.kind) {
+    case 'foryou':   return 'For You';
+    case 'timeline': return 'Following';
+    case 'trending': return 'Trending 24h';
+    case 'hashtag':  return `#${tab.tag}`;
+    case 'author':   return 'Author wall';
+  }
+}
+
+async function fetchByTab(tab: FeedTab, selfPub: string | undefined): Promise<FeedPostItem[]> {
+  switch (tab.kind) {
+    case 'foryou':
+      if (!selfPub) return fetchTrending(24, 30);
+      return fetchForYou(selfPub, 30);
+    case 'timeline':
+      if (!selfPub) return [];
+      return fetchTimeline(selfPub, { limit: 30 });
+    case 'trending':
+      return fetchTrending(24, 30);
+    case 'hashtag':
+      return fetchHashtag(tab.tag, 30);
+    case 'author':
+      return fetchAuthorPosts(tab.pub, { limit: 30 });
+  }
+}

desktop/src/sections/feed/FeedTabs.tsx

@@ -0,0 +1,146 @@
+// FeedTabs — left-pane navigation for the Feed section.
+//
+// Four top-level tabs (For You / Following / Trending / Hashtag) plus
+// an inline hashtag input that promotes to a dedicated tab when you
+// press Enter. Sub-states — viewing a specific author's wall — are
+// reachable by clicking an @handle in the post list; a breadcrumb
+// appears at the top for back-navigation.
+
+import React, { useState } from 'react';
+import { useStore, type FeedTab } from '@/lib/store';
+import { shortAddr } from '@/lib/crypto';
+
+interface TabOption {
+  kind:  FeedTab['kind'];
+  label: string;
+  hint:  string;
+}
+
+const STATIC_TABS: TabOption[] = [
+  { kind: 'foryou',   label: 'For You',       hint: 'Recommended posts from authors you don\'t follow yet' },
+  { kind: 'timeline', label: 'Following',     hint: 'Posts from authors you follow'                     },
+  { kind: 'trending', label: 'Trending 24h',  hint: 'Top posts by engagement in the last day'           },
+];
+
+export function FeedTabs(): React.ReactElement {
+  const tab        = useStore(s => s.feedTab);
+  const setTab     = useStore(s => s.setFeedTab);
+  const [tagInput, setTagInput] = useState('');
+
+  // Sub-tab renderers reachable from list items (author wall, hashtag tab).
+  // Instead of hiding them in a dropdown we surface a breadcrumb so the
+  // operator can jump back out cleanly.
+  const breadcrumb = renderBreadcrumb(tab, setTab);
+
+  return (
+    <div style={{ padding: 10 }}>
+      {breadcrumb}
+
+      {STATIC_TABS.map(t => (
+        <TabRow
+          key={t.kind}
+          label={t.label}
+          hint={t.hint}
+          active={tab.kind === t.kind}
+          onClick={() => setTab({ kind: t.kind } as FeedTab)}
+        />
+      ))}
+
+      {/* Hashtag input — promotes to a tab on Enter. */}
+      <div style={{
+        marginTop: 14, padding: 10, borderRadius: 10,
+        background: '#0a0a0a', border: '1px solid #1f1f1f',
+      }}>
+        <div style={{
+          color: '#5a5a5a', fontSize: 11, fontWeight: 700,
+          letterSpacing: 1.2, textTransform: 'uppercase', marginBottom: 6,
+        }}>Hashtag</div>
+        <input
+          value={tagInput}
+          onChange={e => setTagInput(e.target.value.replace(/^#/, ''))}
+          onKeyDown={e => {
+            if (e.key === 'Enter' && tagInput.trim().length > 0) {
+              setTab({ kind: 'hashtag', tag: tagInput.trim() });
+            }
+          }}
+          placeholder="type a tag…"
+          style={{
+            width: '100%', background: '#000',
+            border: '1px solid #1f1f1f', borderRadius: 8,
+            padding: '8px 10px', color: '#fff', fontSize: 13,
+            fontFamily: 'monospace', outline: 'none',
+          }}
+        />
+      </div>
+    </div>
+  );
+}
+
+function TabRow({
+  label, hint, active, onClick,
+}: {
+  label: string; hint: string; active: boolean; onClick: () => void;
+}) {
+  return (
+    <div
+      onClick={onClick}
+      style={{
+        padding: '10px 12px', borderRadius: 10, cursor: 'pointer',
+        background: active ? '#0a1a29' : 'transparent',
+        border: active ? '1px solid #1d9bf022' : '1px solid transparent',
+      }}
+      onMouseEnter={e => { if (!active) (e.currentTarget as HTMLDivElement).style.background = '#0a0a0a'; }}
+      onMouseLeave={e => { if (!active) (e.currentTarget as HTMLDivElement).style.background = 'transparent'; }}
+    >
+      <div style={{
+        color: active ? '#1d9bf0' : '#fff',
+        fontSize: 14, fontWeight: 700,
+      }}>{label}</div>
+      <div style={{ color: '#6a6a6a', fontSize: 11, marginTop: 2, lineHeight: 1.4 }}>
+        {hint}
+      </div>
+    </div>
+  );
+}
+
+function renderBreadcrumb(tab: FeedTab, setTab: (t: FeedTab) => void): React.ReactNode | null {
+  if (tab.kind === 'hashtag') {
+    return (
+      <Breadcrumb
+        label={`#${tab.tag}`}
+        onClear={() => setTab({ kind: 'foryou' })}
+      />
+    );
+  }
+  if (tab.kind === 'author') {
+    return (
+      <Breadcrumb
+        label={`Author: ${shortAddr(tab.pub, 6)}`}
+        onClear={() => setTab({ kind: 'foryou' })}
+      />
+    );
+  }
+  return null;
+}
+
+function Breadcrumb({ label, onClear }: { label: string; onClear: () => void }) {
+  return (
+    <div style={{
+      display: 'flex', alignItems: 'center', gap: 8,
+      padding: '8px 10px', marginBottom: 10,
+      borderRadius: 8, background: '#0a0a0a',
+      border: '1px solid #1f1f1f',
+    }}>
+      <button
+        onClick={onClear}
+        style={{
+          background: 'transparent', border: 'none', color: '#8b8b8b',
+          cursor: 'pointer', padding: 0, fontSize: 14,
+        }}
+      >←</button>
+      <div style={{ color: '#fff', fontSize: 13, fontWeight: 700, flex: 1 }}>
+        {label}
+      </div>
+    </div>
+  );
+}

desktop/src/sections/feed/PostDetail.tsx

@@ -0,0 +1,230 @@
+// PostDetail — right-hand-inner pane showing a single post with full
+// body, attachment, engagement bar, delete-if-mine.
+//
+// Side effects on mount:
+//   * bumps the view counter (off-chain)
+//   * refreshes stats for the liked-by-me badge
+
+import React, { useCallback, useEffect, useState } from 'react';
+import { useStore } from '@/lib/store';
+import {
+  fetchPost, fetchStats, bumpView, likePost, unlikePost, deletePost,
+  attachmentURL, type FeedPostItem, type PostStats,
+} from '@/lib/feed';
+import { shortAddr } from '@/lib/crypto';
+import { humanizeTxError } from '@/lib/tx';
+
+interface Props {
+  postID:    string | null;
+  onDeleted: () => void;
+}
+
+export function PostDetail({ postID, onDeleted }: Props): React.ReactElement {
+  const keyFile  = useStore(s => s.keyFile);
+  const setTab   = useStore(s => s.setFeedTab);
+
+  const [post,   setPost]   = useState<FeedPostItem | null>(null);
+  const [stats,  setStats]  = useState<PostStats | null>(null);
+  const [busy,   setBusy]   = useState(false);
+  const [error,  setError]  = useState<string | null>(null);
+
+  // Load + side-effects.
+  useEffect(() => {
+    if (!postID) { setPost(null); setStats(null); return; }
+    let cancelled = false;
+    setError(null);
+    fetchPost(postID).then(p => { if (!cancelled) setPost(p); }).catch(() => {});
+    fetchStats(postID, keyFile?.pub_key).then(s => { if (!cancelled) setStats(s); }).catch(() => {});
+    bumpView(postID);
+    return () => { cancelled = true; };
+  }, [postID, keyFile?.pub_key]);
+
+  const toggleLike = useCallback(async () => {
+    if (!keyFile || !post || busy) return;
+    const liked = stats?.liked_by_me ?? false;
+    setBusy(true); setError(null);
+    // Optimistic — roll back if the tx fails.
+    setStats(s => s ? { ...s, liked_by_me: !liked, likes: s.likes + (liked ? -1 : 1) } : s);
+    try {
+      if (liked) await unlikePost({ from: keyFile.pub_key, privKey: keyFile.priv_key, postID: post.post_id });
+      else       await likePost  ({ from: keyFile.pub_key, privKey: keyFile.priv_key, postID: post.post_id });
+    } catch (e) {
+      setStats(s => s ? { ...s, liked_by_me: liked, likes: s.likes + (liked ? 1 : -1) } : s);
+      setError(humanizeTxError(e));
+    } finally {
+      setBusy(false);
+    }
+  }, [keyFile, post, stats, busy]);
+
+  const onDelete = useCallback(async () => {
+    if (!keyFile || !post || busy) return;
+    if (!confirm('Delete this post? This cannot be undone.')) return;
+    setBusy(true); setError(null);
+    try {
+      await deletePost({ from: keyFile.pub_key, privKey: keyFile.priv_key, postID: post.post_id });
+      onDeleted();
+      useStore.getState().setFeedSelectedPost(null);
+    } catch (e) {
+      setError(humanizeTxError(e));
+    } finally {
+      setBusy(false);
+    }
+  }, [keyFile, post, busy, onDeleted]);
+
+  if (!postID) {
+    return (
+      <div style={{
+        height: '100%',
+        display: 'flex', alignItems: 'center', justifyContent: 'center',
+        color: '#6a6a6a', fontSize: 13, padding: 40, textAlign: 'center',
+      }}>
+        Select a post from the list on the left.
+      </div>
+    );
+  }
+
+  if (!post) {
+    return (
+      <div style={{
+        height: '100%',
+        display: 'flex', alignItems: 'center', justifyContent: 'center',
+        color: '#6a6a6a', fontSize: 13,
+      }}>
+        Loading…
+      </div>
+    );
+  }
+
+  const mine = !!keyFile && keyFile.pub_key === post.author;
+
+  return (
+    <div style={{
+      height: '100%', overflowY: 'auto',
+      padding: '18px 22px', background: '#000',
+    }}>
+      {/* Author line */}
+      <div style={{
+        display: 'flex', alignItems: 'center', gap: 10, marginBottom: 12,
+      }}>
+        <div style={{
+          width: 36, height: 36, borderRadius: 18,
+          background: '#1a1a1a',
+          display: 'flex', alignItems: 'center', justifyContent: 'center',
+          color: '#d0d0d0', fontWeight: 700,
+        }}>
+          {post.author.slice(0, 1).toUpperCase()}
+        </div>
+        <div style={{ flex: 1 }}>
+          <button
+            onClick={() => setTab({ kind: 'author', pub: post.author })}
+            style={{
+              background: 'transparent', border: 'none', padding: 0,
+              color: '#fff', fontWeight: 700, fontSize: 14, cursor: 'pointer',
+              fontFamily: 'monospace',
+            }}
+          >
+            {shortAddr(post.author, 8)}
+          </button>
+          <div style={{ color: '#8b8b8b', fontSize: 11 }}>
+            {new Date(post.created_at * 1000).toLocaleString()}
+          </div>
+        </div>
+        {mine && (
+          <button
+            onClick={onDelete}
+            disabled={busy}
+            style={{
+              padding: '6px 12px', borderRadius: 999,
+              border: '1px solid #3a2020', background: 'transparent',
+              color: '#ff6b6b', fontSize: 11, fontWeight: 700,
+              cursor: busy ? 'default' : 'pointer',
+            }}
+          >Delete</button>
+        )}
+      </div>
+
+      {/* Body */}
+      <div className="selectable" style={{
+        color: '#fff', fontSize: 15, lineHeight: 1.55,
+        whiteSpace: 'pre-wrap', wordBreak: 'break-word',
+        marginBottom: 14,
+      }}>
+        {renderBody(post.content, setTab)}
+      </div>
+
+      {post.has_attachment && (
+        <img
+          src={attachmentURL(post.post_id)}
+          alt=""
+          style={{
+            maxWidth: '100%', maxHeight: 520, borderRadius: 14,
+            display: 'block', marginBottom: 14,
+          }}
+          onError={e => { (e.currentTarget as HTMLImageElement).style.display = 'none'; }}
+        />
+      )}
+
+      {/* Engagement bar */}
+      <div style={{
+        display: 'flex', gap: 16, alignItems: 'center',
+        padding: '10px 0', borderTop: '1px solid #1f1f1f',
+      }}>
+        <button
+          onClick={toggleLike}
+          disabled={busy || !keyFile}
+          style={{
+            background: 'transparent', border: 'none',
+            color: stats?.liked_by_me ? '#f4212e' : '#8b8b8b',
+            fontSize: 13, fontWeight: 700, cursor: keyFile ? 'pointer' : 'default',
+            display: 'flex', alignItems: 'center', gap: 6,
+          }}
+        >
+          {stats?.liked_by_me ? '❤' : '♡'} {stats?.likes ?? post.likes}
+        </button>
+        <div style={{ color: '#8b8b8b', fontSize: 13 }}>
+          👁 {stats?.views ?? post.views}
+        </div>
+      </div>
+
+      {error && (
+        <div style={{
+          marginTop: 12, padding: 10, borderRadius: 10,
+          background: '#2a1414', color: '#ff9b9b', fontSize: 12,
+        }}>{error}</div>
+      )}
+    </div>
+  );
+}
+
+/**
+ * Render post body with #hashtags turned into clickable buttons that
+ * jump the feed tab. Basic — no markdown, no emoji polish yet.
+ */
+function renderBody(
+  text: string,
+  setTab: (t: { kind: 'hashtag'; tag: string }) => void,
+): React.ReactNode[] {
+  const parts: React.ReactNode[] = [];
+  const re = /(#[A-Za-z0-9_\u0400-\u04FF]{1,40})/g;
+  let last = 0;
+  let m: RegExpExecArray | null;
+  while ((m = re.exec(text))) {
+    if (m.index > last) parts.push(text.slice(last, m.index));
+    const tag = m[1].slice(1);
+    parts.push(
+      <button
+        key={`tag-${m.index}`}
+        onClick={() => setTab({ kind: 'hashtag', tag })}
+        style={{
+          color: '#1d9bf0', background: 'transparent', border: 'none',
+          padding: 0, font: 'inherit', cursor: 'pointer',
+        }}
+      >
+        {m[1]}
+      </button>,
+    );
+    last = m.index + m[1].length;
+  }
+  if (last < text.length) parts.push(text.slice(last));
+  return parts;
+}

desktop/src/sections/feed/PostList.tsx

@@ -0,0 +1,93 @@
+// PostList — rows within the Feed middle column. Clicking a row sets
+// the selected post in the store; the detail pane reacts.
+
+import React from 'react';
+import { useStore } from '@/lib/store';
+import type { FeedPostItem } from '@/lib/feed';
+import { shortAddr } from '@/lib/crypto';
+
+interface Props {
+  posts:    FeedPostItem[];
+  activeID: string | null;
+}
+
+export function PostList({ posts, activeID }: Props): React.ReactElement {
+  const select = useStore(s => s.setFeedSelectedPost);
+  return (
+    <div>
+      {posts.map(p => (
+        <PostRow
+          key={p.post_id}
+          post={p}
+          active={p.post_id === activeID}
+          onClick={() => select(p.post_id)}
+        />
+      ))}
+    </div>
+  );
+}
+
+function PostRow({ post, active, onClick }: {
+  post: FeedPostItem; active: boolean; onClick: () => void;
+}) {
+  const author = shortAddr(post.author, 6);
+  return (
+    <div
+      onClick={onClick}
+      style={{
+        padding: '12px 14px', borderBottom: '1px solid #1f1f1f',
+        cursor: 'pointer',
+        background: active ? '#0a1a29' : 'transparent',
+      }}
+      onMouseEnter={e => { if (!active) (e.currentTarget as HTMLDivElement).style.background = '#0a0a0a'; }}
+      onMouseLeave={e => { if (!active) (e.currentTarget as HTMLDivElement).style.background = 'transparent'; }}
+    >
+      <div style={{
+        display: 'flex', alignItems: 'center', gap: 8,
+        color: '#8b8b8b', fontSize: 11, marginBottom: 4,
+      }}>
+        <span style={{ fontFamily: 'monospace', color: '#d0d0d0' }}>{author}</span>
+        <span>·</span>
+        <span>{formatRelative(post.created_at)}</span>
+      </div>
+      <div className="selectable" style={{
+        color: '#fff', fontSize: 13, lineHeight: 1.45,
+        whiteSpace: 'pre-wrap', wordBreak: 'break-word',
+        // Visual truncate; the detail pane shows the full thing.
+        display: '-webkit-box',
+        WebkitLineClamp: 4,
+        WebkitBoxOrient: 'vertical',
+        overflow: 'hidden',
+      } as React.CSSProperties}>
+        {post.content}
+      </div>
+      {post.has_attachment && (
+        <div style={{ color: '#6a6a6a', fontSize: 11, marginTop: 4 }}>
+          🖼 attachment
+        </div>
+      )}
+      <div style={{
+        color: '#6a6a6a', fontSize: 11, marginTop: 6,
+        display: 'flex', gap: 12,
+      }}>
+        <span>❤ {post.likes}</span>
+        <span>👁 {post.views}</span>
+        {post.hashtags && post.hashtags.length > 0 && (
+          <span style={{ color: '#1d9bf0' }}>
+            {post.hashtags.slice(0, 3).map(t => `#${t}`).join(' ')}
+          </span>
+        )}
+      </div>
+    </div>
+  );
+}
+
+function formatRelative(unixSec: number): string {
+  const diff = Math.floor(Date.now() / 1000) - unixSec;
+  if (diff < 60)    return `${diff}s`;
+  if (diff < 3600)  return `${Math.floor(diff / 60)}m`;
+  if (diff < 86400) return `${Math.floor(diff / 3600)}h`;
+  if (diff < 604800) return `${Math.floor(diff / 86400)}d`;
+  const d = new Date(unixSec * 1000);
+  return d.toLocaleDateString([], { month: 'short', day: 'numeric' });
+}

desktop/src/sections/feed/index.tsx

@@ -0,0 +1,6 @@
+// Feed section — re-exports into the Shell's PANES map. Real
+// implementation lives in FeedTabs (left) + FeedPane (right); they
+// share state via zustand's store.feedTab / store.feedSelectedPost.
+
+export { FeedTabs as FeedList } from './FeedTabs';
+export { FeedPane as FeedDetail } from './FeedPane';

desktop/src/sections/messages/ChatList.tsx

@@ -0,0 +1,165 @@
+// ChatList — the Messages left-pane list of conversations.
+// Rows sort by last-activity timestamp (most recent first); empty state
+// renders as a full-height notice so the layout doesn't collapse.
+
+import React from 'react';
+import { useStore } from '@/lib/store';
+import type { Contact, Message } from '@/lib/types';
+import { shortAddr } from '@/lib/crypto';
+
+export function ChatList(): React.ReactElement {
+  const contacts   = useStore(s => s.contacts);
+  const messages   = useStore(s => s.messages);
+  const unread     = useStore(s => s.unread);
+  const activeChat = useStore(s => s.activeChat);
+  const setActive  = useStore(s => s.setActiveChat);
+
+  const lastOf = (c: Contact): Message | null => {
+    const list = messages[c.address];
+    return list && list.length > 0 ? list[list.length - 1] : null;
+  };
+
+  const sorted = [...contacts]
+    .map(c => ({ c, last: lastOf(c) }))
+    .sort((a, b) => {
+      const ka = a.last ? a.last.timestamp : a.c.addedAt / 1000;
+      const kb = b.last ? b.last.timestamp : b.c.addedAt / 1000;
+      return kb - ka;
+    });
+
+  if (sorted.length === 0) {
+    return (
+      <div style={{
+        padding: 28, textAlign: 'center', color: '#8b8b8b', fontSize: 13,
+      }}>
+        No conversations yet. Messages from pairing devices or contacts
+        will appear here.
+      </div>
+    );
+  }
+
+  return (
+    <div>
+      {sorted.map(({ c, last }) => (
+        <ChatRow
+          key={c.address}
+          contact={c}
+          last={last}
+          unread={unread[c.address] ?? 0}
+          active={activeChat === c.address}
+          onClick={() => {
+            setActive(c.address);
+            useStore.getState().clearUnread(c.address);
+          }}
+        />
+      ))}
+    </div>
+  );
+}
+
+function ChatRow({
+  contact, last, unread, active, onClick,
+}: {
+  contact: Contact;
+  last: Message | null;
+  unread: number;
+  active: boolean;
+  onClick: () => void;
+}) {
+  const name = contact.alias || contact.username
+    ? (contact.username ? `@${contact.username}` : contact.alias!)
+    : shortAddr(contact.address, 6);
+
+  const time = last
+    ? formatWhen(last.timestamp)
+    : '';
+
+  return (
+    <div
+      onClick={onClick}
+      style={{
+        padding: '12px 14px',
+        borderBottom: '1px solid #1f1f1f',
+        background: active ? '#0a1a29' : 'transparent',
+        cursor: 'pointer',
+        display: 'flex', alignItems: 'center', gap: 12,
+      }}
+      onMouseEnter={e => { if (!active) (e.currentTarget as HTMLDivElement).style.background = '#0a0a0a'; }}
+      onMouseLeave={e => { if (!active) (e.currentTarget as HTMLDivElement).style.background = 'transparent'; }}
+    >
+      <Avatar name={name} />
+      <div style={{ flex: 1, minWidth: 0 }}>
+        <div style={{
+          display: 'flex', justifyContent: 'space-between',
+          alignItems: 'center', gap: 8,
+        }}>
+          <div style={{
+            color: '#fff', fontSize: 14, fontWeight: 700,
+            whiteSpace: 'nowrap', overflow: 'hidden', textOverflow: 'ellipsis',
+          }}>
+            {name}
+          </div>
+          {time && (
+            <div style={{ color: '#6a6a6a', fontSize: 11, flexShrink: 0 }}>
+              {time}
+            </div>
+          )}
+        </div>
+        <div style={{
+          display: 'flex', alignItems: 'center', gap: 6, marginTop: 3,
+        }}>
+          <div style={{
+            flex: 1, color: '#8b8b8b', fontSize: 12,
+            whiteSpace: 'nowrap', overflow: 'hidden', textOverflow: 'ellipsis',
+          }}>
+            {last ? preview(last) : 'Tap to start'}
+          </div>
+          {unread > 0 && (
+            <div style={{
+              minWidth: 18, height: 18, borderRadius: 9,
+              padding: '0 6px', background: '#1d9bf0', color: '#fff',
+              fontSize: 11, fontWeight: 700,
+              display: 'flex', alignItems: 'center', justifyContent: 'center',
+            }}>
+              {unread > 99 ? '99+' : unread}
+            </div>
+          )}
+        </div>
+      </div>
+    </div>
+  );
+}
+
+function Avatar({ name }: { name: string }) {
+  const letter = name.replace(/^@/, '').charAt(0).toUpperCase() || '?';
+  return (
+    <div style={{
+      width: 40, height: 40, borderRadius: 20, flexShrink: 0,
+      background: '#1a1a1a',
+      display: 'flex', alignItems: 'center', justifyContent: 'center',
+      color: '#d0d0d0', fontWeight: 700,
+    }}>{letter}</div>
+  );
+}
+
+function preview(m: Message): string {
+  const t = m.text.trim();
+  if (t.length === 0) return m.attachment ? '(attachment)' : '';
+  return t.length > 60 ? t.slice(0, 60) + '…' : t;
+}
+
+function formatWhen(unixSec: number): string {
+  const d = new Date(unixSec * 1000);
+  const now = new Date();
+  const sameDay =
+    d.getFullYear() === now.getFullYear() &&
+    d.getMonth() === now.getMonth() &&
+    d.getDate() === now.getDate();
+  if (sameDay) {
+    return d.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
+  }
+  const sameYear = d.getFullYear() === now.getFullYear();
+  return sameYear
+    ? d.toLocaleDateString([], { month: 'short', day: 'numeric' })
+    : d.toLocaleDateString();
+}

desktop/src/sections/messages/Conversation.tsx

@@ -0,0 +1,213 @@
+// Conversation — the Messages right-pane showing one chat + composer.
+//
+// Responsibilities:
+//   * Render header with contact identity + close button.
+//   * Auto-scroll the message list to the bottom on new arrival.
+//   * Composer with Enter-to-send, Shift+Enter for newline.
+//   * Fan out every outgoing message across the recipient's device
+//     registry (falls back to legacy single-X25519 for pre-v2.2.0
+//     peers). One envelope per device; Promise.all, any failure
+//     rejects the batch so the user sees it.
+
+import React, { useEffect, useRef, useState } from 'react';
+import { useStore } from '@/lib/store';
+import { encryptMessage, shortAddr } from '@/lib/crypto';
+import { sendEnvelope, resolveRecipientKeys } from '@/lib/relay';
+import { appendMessage as persist } from '@/lib/storage';
+import type { Message } from '@/lib/types';
+
+export function Conversation({ address }: { address: string }): React.ReactElement {
+  const keyFile  = useStore(s => s.keyFile);
+  const contact  = useStore(s => s.contacts.find(c => c.address === address));
+  const messages = useStore(s => s.messages[address] ?? []);
+  const clearUnread = useStore(s => s.clearUnread);
+  const appendMsg   = useStore(s => s.appendMessage);
+
+  const [text,    setText]    = useState('');
+  const [sending, setSending] = useState(false);
+  const [error,   setError]   = useState<string | null>(null);
+
+  const scrollRef = useRef<HTMLDivElement>(null);
+
+  // Seeing a conversation drops its unread count.
+  useEffect(() => { clearUnread(address); }, [address, clearUnread]);
+
+  // Pin the scroll to the bottom on new messages. Only if the user
+  // is already near the bottom — don't yank them back if they're
+  // scrolling through older history.
+  useEffect(() => {
+    const el = scrollRef.current;
+    if (!el) return;
+    const nearBottom = el.scrollHeight - el.scrollTop - el.clientHeight < 120;
+    if (nearBottom) el.scrollTop = el.scrollHeight;
+  }, [messages.length]);
+
+  const isSelf = !!keyFile && keyFile.pub_key === address;
+
+  const send = async () => {
+    if (!keyFile || sending) return;
+    const body = text.trim();
+    if (!body) return;
+
+    setSending(true); setError(null);
+    try {
+      // Saved Messages path — the conversation address equals our own
+      // master pub. Mobile parity: append locally, skip the relay
+      // round-trip entirely (no fees, no ciphertext ever leaves).
+      if (!isSelf) {
+        const pubs = await resolveRecipientKeys(address);
+        if (pubs.length === 0) {
+          throw new Error('recipient has no encryption key published');
+        }
+        await Promise.all(pubs.map(async (rpub) => {
+          const { nonce, ciphertext } = encryptMessage(
+            body, keyFile.x25519_priv, rpub,
+          );
+          await sendEnvelope({
+            senderPub:    keyFile.x25519_pub,
+            recipientPub: rpub,
+            senderEd25519Pub: keyFile.pub_key,
+            nonce, ciphertext,
+          });
+        }));
+      }
+
+      const m: Message = {
+        id:        `out-${Date.now()}${Math.floor(Math.random() * 1e6)}`,
+        from:      keyFile.x25519_pub,
+        text:      body,
+        timestamp: Math.floor(Date.now() / 1000),
+        mine:      true,
+        read:      false,
+        edited:    false,
+      };
+      appendMsg(address, m);
+      persist(address, m);
+      setText('');
+    } catch (e) {
+      setError(e instanceof Error ? e.message : String(e));
+    } finally {
+      setSending(false);
+    }
+  };
+
+  const onKeyDown = (e: React.KeyboardEvent<HTMLTextAreaElement>) => {
+    if (e.key === 'Enter' && !e.shiftKey) {
+      e.preventDefault();
+      send();
+    }
+  };
+
+  const name = contact?.username ? `@${contact.username}`
+    : contact?.alias
+      ? contact.alias
+      : isSelf
+        ? 'Saved Messages'
+        : shortAddr(address, 8);
+
+  return (
+    <div style={{ height: '100%', display: 'flex', flexDirection: 'column' }}>
+      {/* Header */}
+      <div style={{
+        padding: '12px 16px', borderBottom: '1px solid #1f1f1f',
+        display: 'flex', alignItems: 'center', gap: 10,
+      }}>
+        <div style={{
+          width: 32, height: 32, borderRadius: 16,
+          background: isSelf ? '#1d9bf0' : '#1a1a1a',
+          color: '#fff', fontWeight: 700, fontSize: 14,
+          display: 'flex', alignItems: 'center', justifyContent: 'center',
+        }}>
+          {isSelf ? '★' : name.replace(/^@/, '').charAt(0).toUpperCase()}
+        </div>
+        <div style={{ flex: 1, minWidth: 0 }}>
+          <div style={{ color: '#fff', fontSize: 14, fontWeight: 700 }}>{name}</div>
+          <div style={{ color: '#6a6a6a', fontSize: 11, fontFamily: 'monospace' }}>
+            {shortAddr(address, 6)}
+          </div>
+        </div>
+      </div>
+
+      {/* Messages */}
+      <div
+        ref={scrollRef}
+        style={{ flex: 1, overflowY: 'auto', padding: '14px 16px' }}
+      >
+        {messages.length === 0 ? (
+          <div style={{
+            color: '#6a6a6a', fontSize: 13, textAlign: 'center',
+            marginTop: 40,
+          }}>
+            {isSelf
+              ? 'Notes to self. Messages here stay on this device only.'
+              : 'No messages yet. Type below to send the first one.'}
+          </div>
+        ) : (
+          <div style={{ display: 'flex', flexDirection: 'column', gap: 8 }}>
+            {messages.map(m => <Bubble key={m.id} message={m} />)}
+          </div>
+        )}
+      </div>
+
+      {/* Composer */}
+      <div style={{
+        borderTop: '1px solid #1f1f1f', padding: 12,
+        display: 'flex', gap: 10, alignItems: 'flex-end',
+      }}>
+        <textarea
+          value={text}
+          onChange={e => setText(e.target.value)}
+          onKeyDown={onKeyDown}
+          placeholder="Message…"
+          rows={1}
+          style={{
+            flex: 1, resize: 'none',
+            background: '#0a0a0a', border: '1px solid #1f1f1f',
+            borderRadius: 10, padding: '10px 12px',
+            color: '#fff', fontSize: 13, fontFamily: 'inherit',
+            outline: 'none', lineHeight: 1.4, maxHeight: 140,
+          }}
+        />
+        <button
+          onClick={send}
+          disabled={sending || text.trim().length === 0}
+          style={{
+            padding: '10px 16px', borderRadius: 999, border: 'none',
+            background: '#1d9bf0', color: '#fff', fontSize: 13, fontWeight: 700,
+            cursor: sending || text.trim().length === 0 ? 'default' : 'pointer',
+            opacity: sending || text.trim().length === 0 ? 0.5 : 1,
+          }}
+        >
+          {sending ? '…' : 'Send'}
+        </button>
+      </div>
+      {error && (
+        <div style={{
+          padding: '6px 16px 10px', fontSize: 11, color: '#ff6b6b',
+        }}>
+          {error}
+        </div>
+      )}
+    </div>
+  );
+}
+
+function Bubble({ message }: { message: Message }) {
+  const mine = message.mine;
+  return (
+    <div style={{
+      display: 'flex', justifyContent: mine ? 'flex-end' : 'flex-start',
+    }}>
+      <div className="selectable" style={{
+        maxWidth: '70%',
+        padding: '8px 12px', borderRadius: 14,
+        background: mine ? '#1d9bf0' : '#1a1a1a',
+        color: mine ? '#fff' : '#e0e0e0',
+        fontSize: 13, lineHeight: 1.45,
+        whiteSpace: 'pre-wrap', wordBreak: 'break-word',
+      }}>
+        {message.text}
+      </div>
+    </div>
+  );
+}

desktop/src/sections/messages/EmptyConversation.tsx

@@ -0,0 +1,13 @@
+import React from 'react';
+
+export function EmptyConversation(): React.ReactElement {
+  return (
+    <div style={{
+      height: '100%',
+      display: 'flex', alignItems: 'center', justifyContent: 'center',
+      padding: 40, color: '#6a6a6a', fontSize: 13, textAlign: 'center',
+    }}>
+      Select a conversation from the list,<br/>or wait for one to appear as messages arrive.
+    </div>
+  );
+}

desktop/src/sections/messages/index.tsx

@@ -0,0 +1,44 @@
+// Messages section — full implementation. Left pane is the chat list;
+// right pane mounts the active conversation or an empty-state.
+
+import React, { useEffect, useRef } from 'react';
+import { useStore } from '@/lib/store';
+import { loadMessages } from '@/lib/storage';
+import { useInboxPoll } from '@/hooks/useInboxPoll';
+import { ChatList } from './ChatList';
+import { Conversation } from './Conversation';
+import { EmptyConversation } from './EmptyConversation';
+
+export function MessagesList(): React.ReactElement {
+  // Warm cached messages from localStorage once per mount, so toggling
+  // back into Messages after visiting another section doesn't forget
+  // history. Zustand wins on conflict — once the hook has appended
+  // live messages, we don't overwrite them with stale disk snapshots.
+  const contacts  = useStore(s => s.contacts);
+  const setMsgs   = useStore(s => s.setMessages);
+  const hydrated  = useRef(false);
+
+  // Kick off the inbox polling loop while Messages is mounted.
+  // Section-scoped for now so we don't pay the bandwidth cost when
+  // the user is in Feed / Wallet / etc.; a future alpha can promote
+  // it to the shell if we want notifications in other sections too.
+  useInboxPoll();
+
+  useEffect(() => {
+    if (hydrated.current) return;
+    hydrated.current = true;
+    const st = useStore.getState();
+    for (const c of contacts) {
+      if ((st.messages[c.address] ?? []).length > 0) continue;
+      const cached = loadMessages(c.address);
+      if (cached.length > 0) setMsgs(c.address, cached);
+    }
+  }, [contacts, setMsgs]);
+
+  return <ChatList />;
+}
+
+export function MessagesDetail(): React.ReactElement {
+  const activeChat = useStore(s => s.activeChat);
+  return activeChat ? <Conversation address={activeChat} /> : <EmptyConversation />;
+}

desktop/src/sections/profile/index.tsx

@@ -0,0 +1,218 @@
+// Profile section — "You" view. List pane shows the avatar card,
+// detail pane shows stats + devices summary.
+
+import React, { useEffect, useState } from 'react';
+import { useStore } from '@/lib/store';
+import { getBalance, getIdentity, fetchDevices, type IdentityInfo, type DeviceInfo } from '@/lib/api';
+import { shortAddr } from '@/lib/crypto';
+
+function formatT(ut: number): string {
+  return (ut / 1_000_000).toLocaleString(undefined, { maximumFractionDigits: 3 });
+}
+
+export function ProfileList(): React.ReactElement {
+  const keyFile = useStore(s => s.keyFile);
+  const contactsCount = useStore(s => s.contacts.length);
+  if (!keyFile) return <></>;
+  const letter = keyFile.pub_key.slice(0, 1).toUpperCase();
+  return (
+    <div style={{ padding: 14 }}>
+      <div style={{
+        padding: 16, borderRadius: 14,
+        background: '#0a0a0a', border: '1px solid #1f1f1f',
+        textAlign: 'center',
+      }}>
+        <div style={{
+          width: 72, height: 72, borderRadius: 36, margin: '0 auto 10px',
+          background: '#1d9bf0', color: '#fff',
+          display: 'flex', alignItems: 'center', justifyContent: 'center',
+          fontSize: 30, fontWeight: 800,
+        }}>{letter}</div>
+        <div style={{ color: '#fff', fontSize: 18, fontWeight: 700 }}>
+          You
+        </div>
+        <div className="selectable" style={{
+          color: '#8b8b8b', fontSize: 11, fontFamily: 'monospace',
+          marginTop: 6, wordBreak: 'break-all',
+        }}>{keyFile.pub_key}</div>
+      </div>
+
+      <div style={{
+        marginTop: 14, padding: 12, borderRadius: 12,
+        background: '#0a0a0a', border: '1px solid #1f1f1f',
+        color: '#8b8b8b', fontSize: 12, lineHeight: 1.5,
+      }}>
+        {contactsCount} contact{contactsCount === 1 ? '' : 's'} stored on this device.
+      </div>
+    </div>
+  );
+}
+
+export function ProfileDetail(): React.ReactElement {
+  const keyFile    = useStore(s => s.keyFile);
+  const setSection = useStore(s => s.setSection);
+  const setPage    = useStore(s => s.setSettingsPage);
+  const setFeedTab = useStore(s => s.setFeedTab);
+
+  const [identity, setIdentity] = useState<IdentityInfo | null>(null);
+  const [balance,  setBalance]  = useState<number | null>(null);
+  const [devices,  setDevices]  = useState<DeviceInfo[]>([]);
+
+  useEffect(() => {
+    if (!keyFile) return;
+    let cancelled = false;
+    (async () => {
+      const [id, bal, devs] = await Promise.all([
+        getIdentity(keyFile.pub_key),
+        getBalance(keyFile.pub_key),
+        fetchDevices(keyFile.pub_key),
+      ]);
+      if (cancelled) return;
+      setIdentity(id);
+      setBalance(bal);
+      setDevices(devs);
+    })();
+    return () => { cancelled = true; };
+  }, [keyFile]);
+
+  if (!keyFile) return <></>;
+
+  const copy = (s: string) => navigator.clipboard.writeText(s).catch(() => {});
+
+  const viewMyPosts = () => {
+    setFeedTab({ kind: 'author', pub: keyFile.pub_key });
+    setSection('feed');
+  };
+  const openDevices = () => {
+    setSection('settings');
+    setPage('devices');
+  };
+
+  return (
+    <div style={{
+      height: '100%', overflowY: 'auto',
+      padding: '22px 26px', background: '#000',
+    }}>
+      <div style={{
+        display: 'flex', alignItems: 'flex-end', justifyContent: 'space-between',
+        gap: 12, flexWrap: 'wrap',
+      }}>
+        <div>
+          <div style={{
+            color: '#8b8b8b', fontSize: 11, letterSpacing: 1, textTransform: 'uppercase',
+          }}>Balance</div>
+          <div style={{ color: '#fff', fontSize: 34, fontWeight: 800 }}>
+            {balance === null ? '—' : `${formatT(balance)} T`}
+          </div>
+        </div>
+        <div style={{ display: 'flex', gap: 8, flexWrap: 'wrap' }}>
+          <Action onClick={viewMyPosts}>My posts</Action>
+          <Action onClick={openDevices}>Manage devices ({devices.length})</Action>
+          <Action onClick={() => copy(keyFile.pub_key)}>Copy address</Action>
+        </div>
+      </div>
+
+      {identity && (
+        <div style={{
+          marginTop: 24, padding: 14, borderRadius: 12,
+          background: '#0a0a0a', border: '1px solid #1f1f1f',
+        }}>
+          <Row k="DC address" v={identity.address} onCopy={() => copy(identity.address)} />
+          <Row k="Username"   v={identity.nickname ? `@${identity.nickname}` : '—'} />
+          <Row k="Published X25519" v={shortAddr(identity.x25519_pub, 10) || '—'} />
+          <Row k="Registered" v={identity.registered ? 'yes' : 'no'} />
+        </div>
+      )}
+
+      {/* Devices summary */}
+      <div style={{
+        marginTop: 14, padding: 14, borderRadius: 12,
+        background: '#0a0a0a', border: '1px solid #1f1f1f',
+      }}>
+        <div style={{
+          color: '#8b8b8b', fontSize: 11, fontWeight: 700,
+          letterSpacing: 1, textTransform: 'uppercase', marginBottom: 10,
+        }}>Linked devices</div>
+        {devices.length === 0 ? (
+          <div style={{ color: '#6a6a6a', fontSize: 13 }}>
+            No devices registered yet.
+          </div>
+        ) : (
+          devices.map((d, i) => (
+            <div
+              key={d.x25519_pub_key}
+              style={{
+                display: 'flex', alignItems: 'center', gap: 10,
+                padding: '8px 0',
+                borderTop: i === 0 ? undefined : '1px solid #141414',
+              }}
+            >
+              <div style={{
+                width: 28, height: 28, borderRadius: 6,
+                background: d.x25519_pub_key === keyFile.x25519_pub ? '#0d2540' : '#1a1a1a',
+                color: d.x25519_pub_key === keyFile.x25519_pub ? '#1d9bf0' : '#d0d0d0',
+                display: 'flex', alignItems: 'center', justifyContent: 'center',
+                fontSize: 14,
+              }}>📱</div>
+              <div style={{ flex: 1 }}>
+                <div style={{ color: '#fff', fontSize: 13, fontWeight: 600 }}>
+                  {d.device_name}
+                </div>
+                <div style={{ color: '#8b8b8b', fontSize: 11, fontFamily: 'monospace' }}>
+                  {shortAddr(d.x25519_pub_key, 8)}
+                </div>
+              </div>
+              {d.x25519_pub_key === keyFile.x25519_pub && (
+                <span style={{
+                  padding: '1px 6px', borderRadius: 6,
+                  background: '#0d2540', color: '#1d9bf0',
+                  fontSize: 10, fontWeight: 700,
+                }}>THIS DEVICE</span>
+              )}
+            </div>
+          ))
+        )}
+      </div>
+    </div>
+  );
+}
+
+function Action({ children, onClick }: {
+  children: React.ReactNode; onClick: () => void;
+}) {
+  return (
+    <button
+      onClick={onClick}
+      style={{
+        padding: '9px 14px', borderRadius: 999,
+        background: 'transparent', border: '1px solid #1f1f1f',
+        color: '#fff', fontSize: 13, fontWeight: 700, cursor: 'pointer',
+      }}
+    >{children}</button>
+  );
+}
+
+function Row({ k, v, onCopy }: { k: string; v: string; onCopy?: () => void }) {
+  return (
+    <div style={{
+      display: 'flex', padding: '6px 0',
+      borderBottom: '1px solid #141414',
+      alignItems: 'center', gap: 10,
+    }}>
+      <div style={{ color: '#8b8b8b', fontSize: 12, flex: '0 0 160px' }}>{k}</div>
+      <div className="selectable" style={{
+        color: '#fff', fontSize: 13, fontFamily: 'monospace',
+        flex: 1, wordBreak: 'break-all',
+      }}>{v}</div>
+      {onCopy && (
+        <button
+          onClick={onCopy}
+          style={{
+            background: 'transparent', border: 'none',
+            color: '#1d9bf0', fontSize: 11, fontWeight: 600, cursor: 'pointer',
+          }}
+        >copy</button>
+      )}
+    </div>
+  );
+}

desktop/src/sections/settings/AboutPage.tsx

@@ -0,0 +1,59 @@
+// AboutPage — version info, platform, build links. Reads app.version
+// via the preload IPC bridge.
+
+import React, { useEffect, useState } from 'react';
+import { PageLayout } from './PageLayout';
+import { Card, Label, Hint } from './NodePage';
+
+export function AboutPage(): React.ReactElement {
+  const [version,  setVersion]  = useState('dev');
+  const [platform, setPlatform] = useState('');
+
+  useEffect(() => {
+    window.dchain?.app.version().then(setVersion).catch(() => {});
+    window.dchain?.app.platform().then(setPlatform).catch(() => {});
+  }, []);
+
+  return (
+    <PageLayout title="About">
+      <Card>
+        <Label>Build</Label>
+        <div style={{ color: '#fff', fontSize: 14, fontFamily: 'monospace' }}>
+          DChain Desktop v{version}
+        </div>
+        <Hint>
+          Running on {platform || 'unknown'} · Electron / Chromium
+        </Hint>
+      </Card>
+
+      <Card>
+        <Label>Links</Label>
+        <div style={{ display: 'flex', flexDirection: 'column', gap: 6 }}>
+          <LinkRow
+            href="https://git.vsecoder.vodka/vsecoder/dchain"
+            label="Source code (Gitea)"
+          />
+          <LinkRow
+            href="https://git.vsecoder.vodka/vsecoder/dchain/releases"
+            label="Releases"
+          />
+          <LinkRow
+            href="https://git.vsecoder.vodka/vsecoder/dchain/src/branch/main/docs"
+            label="Documentation"
+          />
+        </div>
+      </Card>
+    </PageLayout>
+  );
+}
+
+function LinkRow({ href, label }: { href: string; label: string }) {
+  return (
+    <a
+      href={href}
+      target="_blank"
+      rel="noreferrer"
+      style={{ color: '#1d9bf0', fontSize: 13, textDecoration: 'none' }}
+    >{label} ↗</a>
+  );
+}

desktop/src/sections/settings/DevicesPage.tsx

@@ -0,0 +1,353 @@
+// DevicesPage — multi-device registry UI.
+//
+// Top: list of on-chain devices for this identity. Each row has:
+//   * badge for "this device" (cannot be unlinked from here — you'd
+//     wipe yourself on next boot)
+//   * device name + truncated X25519 pub + added-at
+//   * Unlink button for others (submits UNLINK_DEVICE tx)
+//
+// Bottom: "Link new device" modal, same protocol as mobile's
+// Settings → Devices → Link new device.
+
+import React, { useCallback, useEffect, useState } from 'react';
+import { useStore } from '@/lib/store';
+import {
+  fetchDevices, type DeviceInfo,
+} from '@/lib/api';
+import { buildLinkDeviceTx, buildUnlinkDeviceTx, submitTx, humanizeTxError } from '@/lib/tx';
+import { sendEnvelope } from '@/lib/relay';
+import { encryptMessage, shortAddr } from '@/lib/crypto';
+import { PageLayout } from './PageLayout';
+import { Card, Label, Hint, inputStyle } from './NodePage';
+import { Button } from './IdentityPage';
+
+export function DevicesPage(): React.ReactElement {
+  const keyFile = useStore(s => s.keyFile);
+
+  const [devs, setDevs]           = useState<DeviceInfo[]>([]);
+  const [loading, setLoading]     = useState(true);
+  const [unlinking, setUnlinking] = useState<string | null>(null);
+  const [notice, setNotice]       = useState<string | null>(null);
+  const [linkOpen, setLinkOpen]   = useState(false);
+
+  const load = useCallback(async () => {
+    if (!keyFile) return;
+    setLoading(true);
+    try {
+      setDevs(await fetchDevices(keyFile.pub_key));
+    } finally {
+      setLoading(false);
+    }
+  }, [keyFile]);
+
+  useEffect(() => { load(); }, [load]);
+
+  const onUnlink = useCallback(async (d: DeviceInfo) => {
+    if (!keyFile) return;
+    if (!confirm(
+      `Unlink "${d.device_name}"? It will stop receiving messages sent to you. ` +
+      `The device itself will wipe its local state next time it checks in. ` +
+      `This costs a small network fee.`,
+    )) return;
+    setUnlinking(d.x25519_pub_key);
+    setNotice(null);
+    try {
+      const tx = buildUnlinkDeviceTx({
+        from:      keyFile.pub_key,
+        x25519Pub: d.x25519_pub_key,
+        privKey:   keyFile.priv_key,
+      });
+      await submitTx(tx);
+      setDevs(prev => prev.filter(x => x.x25519_pub_key !== d.x25519_pub_key));
+      setNotice(`Unlinked — registry will converge in a block or two.`);
+    } catch (e) {
+      setNotice(`Unlink failed: ${humanizeTxError(e)}`);
+    } finally {
+      setUnlinking(null);
+    }
+  }, [keyFile]);
+
+  const meX25519 = keyFile?.x25519_pub ?? '';
+
+  return (
+    <PageLayout
+      title="Devices"
+      subtitle="Every linked device gets its own encryption key; messages sent to you are delivered to all of them."
+    >
+      <Card>
+        <div style={{
+          display: 'flex', alignItems: 'center', justifyContent: 'space-between',
+          gap: 12,
+        }}>
+          <Label>Linked devices</Label>
+          <Button onClick={() => setLinkOpen(true)}>Link new device</Button>
+        </div>
+
+        {loading ? (
+          <div style={{ color: '#6a6a6a', fontSize: 13, padding: 12 }}>Loading…</div>
+        ) : devs.length === 0 ? (
+          <div style={{ color: '#6a6a6a', fontSize: 13, padding: 12 }}>
+            No devices registered yet. This device auto-links once a small
+            network fee is available in your balance — pull to refresh after
+            a first transfer if the list stays empty.
+          </div>
+        ) : (
+          <div style={{ marginTop: 4 }}>
+            {devs.map((d, i) => (
+              <DeviceRow
+                key={d.x25519_pub_key}
+                d={d}
+                isMe={d.x25519_pub_key === meX25519}
+                unlinking={unlinking === d.x25519_pub_key}
+                onUnlink={() => onUnlink(d)}
+                first={i === 0}
+              />
+            ))}
+          </div>
+        )}
+
+        {notice && (
+          <div style={{
+            marginTop: 10, padding: 10, borderRadius: 8,
+            background: notice.startsWith('Unlink failed')
+              ? '#2a1414' : '#0d2540',
+            color: notice.startsWith('Unlink failed') ? '#ff9b9b' : '#1d9bf0',
+            fontSize: 12,
+          }}>{notice}</div>
+        )}
+      </Card>
+
+      {linkOpen && (
+        <LinkNewDeviceModal
+          onClose={() => setLinkOpen(false)}
+          onLinked={() => { setLinkOpen(false); setTimeout(load, 1000); }}
+        />
+      )}
+    </PageLayout>
+  );
+}
+
+// ─── Row ─────────────────────────────────────────────────────────────────
+
+function DeviceRow({
+  d, isMe, unlinking, onUnlink, first,
+}: {
+  d: DeviceInfo; isMe: boolean; unlinking: boolean;
+  onUnlink: () => void; first: boolean;
+}) {
+  return (
+    <div style={{
+      display: 'flex', alignItems: 'center', gap: 12,
+      padding: '12px 0',
+      borderTop: first ? undefined : '1px solid #1f1f1f',
+    }}>
+      <div style={{
+        width: 32, height: 32, borderRadius: 8,
+        background: isMe ? '#0d2540' : '#1a1a1a',
+        color: isMe ? '#1d9bf0' : '#d0d0d0',
+        display: 'flex', alignItems: 'center', justifyContent: 'center',
+        fontSize: 16,
+      }}>📱</div>
+      <div style={{ flex: 1, minWidth: 0 }}>
+        <div style={{
+          display: 'flex', alignItems: 'center', gap: 6,
+        }}>
+          <span style={{ color: '#fff', fontSize: 14, fontWeight: 700 }}>
+            {d.device_name || 'Unnamed device'}
+          </span>
+          {isMe && (
+            <span style={{
+              padding: '1px 6px', borderRadius: 6,
+              background: '#0d2540', color: '#1d9bf0',
+              fontSize: 10, fontWeight: 700, letterSpacing: 0.5,
+            }}>THIS DEVICE</span>
+          )}
+        </div>
+        <div style={{
+          color: '#8b8b8b', fontSize: 11, fontFamily: 'monospace',
+          marginTop: 3,
+        }}>
+          {shortAddr(d.x25519_pub_key, 10)}
+        </div>
+        <div style={{ color: '#6a6a6a', fontSize: 11, marginTop: 2 }}>
+          Linked {new Date(d.added_at * 1000).toLocaleString()}
+        </div>
+      </div>
+      {!isMe && (
+        <button
+          onClick={onUnlink}
+          disabled={unlinking}
+          style={{
+            padding: '6px 12px', borderRadius: 999,
+            background: 'transparent', border: '1px solid #3a2020',
+            color: '#ff6b6b', fontSize: 11, fontWeight: 700,
+            cursor: unlinking ? 'default' : 'pointer',
+            opacity: unlinking ? 0.5 : 1,
+          }}
+        >{unlinking ? '…' : 'Unlink'}</button>
+      )}
+    </div>
+  );
+}
+
+// ─── Link New Device modal ───────────────────────────────────────────────
+
+function LinkNewDeviceModal({
+  onClose, onLinked,
+}: {
+  onClose: () => void;
+  onLinked: () => void;
+}): React.ReactElement {
+  const keyFile = useStore(s => s.keyFile);
+
+  const [code, setCode] = useState('');
+  const [key,  setKey]  = useState('');
+  const [name, setName] = useState('');
+  const [busy, setBusy] = useState(false);
+  const [err,  setErr]  = useState<string | null>(null);
+
+  const submit = async () => {
+    if (!keyFile) return;
+    const c = code.replace(/\s+/g, '').trim();
+    const k = key.replace(/\s+/g, '').trim().toLowerCase();
+    if (!/^\d{6}$/.test(c)) { setErr('Code must be 6 digits.'); return; }
+    if (!/^[0-9a-f]{64}$/.test(k)) { setErr('Device key must be 64 hex chars.'); return; }
+    const nm = name.trim() || 'New device';
+    setBusy(true); setErr(null);
+    try {
+      // 1. LINK_DEVICE tx → registry learns the new pub.
+      const linkTx = buildLinkDeviceTx({
+        from:       keyFile.pub_key,
+        x25519Pub:  k,
+        deviceName: nm,
+        privKey:    keyFile.priv_key,
+      });
+      await submitTx(linkTx);
+      // 2. Handshake envelope — encrypt master priv for the new device.
+      const payload = JSON.stringify({
+        v: 1,
+        type: 'pair-handshake',
+        code: c,
+        master_pub:        keyFile.pub_key,
+        master_priv:       keyFile.priv_key,
+        master_x25519_pub: keyFile.x25519_pub,
+      });
+      const { nonce, ciphertext } = encryptMessage(
+        payload, keyFile.x25519_priv, k,
+      );
+      await sendEnvelope({
+        senderPub:        keyFile.x25519_pub,
+        recipientPub:     k,
+        senderEd25519Pub: keyFile.pub_key,
+        nonce, ciphertext,
+      });
+      onLinked();
+    } catch (e) {
+      setErr(humanizeTxError(e));
+    } finally {
+      setBusy(false);
+    }
+  };
+
+  return (
+    <div
+      onClick={() => !busy && onClose()}
+      style={{
+        position: 'fixed', inset: 0, zIndex: 20,
+        background: 'rgba(0,0,0,0.7)',
+        display: 'flex', alignItems: 'center', justifyContent: 'center',
+        padding: 24,
+      }}
+    >
+      <div
+        onClick={e => e.stopPropagation()}
+        style={{
+          width: '100%', maxWidth: 520, padding: 20, borderRadius: 16,
+          background: '#0a0a0a', border: '1px solid #1f1f1f',
+        }}
+      >
+        <div style={{
+          display: 'flex', alignItems: 'center', justifyContent: 'space-between',
+          marginBottom: 12,
+        }}>
+          <div style={{ color: '#fff', fontSize: 16, fontWeight: 700 }}>
+            Link new device
+          </div>
+          <button
+            onClick={onClose} disabled={busy}
+            style={{
+              background: 'transparent', border: 'none',
+              color: '#8b8b8b', fontSize: 20, cursor: 'pointer',
+            }}
+          >×</button>
+        </div>
+        <Hint>
+          On the new device, tap <b>Pair</b> on the welcome screen and
+          transcribe the 6-digit code and device key from there into the
+          fields below.
+        </Hint>
+
+        <div style={{ marginTop: 14, display: 'flex', flexDirection: 'column', gap: 12 }}>
+          <Field>
+            <Label>6-digit code</Label>
+            <input
+              value={code}
+              onChange={e => setCode(e.target.value)}
+              placeholder="000000"
+              inputMode="numeric"
+              maxLength={6}
+              style={{ ...inputStyle, letterSpacing: 4, textAlign: 'center' }}
+            />
+          </Field>
+          <Field>
+            <Label>Device key (64 hex)</Label>
+            <input
+              value={key}
+              onChange={e => setKey(e.target.value)}
+              placeholder="a1b2c3…"
+              spellCheck={false}
+              style={inputStyle}
+            />
+          </Field>
+          <Field>
+            <Label>Name (optional)</Label>
+            <input
+              value={name}
+              onChange={e => setName(e.target.value)}
+              placeholder="e.g. Alice's laptop"
+              maxLength={64}
+              style={{ ...inputStyle, fontFamily: 'inherit' }}
+            />
+          </Field>
+        </div>
+
+        {err && (
+          <div style={{
+            marginTop: 12, padding: 10, borderRadius: 8,
+            background: '#2a1414', color: '#ff9b9b', fontSize: 12,
+          }}>{err}</div>
+        )}
+
+        <div style={{
+          marginTop: 16, display: 'flex', justifyContent: 'flex-end', gap: 10,
+        }}>
+          <button
+            onClick={onClose}
+            disabled={busy}
+            style={{
+              padding: '9px 14px', borderRadius: 999,
+              background: 'transparent', border: '1px solid #1f1f1f',
+              color: '#8b8b8b', fontSize: 13, fontWeight: 700,
+              cursor: busy ? 'default' : 'pointer',
+            }}
+          >Cancel</button>
+          <Button onClick={submit} disabled={busy}>{busy ? '…' : 'Link'}</Button>
+        </div>
+      </div>
+    </div>
+  );
+}
+
+function Field({ children }: { children: React.ReactNode }) {
+  return <div>{children}</div>;
+}

desktop/src/sections/settings/IdentityPage.tsx

@@ -0,0 +1,159 @@
+// Identity settings — pub key, copy, export/import key file, delete account.
+
+import React, { useState } from 'react';
+import { useStore } from '@/lib/store';
+import { saveKeyFile, wipeAllLocalState } from '@/lib/storage';
+import type { KeyFile } from '@/lib/types';
+import { PageLayout } from './PageLayout';
+import { Card, Label, Hint } from './NodePage';
+
+export function IdentityPage(): React.ReactElement {
+  const keyFile    = useStore(s => s.keyFile);
+  const setKeyFile = useStore(s => s.setKeyFile);
+  const [notice, setNotice] = useState<string | null>(null);
+
+  if (!keyFile) return <PageLayout title="Identity"><div>No identity loaded.</div></PageLayout>;
+
+  const copy = async (s: string, label: string) => {
+    await navigator.clipboard.writeText(s);
+    setNotice(`${label} copied`);
+    setTimeout(() => setNotice(null), 1500);
+  };
+
+  const exportKey = async () => {
+    const target = await window.dchain.dialog.saveFile({
+      title: 'Export key file',
+      defaultPath: 'node.json',
+      filters: [{ name: 'JSON', extensions: ['json'] }],
+    });
+    if (!target) return;
+    try {
+      await window.dchain.fs.writeText(target, JSON.stringify(keyFile, null, 2));
+      setNotice('Key saved — keep it offline + backed up.');
+    } catch (e) {
+      setNotice(`Export failed: ${e}`);
+    }
+  };
+
+  const importKey = async () => {
+    const src = await window.dchain.dialog.openFile({
+      title: 'Import key file',
+      filters: [{ name: 'JSON', extensions: ['json'] }],
+      properties: ['openFile'],
+    });
+    if (!src) return;
+    try {
+      const raw = await window.dchain.fs.readText(src);
+      const parsed = JSON.parse(raw) as KeyFile;
+      if (!parsed.pub_key || !parsed.priv_key) throw new Error('not a key file');
+      if (!confirm('Replace the current identity with the imported one? The current identity will be wiped from this device.')) return;
+      await wipeAllLocalState();
+      await saveKeyFile(parsed);
+      setKeyFile(parsed);
+      setNotice('Imported — reload is not needed, new identity active.');
+    } catch (e) {
+      setNotice(`Import failed: ${e}`);
+    }
+  };
+
+  const deleteAccount = async () => {
+    if (!confirm('Delete this identity from this device? Keys are NOT recoverable from the server — export first if you want to keep them.')) return;
+    await wipeAllLocalState();
+    setKeyFile(null);
+  };
+
+  return (
+    <PageLayout title="Identity" subtitle="Your Ed25519 master key. Keep it safe — there is no password recovery.">
+      <Card>
+        <Label>Public key (Ed25519, hex)</Label>
+        <div className="selectable" style={{
+          color: '#fff', fontSize: 12, fontFamily: 'monospace',
+          wordBreak: 'break-all', lineHeight: 1.5,
+        }}>
+          {keyFile.pub_key}
+        </div>
+        <ActionRow>
+          <Button onClick={() => copy(keyFile.pub_key, 'Pub key')}>Copy</Button>
+        </ActionRow>
+      </Card>
+
+      <Card>
+        <Label>Device encryption key (X25519, hex)</Label>
+        <div className="selectable" style={{
+          color: '#fff', fontSize: 12, fontFamily: 'monospace',
+          wordBreak: 'break-all', lineHeight: 1.5,
+        }}>
+          {keyFile.x25519_pub}
+        </div>
+        <Hint>
+          Only this device uses this X25519 pair. Sharing the master Ed25519
+          pub (above) is how contacts find you across all your devices.
+        </Hint>
+      </Card>
+
+      <Card>
+        <Label>Backup</Label>
+        <ActionRow>
+          <Button onClick={exportKey}>Export key file</Button>
+          <Button onClick={importKey} danger>Import / replace</Button>
+        </ActionRow>
+        <Hint>
+          Exports a JSON file compatible with the mobile client and
+          server's <code>--key</code> flag. The file is <strong>not</strong>
+          encrypted on disk — store it somewhere safe.
+        </Hint>
+      </Card>
+
+      <Card>
+        <Label>Danger zone</Label>
+        <ActionRow>
+          <Button onClick={deleteAccount} danger>Delete this identity</Button>
+        </ActionRow>
+        <Hint>
+          Wipes the key, contacts, and chat cache from this device.
+          Without an export, this is irreversible.
+        </Hint>
+      </Card>
+
+      {notice && (
+        <div style={{
+          padding: 10, borderRadius: 8,
+          background: '#0d2540', color: '#1d9bf0', fontSize: 12,
+        }}>{notice}</div>
+      )}
+    </PageLayout>
+  );
+}
+
+function ActionRow({ children }: { children: React.ReactNode }) {
+  return (
+    <div style={{
+      display: 'flex', gap: 8, marginTop: 10, flexWrap: 'wrap',
+    }}>{children}</div>
+  );
+}
+
+export function Button({
+  children, onClick, danger, disabled,
+}: {
+  children: React.ReactNode;
+  onClick: () => void;
+  danger?: boolean;
+  disabled?: boolean;
+}) {
+  return (
+    <button
+      onClick={onClick}
+      disabled={disabled}
+      style={{
+        padding: '8px 14px', borderRadius: 999,
+        background: danger ? 'transparent' : '#1d9bf0',
+        border: danger ? '1px solid #3a2020' : 'none',
+        color: danger ? '#ff6b6b' : '#fff',
+        fontSize: 12, fontWeight: 700,
+        cursor: disabled ? 'default' : 'pointer',
+        opacity: disabled ? 0.5 : 1,
+      }}
+    >{children}</button>
+  );
+}

desktop/src/sections/settings/NodePage.tsx

@@ -0,0 +1,115 @@
+// Node settings page — URL, connection ping-on-commit, token field.
+
+import React, { useEffect, useState } from 'react';
+import { useStore } from '@/lib/store';
+import { getNetStats, setNodeUrl, setApiToken } from '@/lib/api';
+import { saveSettings } from '@/lib/storage';
+import { PageLayout } from './PageLayout';
+
+export function NodePage(): React.ReactElement {
+  const settings    = useStore(s => s.settings);
+  const setSettings = useStore(s => s.setSettings);
+
+  const [url,   setUrl]   = useState(settings.nodeUrl);
+  const [token, setToken] = useState(settings.apiToken ?? '');
+  const [ok,    setOk]    = useState<boolean | null>(null);
+  const [busy,  setBusy]  = useState(false);
+
+  useEffect(() => { setUrl(settings.nodeUrl); setToken(settings.apiToken ?? ''); },
+    [settings.nodeUrl, settings.apiToken]);
+
+  const apply = async () => {
+    const clean = url.trim().replace(/\/$/, '');
+    if (!clean) return;
+    setBusy(true); setOk(null);
+    setNodeUrl(clean);
+    setApiToken(token.trim() || null);
+    try {
+      await getNetStats();
+      setOk(true);
+      const next = { nodeUrl: clean, apiToken: token.trim() || undefined };
+      setSettings(next);
+      saveSettings(next);
+    } catch {
+      setOk(false);
+    } finally {
+      setBusy(false);
+    }
+  };
+
+  const dot = ok === true ? '#3ba55d' : ok === false ? '#f4212e' : '#8b8b8b';
+
+  return (
+    <PageLayout title="Node" subtitle="Which DChain node this client talks to">
+      <Card>
+        <Label>Node URL</Label>
+        <div style={{ display: 'flex', alignItems: 'center', gap: 8 }}>
+          <span style={{ width: 7, height: 7, borderRadius: 3.5, background: dot }} />
+          <input
+            value={url}
+            onChange={e => { setUrl(e.target.value); setOk(null); }}
+            onBlur={apply}
+            onKeyDown={e => { if (e.key === 'Enter') apply(); }}
+            placeholder="http://node.example:8080"
+            spellCheck={false}
+            style={inputStyle}
+          />
+          {busy && <span style={{ color: '#8b8b8b', fontSize: 11 }}>…</span>}
+        </div>
+        <Hint>
+          Enter or tab-out to ping. Green dot = `/api/netstats` replied.
+        </Hint>
+      </Card>
+
+      <Card>
+        <Label>API token (optional)</Label>
+        <input
+          type="password"
+          value={token}
+          onChange={e => setToken(e.target.value)}
+          onBlur={apply}
+          placeholder="paste Bearer token if node requires it"
+          spellCheck={false}
+          style={inputStyle}
+        />
+        <Hint>
+          Some nodes gate writes with DCHAIN_API_TOKEN; leave blank for
+          public ones.
+        </Hint>
+      </Card>
+    </PageLayout>
+  );
+}
+
+// ─── Reusable primitives (also imported by Identity / Devices / About) ───
+
+export function Card({ children }: { children: React.ReactNode }) {
+  return (
+    <div style={{
+      padding: 14, marginBottom: 14, borderRadius: 12,
+      background: '#0a0a0a', border: '1px solid #1f1f1f',
+    }}>{children}</div>
+  );
+}
+export function Label({ children }: { children: React.ReactNode }) {
+  return (
+    <div style={{
+      color: '#8b8b8b', fontSize: 11, fontWeight: 700,
+      letterSpacing: 1.2, textTransform: 'uppercase', marginBottom: 8,
+    }}>{children}</div>
+  );
+}
+export function Hint({ children }: { children: React.ReactNode }) {
+  return (
+    <div style={{ color: '#6a6a6a', fontSize: 11, marginTop: 6, lineHeight: 1.5 }}>
+      {children}
+    </div>
+  );
+}
+export const inputStyle: React.CSSProperties = {
+  flex: 1, boxSizing: 'border-box',
+  background: '#000', border: '1px solid #1f1f1f',
+  borderRadius: 8, padding: '10px 12px',
+  color: '#fff', fontSize: 13, fontFamily: 'monospace',
+  outline: 'none', width: '100%',
+};

desktop/src/sections/settings/PageLayout.tsx

@@ -0,0 +1,33 @@
+// Shared layout for Settings subsection pages — sticky header with the
+// page title + scroll body. Keeps spacing consistent across Node /
+// Identity / Devices / About.
+
+import React from 'react';
+
+export function PageLayout({
+  title, subtitle, children,
+}: {
+  title: string;
+  subtitle?: string;
+  children: React.ReactNode;
+}): React.ReactElement {
+  return (
+    <div style={{
+      height: '100%', overflowY: 'auto', background: '#000',
+    }}>
+      <div style={{
+        position: 'sticky', top: 0, zIndex: 1,
+        padding: '14px 22px', borderBottom: '1px solid #1f1f1f',
+        background: 'rgba(0,0,0,0.9)', backdropFilter: 'blur(6px)',
+      }}>
+        <div style={{ color: '#fff', fontSize: 16, fontWeight: 800 }}>{title}</div>
+        {subtitle && (
+          <div style={{ color: '#8b8b8b', fontSize: 12, marginTop: 2 }}>{subtitle}</div>
+        )}
+      </div>
+      <div style={{ padding: '18px 22px' }}>
+        {children}
+      </div>
+    </div>
+  );
+}

desktop/src/sections/settings/SettingsDetail.tsx

@@ -0,0 +1,18 @@
+// Right-pane content for Settings. Renders by store.settingsPage.
+
+import React from 'react';
+import { useStore } from '@/lib/store';
+import { NodePage } from './NodePage';
+import { IdentityPage } from './IdentityPage';
+import { DevicesPage } from './DevicesPage';
+import { AboutPage } from './AboutPage';
+
+export function SettingsDetail(): React.ReactElement {
+  const page = useStore(s => s.settingsPage);
+  switch (page) {
+    case 'node':     return <NodePage />;
+    case 'identity': return <IdentityPage />;
+    case 'devices':  return <DevicesPage />;
+    case 'about':    return <AboutPage />;
+  }
+}

desktop/src/sections/settings/SettingsNav.tsx

@@ -0,0 +1,61 @@
+// Left-pane category list for Settings. Keeps selection in
+// store.settingsPage so switching away and back preserves place.
+
+import React from 'react';
+import { useStore, type SettingsPage } from '@/lib/store';
+
+interface Row {
+  key:   SettingsPage;
+  label: string;
+  hint:  string;
+}
+
+const ROWS: Row[] = [
+  { key: 'node',     label: 'Node',     hint: 'URL, connection status'         },
+  { key: 'identity', label: 'Identity', hint: 'Your keys and address'          },
+  { key: 'devices',  label: 'Devices',  hint: 'Linked devices, pair a new one' },
+  { key: 'about',    label: 'About',    hint: 'Version, links'                 },
+];
+
+export function SettingsNav(): React.ReactElement {
+  const page    = useStore(s => s.settingsPage);
+  const setPage = useStore(s => s.setSettingsPage);
+  return (
+    <div style={{ padding: 10 }}>
+      {ROWS.map(r => (
+        <NavEntry
+          key={r.key}
+          label={r.label}
+          hint={r.hint}
+          active={page === r.key}
+          onClick={() => setPage(r.key)}
+        />
+      ))}
+    </div>
+  );
+}
+
+function NavEntry({
+  label, hint, active, onClick,
+}: { label: string; hint: string; active: boolean; onClick: () => void }) {
+  return (
+    <div
+      onClick={onClick}
+      style={{
+        padding: '10px 12px', borderRadius: 10, cursor: 'pointer',
+        background: active ? '#0a1a29' : 'transparent',
+        border: active ? '1px solid #1d9bf022' : '1px solid transparent',
+      }}
+      onMouseEnter={e => { if (!active) (e.currentTarget as HTMLDivElement).style.background = '#0a0a0a'; }}
+      onMouseLeave={e => { if (!active) (e.currentTarget as HTMLDivElement).style.background = 'transparent'; }}
+    >
+      <div style={{
+        color: active ? '#1d9bf0' : '#fff',
+        fontSize: 14, fontWeight: 700,
+      }}>{label}</div>
+      <div style={{ color: '#6a6a6a', fontSize: 11, marginTop: 2 }}>
+        {hint}
+      </div>
+    </div>
+  );
+}

desktop/src/sections/settings/index.tsx

@@ -0,0 +1,6 @@
+// Settings section — two-pane.
+//   List pane: category nav (Node, Identity, Devices, About).
+//   Detail pane: selected category's content.
+
+export { SettingsNav as SettingsList } from './SettingsNav';
+export { SettingsDetail } from './SettingsDetail';

desktop/src/sections/wallet/ReceiveModal.tsx

@@ -0,0 +1,75 @@
+// ReceiveModal — shows this wallet's pub key + a copy button. QR-code
+// polish goes in rc1 (needs a deps pull for qrcode-svg or similar).
+
+import React, { useEffect, useRef, useState } from 'react';
+import QRCode from 'qrcode';
+import { useStore } from '@/lib/store';
+import { Backdrop, Header, primaryBtnStyle } from './SendModal';
+
+export function ReceiveModal({ onClose }: { onClose: () => void }): React.ReactElement {
+  const keyFile = useStore(s => s.keyFile);
+  const [copied, setCopied] = useState(false);
+  const canvasRef = useRef<HTMLCanvasElement>(null);
+
+  // Paint the QR on mount. Skip if there's no key (shouldn't happen but
+  // component is safe against it).
+  useEffect(() => {
+    if (!keyFile || !canvasRef.current) return;
+    QRCode.toCanvas(canvasRef.current, keyFile.pub_key, {
+      width: 196,
+      margin: 1,
+      color: { dark: '#ffffff', light: '#00000000' },
+      errorCorrectionLevel: 'M',
+    }).catch(() => { /* fall back to text only */ });
+  }, [keyFile]);
+
+  if (!keyFile) return <></>;
+
+  const copy = async () => {
+    try { await navigator.clipboard.writeText(keyFile.pub_key); setCopied(true); }
+    catch { /* ignore */ }
+    setTimeout(() => setCopied(false), 1400);
+  };
+
+  return (
+    <Backdrop onClose={onClose}>
+      <div style={{
+        width: '100%', maxWidth: 460, padding: 20, borderRadius: 16,
+        background: '#0a0a0a', border: '1px solid #1f1f1f',
+      }}>
+        <Header title="Receive" onClose={onClose} busy={false} />
+
+        <div style={{ color: '#8b8b8b', fontSize: 12, lineHeight: 1.5 }}>
+          Share your public key — anyone can send you tokens or add you as
+          a contact using this address.
+        </div>
+
+        <div style={{
+          marginTop: 14, display: 'flex', justifyContent: 'center',
+          padding: 16, borderRadius: 10,
+          background: '#000', border: '1px solid #1f1f1f',
+        }}>
+          <canvas ref={canvasRef} style={{ imageRendering: 'pixelated' }} />
+        </div>
+
+        <div className="selectable" style={{
+          marginTop: 10, padding: 14, borderRadius: 10,
+          background: '#000', border: '1px solid #1f1f1f',
+          color: '#fff', fontFamily: 'monospace', fontSize: 12,
+          wordBreak: 'break-all', lineHeight: 1.5,
+        }}>
+          {keyFile.pub_key}
+        </div>
+
+        <div style={{
+          marginTop: 16, display: 'flex', justifyContent: 'flex-end', gap: 10,
+        }}>
+          <button
+            onClick={copy}
+            style={primaryBtnStyle(false)}
+          >{copied ? 'Copied!' : 'Copy'}</button>
+        </div>
+      </div>
+    </Backdrop>
+  );
+}

desktop/src/sections/wallet/SendModal.tsx

@@ -0,0 +1,219 @@
+// SendModal — a focused little dialog for Transfer tx's. Accepts a
+// hex pub, DC-address, or @username and resolves to the Ed25519 pub
+// before submitting. Validates amount against balance + min fee.
+
+import React, { useEffect, useMemo, useState } from 'react';
+import { useStore } from '@/lib/store';
+import { getBalance, resolveAccount } from '@/lib/api';
+import { buildTransferTx, submitTx, humanizeTxError } from '@/lib/tx';
+
+const MIN_FEE_UT = 1_000;
+
+function parseAmountT(s: string): number | null {
+  const n = parseFloat(s);
+  if (!Number.isFinite(n) || n <= 0) return null;
+  return Math.round(n * 1_000_000);
+}
+
+export function SendModal({
+  onClose, onSent,
+}: {
+  onClose: () => void;
+  onSent: () => void;
+}): React.ReactElement {
+  const keyFile = useStore(s => s.keyFile);
+
+  const [toInput, setToInput] = useState('');
+  const [amount,  setAmount]  = useState('');
+  const [memo,    setMemo]    = useState('');
+  const [busy,    setBusy]    = useState(false);
+  const [err,     setErr]     = useState<string | null>(null);
+  const [balance, setBalance] = useState<number | null>(null);
+
+  useEffect(() => {
+    if (!keyFile) return;
+    getBalance(keyFile.pub_key).then(setBalance).catch(() => setBalance(null));
+  }, [keyFile]);
+
+  const amountUT = useMemo(() => parseAmountT(amount), [amount]);
+  const totalUT  = amountUT === null ? null : amountUT + MIN_FEE_UT;
+
+  const canSend = !!keyFile && !busy && amountUT !== null
+                && balance !== null && totalUT !== null && balance >= totalUT
+                && toInput.trim().length > 0;
+
+  const submit = async () => {
+    if (!keyFile || !canSend || amountUT === null) return;
+    setBusy(true); setErr(null);
+    try {
+      const to = await resolveAccount(toInput);
+      if (!to) throw new Error('Can\'t resolve recipient');
+      if (to === keyFile.pub_key) throw new Error('Refusing self-transfer');
+      const tx = buildTransferTx({
+        from:    keyFile.pub_key,
+        to,
+        amount:  amountUT,
+        fee:     MIN_FEE_UT,
+        privKey: keyFile.priv_key,
+        memo:    memo.trim() || undefined,
+      });
+      await submitTx(tx);
+      onSent();
+      onClose();
+    } catch (e) {
+      setErr(humanizeTxError(e));
+    } finally {
+      setBusy(false);
+    }
+  };
+
+  return (
+    <Backdrop onClose={busy ? () => {} : onClose}>
+      <div style={{
+        width: '100%', maxWidth: 460, padding: 20, borderRadius: 16,
+        background: '#0a0a0a', border: '1px solid #1f1f1f',
+      }}>
+        <Header title="Send" onClose={onClose} busy={busy} />
+        <div style={{ display: 'flex', flexDirection: 'column', gap: 12 }}>
+          <Field label="To" hint="@username, DC-address or hex pubkey">
+            <input
+              value={toInput}
+              onChange={e => setToInput(e.target.value)}
+              placeholder="@alice or DC… or <hex>"
+              spellCheck={false}
+              autoFocus
+              style={inputStyle}
+            />
+          </Field>
+          <Field label="Amount (T)">
+            <input
+              value={amount}
+              onChange={e => setAmount(e.target.value)}
+              placeholder="0.0"
+              inputMode="decimal"
+              style={inputStyle}
+            />
+            <div style={{ color: '#6a6a6a', fontSize: 11, marginTop: 4 }}>
+              Balance: {balance === null ? '…' : `${(balance / 1_000_000).toLocaleString(undefined, { maximumFractionDigits: 6 })} T`}
+              {amountUT !== null && (
+                <> · Fee: {(MIN_FEE_UT / 1_000_000).toFixed(6)} T</>
+              )}
+            </div>
+          </Field>
+          <Field label="Memo (optional)">
+            <input
+              value={memo}
+              onChange={e => setMemo(e.target.value)}
+              placeholder="Invoice #42"
+              style={inputStyle}
+            />
+          </Field>
+        </div>
+
+        {err && (
+          <div style={{
+            marginTop: 12, padding: 10, borderRadius: 8,
+            background: '#2a1414', color: '#ff9b9b', fontSize: 12,
+          }}>{err}</div>
+        )}
+
+        <div style={{
+          marginTop: 16, display: 'flex', justifyContent: 'flex-end', gap: 10,
+        }}>
+          <button
+            onClick={onClose}
+            disabled={busy}
+            style={secondaryBtnStyle(busy)}
+          >Cancel</button>
+          <button
+            onClick={submit}
+            disabled={!canSend}
+            style={primaryBtnStyle(!canSend)}
+          >{busy ? '…' : 'Send'}</button>
+        </div>
+      </div>
+    </Backdrop>
+  );
+}
+
+// ─── Shared modal primitives used by Send/Receive ────────────────────────
+
+function Backdrop({ children, onClose }: { children: React.ReactNode; onClose: () => void }) {
+  return (
+    <div
+      onClick={onClose}
+      style={{
+        position: 'fixed', inset: 0, zIndex: 20,
+        background: 'rgba(0,0,0,0.7)',
+        display: 'flex', alignItems: 'center', justifyContent: 'center',
+        padding: 24,
+      }}
+    >
+      <div onClick={e => e.stopPropagation()} style={{ width: '100%', display: 'flex', justifyContent: 'center' }}>
+        {children}
+      </div>
+    </div>
+  );
+}
+
+function Header({ title, onClose, busy }: {
+  title: string; onClose: () => void; busy: boolean;
+}) {
+  return (
+    <div style={{
+      display: 'flex', alignItems: 'center', justifyContent: 'space-between',
+      marginBottom: 14,
+    }}>
+      <div style={{ color: '#fff', fontSize: 16, fontWeight: 700 }}>{title}</div>
+      <button
+        onClick={onClose}
+        disabled={busy}
+        style={{
+          background: 'transparent', border: 'none',
+          color: '#8b8b8b', fontSize: 20, cursor: 'pointer',
+        }}
+      >×</button>
+    </div>
+  );
+}
+
+function Field({ label, hint, children }: {
+  label: string; hint?: string; children: React.ReactNode;
+}) {
+  return (
+    <div>
+      <div style={{
+        color: '#8b8b8b', fontSize: 11, fontWeight: 700,
+        letterSpacing: 1, textTransform: 'uppercase', marginBottom: 6,
+      }}>{label}</div>
+      {children}
+      {hint && (
+        <div style={{ color: '#6a6a6a', fontSize: 11, marginTop: 4 }}>{hint}</div>
+      )}
+    </div>
+  );
+}
+
+const inputStyle: React.CSSProperties = {
+  width: '100%', boxSizing: 'border-box',
+  background: '#000', border: '1px solid #1f1f1f',
+  borderRadius: 8, padding: '10px 12px',
+  color: '#fff', fontSize: 13, fontFamily: 'inherit',
+  outline: 'none',
+};
+
+const primaryBtnStyle = (disabled: boolean): React.CSSProperties => ({
+  padding: '9px 18px', borderRadius: 999, border: 'none',
+  background: '#1d9bf0', color: '#fff',
+  fontSize: 13, fontWeight: 700,
+  cursor: disabled ? 'default' : 'pointer',
+  opacity: disabled ? 0.5 : 1,
+});
+const secondaryBtnStyle = (disabled: boolean): React.CSSProperties => ({
+  padding: '9px 14px', borderRadius: 999,
+  background: 'transparent', border: '1px solid #1f1f1f',
+  color: '#8b8b8b', fontSize: 13, fontWeight: 700,
+  cursor: disabled ? 'default' : 'pointer',
+});
+
+export { Backdrop, Header, Field, inputStyle, primaryBtnStyle, secondaryBtnStyle };

desktop/src/sections/wallet/WalletDetailPane.tsx

@@ -0,0 +1,147 @@
+// WalletDetailPane — right pane of the Wallet section. Either the
+// selected tx's detail or a placeholder when nothing is selected.
+
+import React, { useEffect, useState } from 'react';
+import { useStore } from '@/lib/store';
+import { getTxDetail, type TxDetail } from '@/lib/api';
+import { shortAddr } from '@/lib/crypto';
+
+function formatT(ut: number | string): string {
+  const n = typeof ut === 'string' ? parseInt(ut, 10) : ut;
+  if (!Number.isFinite(n)) return '—';
+  return (n / 1_000_000).toLocaleString(undefined, { maximumFractionDigits: 6 });
+}
+
+export function WalletDetailPane(): React.ReactElement {
+  const sel = useStore(s => s.walletSel);
+  const keyFile = useStore(s => s.keyFile);
+  const [tx, setTx]   = useState<TxDetail | null>(null);
+  const [loading, setLoading] = useState(false);
+
+  useEffect(() => {
+    if (sel.kind !== 'tx') { setTx(null); return; }
+    let cancelled = false;
+    setLoading(true);
+    getTxDetail(sel.id)
+      .then(t => { if (!cancelled) setTx(t); })
+      .catch(() => { if (!cancelled) setTx(null); })
+      .finally(() => { if (!cancelled) setLoading(false); });
+    return () => { cancelled = true; };
+  }, [sel]);
+
+  if (sel.kind !== 'tx') {
+    return (
+      <div style={{
+        height: '100%', display: 'flex',
+        alignItems: 'center', justifyContent: 'center',
+        color: '#6a6a6a', fontSize: 13, padding: 40, textAlign: 'center',
+      }}>
+        Pick a transaction from the list on the left to see its details.
+      </div>
+    );
+  }
+
+  if (loading) return <Placeholder note="Loading…" />;
+  if (!tx)     return <Placeholder note="Transaction not found on this node." />;
+
+  const outgoing = !!keyFile && tx.from === keyFile.pub_key;
+  const amountUT = tx.amount_ut;
+  const amountColor = amountUT === 0 ? '#8b8b8b'
+    : outgoing ? '#f0b35a' : '#3ba55d';
+
+  return (
+    <div style={{
+      height: '100%', overflowY: 'auto',
+      padding: '20px 24px', background: '#000',
+    }}>
+      <div style={{ color: '#8b8b8b', fontSize: 11, letterSpacing: 1, textTransform: 'uppercase' }}>
+        {tx.type.replace(/_/g, ' ')}
+      </div>
+      <div style={{
+        color: amountColor, fontSize: 30, fontWeight: 800, marginTop: 4,
+      }}>
+        {amountUT === 0 ? '—' : `${outgoing ? '−' : '+'}${formatT(amountUT)} T`}
+      </div>
+      {tx.memo && (
+        <div style={{ color: '#e0e0e0', fontSize: 13, marginTop: 6, fontStyle: 'italic' }}>
+          “{tx.memo}”
+        </div>
+      )}
+
+      <div style={{
+        marginTop: 22, display: 'grid',
+        gridTemplateColumns: 'minmax(120px, auto) 1fr', rowGap: 10, columnGap: 20,
+      }}>
+        <Cell label="ID">{tx.id}</Cell>
+        <Cell label="From">{tx.from_addr ?? shortAddr(tx.from, 8)}</Cell>
+        {tx.to && <Cell label="To">{tx.to_addr ?? shortAddr(tx.to, 8)}</Cell>}
+        <Cell label="Amount">{formatT(tx.amount_ut)} T</Cell>
+        <Cell label="Fee">{formatT(tx.fee_ut)} T</Cell>
+        <Cell label="Time">{new Date(tx.time).toLocaleString()}</Cell>
+        <Cell label="Block">#{tx.block_index} · {shortAddr(tx.block_hash, 8)}</Cell>
+        {typeof tx.gas_used === 'number' && tx.gas_used > 0 && (
+          <Cell label="Gas used">{tx.gas_used.toLocaleString()}</Cell>
+        )}
+      </div>
+
+      {Boolean(tx.payload) && (
+        <details style={{
+          marginTop: 22, background: '#0a0a0a',
+          borderRadius: 10, border: '1px solid #1f1f1f', padding: 12,
+        }}>
+          <summary style={{ cursor: 'pointer', color: '#8b8b8b', fontSize: 12, fontWeight: 700 }}>
+            Payload
+          </summary>
+          <pre className="selectable" style={{
+            marginTop: 8, color: '#d0d0d0', fontSize: 11, lineHeight: 1.5,
+            whiteSpace: 'pre-wrap', wordBreak: 'break-word',
+          }}>
+{JSON.stringify(tx.payload, null, 2)}
+          </pre>
+        </details>
+      )}
+
+      {tx.payload_hex && (
+        <details style={{
+          marginTop: 10, background: '#0a0a0a',
+          borderRadius: 10, border: '1px solid #1f1f1f', padding: 12,
+        }}>
+          <summary style={{ cursor: 'pointer', color: '#8b8b8b', fontSize: 12, fontWeight: 700 }}>
+            Payload (hex)
+          </summary>
+          <div className="selectable" style={{
+            marginTop: 8, color: '#d0d0d0', fontSize: 11, fontFamily: 'monospace',
+            wordBreak: 'break-all',
+          }}>
+            {tx.payload_hex}
+          </div>
+        </details>
+      )}
+    </div>
+  );
+}
+
+function Cell({ label, children }: { label: string; children: React.ReactNode }) {
+  return (
+    <>
+      <div style={{
+        color: '#8b8b8b', fontSize: 11, fontWeight: 700,
+        letterSpacing: 1, textTransform: 'uppercase',
+      }}>{label}</div>
+      <div className="selectable" style={{
+        color: '#fff', fontSize: 13, fontFamily: 'monospace',
+        wordBreak: 'break-all',
+      }}>{children}</div>
+    </>
+  );
+}
+
+function Placeholder({ note }: { note: string }) {
+  return (
+    <div style={{
+      height: '100%', display: 'flex',
+      alignItems: 'center', justifyContent: 'center',
+      color: '#6a6a6a', fontSize: 13, padding: 40,
+    }}>{note}</div>
+  );
+}

desktop/src/sections/wallet/WalletOverview.tsx

@@ -0,0 +1,222 @@
+// WalletOverview — Wallet section left pane.
+//
+// Top card: address + balance + primary actions (Send, Receive).
+// Bottom list: tx history pulled from /api/address/{pub}?limit=100,
+// clicking a row sets store.walletSel = { kind: 'tx', id } so the
+// detail pane renders it.
+
+import React, { useCallback, useEffect, useState } from 'react';
+import { useStore } from '@/lib/store';
+import { getBalance, getTxHistory, type TxRow } from '@/lib/api';
+import { shortAddr } from '@/lib/crypto';
+import { SendModal } from './SendModal';
+import { ReceiveModal } from './ReceiveModal';
+
+function formatT(ut: number): string {
+  return (ut / 1_000_000).toLocaleString(undefined, { maximumFractionDigits: 6 });
+}
+
+export function WalletOverview(): React.ReactElement {
+  const keyFile = useStore(s => s.keyFile);
+  const sel     = useStore(s => s.walletSel);
+  const setSel  = useStore(s => s.setWalletSel);
+
+  const [balance, setBalance] = useState<number | null>(null);
+  const [txs, setTxs]         = useState<TxRow[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [sendOpen,    setSendOpen]    = useState(false);
+  const [receiveOpen, setReceiveOpen] = useState(false);
+
+  const load = useCallback(async () => {
+    if (!keyFile) return;
+    setLoading(true);
+    try {
+      const [bal, rows] = await Promise.all([
+        getBalance(keyFile.pub_key),
+        getTxHistory(keyFile.pub_key, 100),
+      ]);
+      setBalance(bal);
+      setTxs(rows);
+    } finally {
+      setLoading(false);
+    }
+  }, [keyFile]);
+
+  useEffect(() => { load(); }, [load]);
+
+  if (!keyFile) return <></>;
+
+  return (
+    <div style={{ padding: 14 }}>
+      {/* Account card */}
+      <div style={{
+        borderRadius: 14, padding: 16,
+        background: '#0a0a0a', border: '1px solid #1f1f1f',
+      }}>
+        <div style={{
+          color: '#5a5a5a', fontSize: 11, fontWeight: 700,
+          letterSpacing: 1.2, textTransform: 'uppercase',
+        }}>Balance</div>
+        <div style={{ color: '#fff', fontSize: 26, fontWeight: 800, marginTop: 4 }}>
+          {balance === null ? '—' : `${formatT(balance)} T`}
+        </div>
+        <div className="selectable" style={{
+          color: '#8b8b8b', fontSize: 11, fontFamily: 'monospace',
+          marginTop: 8, wordBreak: 'break-all',
+        }}>
+          {keyFile.pub_key}
+        </div>
+
+        <div style={{ display: 'flex', gap: 8, marginTop: 12 }}>
+          <PrimaryBtn label="Send"    onClick={() => setSendOpen(true)} />
+          <SecondaryBtn label="Receive" onClick={() => setReceiveOpen(true)} />
+          <SecondaryBtn label="Refresh" onClick={load} />
+        </div>
+      </div>
+
+      {/* TX list */}
+      <div style={{ marginTop: 16 }}>
+        <div style={{
+          color: '#5a5a5a', fontSize: 11, fontWeight: 700,
+          letterSpacing: 1.2, textTransform: 'uppercase',
+          padding: '0 4px 6px',
+        }}>History</div>
+        {loading ? (
+          <div style={{ color: '#6a6a6a', fontSize: 13, padding: 20, textAlign: 'center' }}>
+            Loading…
+          </div>
+        ) : txs.length === 0 ? (
+          <div style={{ color: '#6a6a6a', fontSize: 13, padding: 20, textAlign: 'center' }}>
+            No transactions yet.
+          </div>
+        ) : (
+          <div style={{
+            borderRadius: 12, overflow: 'hidden',
+            background: '#0a0a0a', border: '1px solid #1f1f1f',
+          }}>
+            {txs.map((t, i) => (
+              <TxRowView
+                key={t.id}
+                tx={t}
+                me={keyFile.pub_key}
+                active={sel.kind === 'tx' && sel.id === t.id}
+                first={i === 0}
+                onClick={() => setSel({ kind: 'tx', id: t.id })}
+              />
+            ))}
+          </div>
+        )}
+      </div>
+
+      {sendOpen && <SendModal onClose={() => setSendOpen(false)} onSent={load} />}
+      {receiveOpen && <ReceiveModal onClose={() => setReceiveOpen(false)} />}
+    </div>
+  );
+}
+
+function TxRowView({
+  tx, me, active, first, onClick,
+}: {
+  tx: TxRow; me: string; active: boolean; first: boolean; onClick: () => void;
+}) {
+  const outgoing = tx.from === me;
+  const amountColor = tx.amount_ut === 0 ? '#8b8b8b'
+    : outgoing ? '#f0b35a' : '#3ba55d';
+  const sign = tx.amount_ut === 0 ? '' : outgoing ? '−' : '+';
+
+  const counterparty = outgoing ? (tx.to_addr || tx.to || '—')
+                                 : (tx.from_addr || tx.from);
+
+  return (
+    <div
+      onClick={onClick}
+      style={{
+        padding: '10px 12px',
+        borderTop: first ? undefined : '1px solid #1f1f1f',
+        background: active ? '#0a1a29' : 'transparent',
+        cursor: 'pointer',
+        display: 'flex', alignItems: 'center', gap: 10,
+      }}
+      onMouseEnter={e => { if (!active) (e.currentTarget as HTMLDivElement).style.background = '#111'; }}
+      onMouseLeave={e => { if (!active) (e.currentTarget as HTMLDivElement).style.background = 'transparent'; }}
+    >
+      <div style={{ flex: 1, minWidth: 0 }}>
+        <div style={{
+          display: 'flex', alignItems: 'center', gap: 6,
+          color: '#fff', fontSize: 13, fontWeight: 600,
+        }}>
+          {prettyType(tx.type)}
+          {tx.memo && (
+            <span style={{ color: '#6a6a6a', fontSize: 11, fontWeight: 400 }}>
+              · {tx.memo.slice(0, 30)}{tx.memo.length > 30 ? '…' : ''}
+            </span>
+          )}
+        </div>
+        <div style={{
+          color: '#8b8b8b', fontSize: 11,
+          fontFamily: 'monospace', marginTop: 2,
+          whiteSpace: 'nowrap', overflow: 'hidden', textOverflow: 'ellipsis',
+        }}>
+          {outgoing ? 'to '   : 'from '}
+          {counterparty.startsWith('DC') ? counterparty : shortAddr(counterparty, 6)}
+        </div>
+      </div>
+      <div style={{ textAlign: 'right', flexShrink: 0 }}>
+        <div style={{ color: amountColor, fontSize: 13, fontWeight: 700 }}>
+          {tx.amount_ut === 0 ? '' : `${sign}${formatT(tx.amount_ut)} T`}
+        </div>
+        <div style={{ color: '#6a6a6a', fontSize: 10 }}>
+          {tx.time ? new Date(tx.time).toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' }) : ''}
+        </div>
+      </div>
+    </div>
+  );
+}
+
+function prettyType(t: string): string {
+  const map: Record<string, string> = {
+    TRANSFER:         'Transfer',
+    RELAY_PROOF:      'Relay fee',
+    REGISTER_RELAY:   'Register relay',
+    HEARTBEAT:        'Heartbeat',
+    CONTACT_REQUEST:  'Contact request',
+    ACCEPT_CONTACT:   'Contact accepted',
+    BLOCK_CONTACT:    'Contact blocked',
+    REGISTER_KEY:     'Identity registered',
+    LINK_DEVICE:      'Device linked',
+    UNLINK_DEVICE:    'Device unlinked',
+    CREATE_POST:      'Post published',
+    DELETE_POST:      'Post deleted',
+    FOLLOW:           'Follow',
+    UNFOLLOW:         'Unfollow',
+    LIKE_POST:        'Like',
+    UNLIKE_POST:      'Unlike',
+    BLOCK_REWARD:     'Block reward',
+  };
+  return map[t] ?? t;
+}
+
+function PrimaryBtn({ label, onClick }: { label: string; onClick: () => void }) {
+  return (
+    <button
+      onClick={onClick}
+      style={{
+        padding: '8px 16px', borderRadius: 999, border: 'none',
+        background: '#1d9bf0', color: '#fff',
+        fontSize: 13, fontWeight: 700, cursor: 'pointer',
+      }}
+    >{label}</button>
+  );
+}
+function SecondaryBtn({ label, onClick }: { label: string; onClick: () => void }) {
+  return (
+    <button
+      onClick={onClick}
+      style={{
+        padding: '8px 14px', borderRadius: 999,
+        background: 'transparent', border: '1px solid #1f1f1f',
+        color: '#fff', fontSize: 13, fontWeight: 700, cursor: 'pointer',
+      }}
+    >{label}</button>
+  );
+}

desktop/src/sections/wallet/index.tsx

@@ -0,0 +1,9 @@
+// Wallet section — full implementation.
+//
+//   List pane: account card (address + balance + Send/Receive buttons)
+//              + transaction history, grouped by day.
+//   Detail pane: picked tx — full block/fee/payload details, or a
+//                prompt to pick one on empty selection.
+
+export { WalletOverview as WalletList } from './WalletOverview';
+export { WalletDetailPane as WalletDetail } from './WalletDetailPane';

desktop/src/shell/NavBar.tsx

@@ -0,0 +1,122 @@
+// NavBar — the left 72px rail. Six icons, one for each section.
+// The active icon is drawn in accent blue; everything else is mid-grey.
+// Keyboard shortcuts (Ctrl/Cmd+1..5) are registered in useKeybinds().
+
+import React, { useEffect } from 'react';
+import { useStore, type Section } from '@/lib/store';
+
+interface Tab {
+  key:    Section;
+  label:  string;
+  icon:   string;
+}
+
+// Icons are SF Symbol-ish monochrome glyphs from lucide's set, inlined as
+// SVGs to avoid another runtime dependency at this stage. If the set
+// grows, we'll move to a lucide-react import.
+const TABS: Tab[] = [
+  { key: 'messages', label: 'Messages', icon: 'chat' },
+  { key: 'feed',     label: 'Feed',     icon: 'feed' },
+  { key: 'wallet',   label: 'Wallet',   icon: 'wallet' },
+  { key: 'contacts', label: 'Contacts', icon: 'contacts' },
+  { key: 'settings', label: 'Settings', icon: 'cog' },
+];
+
+export function NavBar(): React.ReactElement {
+  const section    = useStore(s => s.section);
+  const setSection = useStore(s => s.setSection);
+
+  // Global keybinds for section switch.
+  useEffect(() => {
+    const onKey = (e: KeyboardEvent) => {
+      const mod = e.ctrlKey || e.metaKey;
+      if (!mod) return;
+      const i = Number(e.key) - 1;
+      if (Number.isInteger(i) && i >= 0 && i < TABS.length) {
+        e.preventDefault();
+        setSection(TABS[i].key);
+      } else if (e.key === ',' || e.key === '.') {
+        // Cmd+, is standard for Settings on macOS
+        e.preventDefault();
+        setSection('settings');
+      }
+    };
+    window.addEventListener('keydown', onKey);
+    return () => window.removeEventListener('keydown', onKey);
+  }, [setSection]);
+
+  return (
+    <nav style={{
+      width: 72, flexShrink: 0,
+      display: 'flex', flexDirection: 'column', alignItems: 'center',
+      padding: '16px 0 10px',
+      borderRight: '1px solid #1f1f1f',
+      background: '#000',
+    }}>
+      <div style={{ display: 'flex', flexDirection: 'column', gap: 4 }}>
+        {TABS.map(t => (
+          <NavItem
+            key={t.key}
+            label={t.label}
+            icon={t.icon}
+            active={section === t.key}
+            onClick={() => setSection(t.key)}
+          />
+        ))}
+      </div>
+      <div style={{ flex: 1 }} />
+      <NavItem
+        key="profile"
+        label="Profile"
+        icon="user"
+        active={section === 'profile'}
+        onClick={() => setSection('profile')}
+      />
+    </nav>
+  );
+}
+
+function NavItem({
+  label, icon, active, onClick,
+}: { label: string; icon: string; active: boolean; onClick: () => void }) {
+  return (
+    <button
+      onClick={onClick}
+      title={label}
+      style={{
+        width: 56, height: 52, borderRadius: 12,
+        background: active ? '#0a1a29' : 'transparent',
+        color: active ? '#1d9bf0' : '#8b8b8b',
+        border: 'none', cursor: 'pointer',
+        display: 'flex', flexDirection: 'column', alignItems: 'center',
+        justifyContent: 'center', gap: 2,
+      }}
+    >
+      <NavGlyph icon={icon} color={active ? '#1d9bf0' : '#8b8b8b'} />
+      <span style={{ fontSize: 10, fontWeight: 600, letterSpacing: 0.2 }}>
+        {label}
+      </span>
+    </button>
+  );
+}
+
+function NavGlyph({ icon, color }: { icon: string; color: string }) {
+  const d = GLYPHS[icon] ?? GLYPHS.cog;
+  return (
+    <svg width={20} height={20} viewBox="0 0 24 24" fill="none"
+         stroke={color} strokeWidth={1.8}
+         strokeLinecap="round" strokeLinejoin="round">
+      <path d={d} />
+    </svg>
+  );
+}
+
+const GLYPHS: Record<string, string> = {
+  // Minimal lucide-style single-path icons.
+  chat:     'M21 12a8.38 8.38 0 0 1-.9 3.8 8.5 8.5 0 0 1-7.6 4.7 8.38 8.38 0 0 1-3.8-.9L3 21l1.9-5.7a8.38 8.38 0 0 1-.9-3.8 8.5 8.5 0 0 1 4.7-7.6 8.38 8.38 0 0 1 3.8-.9h.5a8.48 8.48 0 0 1 8 8v.5z',
+  feed:     'M4 11a9 9 0 0 1 9 9 M4 4a16 16 0 0 1 16 16 M5 19a2 2 0 1 0 0 .01',
+  wallet:   'M20 12V8H4a2 2 0 0 1 0-4h12 M4 6v12a2 2 0 0 0 2 2h14v-4 M18 12a2 2 0 1 0 0 4h4v-4h-4z',
+  contacts: 'M17 21v-2a4 4 0 0 0-4-4H5a4 4 0 0 0-4 4v2 M9 11a4 4 0 1 0 0-8 4 4 0 0 0 0 8 M23 21v-2a4 4 0 0 0-3-3.87 M16 3.13a4 4 0 0 1 0 7.75',
+  cog:      'M12 15a3 3 0 1 0 0-6 3 3 0 0 0 0 6z M19.4 15a1.65 1.65 0 0 0 .33 1.82l.06.06a2 2 0 0 1 0 2.83 2 2 0 0 1-2.83 0l-.06-.06a1.65 1.65 0 0 0-1.82-.33 1.65 1.65 0 0 0-1 1.51V21a2 2 0 0 1-4 0v-.09A1.65 1.65 0 0 0 9 19.4a1.65 1.65 0 0 0-1.82.33l-.06.06a2 2 0 0 1-2.83 0 2 2 0 0 1 0-2.83l.06-.06a1.65 1.65 0 0 0 .33-1.82 1.65 1.65 0 0 0-1.51-1H3a2 2 0 0 1 0-4h.09A1.65 1.65 0 0 0 4.6 9a1.65 1.65 0 0 0-.33-1.82l-.06-.06a2 2 0 0 1 0-2.83 2 2 0 0 1 2.83 0l.06.06a1.65 1.65 0 0 0 1.82.33H9a1.65 1.65 0 0 0 1-1.51V3a2 2 0 0 1 4 0v.09a1.65 1.65 0 0 0 1 1.51 1.65 1.65 0 0 0 1.82-.33l.06-.06a2 2 0 0 1 2.83 0 2 2 0 0 1 0 2.83l-.06.06a1.65 1.65 0 0 0-.33 1.82V9a1.65 1.65 0 0 0 1.51 1H21a2 2 0 0 1 0 4h-.09a1.65 1.65 0 0 0-1.51 1z',
+  user:     'M20 21v-2a4 4 0 0 0-4-4H8a4 4 0 0 0-4 4v2 M12 11a4 4 0 1 0 0-8 4 4 0 0 0 0 8z',
+};

desktop/src/shell/SectionPlaceholder.tsx

@@ -0,0 +1,40 @@
+// Simple inner placeholder used by every section until real content
+// lands. Shows a title + a short note; `centered` flips the layout into
+// a vertically centred message for empty-detail panes.
+
+import React from 'react';
+
+interface Props {
+  title:    string;
+  note?:    string;
+  centered?: boolean;
+}
+
+export function SectionPlaceholder({ title, note, centered }: Props): React.ReactElement {
+  if (centered) {
+    return (
+      <div style={{
+        height: '100%',
+        display: 'flex', alignItems: 'center', justifyContent: 'center',
+        padding: 32,
+      }}>
+        <div style={{ textAlign: 'center', maxWidth: 360 }}>
+          <div style={{ color: '#d0d0d0', fontSize: 16, fontWeight: 700 }}>{title}</div>
+          {note && (
+            <div style={{ color: '#6a6a6a', fontSize: 13, lineHeight: 1.5, marginTop: 6 }}>
+              {note}
+            </div>
+          )}
+        </div>
+      </div>
+    );
+  }
+  return (
+    <div style={{ padding: 14 }}>
+      <div style={{ color: '#fff', fontSize: 15, fontWeight: 700 }}>{title}</div>
+      {note && (
+        <div style={{ color: '#8b8b8b', fontSize: 12, marginTop: 6 }}>{note}</div>
+      )}
+    </div>
+  );
+}

desktop/src/shell/Shell.tsx

@@ -0,0 +1,76 @@
+// Shell — the permanent 3-panel chrome around every non-auth screen.
+//
+// Layout:
+//   ┌──────────────────────────────────────────────────────────────┐
+//   │  DChain                        [ minimise | maximise | × ]    │ 32px titlebar (drag region)
+//   ├──────┬───────────────────┬─────────────────────────────────────┤
+//   │      │                   │                                    │
+//   │ nav  │      list         │              detail                 │
+//   │ 72px │   ~340px fixed    │             flex 1                  │
+//   │      │                   │                                    │
+//   ├──────┴───────────────────┴─────────────────────────────────────┤
+//   │ ● online  ·  height 10942  ·  fee 1000 µT                      │ 28px status bar
+//   └──────────────────────────────────────────────────────────────┘
+//
+// Current section is driven by store.section. NavBar flips it. List +
+// Detail are each decided by the section, composed from the appropriate
+// module under sections/. Until sections ship their real content, they
+// render simple placeholders so we can walk through the shell end-to-end.
+
+import React from 'react';
+import { useStore, type Section } from '@/lib/store';
+import { useGlobalKeybinds } from '@/hooks/useGlobalKeybinds';
+import { TitleBar } from './TitleBar';
+import { NavBar } from './NavBar';
+import { StatusBar } from './StatusBar';
+import { UpdateBanner } from './UpdateBanner';
+import { MessagesList, MessagesDetail } from '@/sections/messages';
+import { FeedList, FeedDetail } from '@/sections/feed';
+import { WalletList, WalletDetail } from '@/sections/wallet';
+import { ContactsList, ContactsDetail } from '@/sections/contacts';
+import { SettingsList, SettingsDetail } from '@/sections/settings';
+import { ProfileList, ProfileDetail } from '@/sections/profile';
+
+export function Shell(): React.ReactElement {
+  const section = useStore(s => s.section);
+  const { List, Detail } = PANES[section];
+  useGlobalKeybinds();
+  return (
+    <div style={{
+      display: 'flex', flexDirection: 'column',
+      height: '100%', background: '#000',
+    }}>
+      <TitleBar />
+      <div style={{
+        flex: 1, display: 'flex', overflow: 'hidden',
+        borderTop: '1px solid #1f1f1f',
+      }}>
+        <NavBar />
+        <div style={{
+          width: 340, flexShrink: 0,
+          borderRight: '1px solid #1f1f1f',
+          overflowY: 'auto',
+        }}>
+          <List />
+        </div>
+        <div style={{ flex: 1, minWidth: 0, overflow: 'hidden' }}>
+          <Detail />
+        </div>
+      </div>
+      <UpdateBanner />
+      <StatusBar />
+    </div>
+  );
+}
+
+const PANES: Record<
+  Section,
+  { List: React.ComponentType; Detail: React.ComponentType }
+> = {
+  messages: { List: MessagesList, Detail: MessagesDetail },
+  feed:     { List: FeedList,     Detail: FeedDetail     },
+  wallet:   { List: WalletList,   Detail: WalletDetail   },
+  contacts: { List: ContactsList, Detail: ContactsDetail },
+  settings: { List: SettingsList, Detail: SettingsDetail },
+  profile:  { List: ProfileList,  Detail: ProfileDetail  },
+};

desktop/src/shell/StatusBar.tsx

@@ -0,0 +1,75 @@
+// StatusBar — the 28px strip at the bottom. Surfaces the three bits of
+// information an operator tends to want at a glance:
+//   * Connection state to the configured node (poll /api/netstats).
+//   * Current chain height (last successful poll).
+//   * Node URL (short, hover-tooltip for the full thing).
+//
+// Poll interval is 5 seconds — low enough to feel live, cheap enough
+// that even a free-tier node won't notice.
+
+import React, { useEffect, useState } from 'react';
+import { useStore } from '@/lib/store';
+import { getNetStats, getNodeUrl, onNodeUrlChange } from '@/lib/api';
+
+type ConnState = 'online' | 'connecting' | 'offline';
+
+export function StatusBar(): React.ReactElement {
+  const nodeUrl = useStore(s => s.settings.nodeUrl);
+  const [conn,   setConn]   = useState<ConnState>('connecting');
+  const [height, setHeight] = useState<number | null>(null);
+  const [url,    setUrl]    = useState<string>(getNodeUrl());
+
+  useEffect(() => onNodeUrlChange(setUrl), []);
+
+  useEffect(() => {
+    let cancelled = false;
+    const poll = async () => {
+      try {
+        const s = await getNetStats();
+        if (cancelled) return;
+        setConn('online');
+        setHeight(s.total_blocks);
+      } catch {
+        if (cancelled) return;
+        setConn('offline');
+      }
+    };
+    setConn('connecting');
+    poll();
+    const t = setInterval(poll, 5_000);
+    return () => {
+      cancelled = true;
+      clearInterval(t);
+    };
+  }, [nodeUrl]);
+
+  const dot = conn === 'online' ? '#3ba55d' :
+              conn === 'connecting' ? '#f0b35a' :
+              '#f4212e';
+
+  const shortUrl = url
+    .replace(/^https?:\/\//, '')
+    .replace(/\/$/, '');
+
+  return (
+    <footer style={{
+      height: 28, minHeight: 28,
+      background: '#000',
+      borderTop: '1px solid #1f1f1f',
+      display: 'flex', alignItems: 'center', padding: '0 16px', gap: 14,
+      fontSize: 11, color: '#8b8b8b',
+    }}>
+      <span style={{ display: 'inline-flex', alignItems: 'center', gap: 6 }}>
+        <span style={{
+          width: 8, height: 8, borderRadius: 4, background: dot,
+        }} />
+        {conn}
+      </span>
+      <span style={{ opacity: 0.5 }}>·</span>
+      <span title={url}>{shortUrl}</span>
+      <span style={{ opacity: 0.5 }}>·</span>
+      <span>height {height ?? '—'}</span>
+      <div style={{ flex: 1 }} />
+    </footer>
+  );
+}

desktop/src/shell/TitleBar.tsx

@@ -0,0 +1,42 @@
+// Titlebar — draws the top 32px strip as a drag region so the user can
+// move the window even though we set frame: false in main.ts.
+//
+// On macOS the native traffic lights show through because main.ts uses
+// `titleBarStyle: 'hiddenInset'`. On Windows, `titleBarOverlay` renders
+// close/min/max in their native style over our bar. On Linux we paint
+// close + min + max ourselves (below).
+
+import React from 'react';
+
+const DRAG: React.CSSProperties = {
+  // @ts-expect-error webkit-only
+  WebkitAppRegion: 'drag',
+};
+const NO_DRAG: React.CSSProperties = {
+  // @ts-expect-error webkit-only
+  WebkitAppRegion: 'no-drag',
+};
+
+export function TitleBar(): React.ReactElement {
+  return (
+    <div
+      style={{
+        ...DRAG,
+        height: 32,
+        minHeight: 32,
+        display: 'flex',
+        alignItems: 'center',
+        paddingLeft: 80, // leaves room for macOS traffic-lights area
+        paddingRight: 12,
+        background: '#000',
+        color: '#d0d0d0',
+        fontSize: 12,
+        fontWeight: 600,
+        letterSpacing: 0.2,
+      }}
+    >
+      <span style={{ opacity: 0.6 }}>DChain</span>
+      <div style={{ flex: 1, ...NO_DRAG }} />
+    </div>
+  );
+}

desktop/src/shell/UpdateBanner.tsx

@@ -0,0 +1,56 @@
+// UpdateBanner — appears just above the status bar when a newer release
+// tag is available on Gitea. Single action: open the release page in
+// the default browser. We deliberately don't auto-download — the user
+// probably wants to read the changelog first, and the binary hosting
+// story is still "Gitea release assets" rather than a signed feed.
+
+import React, { useState } from 'react';
+import { useUpdateCheck } from '@/hooks/useUpdateCheck';
+
+export function UpdateBanner(): React.ReactElement | null {
+  const info = useUpdateCheck();
+  const [dismissed, setDismissed] = useState<string | null>(null);
+
+  if (!info) return null;
+  if (dismissed === info.latestTag) return null;
+
+  return (
+    <div style={{
+      padding: '8px 16px',
+      background: '#0d2540',
+      borderTop: '1px solid #1d9bf022',
+      color: '#fff',
+      fontSize: 12,
+      display: 'flex', alignItems: 'center', gap: 12,
+    }}>
+      <span style={{ color: '#1d9bf0', fontSize: 16 }}>↗</span>
+      <span style={{ flex: 1 }}>
+        Update available: <b>{info.latestTag}</b>
+        {info.publishedAt && (
+          <span style={{ color: '#8b8b8b', marginLeft: 8 }}>
+            published {new Date(info.publishedAt).toLocaleDateString()}
+          </span>
+        )}
+      </span>
+      <a
+        href={info.url}
+        target="_blank"
+        rel="noreferrer"
+        style={{
+          padding: '5px 12px', borderRadius: 999,
+          background: '#1d9bf0', color: '#fff',
+          fontSize: 11, fontWeight: 700,
+          textDecoration: 'none',
+        }}
+      >Download</a>
+      <button
+        onClick={() => setDismissed(info.latestTag)}
+        style={{
+          background: 'transparent', border: 'none',
+          color: '#8b8b8b', fontSize: 16, cursor: 'pointer',
+          padding: 0, lineHeight: 1,
+        }}
+      >×</button>
+    </div>
+  );
+}

desktop/src/vite-env.d.ts

@@ -0,0 +1,12 @@
+/// <reference types="vite/client" />
+
+// Vite auto-surfaces VITE_* env vars on import.meta.env. The Electron main
+// process sets VITE_DEV_SERVER_URL separately at spawn time, so we only
+// need to tell TS about the one variable the renderer reads.
+
+interface ImportMetaEnv {
+  readonly VITE_DEV_SERVER_URL?: string;
+}
+interface ImportMeta {
+  readonly env: ImportMetaEnv;
+}

desktop/tsconfig.json

@@ -0,0 +1,26 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "useDefineForClassFields": true,
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
+    "module": "ESNext",
+    "skipLibCheck": true,
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": false,
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "noEmit": true,
+    "jsx": "react-jsx",
+    "strict": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noFallthroughCasesInSwitch": true,
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "baseUrl": ".",
+    "paths": {
+      "@/*": ["src/*"]
+    }
+  },
+  "include": ["src"]
+}

desktop/vite.config.ts

@@ -0,0 +1,22 @@
+import { defineConfig } from 'vite';
+import react from '@vitejs/plugin-react';
+import path from 'node:path';
+
+// Vite config for the renderer process. Electron main/preload build
+// separately via `tsc -p electron/tsconfig.json`.
+export default defineConfig({
+  plugins: [react()],
+  resolve: {
+    alias: {
+      '@': path.resolve(__dirname, './src'),
+    },
+  },
+  build: {
+    outDir: 'dist',
+    emptyOutDir: true,
+  },
+  server: {
+    port: 5173,
+    strictPort: true,
+  },
+});

docs/ROADMAP.md

@@ -0,0 +1,232 @@
+# Roadmap
+
+Living doc — «куда идём дальше». Два активных вектора: **v2.2.0 multi-device**
+и **desktop Electron client**. Всё что tentative — помечено `?`; всё что
+решено и принято к работе — без знаков.
+
+---
+
+## v2.2.0 — Multi-device (per-device X25519, on-chain device registry)
+
+### Проблема
+
+Сейчас у пользователя одна пара X25519 (хранится в `keyFile`), и relay-mailbox —
+queue с DELETE-после-чтения. При двух устройствах:
+
+- Конверт забирает то устройство, что первое дёрнуло `/relay/inbox` — второе
+  теряет сообщение навсегда.
+- История чатов per-device, не синхронизируется (`AsyncStorage` на каждом
+  устройстве свой).
+
+On-chain часть (posts, follows, tx, wallet) работает нормально — оба устройства
+читают один чейн и видят одно и то же. Чинить надо только мессенджер.
+
+### Решение — путь А (Signal-style): X25519 на устройство + device registry
+
+1. **Master identity = Ed25519** (как сейчас). Подписывает tx, владеет
+   балансом, — один на всю identity.
+2. **X25519 — per-device**. Каждое устройство при первом старте генерит
+   свою пару. Relay-mailbox остаётся queue'ом, но адресуется по
+   **устройству**, не по identity.
+3. **Device registry on-chain**: новые tx-типы `LINK_DEVICE` / `UNLINK_DEVICE`,
+   подписываются master Ed25519, публикуют/отзывают связку
+   `(master_pub → device_x25519_pub, device_name)`.
+4. **Sender-side fan-out**: при отправке — один envelope на каждое
+   активное устройство получателя. Мессадж → N конвертов.
+5. **Revoke**: master подписывает `UNLINK_DEVICE`, клиент, обнаруживший
+   свой `x25519_pub` в revoked — wipe'ит локальную БД (zeroize master
+   Ed25519 + delete chats).
+
+### План работ (PR-by-PR)
+
+#### PR #1 — Chain-side (backend) — _v2.2.0-alpha1_
+
+- [ ] `blockchain/types.go`: `EventLinkDevice`, `EventUnlinkDevice`
+  + payload structs `LinkDevicePayload`, `UnlinkDevicePayload`.
+- [ ] `blockchain/chain.go`: applyTx-ветки, state persistence:
+  - `prefixDevice + x25519_pub → DeviceRecord{owner, name, added_at, revoked_at?}`.
+  - Обратный индекс `prefixDevicesByOwner + master_pub → [x25519_pub, …]`.
+- [ ] Константа `MaxDevicesPerOwner = 10`.
+- [ ] Validation:
+  - Tx подписана master'ом; подпись matches `payload.Owner`.
+  - `x25519_pub` уникален в registry (не занят другим master'ом).
+  - `device_name` ≤ 64 символов; printable.
+  - При `UNLINK_DEVICE`: запись существует, owner совпадает с signer'ом.
+- [ ] HTTP: `GET /api/devices/{master_pub}` → `[{x25519_pub, device_name, added_at}, …]`,
+  фильтрует revoked.
+- [ ] В `/api/identity/{pub}` добавить поле `device_count`.
+- [ ] Unit-тесты:
+  - Happy path link + list.
+  - Unlink → list сократился.
+  - Лимит `MaxDevicesPerOwner`.
+  - Чужая подпись → reject.
+  - Duplicate x25519_pub → reject.
+- [ ] Swagger + `docs/api/devices.md`.
+
+Совместимость: старые клиенты, которые не обновили identity, продолжают
+работать по old-schema (envelope на published X25519 из identity). Sender
+fall-back'ит на identity.x25519, если `device_count == 0`.
+
+#### PR #2 — Client fan-out (mobile) — _v2.2.0-alpha2_
+
+- [ ] `lib/api.ts`: `fetchDevices(masterPub): Promise<DeviceRecord[]>`,
+  с кэшем в zustand store + инвалидацией по WS-ивенту `tx:LINK_DEVICE|UNLINK_DEVICE`.
+- [ ] `chats/[id].tsx` → `sendCore`: `Promise.all` по `devices[]`;
+  если `devices.length == 0` — fall-back на identity.x25519 (legacy path).
+- [ ] При первом старте (онбординг): если identity ещё не зарегистрирована —
+  `PUBLISH_KEY` tx + `LINK_DEVICE` tx (**этот** девайс как первый в списке).
+- [ ] UI: в chat-list tile бейдж `2/2` на своих сообщениях (доставлено
+  на N устройств получателя).
+- [ ] Тест: два клиента на одну identity, отправляем на contact — оба
+  получают.
+
+#### PR #3 — Devices screen + pairing flow (mobile + desktop) — _v2.2.0-alpha3_
+
+- [ ] Settings → **Devices**: список активных, unlink-кнопка у каждого
+  (кроме `this device`).
+- [ ] «Link new device» flow:
+  - Новое устройство генерит свой X25519, показывает QR
+    `{x25519_pub, device_name, nonce, rendezvous_id}`.
+  - Старое сканирует → Confirm → подписывает `LINK_DEVICE` tx +
+    шлёт через relay envelope `{master_ed25519_priv, recent_history}` —
+    encrypted for new device's X25519, TTL ≤ 60 сек.
+  - Новое читает envelope, сохраняет master + history, готово.
+- [ ] Self-wipe при обнаружении своего `x25519_pub` в revoked:
+  zeroize master, clear AsyncStorage/keychain, redirect на onboarding.
+
+#### PR #4 — Desktop Electron shell — _v2.2.0-rc1_
+
+См. отдельный раздел ниже.
+
+### Нерешённые вопросы
+
+- **QR-pairing UX на desktop'е**: у ноутбука камеры часто нет. Вариант:
+  master на phone шлёт invite-envelope по pre-shared secret (6-digit code,
+  вводится в обе стороны), без QR. Подумать после PR #2.
+- **History-sync backup формат**: JSON export всей ChatStorage shreds'ов?
+  Ограничение по размеру? TTL у backup-конверта? — в PR #3.
+- **Revoked-device-wipe race**: если устройство оффлайн 6 месяцев, потом
+  поднимается — первое что видит это свой revoked. Должен успеть wipe'нуться
+  **до** попытки послать tx с master-ключом. Продумать порядок bootstrap'а.
+
+---
+
+## Desktop client (Electron)
+
+Цель: 1:1 функциональный паритет с мобильным, десктопная эргономика, keyboard-first.
+
+### Архитектура
+
+- **Electron** + **React (Vite)** + **TypeScript**.
+- 80% `lib/` переиспользуется из `client-app/lib/` (api, feed, crypto, store, types).
+- Нативные модули: `electron-store` (+ `safeStorage`) для keys, `clipboard`,
+  `Notification`, `dialog.showOpenDialog`.
+- Custom title bar (frame-less), 3-panel layout.
+
+### Экраны
+
+Full design — `docs/desktop-design.md` (TODO). Sections:
+
+- **Messages** — список чатов + conversation panel. Saved Messages pinned top.
+- **Feed** — tabs (For You / Following / Trending 24h / 7d / Hashtag) +
+  post list + thread panel.
+- **Wallet** — account overview + tx history + tx detail.
+- **Contacts** — grouped list (All / Online / Blocked / Requests) + contact profile.
+- **Settings** — grouped: Node, Identity, **Devices**, Privacy, Feed, Notifications,
+  Advanced, About.
+- **Profile** (внизу nav) — self profile; чужой — в detail pane.
+- **Auth/Onboarding** — Welcome / Create / Import / Pair-with-phone (QR/code).
+
+### Стилистика (переносим)
+
+Чёрный `#000`, карточки `#0a0a0a`, бордеры `#1f1f1f`, текст `#fff`/`#8b8b8b`.
+Синий accent `#1d9bf0`, оранж warning `#f0b35a`. Синий bookmark-avatar для Saved Messages.
+
+### Не переносим
+
+Все React-Native-анимации (Pressable-animations, `scaleY: -1`, gesture-handler
+long-press). На десктопе — правый клик, hover-states, keyboard shortcuts,
+обычный scroll вместо inverted FlatList.
+
+### Global keybinds
+
+| Key | Action |
+|---|---|
+| `Ctrl/Cmd+1..5` | Переключение секций |
+| `Ctrl/Cmd+N` | Новый пост / новый контакт (контекстно) |
+| `Ctrl/Cmd+K` | Global search |
+| `Ctrl/Cmd+F` | Search в текущей list pane |
+| `Ctrl/Cmd+,` | Settings |
+| `Ctrl/Cmd+Enter` | Send (chat / publish post) |
+| `Esc` | Close modal / cancel selection |
+
+### Структура папок
+
+```
+desktop/
+├── electron/
+│   ├── main.ts          # BrowserWindow, IPC, auto-update
+│   ├── preload.ts       # contextBridge — safe API
+│   ├── menu.ts          # native menu bar
+│   └── deep-link.ts     # dchain:// protocol handler
+├── src/                 # renderer
+│   ├── App.tsx
+│   ├── shell/           # nav, status bar, title bar
+│   ├── sections/
+│   │   ├── messages/
+│   │   ├── feed/
+│   │   ├── wallet/
+│   │   ├── contacts/
+│   │   ├── settings/
+│   │   └── profile/
+│   ├── modals/
+│   ├── auth/
+│   ├── lib/             # reuse из client-app/lib
+│   └── styles/
+└── package.json
+```
+
+### План работ
+
+- [x] **v2.2.0-alpha4** — Boilerplate, 3-panel shell, safeStorage IPC,
+      Welcome / Create / Import auth, section stubs.
+- [x] **v2.2.0-alpha5** — Messages section + pairing poll loop; chain
+      + clients learn to attribute conversations by master Ed25519.
+- [x] **v2.2.0-alpha6** — Feed (tabs + list + detail + compose) +
+      Wallet (history + detail + Send/Receive).
+- [x] **v2.2.0-rc1** — Contacts section (list + profile detail + actions),
+      Settings → Devices (list + unlink + link-new-device modal with the
+      same protocol as mobile), expanded Profile, QR in Receive, global
+      keybinds (Ctrl+W close chat / Ctrl+K jump to Contacts / Ctrl+, Settings).
+- [x] **v2.2.0** — Contact-request flow (New contact modal + Requests
+      inbox tab with Accept/Block), auto-update banner that polls
+      `/api/update-check` and offers the latest Gitea release,
+      electron-builder config ready for `.dmg` / `.exe` / `.AppImage` /
+      `.deb` + NSIS installer + macOS hardenedRuntime.
+- [ ] **post-v2.2.0** — Attachments in Compose (file picker +
+      client-side image resize + metadata scrub), code signing
+      certificates, draft group chats (multi-recipient envelopes or
+      MLS integration).
+
+### Открытые вопросы (desktop)
+
+- **Auto-update channel**: гнать через Gitea releases (как node) или отдельный S3/Gitea-attachments?
+- **Sandbox**: desktop хранит master Ed25519 — обязательно `safeStorage` (macOS Keychain, Windows DPAPI, libsecret на Linux). На Linux без libsecret — fallback на plaintext + warning.
+- **Deep-link**: `dchain://chat/<pub>` для шаринга профилей/постов из браузера.
+
+---
+
+## Меньшие хвосты (неприоритетно)
+
+- `prev_hash mismatch` при двойной gossip-доставке — понизить до Debug уровня,
+  не пугать операторов (см. history с joiner-node bring-up).
+- `/api/network-info.peers` у seed'а возвращает `[]` если
+  `DCHAIN_ANNOUNCE` не задан — добавить fallback:
+  если announce пустой, публиковать *первый listen-addr + свой peer_id*
+  (не `127.0.0.1`), чтобы joiner'ы не упирались в `peers:[]`.
+- **Groups (3+ участников)** в чатах — тип `Contact.kind == 'group'`
+  в клиенте есть, а на backend'е не реализован. После v2.2.0, потому что
+  pairwise messaging ↔ group messaging на multi-device — это другой
+  математический слой (MLS или Sender Keys).
+- Repa как weight в selection-lider PBFT — сейчас только scoring; для
+  настоящего proof-of-reputation нужно переписать leader-rotation.

node/api_common.go

@@ -15,13 +15,11 @@ import (
 
 func jsonOK(w http.ResponseWriter, v any) {
 	w.Header().Set("Content-Type", "application/json")
-	w.Header().Set("Access-Control-Allow-Origin", "*")
 	_ = json.NewEncoder(w).Encode(v)
 }
 
 func jsonErr(w http.ResponseWriter, err error, code int) {
 	w.Header().Set("Content-Type", "application/json")
-	w.Header().Set("Access-Control-Allow-Origin", "*")
 	w.WriteHeader(code)
 	_ = json.NewEncoder(w).Encode(map[string]string{"error": err.Error()})
 }

node/api_explorer.go

@@ -510,10 +510,63 @@ func apiIdentity(q ExplorerQuery) http.HandlerFunc {
 			jsonErr(w, err, 500)
 			return
 		}
+		// Multi-device (v2.2.0): stuff the active device count into the
+		// identity payload so a sender can decide upfront whether to
+		// fan out envelopes or fall back to the legacy single-X25519
+		// path (device_count == 0).
+		if q.DevicesOf != nil {
+			if devs, derr := q.DevicesOf(pubKey); derr == nil {
+				info.DeviceCount = len(devs)
+			}
+		}
 		jsonOK(w, info)
 	}
 }
 
+// apiDevices — GET /api/devices/{master_pub_or_addr}
+//
+// Returns the active (non-revoked) devices linked to a master Ed25519
+// identity. Used by senders to fan out one envelope per device. Legacy
+// identities (count=0) should be handled by the caller by falling back
+// to IdentityInfo.X25519Pub — this endpoint is strictly the new registry.
+func apiDevices(q ExplorerQuery) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		input := strings.TrimPrefix(r.URL.Path, "/api/devices/")
+		input = strings.Trim(input, "/")
+		if input == "" {
+			jsonErr(w, fmt.Errorf("master pubkey or address required"), 400)
+			return
+		}
+		if q.DevicesOf == nil {
+			jsonErr(w, fmt.Errorf("device registry not available"), 503)
+			return
+		}
+		pubKey, err := resolveAccountID(q, input)
+		if err != nil {
+			jsonErr(w, err, 404)
+			return
+		}
+		recs, err := q.DevicesOf(pubKey)
+		if err != nil {
+			jsonErr(w, err, 500)
+			return
+		}
+		out := make([]blockchain.DeviceInfo, 0, len(recs))
+		for _, rec := range recs {
+			out = append(out, blockchain.DeviceInfo{
+				X25519PubKey: rec.X25519PubKey,
+				DeviceName:   rec.DeviceName,
+				AddedAt:      rec.AddedAt,
+			})
+		}
+		jsonOK(w, map[string]any{
+			"master_pub": pubKey,
+			"count":      len(out),
+			"devices":    out,
+		})
+	}
+}
+
 func apiSubmitTx(q ExplorerQuery) http.HandlerFunc {
 	// The returned handler is wrapped in withSubmitTxGuards() by the caller:
 	// body size is capped at MaxTxRequestBytes and per-IP rate limiting is

node/api_relay.go

@@ -91,7 +91,8 @@ func relayInboxList(rc RelayConfig) http.HandlerFunc {
 
 		type item struct {
 			ID                 string `json:"id"`
-			SenderPub    string `json:"sender_pub"`
+			SenderPub          string `json:"sender_pub"`           // X25519 hex
+			SenderEd25519Pub   string `json:"sender_ed25519_pub"`   // master Ed25519 hex (optional; may be empty for legacy senders)
 			RecipientPub       string `json:"recipient_pub"`
 			FeeUT              uint64 `json:"fee_ut,omitempty"`
 			SentAt             int64  `json:"sent_at"`
@@ -105,6 +106,7 @@ func relayInboxList(rc RelayConfig) http.HandlerFunc {
 			out = append(out, item{
 				ID:               env.ID,
 				SenderPub:        env.SenderPub,
+				SenderEd25519Pub: env.SenderEd25519PubKey,
 				RecipientPub:     env.RecipientPub,
 				FeeUT:            env.FeeUT,
 				SentAt:           env.SentAt,

node/api_routes.go

@@ -53,6 +53,10 @@ type ExplorerQuery struct {
 	NetStats         func() (blockchain.NetStats, error)
 	RegisteredRelays func() ([]blockchain.RegisteredRelayInfo, error)
 	IdentityInfo     func(pubKeyOrAddr string) (*blockchain.IdentityInfo, error)
+	// DevicesOf (multi-device v2.2.0) returns the identity's non-revoked
+	// device records. Empty slice if the identity hasn't linked any yet
+	// — senders fall back to IdentityInfo.X25519Pub for legacy clients.
+	DevicesOf        func(masterPub string) ([]blockchain.DeviceRecord, error)
 	ValidatorSet     func() ([]string, error)
 	SubmitTx         func(tx *blockchain.Transaction) error
 	// ConnectedPeers (optional) returns the local libp2p view of currently
@@ -222,6 +226,7 @@ func registerExplorerAPI(mux *http.ServeMux, q ExplorerQuery) {
 	mux.HandleFunc("/api/node/", apiNode(q))           // GET /api/node/{pubkey|DC...}
 	mux.HandleFunc("/api/relays", apiRelays(q))        // GET /api/relays
 	mux.HandleFunc("/api/identity/", apiIdentity(q))   // GET /api/identity/{pubkey|addr}
+	mux.HandleFunc("/api/devices/", apiDevices(q))     // GET /api/devices/{master_pub} — multi-device registry (v2.2.0)
 	mux.HandleFunc("/api/validators", apiValidators(q))// GET /api/validators
 	mux.HandleFunc("/api/tx", withWriteTokenGuard(withSubmitTxGuards(apiSubmitTx(q)))) // POST /api/tx (body size + per-IP rate limit + optional token gate)
 	// Live event stream (SSE) — GET /api/events

node/cors.go

@@ -0,0 +1,32 @@
+package node
+
+import "net/http"
+
+// withCORS wraps any http.Handler so every response carries the CORS
+// headers browser-based clients (Electron renderer, web explorer from a
+// different origin, mobile webview) need. Also short-circuits OPTIONS
+// preflight requests with a 204 — without this, POST /api/tx with a
+// JSON body triggers a preflight that the regular handler answers as
+// 404/405 and the browser refuses the follow-up.
+//
+// The allow-list is wide on purpose. The node's security model doesn't
+// rely on same-origin — API tokens (DCHAIN_API_TOKEN + DCHAIN_API_PRIVATE)
+// and Ed25519 tx signatures are what gate writes. Cross-origin access is
+// a first-class feature here, not an attack vector.
+func withCORS(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		h := w.Header()
+		h.Set("Access-Control-Allow-Origin", "*")
+		h.Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS, HEAD, PATCH")
+		h.Set("Access-Control-Allow-Headers", "Authorization, Content-Type, X-Requested-With")
+		h.Set("Access-Control-Expose-Headers", "Content-Length, Content-Type")
+		h.Set("Access-Control-Max-Age", "86400") // cache preflight for a day
+
+		if r.Method == http.MethodOptions {
+			// Preflight. Don't hand to the mux — just answer.
+			w.WriteHeader(http.StatusNoContent)
+			return
+		}
+		next.ServeHTTP(w, r)
+	})
+}

node/stats.go

@@ -310,7 +310,10 @@ func (t *Tracker) ServeHTTP(q QueryFunc, fns ...func(*http.ServeMux)) http.Handl
 }
 
 // ListenAndServe starts the HTTP stats server on addr (e.g. ":8080").
+// All responses pass through withCORS so browser + Electron clients
+// get correct Access-Control-* headers and preflight OPTIONS requests
+// are answered with 204 instead of falling through to the 404 handler.
 func (t *Tracker) ListenAndServe(addr string, q QueryFunc, fns ...func(*http.ServeMux)) error {
-	handler := t.ServeHTTP(q, fns...)
+	handler := withCORS(t.ServeHTTP(q, fns...))
 	return http.ListenAndServe(addr, handler)
 }