diff --git a/src/db/messaging-groups.ts b/src/db/messaging-groups.ts
index 3f9b2c4..33c8715 100644
--- a/src/db/messaging-groups.ts
+++ b/src/db/messaging-groups.ts
@@ -100,6 +100,20 @@ export function deleteMessagingGroup(id: string): void {
   getDb().prepare('DELETE FROM messaging_groups WHERE id = ?').run(id);
 }
 
+/**
+ * Mark a messaging group as denied by the owner (channel-registration flow).
+ * Future mentions on this channel silently drop until an admin explicitly
+ * wires it via `createMessagingGroupAgent`, which implicitly clears the
+ * denied state by making `agentCount > 0` — the router's denied-channel
+ * check sits on the `agentCount === 0` branch.
+ *
+ * Passing null unsets the flag (used by tests or a future "unblock channel"
+ * admin command).
+ */
+export function setMessagingGroupDeniedAt(id: string, deniedAt: string | null): void {
+  getDb().prepare('UPDATE messaging_groups SET denied_at = ? WHERE id = ?').run(deniedAt, id);
+}
+
 // ── Messaging Group Agents ──
 
 /**
diff --git a/src/db/migrations/012-channel-registration.ts b/src/db/migrations/012-channel-registration.ts
new file mode 100644
index 0000000..eca8911
--- /dev/null
+++ b/src/db/migrations/012-channel-registration.ts
@@ -0,0 +1,48 @@
+/**
+ * Unknown-channel registration flow.
+ *
+ * When a channel that isn't wired to any agent group receives a mention or
+ * DM, the router escalates to the owner for approval before wiring. Approve
+ * creates a `messaging_group_agents` row (with conservative defaults) and
+ * replays the triggering event. Deny marks the channel denied forever
+ * (stored as a timestamp on `messaging_groups.denied_at`) so future
+ * messages on that channel drop silently without re-prompting.
+ *
+ * Two changes:
+ *   1. `messaging_groups.denied_at TEXT NULL` — set on deny, checked in the
+ *      router before re-escalating. ALTER TABLE ADD COLUMN is FK-safe
+ *      unlike the table rebuild that bit us in migration 011.
+ *   2. `pending_channel_approvals` table. PRIMARY KEY on
+ *      `messaging_group_id` gives free in-flight dedup — a second mention
+ *      while the card is pending is silently dropped by INSERT OR IGNORE,
+ *      preventing card spam.
+ */
+import type Database from 'better-sqlite3';
+import type { Migration } from './index.js';
+
+export const migration012: Migration = {
+  version: 12,
+  name: 'channel-registration',
+  up: (db: Database.Database) => {
+    // 1. Add denied_at to messaging_groups. Idempotent guard in case the
+    //    column was added by some other path before this migration ran.
+    const cols = db.prepare("PRAGMA table_info('messaging_groups')").all() as Array<{ name: string }>;
+    if (!cols.some((c) => c.name === 'denied_at')) {
+      db.exec(`ALTER TABLE messaging_groups ADD COLUMN denied_at TEXT`);
+    }
+
+    // 2. pending_channel_approvals.
+    db.exec(`
+      CREATE TABLE IF NOT EXISTS pending_channel_approvals (
+        messaging_group_id   TEXT PRIMARY KEY REFERENCES messaging_groups(id),
+        agent_group_id       TEXT NOT NULL REFERENCES agent_groups(id),
+                             -- The agent the approved wiring will target.
+                             -- Picked at request time (currently: earliest
+                             -- agent_group by created_at).
+        original_message     TEXT NOT NULL,      -- JSON serialized InboundEvent
+        approver_user_id     TEXT NOT NULL,
+        created_at           TEXT NOT NULL
+      );
+    `);
+  },
+};
diff --git a/src/db/migrations/index.ts b/src/db/migrations/index.ts
index 1015f40..33e6963 100644
--- a/src/db/migrations/index.ts
+++ b/src/db/migrations/index.ts
@@ -8,6 +8,7 @@ import { migration008 } from './008-dropped-messages.js';
 import { migration009 } from './009-drop-pending-credentials.js';
 import { migration010 } from './010-engage-modes.js';
 import { migration011 } from './011-pending-sender-approvals.js';
+import { migration012 } from './012-channel-registration.js';
 import { moduleApprovalsPendingApprovals } from './module-approvals-pending-approvals.js';
 import { moduleApprovalsTitleOptions } from './module-approvals-title-options.js';
 
@@ -27,6 +28,7 @@ const migrations: Migration[] = [
   migration009,
   migration010,
   migration011,
+  migration012,
 ];
 
 export function runMigrations(db: Database.Database): void {
diff --git a/src/modules/permissions/channel-approval.test.ts b/src/modules/permissions/channel-approval.test.ts
new file mode 100644
index 0000000..f3ea7e9
--- /dev/null
+++ b/src/modules/permissions/channel-approval.test.ts
@@ -0,0 +1,392 @@
+/**
+ * Integration tests for the unknown-channel registration flow (ACTION-ITEMS
+ * item 22).
+ *
+ * Covers:
+ *  - Mention on an unwired channel fires an owner-approval card
+ *  - DM on an unwired channel fires a card (engage_mode will default to pattern='.')
+ *  - In-flight dedup: second mention while a card is pending doesn't spam
+ *  - Approve: wiring created with correct defaults, triggering sender added
+ *    as member, replay wakes the container
+ *  - Deny: messaging_groups.denied_at set, future mentions drop silently
+ *  - Unauthorized clicker is rejected (same pattern as sender-approval)
+ *  - No-owner install: no card, no row
+ *  - No agent groups configured: no card, no row
+ */
+import fs from 'fs';
+import { beforeEach, afterEach, describe, expect, it, vi } from 'vitest';
+
+import { initTestDb, closeDb, runMigrations } from '../../db/index.js';
+import { createAgentGroup } from '../../db/agent-groups.js';
+import { createMessagingGroup, getMessagingGroupByPlatform } from '../../db/messaging-groups.js';
+import { upsertUser } from './db/users.js';
+import { grantRole } from './db/user-roles.js';
+
+// Mock container runner — prevent actual docker spawn.
+vi.mock('../../container-runner.js', () => ({
+  wakeContainer: vi.fn().mockResolvedValue(undefined),
+  isContainerRunning: vi.fn().mockReturnValue(false),
+  getActiveContainerCount: vi.fn().mockReturnValue(0),
+  killContainer: vi.fn(),
+}));
+
+// Mock delivery adapter.
+const deliverMock = vi.fn().mockResolvedValue('plat-msg-id');
+vi.mock('../../delivery.js', () => ({
+  getDeliveryAdapter: () => ({ deliver: deliverMock }),
+}));
+
+// Mock ensureUserDm — look up the owner's preconfigured DM row instead of
+// hitting a real openDM RPC.
+vi.mock('./user-dm.js', () => ({
+  ensureUserDm: vi.fn(async (userId: string) => {
+    const { getDb } = await import('../../db/connection.js');
+    const row = getDb()
+      .prepare(
+        `SELECT mg.* FROM messaging_groups mg
+           JOIN user_dms ud ON ud.messaging_group_id = mg.id
+          WHERE ud.user_id = ?`,
+      )
+      .get(userId);
+    return row;
+  }),
+}));
+
+vi.mock('../../config.js', async () => {
+  const actual = await vi.importActual('../../config.js');
+  return { ...actual, DATA_DIR: '/tmp/nanoclaw-test-channel-approval' };
+});
+
+const TEST_DIR = '/tmp/nanoclaw-test-channel-approval';
+
+function now() {
+  return new Date().toISOString();
+}
+
+beforeEach(async () => {
+  if (fs.existsSync(TEST_DIR)) fs.rmSync(TEST_DIR, { recursive: true });
+  fs.mkdirSync(TEST_DIR, { recursive: true });
+  const db = initTestDb();
+  runMigrations(db);
+
+  await import('./index.js'); // register hooks
+
+  // Base fixtures: one agent group + owner with a DM on 'telegram'.
+  createAgentGroup({ id: 'ag-1', name: 'Andy', folder: 'andy', agent_provider: null, created_at: now() });
+
+  upsertUser({ id: 'telegram:owner', kind: 'telegram', display_name: 'Owner', created_at: now() });
+  grantRole({
+    user_id: 'telegram:owner',
+    role: 'owner',
+    agent_group_id: null,
+    granted_by: null,
+    granted_at: now(),
+  });
+
+  // Pre-seed owner's DM messaging group + user_dms mapping.
+  createMessagingGroup({
+    id: 'mg-dm-owner',
+    channel_type: 'telegram',
+    platform_id: 'dm-owner',
+    name: 'Owner DM',
+    is_group: 0,
+    unknown_sender_policy: 'public',
+    created_at: now(),
+  });
+  const { getDb } = await import('../../db/connection.js');
+  getDb()
+    .prepare(
+      `INSERT INTO user_dms (user_id, channel_type, messaging_group_id, resolved_at)
+       VALUES (?, ?, ?, ?)`,
+    )
+    .run('telegram:owner', 'telegram', 'mg-dm-owner', now());
+
+  deliverMock.mockClear();
+});
+
+afterEach(() => {
+  closeDb();
+  if (fs.existsSync(TEST_DIR)) fs.rmSync(TEST_DIR, { recursive: true });
+});
+
+function groupMention(platformId: string, text = '@bot hello') {
+  return {
+    channelType: 'telegram',
+    platformId,
+    threadId: 'thread-1', // non-null → is_group=true per channel-approval default-picker logic
+    message: {
+      id: `msg-${Math.random().toString(36).slice(2, 8)}`,
+      kind: 'chat' as const,
+      content: JSON.stringify({ senderId: 'caller', senderName: 'Caller', text }),
+      timestamp: now(),
+      isMention: true,
+    },
+  };
+}
+
+function dmEvent(platformId: string, text = 'hello') {
+  return {
+    channelType: 'telegram',
+    platformId,
+    threadId: null,
+    message: {
+      id: `msg-${Math.random().toString(36).slice(2, 8)}`,
+      kind: 'chat' as const,
+      content: JSON.stringify({ senderId: 'stranger', senderName: 'Stranger', text }),
+      timestamp: now(),
+      isMention: true, // DM bridge sets isMention=true
+    },
+  };
+}
+
+describe('unknown-channel registration flow', () => {
+  it('delivers an approval card on mention into an unwired group', async () => {
+    const { routeInbound } = await import('../../router.js');
+    await routeInbound(groupMention('chat-new'));
+    await new Promise((r) => setTimeout(r, 10));
+
+    expect(deliverMock).toHaveBeenCalledTimes(1);
+    const [channel, platformId, thread, kind, content] = deliverMock.mock.calls[0];
+    expect(channel).toBe('telegram');
+    expect(platformId).toBe('dm-owner'); // delivered to owner's DM
+    expect(thread).toBeNull();
+    expect(kind).toBe('chat-sdk');
+    const payload = JSON.parse(content as string);
+    expect(payload.type).toBe('ask_question');
+    // Card names the target agent so the owner knows what they're wiring to.
+    expect(payload.question).toContain('Andy');
+
+    const { getDb } = await import('../../db/connection.js');
+    const rows = getDb().prepare('SELECT * FROM pending_channel_approvals').all() as Array<{
+      messaging_group_id: string;
+    }>;
+    expect(rows).toHaveLength(1);
+  });
+
+  it('delivers a card on DM too (non-threaded event)', async () => {
+    const { routeInbound } = await import('../../router.js');
+    await routeInbound(dmEvent('dm-new-user'));
+    await new Promise((r) => setTimeout(r, 10));
+
+    expect(deliverMock).toHaveBeenCalledTimes(1);
+    const { getDb } = await import('../../db/connection.js');
+    const count = (getDb().prepare('SELECT COUNT(*) AS c FROM pending_channel_approvals').get() as { c: number }).c;
+    expect(count).toBe(1);
+  });
+
+  it('dedups a second mention while the card is pending', async () => {
+    const { routeInbound } = await import('../../router.js');
+    await routeInbound(groupMention('chat-busy'));
+    await new Promise((r) => setTimeout(r, 10));
+    await routeInbound(groupMention('chat-busy', '@bot still here'));
+    await new Promise((r) => setTimeout(r, 10));
+
+    expect(deliverMock).toHaveBeenCalledTimes(1);
+    const { getDb } = await import('../../db/connection.js');
+    const count = (getDb().prepare('SELECT COUNT(*) AS c FROM pending_channel_approvals').get() as { c: number }).c;
+    expect(count).toBe(1);
+  });
+
+  it('approve → creates wiring, admits triggering sender, replays', async () => {
+    const { routeInbound } = await import('../../router.js');
+    const { getResponseHandlers } = await import('../../response-registry.js');
+    const { wakeContainer } = await import('../../container-runner.js');
+    (wakeContainer as unknown as ReturnType<typeof vi.fn>).mockClear();
+
+    await routeInbound(groupMention('chat-approve'));
+    await new Promise((r) => setTimeout(r, 10));
+
+    const { getDb } = await import('../../db/connection.js');
+    const pending = getDb()
+      .prepare('SELECT messaging_group_id FROM pending_channel_approvals')
+      .get() as { messaging_group_id: string };
+    expect(pending).toBeDefined();
+
+    // Owner clicks approve.
+    for (const handler of getResponseHandlers()) {
+      const claimed = await handler({
+        questionId: pending.messaging_group_id,
+        value: 'approve',
+        userId: 'owner', // raw platform id — handler namespaces it
+        channelType: 'telegram',
+        platformId: 'dm-owner',
+        threadId: null,
+      });
+      if (claimed) break;
+    }
+
+    // Wiring created with MVP defaults.
+    const mga = getDb()
+      .prepare('SELECT * FROM messaging_group_agents WHERE messaging_group_id = ?')
+      .get(pending.messaging_group_id) as {
+      engage_mode: string;
+      engage_pattern: string | null;
+      sender_scope: string;
+      ignored_message_policy: string;
+      agent_group_id: string;
+    };
+    expect(mga).toBeDefined();
+    expect(mga.engage_mode).toBe('mention-sticky'); // group (threadId != null)
+    expect(mga.engage_pattern).toBeNull();
+    expect(mga.sender_scope).toBe('known');
+    expect(mga.ignored_message_policy).toBe('accumulate');
+    expect(mga.agent_group_id).toBe('ag-1');
+
+    // Triggering sender auto-admitted so sender_scope='known' doesn't
+    // bounce the replay into sender-approval.
+    const member = getDb()
+      .prepare('SELECT 1 AS x FROM agent_group_members WHERE user_id = ? AND agent_group_id = ?')
+      .get('telegram:caller', 'ag-1');
+    expect(member).toBeDefined();
+
+    // Pending row cleared and container woken via replay.
+    const stillPending = (
+      getDb().prepare('SELECT COUNT(*) AS c FROM pending_channel_approvals').get() as { c: number }
+    ).c;
+    expect(stillPending).toBe(0);
+    expect(wakeContainer).toHaveBeenCalled();
+  });
+
+  it('approve on a DM wires with pattern="." defaults', async () => {
+    const { routeInbound } = await import('../../router.js');
+    const { getResponseHandlers } = await import('../../response-registry.js');
+
+    await routeInbound(dmEvent('dm-approve-user'));
+    await new Promise((r) => setTimeout(r, 10));
+
+    const { getDb } = await import('../../db/connection.js');
+    const pending = getDb()
+      .prepare('SELECT messaging_group_id FROM pending_channel_approvals')
+      .get() as { messaging_group_id: string };
+
+    for (const handler of getResponseHandlers()) {
+      const claimed = await handler({
+        questionId: pending.messaging_group_id,
+        value: 'approve',
+        userId: 'owner',
+        channelType: 'telegram',
+        platformId: 'dm-owner',
+        threadId: null,
+      });
+      if (claimed) break;
+    }
+
+    const mga = getDb()
+      .prepare('SELECT engage_mode, engage_pattern FROM messaging_group_agents WHERE messaging_group_id = ?')
+      .get(pending.messaging_group_id) as { engage_mode: string; engage_pattern: string };
+    expect(mga.engage_mode).toBe('pattern');
+    expect(mga.engage_pattern).toBe('.');
+  });
+
+  it('deny → sets denied_at; future mentions drop silently without a second card', async () => {
+    const { routeInbound } = await import('../../router.js');
+    const { getResponseHandlers } = await import('../../response-registry.js');
+
+    await routeInbound(groupMention('chat-deny'));
+    await new Promise((r) => setTimeout(r, 10));
+    const { getDb } = await import('../../db/connection.js');
+    const pending = getDb()
+      .prepare('SELECT messaging_group_id FROM pending_channel_approvals')
+      .get() as { messaging_group_id: string };
+
+    for (const handler of getResponseHandlers()) {
+      const claimed = await handler({
+        questionId: pending.messaging_group_id,
+        value: 'reject',
+        userId: 'owner',
+        channelType: 'telegram',
+        platformId: 'dm-owner',
+        threadId: null,
+      });
+      if (claimed) break;
+    }
+
+    // denied_at set, pending row cleared, no wiring.
+    const mg = getMessagingGroupByPlatform('telegram', 'chat-deny');
+    expect(mg?.denied_at).not.toBeNull();
+    expect(mg?.denied_at).toBeTruthy();
+    const mgaCount = (
+      getDb()
+        .prepare('SELECT COUNT(*) AS c FROM messaging_group_agents WHERE messaging_group_id = ?')
+        .get(pending.messaging_group_id) as { c: number }
+    ).c;
+    expect(mgaCount).toBe(0);
+
+    // A follow-up mention on the denied channel: no new card, no new pending row.
+    deliverMock.mockClear();
+    await routeInbound(groupMention('chat-deny', '@bot please'));
+    await new Promise((r) => setTimeout(r, 10));
+    expect(deliverMock).not.toHaveBeenCalled();
+    const stillPending = (
+      getDb().prepare('SELECT COUNT(*) AS c FROM pending_channel_approvals').get() as { c: number }
+    ).c;
+    expect(stillPending).toBe(0);
+  });
+
+  it('rejects clicks from an unauthorized user (prevents self-admit via forwarded card)', async () => {
+    const { routeInbound } = await import('../../router.js');
+    const { getResponseHandlers } = await import('../../response-registry.js');
+
+    await routeInbound(groupMention('chat-unauth'));
+    await new Promise((r) => setTimeout(r, 10));
+    const { getDb } = await import('../../db/connection.js');
+    const pending = getDb()
+      .prepare('SELECT messaging_group_id FROM pending_channel_approvals')
+      .get() as { messaging_group_id: string };
+
+    for (const handler of getResponseHandlers()) {
+      const claimed = await handler({
+        questionId: pending.messaging_group_id,
+        value: 'approve',
+        userId: 'random-bystander',
+        channelType: 'telegram',
+        platformId: 'dm-random',
+        threadId: null,
+      });
+      if (claimed) break;
+    }
+
+    // No wiring created, pending row preserved so a real approver can act on it.
+    const mgaCount = (
+      getDb()
+        .prepare('SELECT COUNT(*) AS c FROM messaging_group_agents WHERE messaging_group_id = ?')
+        .get(pending.messaging_group_id) as { c: number }
+    ).c;
+    expect(mgaCount).toBe(0);
+    const stillPending = (
+      getDb().prepare('SELECT COUNT(*) AS c FROM pending_channel_approvals').get() as { c: number }
+    ).c;
+    expect(stillPending).toBe(1);
+  });
+});
+
+describe('no-owner / no-agent failure modes', () => {
+  it('no owner → no card, no pending row (fresh-install bootstrap path)', async () => {
+    // Wipe the owner grant set up in the outer beforeEach.
+    const { getDb } = await import('../../db/connection.js');
+    getDb().prepare('DELETE FROM user_roles').run();
+
+    const { routeInbound } = await import('../../router.js');
+    await routeInbound(groupMention('chat-noowner'));
+    await new Promise((r) => setTimeout(r, 10));
+
+    expect(deliverMock).not.toHaveBeenCalled();
+    const count = (getDb().prepare('SELECT COUNT(*) AS c FROM pending_channel_approvals').get() as { c: number }).c;
+    expect(count).toBe(0);
+  });
+
+  it('no agent groups → no card, no pending row', async () => {
+    const { getDb } = await import('../../db/connection.js');
+    // Drop foreign-key-dependent rows first, then the agent group itself.
+    getDb().prepare('DELETE FROM user_roles').run();
+    getDb().prepare('DELETE FROM agent_groups').run();
+
+    const { routeInbound } = await import('../../router.js');
+    await routeInbound(groupMention('chat-noagent'));
+    await new Promise((r) => setTimeout(r, 10));
+
+    expect(deliverMock).not.toHaveBeenCalled();
+    const count = (getDb().prepare('SELECT COUNT(*) AS c FROM pending_channel_approvals').get() as { c: number }).c;
+    expect(count).toBe(0);
+  });
+});
diff --git a/src/modules/permissions/channel-approval.ts b/src/modules/permissions/channel-approval.ts
new file mode 100644
index 0000000..9c65f8e
--- /dev/null
+++ b/src/modules/permissions/channel-approval.ts
@@ -0,0 +1,159 @@
+/**
+ * Unknown-channel registration flow.
+ *
+ * When the router hits an unwired messaging group AND the message was
+ * addressed to the bot (SDK-confirmed mention or DM), it calls
+ * `requestChannelApproval` instead of silently dropping. The flow:
+ *
+ *   1. Pick the target agent group we'd wire to (MVP: first by name).
+ *      Multi-agent picker is a follow-up — see ACTION-ITEMS.
+ *   2. Pick an eligible approver (owner / admin) and a reachable DM for
+ *      them, reusing the same primitives the sender-approval flow uses.
+ *   3. Deliver an Approve / Ignore card that names the target agent
+ *      explicitly so the owner knows what they're wiring to.
+ *   4. Record a `pending_channel_approvals` row holding the original event
+ *      so it can be re-routed on approve.
+ *
+ * On approve (handler in index.ts):
+ *   - Create `messaging_group_agents` with MVP defaults
+ *     (mention-sticky for groups / pattern='.' for DMs,
+ *      sender_scope='known', ignored_message_policy='accumulate')
+ *   - Add the triggering sender to `agent_group_members` so sender_scope
+ *     doesn't bounce the replayed message into a sender-approval cascade
+ *   - Delete the pending row, replay the original event
+ *
+ * On ignore:
+ *   - Set `messaging_groups.denied_at = now()` so the router stops
+ *     escalating on this channel until an admin explicitly re-wires
+ *   - Delete the pending row
+ *
+ * Dedup: `pending_channel_approvals` PK on messaging_group_id. Second
+ * mention while pending silently dropped.
+ *
+ * Failure modes (log + no row, so a future attempt can try again):
+ *   - No agent groups exist (install never set up a first agent).
+ *   - No eligible approver in user_roles (no owner yet).
+ *   - Approver has no reachable DM.
+ *   - Delivery adapter missing.
+ */
+import { normalizeOptions, type RawOption } from '../../channels/ask-question.js';
+import { getAllAgentGroups } from '../../db/agent-groups.js';
+import { getMessagingGroup } from '../../db/messaging-groups.js';
+import { getDeliveryAdapter } from '../../delivery.js';
+import { log } from '../../log.js';
+import type { InboundEvent } from '../../router.js';
+import { pickApprovalDelivery, pickApprover } from '../approvals/primitive.js';
+import { createPendingChannelApproval, hasInFlightChannelApproval } from './db/pending-channel-approvals.js';
+
+const APPROVAL_OPTIONS: RawOption[] = [
+  { label: 'Approve', selectedLabel: '✅ Wired', value: 'approve' },
+  { label: 'Ignore', selectedLabel: '🙅 Ignored', value: 'reject' },
+];
+
+export interface RequestChannelApprovalInput {
+  messagingGroupId: string;
+  event: InboundEvent;
+}
+
+export async function requestChannelApproval(input: RequestChannelApprovalInput): Promise<void> {
+  const { messagingGroupId, event } = input;
+
+  // In-flight dedup: don't spam the owner if the same unwired channel
+  // gets more mentions / DMs while a card is already pending.
+  if (hasInFlightChannelApproval(messagingGroupId)) {
+    log.debug('Channel registration already in flight — dropping retry', {
+      messagingGroupId,
+    });
+    return;
+  }
+
+  // MVP: pick the first agent group by name. Multi-agent systems will get
+  // a richer card later (user picks the target from a list).
+  const agentGroups = getAllAgentGroups();
+  if (agentGroups.length === 0) {
+    log.warn('Channel registration skipped — no agent groups configured. Run /init-first-agent.', {
+      messagingGroupId,
+    });
+    return;
+  }
+  const target = agentGroups[0];
+
+  // pickApprover takes the target agent group's id — gets scoped admins +
+  // global admins + owners. For fresh installs with only an owner, the
+  // owner is returned.
+  const approvers = pickApprover(target.id);
+  if (approvers.length === 0) {
+    log.warn('Channel registration skipped — no owner or admin configured', {
+      messagingGroupId,
+      targetAgentGroupId: target.id,
+    });
+    return;
+  }
+
+  const originMg = getMessagingGroup(messagingGroupId);
+  const originChannelType = originMg?.channel_type ?? '';
+  const delivery = await pickApprovalDelivery(approvers, originChannelType);
+  if (!delivery) {
+    log.warn('Channel registration skipped — no DM channel for any approver', {
+      messagingGroupId,
+      targetAgentGroupId: target.id,
+    });
+    return;
+  }
+
+  const originName = originMg?.name ?? originMg?.platform_id ?? 'an unfamiliar chat';
+  const isGroup = originMg?.is_group === 1;
+
+  const title = isGroup ? '📣 Bot mentioned in new chat' : '💬 New direct message';
+  const question = isGroup
+    ? `Your agent was mentioned in ${originName} on ${originChannelType}. Wire it to ${target.name} and let it engage?`
+    : `Someone DM'd your agent on ${originChannelType} (${originName}). Wire it to ${target.name} and let it respond?`;
+
+  createPendingChannelApproval({
+    messaging_group_id: messagingGroupId,
+    agent_group_id: target.id,
+    original_message: JSON.stringify(event),
+    approver_user_id: delivery.userId,
+    created_at: new Date().toISOString(),
+  });
+
+  const adapter = getDeliveryAdapter();
+  if (!adapter) {
+    log.error('Channel registration row created but no delivery adapter is wired', {
+      messagingGroupId,
+    });
+    return;
+  }
+
+  try {
+    await adapter.deliver(
+      delivery.messagingGroup.channel_type,
+      delivery.messagingGroup.platform_id,
+      null,
+      'chat-sdk',
+      JSON.stringify({
+        type: 'ask_question',
+        // Use messaging_group_id as the questionId — it's unique per card
+        // (PK on pending table dedups) and lets the response handler look
+        // up the pending row directly without another index.
+        questionId: messagingGroupId,
+        title,
+        question,
+        options: normalizeOptions(APPROVAL_OPTIONS),
+      }),
+    );
+    log.info('Channel registration card delivered', {
+      messagingGroupId,
+      targetAgentGroupId: target.id,
+      approver: delivery.userId,
+    });
+  } catch (err) {
+    log.error('Channel registration card delivery failed', {
+      messagingGroupId,
+      err,
+    });
+  }
+}
+
+export const APPROVE_VALUE = 'approve';
+export const REJECT_VALUE = 'reject';
diff --git a/src/modules/permissions/db/pending-channel-approvals.ts b/src/modules/permissions/db/pending-channel-approvals.ts
new file mode 100644
index 0000000..d3e665a
--- /dev/null
+++ b/src/modules/permissions/db/pending-channel-approvals.ts
@@ -0,0 +1,52 @@
+/**
+ * CRUD for pending_channel_approvals — the in-flight state for the
+ * unknown-channel registration flow. A row exists while an owner-approval
+ * card is outstanding; it's deleted on approve (after wiring is created)
+ * or deny (after denied_at is set on the messaging_group).
+ *
+ * PRIMARY KEY on messaging_group_id gives free in-flight dedup. A second
+ * mention/DM while a card is pending resolves via
+ * `hasInFlightChannelApproval` in the request flow and drops silently
+ * instead of spamming the owner.
+ */
+import { getDb } from '../../../db/connection.js';
+
+export interface PendingChannelApproval {
+  messaging_group_id: string;
+  agent_group_id: string;
+  original_message: string;
+  approver_user_id: string;
+  created_at: string;
+}
+
+export function createPendingChannelApproval(row: PendingChannelApproval): void {
+  getDb()
+    .prepare(
+      `INSERT INTO pending_channel_approvals (
+         messaging_group_id, agent_group_id, original_message,
+         approver_user_id, created_at
+       )
+       VALUES (
+         @messaging_group_id, @agent_group_id, @original_message,
+         @approver_user_id, @created_at
+       )`,
+    )
+    .run(row);
+}
+
+export function getPendingChannelApproval(messagingGroupId: string): PendingChannelApproval | undefined {
+  return getDb()
+    .prepare('SELECT * FROM pending_channel_approvals WHERE messaging_group_id = ?')
+    .get(messagingGroupId) as PendingChannelApproval | undefined;
+}
+
+export function hasInFlightChannelApproval(messagingGroupId: string): boolean {
+  const row = getDb()
+    .prepare('SELECT 1 AS x FROM pending_channel_approvals WHERE messaging_group_id = ?')
+    .get(messagingGroupId) as { x: number } | undefined;
+  return row !== undefined;
+}
+
+export function deletePendingChannelApproval(messagingGroupId: string): void {
+  getDb().prepare('DELETE FROM pending_channel_approvals WHERE messaging_group_id = ?').run(messagingGroupId);
+}
diff --git a/src/modules/permissions/index.ts b/src/modules/permissions/index.ts
index d13797b..e2f100c 100644
--- a/src/modules/permissions/index.ts
+++ b/src/modules/permissions/index.ts
@@ -16,9 +16,14 @@
  * access gate is not registered and core defaults to allow-all.
  */
 import { recordDroppedMessage } from '../../db/dropped-messages.js';
+import {
+  createMessagingGroupAgent,
+  setMessagingGroupDeniedAt,
+} from '../../db/messaging-groups.js';
 import {
   routeInbound,
   setAccessGate,
+  setChannelRequestGate,
   setSenderResolver,
   setSenderScopeGate,
   type AccessGateResult,
@@ -28,7 +33,12 @@ import { registerResponseHandler, type ResponsePayload } from '../../response-re
 import { log } from '../../log.js';
 import type { MessagingGroup, MessagingGroupAgent } from '../../types.js';
 import { canAccessAgentGroup } from './access.js';
+import { requestChannelApproval } from './channel-approval.js';
 import { addMember } from './db/agent-group-members.js';
+import {
+  deletePendingChannelApproval,
+  getPendingChannelApproval,
+} from './db/pending-channel-approvals.js';
 import { deletePendingSenderApproval, getPendingSenderApproval } from './db/pending-sender-approvals.js';
 import { hasAdminPrivilege } from './db/user-roles.js';
 import { getUser, upsertUser } from './db/users.js';
@@ -253,3 +263,137 @@ async function handleSenderApprovalResponse(payload: ResponsePayload): Promise<b
 }
 
 registerResponseHandler(handleSenderApprovalResponse);
+
+// ── Unknown-channel registration flow ──
+
+setChannelRequestGate(async (mg, event) => {
+  await requestChannelApproval({ messagingGroupId: mg.id, event });
+});
+
+/**
+ * Response handler for the unknown-channel registration card.
+ *
+ * Claim rule: questionId matches a pending_channel_approvals row (keyed
+ * by messaging_group_id). If no such row, return false so downstream
+ * handlers get a shot.
+ *
+ * Approve: create the wiring with MVP defaults (mention-sticky for
+ * groups / pattern='.' for DMs; sender_scope='known';
+ * ignored_message_policy='accumulate'), add the triggering sender as a
+ * member so sender_scope doesn't immediately bounce them into a
+ * sender-approval card, then replay the original event.
+ *
+ * Deny: set `messaging_groups.denied_at = now()` so future mentions on
+ * this channel drop silently until an admin explicitly wires it.
+ */
+async function handleChannelApprovalResponse(payload: ResponsePayload): Promise<boolean> {
+  const row = getPendingChannelApproval(payload.questionId);
+  if (!row) return false;
+
+  // Click-auth: same pattern as sender-approval (see commit 68058cb).
+  // Raw platform userId → namespace with channelType → must match the
+  // designated approver OR have admin privilege over the target agent.
+  const clickerId = payload.userId ? `${payload.channelType}:${payload.userId}` : null;
+  const isAuthorized =
+    clickerId !== null && (clickerId === row.approver_user_id || hasAdminPrivilege(clickerId, row.agent_group_id));
+  if (!isAuthorized) {
+    log.warn('Channel registration click rejected — unauthorized clicker', {
+      messagingGroupId: row.messaging_group_id,
+      clickerId,
+      expectedApprover: row.approver_user_id,
+    });
+    return true; // claim but take no action
+  }
+  const approverId = clickerId;
+  const approved = payload.value === 'approve';
+
+  if (!approved) {
+    setMessagingGroupDeniedAt(row.messaging_group_id, new Date().toISOString());
+    deletePendingChannelApproval(row.messaging_group_id);
+    log.info('Channel registration denied', {
+      messagingGroupId: row.messaging_group_id,
+      agentGroupId: row.agent_group_id,
+      approverId,
+    });
+    return true;
+  }
+
+  // Rehydrate the original event to know (a) whether it was a DM or group
+  // (chooses engage_mode default), and (b) who the triggering sender was
+  // (auto-member-add so sender_scope='known' doesn't bounce the replay).
+  let event: InboundEvent;
+  try {
+    event = JSON.parse(row.original_message) as InboundEvent;
+  } catch (err) {
+    log.error('Channel registration: failed to parse stored event', {
+      messagingGroupId: row.messaging_group_id,
+      err,
+    });
+    deletePendingChannelApproval(row.messaging_group_id);
+    return true;
+  }
+
+  // Decide engage_mode from the original event. DMs (`isMention=true` &
+  // not in a group) get `pattern='.'` (always respond). Group mentions
+  // get `mention-sticky` (respond now + follow the thread).
+  //
+  // We can't read `mg.is_group` reliably here because we only auto-create
+  // the mg with `is_group=0` on first sight — the adapter hasn't told us
+  // yet whether it's actually a group. Fall back to the InboundEvent's
+  // `threadId`: a non-null threadId implies a threaded platform (Slack
+  // channel thread, Discord thread), which we treat as a group.
+  const isGroup = event.threadId !== null;
+  const engageMode: MessagingGroupAgent['engage_mode'] = isGroup ? 'mention-sticky' : 'pattern';
+  const engagePattern = isGroup ? null : '.';
+
+  const mgaId = `mga-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
+  createMessagingGroupAgent({
+    id: mgaId,
+    messaging_group_id: row.messaging_group_id,
+    agent_group_id: row.agent_group_id,
+    engage_mode: engageMode,
+    engage_pattern: engagePattern,
+    sender_scope: 'known',
+    ignored_message_policy: 'accumulate',
+    session_mode: 'shared',
+    priority: 0,
+    created_at: new Date().toISOString(),
+  });
+  log.info('Channel registration approved — wiring created', {
+    messagingGroupId: row.messaging_group_id,
+    agentGroupId: row.agent_group_id,
+    mgaId,
+    engageMode,
+    approverId,
+  });
+
+  // Auto-admit the triggering sender. Without this, the replay below
+  // would bounce through sender-approval (sender_scope='known' +
+  // sender-is-not-a-member).
+  const senderUserId = extractAndUpsertUser(event);
+  if (senderUserId) {
+    addMember({
+      user_id: senderUserId,
+      agent_group_id: row.agent_group_id,
+      added_by: approverId,
+      added_at: new Date().toISOString(),
+    });
+  }
+
+  // Clear the pending row BEFORE replay so the gate check on the second
+  // attempt sees a wired channel (agentCount > 0) and takes the fan-out
+  // path normally.
+  deletePendingChannelApproval(row.messaging_group_id);
+
+  try {
+    await routeInbound(event);
+  } catch (err) {
+    log.error('Failed to replay message after channel approval', {
+      messagingGroupId: row.messaging_group_id,
+      err,
+    });
+  }
+  return true;
+}
+
+registerResponseHandler(handleChannelApprovalResponse);
diff --git a/src/router.ts b/src/router.ts
index 1d819c0..4289f1f 100644
--- a/src/router.ts
+++ b/src/router.ts
@@ -127,6 +127,27 @@ export function setSenderScopeGate(fn: SenderScopeGateFn): void {
   senderScopeGate = fn;
 }
 
+/**
+ * Channel-registration hook. Runs when the router sees a mention/DM on a
+ * messaging group that has no wirings AND hasn't been denied. The hook is
+ * expected to escalate to an owner (card, etc.) and arrange for future
+ * replay via routeInbound after approval. Fire-and-forget from the
+ * router's perspective.
+ *
+ * Registered by the permissions module. Without the module the router
+ * silently records the drop with reason='no_agent_wired' and moves on.
+ */
+export type ChannelRequestGateFn = (mg: MessagingGroup, event: InboundEvent) => Promise<void>;
+
+let channelRequestGate: ChannelRequestGateFn | null = null;
+
+export function setChannelRequestGate(fn: ChannelRequestGateFn): void {
+  if (channelRequestGate) {
+    log.warn('Channel-request gate overwritten');
+  }
+  channelRequestGate = fn;
+}
+
 function safeParseContent(raw: string): { text?: string; sender?: string; senderId?: string } {
   try {
     return JSON.parse(raw);
@@ -156,12 +177,12 @@ export async function routeInbound(event: InboundEvent): Promise<void> {
   const found = getMessagingGroupWithAgentCount(event.channelType, event.platformId);
 
   let mg: MessagingGroup;
+  let agentCount: number;
   if (!found) {
     // No messaging_groups row. Auto-create only when the message warrants
     // attention (the bot was addressed — @mention or DM). Plain chatter in
     // channels we merely sit in stays silent — no row, no DB writes.
     if (!isMention) return;
-
     const mgId = `mg-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
     mg = {
       id: mgId,
@@ -170,6 +191,7 @@ export async function routeInbound(event: InboundEvent): Promise<void> {
       name: null,
       is_group: 0,
       unknown_sender_policy: 'request_approval',
+      denied_at: null,
       created_at: new Date().toISOString(),
     };
     createMessagingGroup(mg);
@@ -178,30 +200,51 @@ export async function routeInbound(event: InboundEvent): Promise<void> {
       channelType: event.channelType,
       platformId: event.platformId,
     });
+    agentCount = 0;
   } else {
     mg = found.mg;
-    if (found.agentCount === 0) {
-      // Messaging group exists but has no wirings. Stay silent for plain
-      // messages; only log + record on explicit mention/DM so admins can
-      // see that someone tried to reach the bot on an unwired channel.
-      if (!isMention) return;
-      log.warn('MESSAGE DROPPED — no agent groups wired to this channel. Run setup register step to configure.', {
+    agentCount = found.agentCount;
+  }
+
+  // 1b. No wirings — either silent drop (plain chatter / denied channel) or
+  //     escalate to owner for channel-registration approval.
+  if (agentCount === 0) {
+    if (!isMention) return;
+    if (mg.denied_at) {
+      log.debug('Message dropped — channel was denied by owner', {
+        messagingGroupId: mg.id,
+        deniedAt: mg.denied_at,
+      });
+      return;
+    }
+
+    const parsed = safeParseContent(event.message.content);
+    recordDroppedMessage({
+      channel_type: event.channelType,
+      platform_id: event.platformId,
+      user_id: null,
+      sender_name: parsed.sender ?? null,
+      reason: 'no_agent_wired',
+      messaging_group_id: mg.id,
+      agent_group_id: null,
+    });
+
+    if (channelRequestGate) {
+      // Fire-and-forget escalation. The gate is expected to build a card,
+      // persist pending_channel_approvals, and replay the event via
+      // routeInbound after approval. Errors are logged internally — the
+      // user's message still stays dropped here either way.
+      void channelRequestGate(mg, event).catch((err) =>
+        log.error('Channel-request gate threw', { messagingGroupId: mg.id, err }),
+      );
+    } else {
+      log.warn('MESSAGE DROPPED — no agent groups wired and no channel-request gate registered', {
         messagingGroupId: mg.id,
         channelType: event.channelType,
         platformId: event.platformId,
       });
-      const parsed = safeParseContent(event.message.content);
-      recordDroppedMessage({
-        channel_type: event.channelType,
-        platform_id: event.platformId,
-        user_id: null,
-        sender_name: parsed.sender ?? null,
-        reason: 'no_agent_wired',
-        messaging_group_id: mg.id,
-        agent_group_id: null,
-      });
-      return;
     }
+    return;
   }
 
   // 2. Sender resolution (permissions module upserts the users row as a
diff --git a/src/types.ts b/src/types.ts
index b2674da..b3e2470 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -17,6 +17,16 @@ export interface MessagingGroup {
   name: string | null;
   is_group: number; // 0 | 1
   unknown_sender_policy: UnknownSenderPolicy;
+  /**
+   * When set, the owner explicitly denied registering this channel — the
+   * router drops silently and does not re-escalate. Cleared by any explicit
+   * wiring mutation (admin command). See migration 012.
+   *
+   * Optional on the TS type so pre-migration-012 callers that build
+   * MessagingGroup objects in code (fixtures, etc.) don't need to update;
+   * the column itself defaults to NULL in SQLite.
+   */
+  denied_at?: string | null;
   created_at: string;
 }