diff --git a/docs/systems/federation.md b/docs/systems/federation.md
index 7a3a6ea7..45fe5bab 100644
--- a/docs/systems/federation.md
+++ b/docs/systems/federation.md
@@ -977,16 +977,79 @@ The mutation log entry for reactions stores a simpler payload (no `messageId`/`m
 
 ## 12. Initial Sync
 
-### `runInitialSyncForNewPeers()` (`federationWorker.ts:739`)
+### `startupBootstrapSync()` (`federationWorker.ts`)
 
-Triggered once at server startup (async, non-blocking). Finds peers with `status = 'active'` and `lastSyncedAt = 0`.
+Triggered once at server startup (async, non-blocking). Finds peers with `status = 'active'` and `lastSyncedAt = 0` and calls `onPeerActivated(peerId, 'startup_bootstrap')` for each. This preserves the original startup-sync semantics while unifying the code path with all other activation sites (see "Peer Activation Recovery" below).
 
-**For each unsynced peer:**
-1. **DM sync pass:** Paginate through `POST {peerOrigin}/api/federation/sync` with `sinceTimestamp = 0`, `limit = 100`
-2. **Direct processing:** Call `processRelayEvents()` to process received events in-process (no HTTP round-trip)
-3. **Friend sync pass:** Same pagination with `contextType: 'friend'`, also processed via `processRelayEvents()`
-4. Update `lastSyncedAt = Date.now()` after completion
-5. On failure: don't update `lastSyncedAt` -- retried on next startup
+### Peer Activation Recovery
+
+Every transition of `federation_peers.status` to `active` invokes `onPeerActivated(peerId, reason)` — one handler wired at all transition sites. Two independent invariants, both unconditional:
+
+1. **`resetOutboxBackoff`** — sets `nextRetryAt = now` and `attempts = 0` for every outbox entry belonging to the peer. Entries that accumulated exponential backoff before the peer went unreachable are immediately eligible again. Attempts counter is also reset so a freshly-healthy peer's next failure starts at `BACKOFF_SCHEDULE_MS[0]` (30s), not wherever the counter left off.
+2. **`syncPeerMutationLog`** — pulls missed events from the peer's `/api/federation/sync` endpoint since `peer.lastSyncedAt`. Three passes: DM, friend, profile (in that order, each paginated). `lastSyncedAt` advances to `Date.now()` on full success; stays put on transient failure so the next activation retries the same window.
+
+#### Call sites (must remain exhaustive)
+
+| File | Context | Reason |
+|---|---|---|
+| `routes/federation.ts` | `/peer/initiate` 200 activation | `initiate_accepted` |
+| `routes/federation.ts` | `/peer/accept` existing-rejected override | `accept_rejected_override` |
+| `routes/federation.ts` | `/peer/accept` existing-awaiting_approval | `accept_awaiting_approval` |
+| `routes/federation.ts` | `/peer/accept` existing-pending | `accept_pending` |
+| `routes/federation.ts` | `/peer/accept` new-peer | `accept_new` |
+| `routes/federation.ts` | `/approval-requests/:id/approve` success | `approval_handshake` |
+| `utils/federationWorker.ts` | Health check unreachable → active | `health_check_recovery` |
+| `utils/federationPeering.ts` | `ensurePeered/performHandshake` 200 | `ensure_peered` |
+| `utils/federationWorker.ts` | Startup scan (status=active, lastSyncedAt=0) | `startup_bootstrap` |
+
+HTTP handler sites dispatch fire-and-forget (`.catch(log)`) so the response is not blocked by sync-pull pagination. Worker-internal sites `await` since the worker tick is already async.
+
+Concurrent activations for the same peer are deduplicated via an in-flight promise map keyed by `peerId`.
+
+#### Peer-state × outbox-enqueue × recovery matrix
+
+| Status | `queueOutboxEvent` enqueue | Mutation log captures | Recovery on transition to `active` |
+|---|---|---|---|
+| `active` | Queue | Yes (for covered event types — see below) | N/A |
+| `pending` | Queue | Yes | `onPeerActivated` |
+| `unreachable` | Queue | Yes | `onPeerActivated` |
+| `awaiting_approval` | **Drop, debug-log** | Yes | `onPeerActivated` |
+| `needs_attention` | **Drop, debug-log** | Yes | `onPeerActivated` (fires when the row is re-created via admin Reset + re-peer) |
+| `rejected` | Drop, debug-log | Yes | `onPeerActivated` |
+| `revoked` | Drop, debug-log | Yes | `onPeerActivated` (fires when the row is re-created via hard-delete + re-initiate) |
+
+`queueOutboxEvent` uses an exhaustive TypeScript `switch` on the narrowed peer-status union — adding a new status value without handling it fails compile-time typecheck (`const _exhaustive: never = status;`).
+
+**Mid-call race catch:** when the initial peers SELECT filters out a peer because its status is non-deliverable, but the fallback loop observes the status has since flipped to `active`/`pending`/`unreachable`, the code re-fetches the peer row and appends it to `matchedPeers` so the outer enqueue loop includes it. Silent drops would lose real-time delivery under asymmetric failure (e.g., `/peer/accept` 200 response lost on the wire, health-check transition firing on only one side).
+
+#### Mutation log coverage
+
+Event types covered by `appendMutationLog` (replayed on sync-pull):
+
+| Event type | `contextType` | Source |
+|---|---|---|
+| DM `create` / `update` / `delete` | `dm` | `federationOutbox.queueDmRelay`, `dm.ts` delete handler |
+| `reaction_add` / `reaction_remove` | `dm` | `ws/events.ts` |
+| `member_add` / `member_remove` / `ownership_transfer` | `dm` | `dm.ts` |
+| `dm_close` / `dm_reopen` | `dm` | `federationOutbox.queueDmCloseRelay` |
+| `read_state_update` | `dm` | `federationOutbox.queueReadStateRelay` |
+| `file_rejected` | `dm` | `federationWorker.handleSizeRejection` |
+| `friend_request_*` / `friend_add` / `friend_remove` | `friend` | `social.ts` |
+| `profile_update` | `profile` | `routes/users.ts` (PATCH `/api/users/@me`) |
+
+Ephemeral events (`dm_typing_*`, `dm_call_*`) are fire-and-forget by design and are NOT captured — missed typing/call-signaling packets are acceptable and carry no durable state.
+
+#### `/api/federation/sync` contextType filter values
+
+| Filter | Returns |
+|---|---|
+| (none) / omitted | DM events (including `dm_close`, `dm_reopen`, `read_state_update`, `file_rejected`) |
+| `'friend'` | Friend events |
+| `'profile'` | Profile update events |
+
+#### Known Issues
+
+- **Poison-pill event in peer's mutation log.** If a peer's mutation log contains a row whose inbound processor throws (e.g., a UNIQUE conflict from a malformed relay payload), `syncPeerMutationLog` catches the error and declines to advance `lastSyncedAt`. Subsequent activations retry the same window and hit the same failure, effectively blocking catch-up for that peer. No automatic poison-pill skip is implemented — recovery requires either: (a) fixing the mutation log on the peer side, or (b) manually advancing `lastSyncedAt` past the offending row via DB admin. Flagged as a follow-up backlog item.
 
 ### Sync Endpoint (`POST /api/federation/sync`)
 
@@ -994,7 +1057,7 @@ HMAC-authenticated. Returns events from the `federation_mutation_log`.
 
 **Request:**
 ```typescript
-{ sinceTimestamp: number, dmChannelId?: string, federatedId?: string, contextType?: 'dm'|'friend', limit?: 1-500 }
+{ sinceTimestamp: number, dmChannelId?: string, federatedId?: string, contextType?: 'dm'|'friend'|'profile', limit?: 1-500 }
 ```
 
 **Response:**
@@ -1125,7 +1188,7 @@ All workers are started by `startFederationWorkers()` on server boot and stopped
 | File download | 30s | 5 | 60s | `processFileQueueTick` |
 | Health check | 15min | all unreachable | 10s | `processHealthCheckTick` |
 | Janitor | 1h | -- | -- | `runFederationJanitor` (sync) |
-| Initial sync | Once at startup | -- | 30s per page | `runInitialSyncForNewPeers` |
+| Startup bootstrap sync | Once at startup | -- | 30s per page | `startupBootstrapSync` → `onPeerActivated` |
 
 ### Janitor Cleanup (`storageJanitor.ts:runFederationJanitor`)
 
diff --git a/docs/systems/social.md b/docs/systems/social.md
index 7f44a131..0864c10f 100644
--- a/docs/systems/social.md
+++ b/docs/systems/social.md
@@ -368,14 +368,16 @@ The sorted join ensures the same pair always produces the same prefix regardless
 
 ## 7. Initial Sync: Friend Backfill
 
-When a new peer is established (`federation_peers.lastSyncedAt = 0`), the federation worker runs `runInitialSyncForNewPeers()` on startup. This includes a dedicated friend sync pass.
+When a peer transitions to `active` (including at startup for peers with `lastSyncedAt = 0`), the federation worker calls `onPeerActivated(peerId, reason)`. One of its two unconditional invariants is `syncPeerMutationLog`, which pulls missed events from the peer's `/api/federation/sync` endpoint — including a dedicated friend sync pass.
 
-**Flow (`federationWorker.ts:runInitialSyncForNewPeers`):**
+**Flow (`federationPeerActivation.ts:syncPeerMutationLog`):**
 
-1. Query all active peers with `lastSyncedAt = 0`
-2. **First pass (DM events):** Paginates through `POST /federation/sync` with no `contextType` filter (defaults to DM events), processing each batch via `processRelayEvents()` directly
-3. **Second pass (friend events):** Paginates through `POST /federation/sync` with `contextType: 'friend'`, same direct processing
-4. After both passes complete, updates `lastSyncedAt = Date.now()` so the sync doesn't repeat
+1. **First pass (DM events):** Paginates through `POST /federation/sync` with no `contextType` filter (defaults to DM events), processing each batch via `processRelayEvents()` directly
+2. **Second pass (friend events):** Paginates through `POST /federation/sync` with `contextType: 'friend'`, same direct processing
+3. **Third pass (profile events):** Paginates through `POST /federation/sync` with `contextType: 'profile'`, same direct processing
+4. After all three passes complete, updates `lastSyncedAt = Date.now()` so the window advances on the next activation
+
+At startup, `startupBootstrapSync()` scans for `status = 'active' AND lastSyncedAt = 0` peers and calls `onPeerActivated(peerId, 'startup_bootstrap')` for each, preserving the original startup-sync semantics while using the unified path.
 
 The sync endpoint (`POST /api/federation/sync`) returns events from the `federation_mutation_log` table, which retains entries for 90 days. This means friend relationships established within the last 90 days are backfilled when a new peer connection is created.
 
diff --git a/packages/server/src/routes/federation.ts b/packages/server/src/routes/federation.ts
index 4263f95d..9d41f8d6 100644
--- a/packages/server/src/routes/federation.ts
+++ b/packages/server/src/routes/federation.ts
@@ -16,6 +16,7 @@ import { sanitizeUser } from '../utils/sanitize.js';
 import { deleteAttachmentFiles, deleteUploadFile } from '../utils/fileCleanup.js';
 import { tombstoneUser, collectDeletionBroadcastTargets, collectProfileBroadcastTargetIds } from '../utils/userDeletion.js';
 import { computeFederatedId, getDmParticipants, sendCallRelay } from '../utils/federationOutbox.js';
+import { onPeerActivated } from '../utils/federationPeerActivation.js';
 import { getDmMessageWithUser } from './dm.js';
 import type { FederationRelayRequest, FederationRelayResponse, FederationRelayEvent, FederationRelayAttachment, FederationSyncRequest, FederationSyncResponse, DmMessageWithUser, DmChannel, FederationRelayProfileSnapshot, FederationIdentityDeleteS2SRequest, FederationProfileUpdatePayload, ServerEvent } from '@backspace/shared';
 
@@ -354,6 +355,9 @@ export async function federationRoutes(app: FastifyInstance): Promise<void> {
           .where(eq(schema.federationPeers.id, peerId))
           .run();
         connectionManager.sendToAdmins({ type: 'federation_peers_changed' as const });
+        onPeerActivated(peerId, 'initiate_accepted').catch(err =>
+          console.error('[federation] onPeerActivated from /peer/initiate failed:', err)
+        );
 
         const peer = db
           .select()
@@ -560,6 +564,9 @@ export async function federationRoutes(app: FastifyInstance): Promise<void> {
           }
 
           connectionManager.sendToAdmins({ type: 'federation_peers_changed' as const });
+          onPeerActivated(existing.id, 'accept_rejected_override').catch(err =>
+            console.error('[federation] onPeerActivated from /peer/accept (rejected override) failed:', err)
+          );
 
           return reply.code(200).send({ accepted: true });
         }
@@ -583,6 +590,9 @@ export async function federationRoutes(app: FastifyInstance): Promise<void> {
           }
 
           connectionManager.sendToAdmins({ type: 'federation_peers_changed' as const });
+          onPeerActivated(existing.id, 'accept_awaiting_approval').catch(err =>
+            console.error('[federation] onPeerActivated from /peer/accept (awaiting_approval) failed:', err)
+          );
 
           return reply.code(200).send({ accepted: true });
         }
@@ -597,6 +607,9 @@ export async function federationRoutes(app: FastifyInstance): Promise<void> {
           .run();
 
         connectionManager.sendToAdmins({ type: 'federation_peers_changed' as const });
+        onPeerActivated(existing.id, 'accept_pending').catch(err =>
+          console.error('[federation] onPeerActivated from /peer/accept (pending) failed:', err)
+        );
 
         return reply.code(200).send({ accepted: true });
       }
@@ -613,6 +626,9 @@ export async function federationRoutes(app: FastifyInstance): Promise<void> {
       }).run();
 
       connectionManager.sendToAdmins({ type: 'federation_peers_changed' as const });
+      onPeerActivated(peerId, 'accept_new').catch(err =>
+        console.error('[federation] onPeerActivated from /peer/accept (new) failed:', err)
+      );
 
       return reply.code(200).send({ accepted: true });
     },
@@ -1136,6 +1152,9 @@ export async function federationRoutes(app: FastifyInstance): Promise<void> {
           .run();
 
         connectionManager.sendToAdmins({ type: 'federation_peers_changed' as const });
+        onPeerActivated(peerId, 'approval_handshake').catch(err =>
+          console.error('[federation] onPeerActivated from /approval-requests/:id/approve failed:', err)
+        );
 
         const peer = db
           .select()
@@ -1615,6 +1634,10 @@ export async function federationRoutes(app: FastifyInstance): Promise<void> {
         payload: string | null;
       }>;
 
+      // Maps local DM channel ID → federatedId for O(1) lookup in serializers.
+      // Only populated in the DM branch (friend/profile branches don't need it).
+      let channelFederatedIdMap = new Map<string, string>();
+
       if (contextTypeFilter === 'friend') {
         // ── Friend event sync: no DM channel logic needed ──
         mutationRows = rawDb.prepare(`
@@ -1624,6 +1647,15 @@ export async function federationRoutes(app: FastifyInstance): Promise<void> {
           ORDER BY mutated_at ASC
           LIMIT ?
         `).all(sinceTimestamp, limit) as typeof mutationRows;
+      } else if (contextTypeFilter === 'profile') {
+        // ── Profile event sync: no DM channel logic needed ──
+        mutationRows = rawDb.prepare(`
+          SELECT id, entity_id, context_id, context_type, mutation_type, mutated_at, payload
+          FROM federation_mutation_log
+          WHERE context_type = 'profile' AND mutated_at > ?
+          ORDER BY mutated_at ASC
+          LIMIT ?
+        `).all(sinceTimestamp, limit) as typeof mutationRows;
       } else {
         // ── DM sync path ──
         // Determine which DM channels to sync.
@@ -1631,11 +1663,14 @@ export async function federationRoutes(app: FastifyInstance): Promise<void> {
         // that should be synced. The peer's relay endpoint will create the channel
         // if it doesn't exist, or match by federated_id if it does.
         const sharedChannelRows = rawDb.prepare(`
-          SELECT id as dm_channel_id FROM dm_channels
+          SELECT id as dm_channel_id, federated_id FROM dm_channels
           WHERE federated_id IS NOT NULL AND deleted_at IS NULL
-        `).all() as Array<{ dm_channel_id: string }>;
+        `).all() as Array<{ dm_channel_id: string; federated_id: string }>;
 
         const sharedChannelIds = sharedChannelRows.map(r => r.dm_channel_id);
+        channelFederatedIdMap = new Map<string, string>(
+          sharedChannelRows.map(r => [r.dm_channel_id, r.federated_id])
+        );
 
         // If filtering by federatedId, resolve to local channel ID
         let effectiveChannelFilter = dmChannelIdFilter;
@@ -1679,7 +1714,10 @@ export async function federationRoutes(app: FastifyInstance): Promise<void> {
             WHERE ml.context_id = ?
               AND ml.context_type = 'dm'
               AND ml.mutated_at > ?
-              AND (dm.id IS NOT NULL OR ml.mutation_type IN ('delete', 'member_add', 'member_remove', 'ownership_transfer'))
+              AND (dm.id IS NOT NULL OR ml.mutation_type IN (
+                'delete', 'member_add', 'member_remove', 'ownership_transfer',
+                'dm_close', 'dm_reopen', 'read_state_update', 'file_rejected'
+              ))
             ORDER BY ml.mutated_at ASC
             LIMIT ?
           `).all(effectiveChannelFilter, sinceTimestamp, limit) as typeof mutationRows;
@@ -1720,7 +1758,10 @@ export async function federationRoutes(app: FastifyInstance): Promise<void> {
             WHERE ml.context_id IN (${placeholders})
               AND ml.context_type = 'dm'
               AND ml.mutated_at > ?
-              AND (dm.id IS NOT NULL OR ml.mutation_type IN ('delete', 'member_add', 'member_remove', 'ownership_transfer'))
+              AND (dm.id IS NOT NULL OR ml.mutation_type IN (
+                'delete', 'member_add', 'member_remove', 'ownership_transfer',
+                'dm_close', 'dm_reopen', 'read_state_update', 'file_rejected'
+              ))
             ORDER BY ml.mutated_at ASC
             LIMIT ?
           `).all(...sharedChannelIds, sinceTimestamp, limit) as typeof mutationRows;
@@ -1760,7 +1801,9 @@ export async function federationRoutes(app: FastifyInstance): Promise<void> {
         const mutationType = mutation.mutation_type as 'create' | 'update' | 'delete' | 'reaction_add' | 'reaction_remove'
           | 'member_add' | 'member_remove' | 'ownership_transfer'
           | 'friend_request_create' | 'friend_request_update' | 'friend_request_cancel'
-          | 'friend_add' | 'friend_remove';
+          | 'friend_add' | 'friend_remove'
+          | 'dm_close' | 'dm_reopen' | 'read_state_update' | 'file_rejected'
+          | 'profile_update';
 
         if (['member_add', 'member_remove', 'ownership_transfer',
              'friend_request_create', 'friend_request_update', 'friend_request_cancel',
@@ -1820,6 +1863,86 @@ export async function federationRoutes(app: FastifyInstance): Promise<void> {
           continue;
         }
 
+        if (mutationType === 'dm_close' || mutationType === 'dm_reopen') {
+          if (!mutation.payload) continue;
+          let dmCloseReopenPayload: { homeUserId: string; homeInstance: string } | null = null;
+          try { dmCloseReopenPayload = JSON.parse(mutation.payload); } catch { continue; }
+          if (!dmCloseReopenPayload) continue;
+          const fedIdCloseReopen = channelFederatedIdMap.get(mutation.context_id);
+          if (!fedIdCloseReopen) continue;
+          events.push({
+            eventType: mutationType,
+            dmChannelId: mutation.context_id,
+            messageId: mutation.entity_id,
+            federatedId: fedIdCloseReopen,
+            encryptionVersion: 0,
+            timestamp: mutation.mutated_at,
+            dmCloseReopen: dmCloseReopenPayload,
+          });
+          continue;
+        }
+
+        if (mutationType === 'read_state_update') {
+          if (!mutation.payload) continue;
+          let readState: NonNullable<FederationRelayEvent['readState']> | null = null;
+          try { readState = JSON.parse(mutation.payload) as NonNullable<FederationRelayEvent['readState']>; } catch { continue; }
+          if (!readState) continue;
+          const fedIdReadState = channelFederatedIdMap.get(mutation.context_id);
+          if (!fedIdReadState) continue;
+          events.push({
+            eventType: 'read_state_update',
+            dmChannelId: mutation.context_id,
+            messageId: mutation.entity_id,
+            federatedId: fedIdReadState,
+            encryptionVersion: 0,
+            timestamp: mutation.mutated_at,
+            readState,
+          });
+          continue;
+        }
+
+        if (mutationType === 'file_rejected') {
+          if (!mutation.payload) continue;
+          let fileRejectedPayload: {
+            attachmentId: string;
+            sourceFilename: string;
+            rejectionReason: string;
+            rejectionLimit: number;
+            affectedUserIds: string[];
+          } | null = null;
+          try { fileRejectedPayload = JSON.parse(mutation.payload); } catch { continue; }
+          if (!fileRejectedPayload) continue;
+          events.push({
+            eventType: 'file_rejected',
+            dmChannelId: mutation.context_id,
+            messageId: mutation.entity_id,
+            encryptionVersion: 0,
+            timestamp: mutation.mutated_at,
+            attachmentId: fileRejectedPayload.attachmentId,
+            sourceFilename: fileRejectedPayload.sourceFilename,
+            rejectionReason: fileRejectedPayload.rejectionReason,
+            rejectionLimit: fileRejectedPayload.rejectionLimit,
+            affectedUserIds: fileRejectedPayload.affectedUserIds,
+          });
+          continue;
+        }
+
+        if (mutationType === 'profile_update') {
+          if (!mutation.payload) continue;
+          let profileOuter: { profileUpdate?: NonNullable<FederationRelayEvent['profileUpdate']> } | null = null;
+          try { profileOuter = JSON.parse(mutation.payload); } catch { continue; }
+          if (!profileOuter?.profileUpdate) continue;
+          events.push({
+            eventType: 'profile_update',
+            contextType: 'profile',
+            messageId: mutation.entity_id,
+            encryptionVersion: 0,
+            timestamp: mutation.mutated_at,
+            profileUpdate: profileOuter.profileUpdate,
+          });
+          continue;
+        }
+
         // For create and update: fetch the current message state
         const message = db
           .select()
diff --git a/packages/server/src/routes/users.ts b/packages/server/src/routes/users.ts
index d49ba692..9d82e6a1 100644
--- a/packages/server/src/routes/users.ts
+++ b/packages/server/src/routes/users.ts
@@ -8,7 +8,7 @@ import { AVATAR_COLORS } from '@backspace/shared';
 import { sanitizeUser } from '../utils/sanitize.js';
 import { deleteUploadFile, deleteAttachmentByFilename } from '../utils/fileCleanup.js';
 import { tombstoneUser, collectDeletionBroadcastTargets, collectProfileBroadcastTargetIds } from '../utils/userDeletion.js';
-import { queueOutboxEvent, isFederationRelayEnabled } from '../utils/federationOutbox.js';
+import { queueOutboxEvent, isFederationRelayEnabled, appendMutationLog } from '../utils/federationOutbox.js';
 import { generateSnowflake } from '../utils/snowflake.js';
 import { resizeProfileImage } from '../utils/thumbnail.js';
 import { config } from '../config.js';
@@ -374,6 +374,13 @@ export async function userRoutes(app: FastifyInstance): Promise<void> {
             bio: preUpdateUser.bio,
           };
 
+          appendMutationLog(
+            preUpdateUser.id,
+            preUpdateUser.id,
+            'profile_update',
+            JSON.stringify({ profileUpdate: profilePayload }),
+            'profile',
+          );
           for (const targetOrigin of newOrigins) {
             queueOutboxEvent(
               preUpdateUser.id,
@@ -529,6 +536,13 @@ export async function userRoutes(app: FastifyInstance): Promise<void> {
           bio: updatedUser!.bio,
         };
 
+        appendMutationLog(
+          updatedUser!.id,
+          updatedUser!.id,
+          'profile_update',
+          JSON.stringify({ profileUpdate: profilePayload }),
+          'profile',
+        );
         queueOutboxEvent(
           updatedUser!.id,    // entityId — user's ID (coalesces rapid edits)
           updatedUser!.id,    // contextId — user-scoped
diff --git a/packages/server/src/utils/federationOutbox.mutationlog.test.ts b/packages/server/src/utils/federationOutbox.mutationlog.test.ts
new file mode 100644
index 00000000..19c5242a
--- /dev/null
+++ b/packages/server/src/utils/federationOutbox.mutationlog.test.ts
@@ -0,0 +1,135 @@
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+import Database from 'better-sqlite3';
+import { drizzle } from 'drizzle-orm/better-sqlite3';
+import fs from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import * as schema from '../db/schema.js';
+import { eq } from 'drizzle-orm';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+type TestDb = ReturnType<typeof drizzle<typeof schema>>;
+let sqlite: Database.Database;
+let testDb: TestDb;
+
+vi.mock('../db/index.js', () => ({
+  getDb: () => testDb,
+  schema,
+}));
+
+vi.mock('../utils/federationAuth.js', () => ({
+  getOurOrigin: () => 'https://test.example',
+  buildFederationHeaders: () => ({}),
+  generateHmacSecret: () => 'secret',
+}));
+
+let _snowflakeCounter = 1;
+vi.mock('../utils/snowflake.js', () => ({
+  generateSnowflake: () => String(_snowflakeCounter++),
+  setWorkerId: vi.fn(),
+}));
+
+function applyMigrations(db: Database.Database): void {
+  const migrationsDir = path.resolve(__dirname, '../../drizzle');
+  const files = fs.readdirSync(migrationsDir).filter(f => f.endsWith('.sql')).sort();
+  for (const f of files) {
+    const sql = fs.readFileSync(path.join(migrationsDir, f), 'utf8');
+    const statements = sql.split(/-->\s*statement-breakpoint/);
+    for (const stmt of statements) {
+      const clean = stmt.trim();
+      if (clean) db.exec(clean);
+    }
+  }
+}
+
+function seedSettings(): void {
+  testDb.insert(schema.instanceSettings).values({
+    id: 1,
+    federationRelayEnabled: 1,
+    updatedAt: Date.now(),
+  }).run();
+}
+
+function seedChannel(id: string, federatedId: string | null): void {
+  testDb.insert(schema.dmChannels).values({
+    id, federatedId, ownerId: null, createdAt: Date.now(),
+  }).run();
+}
+
+function seedUser(id: string, username: string): void {
+  testDb.insert(schema.users).values({
+    id, username, displayName: username, passwordHash: 'x',
+    createdAt: Date.now(),
+  }).run();
+}
+
+function seedDmMember(channelId: string, userId: string): void {
+  testDb.insert(schema.dmMembers).values({
+    dmChannelId: channelId, userId, closed: 0,
+  }).run();
+}
+
+describe('queueDmCloseRelay — mutation log capture', () => {
+  beforeEach(() => {
+    sqlite = new Database(':memory:');
+    testDb = drizzle(sqlite, { schema });
+    applyMigrations(sqlite);
+    seedSettings();
+  });
+
+  it('appends a mutation log row for dm_close', async () => {
+    const { queueDmCloseRelay } = await import('./federationOutbox.js');
+    seedUser('u-1', 'alice');
+    seedChannel('ch-1', 'fed-1');
+    seedDmMember('ch-1', 'u-1');
+
+    queueDmCloseRelay('ch-1', 'u-1', 'dm_close');
+
+    const rows = testDb.select().from(schema.federationMutationLog)
+      .where(eq(schema.federationMutationLog.mutationType, 'dm_close')).all();
+    expect(rows.length).toBe(1);
+    expect(rows[0]?.contextId).toBe('ch-1');
+    expect(rows[0]?.contextType).toBe('dm');
+  });
+
+  it('appends a mutation log row for dm_reopen', async () => {
+    const { queueDmCloseRelay } = await import('./federationOutbox.js');
+    seedUser('u-1', 'alice');
+    seedChannel('ch-2', 'fed-2');
+    seedDmMember('ch-2', 'u-1');
+
+    queueDmCloseRelay('ch-2', 'u-1', 'dm_reopen');
+
+    const rows = testDb.select().from(schema.federationMutationLog)
+      .where(eq(schema.federationMutationLog.mutationType, 'dm_reopen')).all();
+    expect(rows.length).toBe(1);
+  });
+});
+
+describe('queueReadStateRelay — mutation log capture', () => {
+  beforeEach(() => {
+    sqlite = new Database(':memory:');
+    testDb = drizzle(sqlite, { schema });
+    applyMigrations(sqlite);
+    seedSettings();
+  });
+
+  it('appends a mutation log row for read_state_update', async () => {
+    const { queueReadStateRelay } = await import('./federationOutbox.js');
+    seedUser('u-2', 'bob');
+    seedChannel('ch-3', 'fed-3');
+    seedDmMember('ch-3', 'u-2');
+    testDb.insert(schema.dmMessages).values({
+      id: 'm-1', dmChannelId: 'ch-3', userId: 'u-2', content: 'hi',
+      type: 'user', createdAt: Date.now(),
+    }).run();
+
+    queueReadStateRelay('ch-3', 'm-1', 'u-2');
+
+    const rows = testDb.select().from(schema.federationMutationLog)
+      .where(eq(schema.federationMutationLog.mutationType, 'read_state_update')).all();
+    expect(rows.length).toBe(1);
+    expect(rows[0]?.contextId).toBe('ch-3');
+    expect(rows[0]?.contextType).toBe('dm');
+  });
+});
diff --git a/packages/server/src/utils/federationOutbox.state.test.ts b/packages/server/src/utils/federationOutbox.state.test.ts
new file mode 100644
index 00000000..68011ffd
--- /dev/null
+++ b/packages/server/src/utils/federationOutbox.state.test.ts
@@ -0,0 +1,92 @@
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+import Database from 'better-sqlite3';
+import { drizzle } from 'drizzle-orm/better-sqlite3';
+import fs from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import * as schema from '../db/schema.js';
+import { eq } from 'drizzle-orm';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+type TestDb = ReturnType<typeof drizzle<typeof schema>>;
+
+// Mutable reference updated in beforeEach — the factory closes over this.
+let testDb: TestDb;
+
+vi.mock('../db/index.js', () => ({
+  getDb: () => testDb,
+  schema,
+}));
+
+// Mock federation-auth helpers to avoid env-var dependency
+vi.mock('../utils/federationAuth.js', () => ({
+  getOurOrigin: () => 'https://local.example',
+  buildFederationHeaders: () => ({}),
+  generateHmacSecret: () => 'test-secret',
+}));
+
+function applyMigrations(db: Database.Database): void {
+  const migrationsDir = path.resolve(__dirname, '../../drizzle');
+  const files = fs.readdirSync(migrationsDir).filter(f => f.endsWith('.sql')).sort();
+  for (const f of files) {
+    const sql = fs.readFileSync(path.join(migrationsDir, f), 'utf8');
+    const statements = sql.split(/-->\s*statement-breakpoint/);
+    for (const stmt of statements) {
+      const clean = stmt.trim();
+      if (clean) db.exec(clean);
+    }
+  }
+}
+
+function seedSettings(): void {
+  testDb.insert(schema.instanceSettings).values({
+    id: 1,
+    federationRelayEnabled: 1,
+    federationRelayTtlDays: 30,
+    updatedAt: Date.now(),
+  }).run();
+}
+
+function seedPeer(id: string, origin: string, status: string): void {
+  testDb.insert(schema.federationPeers).values({
+    id, origin, hmacSecret: 'secret',
+    status, lastSyncedAt: 0, createdAt: Date.now(),
+  }).run();
+}
+
+function countOutbox(peerId: string): number {
+  return testDb.select().from(schema.federationOutbox)
+    .where(eq(schema.federationOutbox.peerId, peerId))
+    .all().length;
+}
+
+// Import once at module level — vi.mock is hoisted and the factory returns the
+// live testDb reference, so re-using the cached import is correct.
+const { queueOutboxEvent } = await import('./federationOutbox.js');
+
+describe('queueOutboxEvent — non-deliverable statuses', () => {
+  beforeEach(() => {
+    const sqlite = new Database(':memory:');
+    testDb = drizzle(sqlite, { schema });
+    applyMigrations(sqlite);
+    seedSettings();
+    vi.restoreAllMocks();
+  });
+
+  it.each([
+    ['awaiting_approval'],
+    ['needs_attention'],
+    ['rejected'],
+    ['revoked'],
+  ])('drops the event and logs a reason for %s peers (no outbox row, no throw)', (status) => {
+    seedPeer('peer-drop', 'https://drop.example', status);
+
+    const debugSpy = vi.spyOn(console, 'debug').mockImplementation(() => {});
+
+    queueOutboxEvent('entity-1', 'ctx-1', 'create', '{}', ['https://drop.example'], 'dm');
+
+    expect(countOutbox('peer-drop')).toBe(0);
+    expect(debugSpy).toHaveBeenCalled();
+    expect(debugSpy.mock.calls[0]![0] as string).toContain(status);
+  });
+});
diff --git a/packages/server/src/utils/federationOutbox.ts b/packages/server/src/utils/federationOutbox.ts
index 36bbb37c..d73ee0df 100644
--- a/packages/server/src/utils/federationOutbox.ts
+++ b/packages/server/src/utils/federationOutbox.ts
@@ -163,40 +163,84 @@ export function queueOutboxEvent(
       for (const origin of targetPeerOrigins) {
         if (matchedOrigins.has(origin)) continue;
 
-        // Check if there's a rejected/revoked peer we should skip
         const existingPeer = db
           .select({ status: schema.federationPeers.status })
           .from(schema.federationPeers)
           .where(eq(schema.federationPeers.origin, origin))
           .get();
 
-        if (existingPeer && (existingPeer.status === 'rejected' || existingPeer.status === 'revoked')) {
-          console.warn(`[federation] queueOutboxEvent: skipping ${existingPeer.status} peer ${origin}`);
-          continue;
-        }
-
-        // No peer record at all — create a pending placeholder
-        const peerId = generateSnowflake();
-        const now = Date.now();
-        db.insert(schema.federationPeers)
-          .values({
+        if (!existingPeer) {
+          // No peer row — create pending placeholder, handshake fires on next tick
+          const peerId = generateSnowflake();
+          const now = Date.now();
+          db.insert(schema.federationPeers).values({
             id: peerId,
             origin,
             hmacSecret: generateHmacSecret(),
             status: 'pending',
             createdAt: now,
-          })
-          .run();
+          }).run();
+          const newPeer = db.select().from(schema.federationPeers)
+            .where(eq(schema.federationPeers.id, peerId)).get();
+          if (newPeer) {
+            matchedPeers = [...matchedPeers, newPeer];
+            console.log(`[federation] queueOutboxEvent: created pending placeholder for ${origin}`);
+          }
+          continue;
+        }
 
-        const newPeer = db
-          .select()
-          .from(schema.federationPeers)
-          .where(eq(schema.federationPeers.id, peerId))
-          .get();
+        // schema.federationPeers.status is plain text — narrow to known union for
+        // compile-time exhaustiveness check without widening to `string`.
+        const status = existingPeer.status as
+          | 'active'
+          | 'pending'
+          | 'unreachable'
+          | 'awaiting_approval'
+          | 'needs_attention'
+          | 'rejected'
+          | 'revoked';
 
-        if (newPeer) {
-          matchedPeers = [...matchedPeers, newPeer];
-          console.log(`[federation] queueOutboxEvent: created pending placeholder for ${origin}`);
+        switch (status) {
+          case 'active':
+          case 'pending':
+          case 'unreachable': {
+            // Race: peer transitioned to a deliverable status between the initial
+            // peers SELECT and this point in the loop. Re-fetch the full row and
+            // add to matchedPeers so the outer enqueue loop includes this peer.
+            // Do NOT silently drop — symmetric onPeerActivated on the peer's side
+            // is not guaranteed to cover asymmetric-failure cases (lost /peer/accept
+            // 200, health-check-only transition on one side).
+            const raced = db
+              .select()
+              .from(schema.federationPeers)
+              .where(eq(schema.federationPeers.origin, origin))
+              .get();
+            if (raced) {
+              matchedPeers = [...matchedPeers, raced];
+              console.log(`[federation] queueOutboxEvent: race-caught ${origin} (now ${status}); enqueueing`);
+            }
+            break;
+          }
+          case 'awaiting_approval':
+            console.debug(`[federation] queueOutboxEvent: skipping ${origin} (awaiting_approval); mutation log will replay on activation`);
+            break;
+          case 'needs_attention':
+            console.debug(`[federation] queueOutboxEvent: skipping ${origin} (needs_attention; admin Reset required); mutation log will replay after Reset + re-peer`);
+            break;
+          case 'rejected':
+            console.debug(`[federation] queueOutboxEvent: skipping ${origin} (rejected peering)`);
+            break;
+          case 'revoked':
+            console.debug(`[federation] queueOutboxEvent: skipping ${origin} (revoked by admin)`);
+            break;
+          default: {
+            // Exhaustiveness check — no `as never` cast. TypeScript enforces
+            // that every status value is handled; adding a new value to the
+            // union without a case here fails typecheck.
+            const _exhaustive: never = status;
+            console.error(`[federation] queueOutboxEvent: unknown peer status for ${origin}: ${String(_exhaustive)}`);
+            break;
+          }
         }
       }
     }
@@ -656,6 +700,12 @@ export function queueReadStateRelay(
   };
 
   const targetOrigins = getGroupDmTargetOrigins(channelId);
+  appendMutationLog(
+    `read_state:${channel.federatedId}:${userId}`,
+    channelId,
+    'read_state_update',
+    JSON.stringify({ user: { homeUserId, homeInstance }, messageRef }),
+  );
   queueOutboxEvent(
     `read_state:${channel.federatedId}:${userId}`,
     channelId,
@@ -711,6 +761,12 @@ export function queueDmCloseRelay(
   };
 
   const targetOrigins = getGroupDmTargetOrigins(dmChannelId);
+  appendMutationLog(
+    `${eventType}:${channel.federatedId}:${userId}`,
+    dmChannelId,
+    eventType,
+    JSON.stringify({ homeUserId, homeInstance }),
+  );
   queueOutboxEvent(
     `${eventType}:${channel.federatedId}:${userId}`,
     dmChannelId,
diff --git a/packages/server/src/utils/federationPeerActivation.test.ts b/packages/server/src/utils/federationPeerActivation.test.ts
new file mode 100644
index 00000000..d1dbc5da
--- /dev/null
+++ b/packages/server/src/utils/federationPeerActivation.test.ts
@@ -0,0 +1,296 @@
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+import Database from 'better-sqlite3';
+import { drizzle } from 'drizzle-orm/better-sqlite3';
+import fs from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import * as schema from '../db/schema.js';
+import { eq } from 'drizzle-orm';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+
+type TestDb = ReturnType<typeof drizzle<typeof schema>>;
+let sqlite: Database.Database;
+let testDb: TestDb;
+
+vi.mock('../db/index.js', () => ({
+  getDb: () => testDb,
+  schema,
+}));
+
+vi.mock('../utils/federationOutbox.js', () => ({
+  isFederationRelayEnabled: () => true,
+}));
+
+vi.mock('../utils/federationAuth.js', () => ({
+  getOurOrigin: () => 'https://local.example',
+  buildFederationHeaders: (_body: string, _secret: string, _origin: string) => ({
+    'Content-Type': 'application/json',
+    'X-Federation-Origin': _origin,
+  }),
+}));
+
+vi.mock('../routes/federation.js', () => ({
+  processRelayEvents: vi.fn().mockResolvedValue({ accepted: [], rejected: [] }),
+}));
+
+vi.mock('../ws/handler.js', () => ({
+  connectionManager: {
+    sendToAdmins: vi.fn(),
+    getAllOnlineUserIds: () => [],
+    sendToUser: vi.fn(),
+    sendToDmMembers: vi.fn(),
+  },
+}));
+
+function applyMigrations(db: Database.Database): void {
+  const migrationsDir = path.resolve(__dirname, '../../drizzle');
+  const files = fs.readdirSync(migrationsDir).filter(f => f.endsWith('.sql')).sort();
+  for (const f of files) {
+    const sql = fs.readFileSync(path.join(migrationsDir, f), 'utf8');
+    const statements = sql.split(/-->\s*statement-breakpoint/);
+    for (const stmt of statements) {
+      const clean = stmt.trim();
+      if (clean) db.exec(clean);
+    }
+  }
+}
+
+function seedPeer(id: string, status: string, lastSyncedAt = 0): void {
+  testDb.insert(schema.federationPeers).values({
+    id, origin: `https://${id}.example`, hmacSecret: 'secret',
+    status, lastSyncedAt, createdAt: Date.now(),
+  }).run();
+}
+
+function seedOutboxEntry(id: string, peerId: string, nextRetryAt: number, attempts: number): void {
+  testDb.insert(schema.federationOutbox).values({
+    id, peerId, contextId: 'ch-1', entityId: `msg-${id}`,
+    contextType: 'dm', eventType: 'create', payload: '{}',
+    encryptionVersion: 0, attempts, nextRetryAt,
+    expiresAt: Date.now() + 30 * 86_400_000,
+    createdAt: Date.now(),
+  }).run();
+}
+
+describe('resetOutboxBackoff', () => {
+  beforeEach(() => {
+    sqlite = new Database(':memory:');
+    testDb = drizzle(sqlite, { schema });
+    applyMigrations(sqlite);
+  });
+
+  it('resets nextRetryAt=now and attempts=0 for all peer entries — including past-due ones', async () => {
+    const { resetOutboxBackoff } = await import('./federationPeerActivation.js');
+    seedPeer('peer-a', 'active');
+    seedPeer('peer-b', 'active');
+    const now = Date.now();
+
+    // Three entries for peer-a: past-due (already eligible), near-future, far-future
+    seedOutboxEntry('entry-1', 'peer-a', now - 1000, 5);
+    seedOutboxEntry('entry-2', 'peer-a', now + 60_000, 3);
+    seedOutboxEntry('entry-3', 'peer-a', now + 86_400_000, 7);
+    // Entry for unrelated peer-b (must NOT be touched)
+    seedOutboxEntry('entry-4', 'peer-b', now + 86_400_000, 9);
+
+    resetOutboxBackoff('peer-a');
+
+    const a1 = testDb.select().from(schema.federationOutbox).where(eq(schema.federationOutbox.id, 'entry-1')).get();
+    const a2 = testDb.select().from(schema.federationOutbox).where(eq(schema.federationOutbox.id, 'entry-2')).get();
+    const a3 = testDb.select().from(schema.federationOutbox).where(eq(schema.federationOutbox.id, 'entry-3')).get();
+    const b4 = testDb.select().from(schema.federationOutbox).where(eq(schema.federationOutbox.id, 'entry-4')).get();
+
+    // All peer-a entries reset — including the past-due one (correctness: attempts=0 on those too)
+    expect(a1?.attempts).toBe(0);
+    expect(a2?.attempts).toBe(0);
+    expect(a3?.attempts).toBe(0);
+    expect(a1?.nextRetryAt).toBeGreaterThanOrEqual(now);
+    expect(a2?.nextRetryAt).toBeLessThanOrEqual(Date.now());
+    expect(a3?.nextRetryAt).toBeLessThanOrEqual(Date.now());
+    // peer-b untouched
+    expect(b4?.attempts).toBe(9);
+    expect(b4?.nextRetryAt).toBe(now + 86_400_000);
+  });
+
+  it('is a no-op when the peer has no outbox entries', async () => {
+    const { resetOutboxBackoff } = await import('./federationPeerActivation.js');
+    seedPeer('peer-empty', 'active');
+    expect(() => resetOutboxBackoff('peer-empty')).not.toThrow();
+  });
+});
+
+describe('syncPeerMutationLog', () => {
+  beforeEach(() => {
+    sqlite = new Database(':memory:');
+    testDb = drizzle(sqlite, { schema });
+    applyMigrations(sqlite);
+    vi.restoreAllMocks();
+  });
+
+  it('seeds sinceTimestamp from peer.lastSyncedAt for each pass', async () => {
+    const { syncPeerMutationLog } = await import('./federationPeerActivation.js');
+    testDb.insert(schema.federationPeers).values({
+      id: 'peer-1', origin: 'https://peer-1.example', hmacSecret: 'secret',
+      status: 'active', lastSyncedAt: 5000, createdAt: Date.now(),
+    }).run();
+
+    const fetchSpy = vi.spyOn(globalThis, 'fetch').mockImplementation(async () =>
+      new Response(JSON.stringify({ events: [], hasMore: false, checkpoint: 5000 }), { status: 200 })
+    );
+
+    await syncPeerMutationLog('peer-1', 'health_check_recovery');
+
+    // Three passes: dm (no contextType), friend, profile
+    expect(fetchSpy).toHaveBeenCalledTimes(3);
+    for (const call of fetchSpy.mock.calls) {
+      const body = JSON.parse(call[1]?.body as string) as { sinceTimestamp: number };
+      expect(body.sinceTimestamp).toBe(5000);
+    }
+    const calls = fetchSpy.mock.calls.map(c => JSON.parse(c[1]?.body as string) as { contextType?: string });
+    expect(calls[0]!.contextType).toBeUndefined();       // DM pass (no contextType filter)
+    expect(calls[1]!.contextType).toBe('friend');
+    expect(calls[2]!.contextType).toBe('profile');
+  });
+
+  it('advances lastSyncedAt on success', async () => {
+    const { syncPeerMutationLog } = await import('./federationPeerActivation.js');
+    testDb.insert(schema.federationPeers).values({
+      id: 'peer-2', origin: 'https://peer-2.example', hmacSecret: 'secret',
+      status: 'active', lastSyncedAt: 0, createdAt: Date.now(),
+    }).run();
+
+    vi.spyOn(globalThis, 'fetch').mockImplementation(async () =>
+      new Response(JSON.stringify({ events: [], hasMore: false, checkpoint: 1000 }), { status: 200 })
+    );
+
+    const before = Date.now();
+    await syncPeerMutationLog('peer-2', 'startup_bootstrap');
+    const after = Date.now();
+
+    const row = testDb.select().from(schema.federationPeers)
+      .where(eq(schema.federationPeers.id, 'peer-2')).get();
+    expect(row?.lastSyncedAt).toBeGreaterThanOrEqual(before);
+    expect(row?.lastSyncedAt).toBeLessThanOrEqual(after);
+  });
+
+  it('does NOT update lastSyncedAt on transient failure', async () => {
+    const { syncPeerMutationLog } = await import('./federationPeerActivation.js');
+    testDb.insert(schema.federationPeers).values({
+      id: 'peer-3', origin: 'https://peer-3.example', hmacSecret: 'secret',
+      status: 'active', lastSyncedAt: 42_000, createdAt: Date.now(),
+    }).run();
+
+    vi.spyOn(globalThis, 'fetch').mockImplementation(async () =>
+      new Response('internal error', { status: 500 })
+    );
+
+    await syncPeerMutationLog('peer-3', 'ensure_peered');
+    const row = testDb.select().from(schema.federationPeers)
+      .where(eq(schema.federationPeers.id, 'peer-3')).get();
+    expect(row?.lastSyncedAt).toBe(42_000);
+  });
+
+  it('does nothing when peer is not active', async () => {
+    const { syncPeerMutationLog } = await import('./federationPeerActivation.js');
+    testDb.insert(schema.federationPeers).values({
+      id: 'peer-4', origin: 'https://peer-4.example', hmacSecret: 'secret',
+      status: 'pending', lastSyncedAt: 0, createdAt: Date.now(),
+    }).run();
+
+    const fetchSpy = vi.spyOn(globalThis, 'fetch');
+    await syncPeerMutationLog('peer-4', 'health_check_recovery');
+    expect(fetchSpy).not.toHaveBeenCalled();
+  });
+
+  it('advances sinceTimestamp within a pass using data.checkpoint when hasMore is true', async () => {
+    const { syncPeerMutationLog } = await import('./federationPeerActivation.js');
+    testDb.insert(schema.federationPeers).values({
+      id: 'peer-5', origin: 'https://peer-5.example', hmacSecret: 'secret',
+      status: 'active', lastSyncedAt: 100, createdAt: Date.now(),
+    }).run();
+
+    let call = 0;
+    const fetchSpy = vi.spyOn(globalThis, 'fetch').mockImplementation(async () => {
+      call++;
+      // First DM call: one event, hasMore=true, checkpoint advances to 2500
+      // Second DM call: empty, hasMore=false, ends the DM pass
+      // Remaining calls (friend, profile): empty/done immediately
+      if (call === 1) {
+        return new Response(
+          JSON.stringify({
+            events: [{ eventType: 'create', messageId: 'm1', timestamp: 200, encryptionVersion: 0 }],
+            hasMore: true,
+            checkpoint: 2500,
+          }),
+          { status: 200 },
+        );
+      }
+      return new Response(JSON.stringify({ events: [], hasMore: false, checkpoint: call === 2 ? 2500 : 100 }), { status: 200 });
+    });
+
+    await syncPeerMutationLog('peer-5', 'health_check_recovery');
+
+    // Call 1: DM pass, since=100 (peer.lastSyncedAt)
+    // Call 2: DM pass continuation, since=2500 (advanced by previous checkpoint)
+    // Call 3: friend pass, since=100 (re-seeded from peer.lastSyncedAt)
+    // Call 4: profile pass, since=100 (re-seeded from peer.lastSyncedAt)
+    expect(fetchSpy).toHaveBeenCalledTimes(4);
+    const bodies = fetchSpy.mock.calls.map(c => JSON.parse(c[1]?.body as string) as { sinceTimestamp: number; contextType?: string });
+    expect(bodies[0]?.sinceTimestamp).toBe(100);
+    expect(bodies[0]?.contextType).toBeUndefined();
+    expect(bodies[1]?.sinceTimestamp).toBe(2500);  // advanced by checkpoint from call 1
+    expect(bodies[1]?.contextType).toBeUndefined();
+    expect(bodies[2]?.sinceTimestamp).toBe(100);   // friend pass re-seeds from peer.lastSyncedAt
+    expect(bodies[2]?.contextType).toBe('friend');
+    expect(bodies[3]?.sinceTimestamp).toBe(100);   // profile pass re-seeds from peer.lastSyncedAt
+    expect(bodies[3]?.contextType).toBe('profile');
+  });
+});
+
+describe('onPeerActivated', () => {
+  beforeEach(() => {
+    sqlite = new Database(':memory:');
+    testDb = drizzle(sqlite, { schema });
+    applyMigrations(sqlite);
+    vi.restoreAllMocks();
+  });
+
+  it('runs resetOutboxBackoff and syncPeerMutationLog once, even under concurrent calls', async () => {
+    const { onPeerActivated } = await import('./federationPeerActivation.js');
+
+    testDb.insert(schema.federationPeers).values({
+      id: 'peer-x', origin: 'https://peer-x.example', hmacSecret: 'secret',
+      status: 'active', lastSyncedAt: 0, createdAt: Date.now(),
+    }).run();
+
+    let fetchCount = 0;
+    vi.spyOn(globalThis, 'fetch').mockImplementation(async () => {
+      fetchCount++;
+      // Deliberately slow to let the second concurrent call share the in-flight promise.
+      await new Promise(r => setTimeout(r, 20));
+      return new Response(JSON.stringify({ events: [], hasMore: false, checkpoint: 0 }), { status: 200 });
+    });
+
+    const p1 = onPeerActivated('peer-x', 'health_check_recovery');
+    const p2 = onPeerActivated('peer-x', 'accept_new');
+    await Promise.all([p1, p2]);
+
+    // Three fetch calls for the three sync passes (dm, friend, profile) — not six.
+    expect(fetchCount).toBe(3);
+  });
+
+  it('swallows errors from syncPeerMutationLog so the handler does not throw', async () => {
+    const { onPeerActivated } = await import('./federationPeerActivation.js');
+
+    testDb.insert(schema.federationPeers).values({
+      id: 'peer-err', origin: 'https://peer-err.example', hmacSecret: 'secret',
+      status: 'active', lastSyncedAt: 0, createdAt: Date.now(),
+    }).run();
+
+    vi.spyOn(globalThis, 'fetch').mockImplementation(async () => {
+      throw new Error('network down');
+    });
+
+    await expect(onPeerActivated('peer-err', 'ensure_peered')).resolves.toBeUndefined();
+  });
+});
diff --git a/packages/server/src/utils/federationPeerActivation.ts b/packages/server/src/utils/federationPeerActivation.ts
new file mode 100644
index 00000000..ee34c265
--- /dev/null
+++ b/packages/server/src/utils/federationPeerActivation.ts
@@ -0,0 +1,179 @@
+import { getDb } from '../db/index.js';
+import * as schema from '../db/schema.js';
+import { and, eq } from 'drizzle-orm';
+import { isFederationRelayEnabled } from './federationOutbox.js';
+import { buildFederationHeaders, getOurOrigin } from './federationAuth.js';
+import type { FederationRelayEvent } from '@backspace/shared';
+
+export type PeerActivationReason =
+  | 'initiate_accepted'
+  | 'accept_rejected_override'
+  | 'accept_awaiting_approval'
+  | 'accept_pending'
+  | 'accept_new'
+  | 'approval_handshake'
+  | 'health_check_recovery'
+  | 'ensure_peered'
+  | 'startup_bootstrap';
+
+// Dedup: concurrent activations for the same peerId share one promise.
+const inFlightActivation = new Map<string, Promise<void>>();
+
+/**
+ * Called whenever federation_peers.status transitions to 'active' for any reason.
+ * Two independent invariants — both run unconditionally:
+ *   1. Reset outbox backoff (nextRetryAt = now, attempts = 0) for this peer.
+ *   2. Pull-sync mutation log from peer's /api/federation/sync since lastSyncedAt.
+ *
+ * Call sites (must remain exhaustive — grep `onPeerActivated(` to audit):
+ *   - routes/federation.ts /peer/initiate activation
+ *   - routes/federation.ts /peer/accept existing-rejected override
+ *   - routes/federation.ts /peer/accept existing-awaiting_approval
+ *   - routes/federation.ts /peer/accept existing-pending
+ *   - routes/federation.ts /peer/accept new-peer
+ *   - routes/federation.ts /approval-requests/:id/approve
+ *   - utils/federationWorker.ts health check recovery
+ *   - utils/federationPeering.ts ensurePeered/performHandshake
+ *   - utils/federationWorker.ts startup bootstrap (via startupBootstrapSync)
+ *
+ * Deduplicated by peerId — concurrent calls share one promise.
+ */
+export async function onPeerActivated(
+  peerId: string,
+  reason: PeerActivationReason,
+): Promise<void> {
+  const existing = inFlightActivation.get(peerId);
+  if (existing) return existing;
+
+  const promise = (async () => {
+    try {
+      resetOutboxBackoff(peerId);
+      await syncPeerMutationLog(peerId, reason);
+      const { connectionManager } = await import('../ws/handler.js');
+      connectionManager.sendToAdmins({ type: 'federation_peers_changed' as const });
+    } catch (err) {
+      console.error(`[federation] onPeerActivated(${peerId}, ${reason}) failed:`, err);
+    }
+  })();
+
+  inFlightActivation.set(peerId, promise);
+  try {
+    await promise;
+  } finally {
+    inFlightActivation.delete(peerId);
+  }
+}
+
+/**
+ * Reset all outbox backoff state for a peer (nextRetryAt = now, attempts = 0).
+ * Unconditional across all entries of the peer — see spec §Invariant 1.
+ */
+export function resetOutboxBackoff(peerId: string): void {
+  const db = getDb();
+  const now = Date.now();
+  const result = db
+    .update(schema.federationOutbox)
+    .set({ nextRetryAt: now, attempts: 0 })
+    .where(eq(schema.federationOutbox.peerId, peerId))
+    .run();
+  if (result.changes > 0) {
+    console.log(`[federation] Reset backoff on ${result.changes} outbox entries for peer ${peerId}`);
+  }
+}
+
+/**
+ * Pull-sync mutation log from the peer's /api/federation/sync endpoint.
+ * Runs three contextType passes (dm, friend, profile), paginating each.
+ * Updates peer.lastSyncedAt to Date.now() on success; leaves it untouched
+ * on transient failure so the next activation retries.
+ */
+export async function syncPeerMutationLog(
+  peerId: string,
+  reason: PeerActivationReason,
+): Promise<void> {
+  if (!isFederationRelayEnabled()) return;
+
+  const db = getDb();
+  const peer = db.select().from(schema.federationPeers)
+    .where(eq(schema.federationPeers.id, peerId)).get();
+  if (!peer || peer.status !== 'active') return;
+
+  const activePeer = peer;  // narrowed by the guard above
+
+  const ourOrigin = getOurOrigin();
+  const signingSecret = (activePeer.pendingHmacSecret && activePeer.secretRotationAt)
+    ? activePeer.pendingHmacSecret
+    : activePeer.hmacSecret;
+
+  console.log(`[federation] Sync-pull from ${activePeer.origin} (reason=${reason}, since=${activePeer.lastSyncedAt ?? 0})`);
+
+  let totalEvents = 0;
+
+  type SyncRequestBody = {
+    sinceTimestamp: number;
+    limit: number;
+    contextType?: 'friend' | 'profile';
+  };
+
+  async function runPass(contextType?: 'friend' | 'profile'): Promise<boolean> {
+    let since = activePeer.lastSyncedAt ?? 0;
+    while (true) {
+      const bodyObj: SyncRequestBody = { sinceTimestamp: since, limit: 100 };
+      if (contextType) bodyObj.contextType = contextType;
+      const body = JSON.stringify(bodyObj);
+      const headers = buildFederationHeaders(body, signingSecret, ourOrigin);
+      const resp = await fetch(`${activePeer.origin}/api/federation/sync`, {
+        method: 'POST', headers, body,
+        signal: AbortSignal.timeout(30_000),
+      });
+      if (!resp.ok) {
+        console.warn(`[federation] Sync-pull ${contextType ?? 'dm'} pass HTTP ${resp.status} for ${activePeer.origin}`);
+        return false;
+      }
+      const data = await resp.json() as { events: FederationRelayEvent[]; hasMore: boolean; checkpoint: number };
+      if (data.events.length === 0) return true;
+      const { processRelayEvents } = await import('../routes/federation.js');
+      await processRelayEvents(data.events, activePeer.origin, activePeer.origin, db);
+      totalEvents += data.events.length;
+      since = data.checkpoint;
+      if (!data.hasMore) return true;
+    }
+  }
+
+  try {
+    if (!(await runPass())) return;
+    if (!(await runPass('friend'))) return;
+    if (!(await runPass('profile'))) return;
+
+    db.update(schema.federationPeers)
+      .set({ lastSyncedAt: Date.now() })
+      .where(eq(schema.federationPeers.id, activePeer.id))
+      .run();
+
+    if (totalEvents > 0) {
+      console.log(`[federation] Sync-pull from ${activePeer.origin} replayed ${totalEvents} events`);
+    }
+  } catch (err) {
+    console.error(`[federation] Sync-pull from ${activePeer.origin} failed:`, err);
+  }
+}
+
+/**
+ * Startup bootstrap — scan for freshly-peered rows (status='active', lastSyncedAt=0)
+ * and run onPeerActivated for each. Replaces runInitialSyncForNewPeers.
+ * Invoked from startFederationWorkers.
+ */
+export async function startupBootstrapSync(): Promise<void> {
+  if (!isFederationRelayEnabled()) return;
+
+  const db = getDb();
+  const peers = db.select().from(schema.federationPeers)
+    .where(and(
+      eq(schema.federationPeers.status, 'active'),
+      eq(schema.federationPeers.lastSyncedAt, 0),
+    )).all();
+
+  for (const peer of peers) {
+    await onPeerActivated(peer.id, 'startup_bootstrap');
+  }
+}
diff --git a/packages/server/src/utils/federationPeering.test.ts b/packages/server/src/utils/federationPeering.test.ts
index 3961dc0b..2b044795 100644
--- a/packages/server/src/utils/federationPeering.test.ts
+++ b/packages/server/src/utils/federationPeering.test.ts
@@ -1,4 +1,4 @@
-import { describe, it, expect, vi } from 'vitest';
+import { describe, it, expect, vi, beforeEach } from 'vitest';
 import type { EnsurePeeredResult } from './federationPeering.js';
 import { racePeering } from './federationPeering.js';
 
@@ -112,3 +112,59 @@ describe('racePeering', () => {
     warnSpy.mockRestore();
   });
 });
+
+describe('ensurePeered needs_attention handling', () => {
+  beforeEach(() => {
+    vi.resetModules();
+  });
+
+  it('returns rejected without calling performHandshake when peer is in needs_attention', async () => {
+    const fakeDbGet = vi.fn().mockReturnValue({
+      id: 'peer-na',
+      origin: 'https://remote.example',
+      status: 'needs_attention',
+      hmacSecret: 'secret',
+      createdAt: Date.now(),
+      lastSyncedAt: 0,
+    });
+
+    vi.doMock('../db/index.js', () => ({
+      getDb: () => ({
+        select: () => ({
+          from: () => ({
+            where: () => ({
+              get: fakeDbGet,
+            }),
+          }),
+        }),
+      }),
+    }));
+
+    vi.doMock('../utils/federationAuth.js', () => ({
+      getOurOrigin: () => 'https://local.example',
+      generateHmacSecret: () => 'new-secret',
+    }));
+
+    vi.doMock('../routes/federation.js', () => ({
+      validateOrigin: (o: string) => o,
+    }));
+
+    vi.doMock('../utils/federationPeerActivation.js', () => ({
+      onPeerActivated: vi.fn(),
+    }));
+
+    const { ensurePeered } = await import('./federationPeering.js');
+    const fetchSpy = vi.spyOn(globalThis, 'fetch');
+
+    const result = await ensurePeered('https://remote.example');
+
+    expect(result.status).toBe('rejected');
+    if (result.status === 'rejected') {
+      expect(result.error).toContain('needs_attention');
+    }
+    // performHandshake must not have fired — no POST to /peer/accept
+    expect(fetchSpy).not.toHaveBeenCalled();
+
+    vi.restoreAllMocks();
+  });
+});
diff --git a/packages/server/src/utils/federationPeering.ts b/packages/server/src/utils/federationPeering.ts
index 2b582413..fc6b9ae2 100644
--- a/packages/server/src/utils/federationPeering.ts
+++ b/packages/server/src/utils/federationPeering.ts
@@ -4,6 +4,7 @@ import { eq } from 'drizzle-orm';
 import { generateSnowflake } from './snowflake.js';
 import { getOurOrigin, generateHmacSecret } from './federationAuth.js';
 import { validateOrigin } from '../routes/federation.js';
+import { onPeerActivated } from './federationPeerActivation.js';
 
 // ─── Types ───────────────────────────────────────────────────────────────────
 
@@ -72,6 +73,9 @@ export async function ensurePeered(origin: string): Promise<EnsurePeeredResult>
         // Unreachable peers were previously active — treat as active for peering
         // (the health check will restore them; don't re-handshake)
         return { status: 'active', peerId: existing.id };
+      case 'needs_attention':
+        // Admin intervention required — do not auto-heal via performHandshake
+        return { status: 'rejected', error: 'Peer in needs_attention — admin Reset required' };
       case 'awaiting_approval':
         return { status: 'pending', error: 'Awaiting admin approval on remote instance' };
       case 'pending':
@@ -158,6 +162,9 @@ async function performHandshake(
         .run();
       const { connectionManager } = await import('../ws/handler.js');
       connectionManager.sendToAdmins({ type: 'federation_peers_changed' as const });
+      onPeerActivated(peerId, 'ensure_peered').catch(err =>
+        console.error('[federation] onPeerActivated from ensurePeered failed:', err)
+      );
       return { status: 'active', peerId };
     }
 
diff --git a/packages/server/src/utils/federationWorker.ts b/packages/server/src/utils/federationWorker.ts
index d444aa53..e9c218e0 100644
--- a/packages/server/src/utils/federationWorker.ts
+++ b/packages/server/src/utils/federationWorker.ts
@@ -2,7 +2,7 @@ import { getDb } from '../db/index.js';
 import * as schema from '../db/schema.js';
 import { eq, and, lte, asc, inArray, sql } from 'drizzle-orm';
 import { config } from '../config.js';
-import { isFederationRelayEnabled, queueOutboxEvent } from './federationOutbox.js';
+import { isFederationRelayEnabled, queueOutboxEvent, appendMutationLog } from './federationOutbox.js';
 import { runFederationJanitor } from './storageJanitor.js';
 import { buildFederationHeaders, getOurOrigin, generateHmacSecret, ROTATION_GRACE_PERIOD_MS } from './federationAuth.js';
 import { evaluateAuthFailure, AUTH_FAILURE_THRESHOLD } from './federationAuthFailure.js';
@@ -10,8 +10,8 @@ import { generateSnowflake } from './snowflake.js';
 import { getDmMessageWithUser } from '../routes/dm.js';
 import { connectionManager } from '../ws/handler.js';
 import { generateThumbnail } from './thumbnail.js';
-import { processRelayEvents } from '../routes/federation.js';
 import type { FederationRelayRequest, FederationRelayResponse, FederationRelayEvent } from '@backspace/shared';
+import { onPeerActivated, startupBootstrapSync } from './federationPeerActivation.js';
 import fs from 'node:fs';
 import path from 'node:path';
 import crypto from 'node:crypto';
@@ -703,6 +703,18 @@ function handleSizeRejection(
     affectedUserIds,
   };
 
+  appendMutationLog(
+    localMsg.sourceMessageId,
+    localMsg.dmChannelId,
+    'file_rejected',
+    JSON.stringify({
+      attachmentId: att?.id ?? entry.sourceUrl,
+      sourceFilename,
+      rejectionReason: 'size_limit_exceeded',
+      rejectionLimit: maxUploadSize,
+      affectedUserIds,
+    }),
+  );
   queueOutboxEvent(
     localMsg.sourceMessageId,
     localMsg.dmChannelId,
@@ -1054,6 +1066,8 @@ async function processHealthCheckTick(): Promise<void> {
         console.log(
           `[federation-worker] Peer ${peer.origin} recovered — marked active`,
         );
+
+        await onPeerActivated(peer.id, 'health_check_recovery');
       }
       // If not ok, leave as unreachable — will check again next cycle
     } catch (err) {
@@ -1076,124 +1090,15 @@ function scheduleJanitorTick(): void {
 
 // ─── Lifecycle ──────────────────────────────────────────────────────────────
 
-/**
- * Trigger checkpoint sync for peers that have never been synced (lastSyncedAt === 0).
- * This catches historical messages that existed before the relay was enabled.
- */
-async function runInitialSyncForNewPeers(): Promise<void> {
-  if (!isFederationRelayEnabled()) return;
-
-  const db = getDb();
-  const unsyncedPeers = db
-    .select()
-    .from(schema.federationPeers)
-    .where(and(
-      eq(schema.federationPeers.status, 'active'),
-      eq(schema.federationPeers.lastSyncedAt, 0),
-    ))
-    .all();
-
-  if (unsyncedPeers.length === 0) return;
-
-  const ourOrigin = getOurOrigin();
-
-  for (const peer of unsyncedPeers) {
-    const signingSecret = (peer.pendingHmacSecret && peer.secretRotationAt)
-      ? peer.pendingHmacSecret
-      : peer.hmacSecret;
-    try {
-      console.log(`[federation-worker] Running initial sync with ${peer.origin}...`);
-      let sinceTimestamp = 0;
-      let totalEvents = 0;
-
-      // Paginate through all events from the peer
-      while (true) {
-        const body = JSON.stringify({ sinceTimestamp, limit: 100 });
-        const headers = buildFederationHeaders(body, signingSecret, ourOrigin);
-
-        const response = await fetch(`${peer.origin}/api/federation/sync`, {
-          method: 'POST',
-          headers,
-          body,
-          signal: AbortSignal.timeout(30_000),
-        });
-
-        if (!response.ok) {
-          console.error(`[federation-worker] Sync with ${peer.origin} failed: ${response.status}`);
-          break;
-        }
-
-        const data = await response.json() as { events: FederationRelayEvent[]; hasMore: boolean; checkpoint: number };
-
-        if (data.events.length === 0) break;
-
-        // Process events directly — no HTTP round-trip (FED-005)
-        await processRelayEvents(data.events, peer.origin, peer.origin, db);
-
-        totalEvents += data.events.length;
-        sinceTimestamp = data.checkpoint;
-
-        if (!data.hasMore) break;
-      }
-
-      // Second pass: sync friend events
-      let friendSinceTimestamp = 0;
-      while (true) {
-        const friendBody = JSON.stringify({ sinceTimestamp: friendSinceTimestamp, contextType: 'friend', limit: 100 });
-        const friendHeaders = buildFederationHeaders(friendBody, signingSecret, ourOrigin);
-
-        const friendResponse = await fetch(`${peer.origin}/api/federation/sync`, {
-          method: 'POST',
-          headers: friendHeaders,
-          body: friendBody,
-          signal: AbortSignal.timeout(30_000),
-        });
-
-        if (!friendResponse.ok) {
-          console.error(`[federation-worker] Friend sync with ${peer.origin} failed: ${friendResponse.status}`);
-          break;
-        }
-
-        const friendData = await friendResponse.json() as { events: FederationRelayEvent[]; hasMore: boolean; checkpoint: number };
-
-        if (friendData.events.length === 0) break;
-
-        // Process events directly — no HTTP round-trip (FED-005)
-        await processRelayEvents(friendData.events, peer.origin, peer.origin, db);
-
-        totalEvents += friendData.events.length;
-        friendSinceTimestamp = friendData.checkpoint;
-
-        if (!friendData.hasMore) break;
-      }
-
-      // Update lastSyncedAt so this doesn't run again
-      db.update(schema.federationPeers)
-        .set({ lastSyncedAt: Date.now() })
-        .where(eq(schema.federationPeers.id, peer.id))
-        .run();
-
-      if (totalEvents > 0) {
-        console.log(`[federation-worker] Initial sync with ${peer.origin}: ${totalEvents} events synced`);
-      } else {
-        console.log(`[federation-worker] Initial sync with ${peer.origin}: no events to sync`);
-      }
-    } catch (err) {
-      console.error(`[federation-worker] Initial sync with ${peer.origin} failed:`, err);
-      // Don't update lastSyncedAt — will retry next startup
-    }
-  }
-}
-
 export function startFederationWorkers(): void {
   console.log('[federation-worker] Federation workers started');
   scheduleOutboxTick();
   scheduleFileQueueTick();
   scheduleHealthCheckTick();
   scheduleJanitorTick();
-  // Run initial sync for newly peered instances (async, non-blocking)
-  runInitialSyncForNewPeers().catch((err) => {
-    console.error('[federation-worker] Initial sync error:', err);
+  // Bootstrap sync for freshly-peered rows (async, non-blocking)
+  startupBootstrapSync().catch((err) => {
+    console.error('[federation-worker] Startup bootstrap sync error:', err);
   });
 }