feat(federation): deleted flag on wire profile snapshots — tombstone markers never leave the instance (dead-incarnation spec §3.3)

packages/server/src/routes/federation.resolveOrCreate.test.ts

@@ -131,4 +131,21 @@ describe('resolveOrCreateReplicatedUser — self-homed identity guard', () => {
     expect(result).not.toBeNull();
     expect(result!.username).toBe('bob@orbit.ddns.net');
   });
+
+  it('refuses stub creation when the wire snapshot marks the identity deleted', async () => {
+    const { resolveOrCreateReplicatedUser } = await import('./federation.js');
+    const result = resolveOrCreateReplicatedUser('remote-del', 'orbit.ddns.net', testDb, { username: null, deleted: true });
+    expect(result).toBeNull();
+    expect(testDb.select().from(schema.users).all()).toHaveLength(0);
+  });
+
+  it('a deleted-marked identity that already resolves locally still returns the existing row', async () => {
+    testDb.insert(schema.users).values({
+      id: 'stub-1', username: 'old@orbit.ddns.net', passwordHash: '!federation-replicated',
+      homeInstance: 'orbit.ddns.net', homeUserId: 'remote-del', createdAt: 1,
+    }).run();
+    const { resolveOrCreateReplicatedUser } = await import('./federation.js');
+    const result = resolveOrCreateReplicatedUser('remote-del', 'orbit.ddns.net', testDb, { deleted: true });
+    expect(result?.id).toBe('stub-1'); // historical attribution stays intact
+  });
 });

packages/server/src/routes/federation.ts

@@ -3661,11 +3661,19 @@ export function resolveOrCreateReplicatedUser(
   homeUserId: string,
   homeInstance: string,
   db: ReturnType<typeof getDb>,
-  hints?: { username?: string | null; status?: 'online' | 'idle' | 'dnd' | 'offline' | null },
+  hints?: { username?: string | null; status?: 'online' | 'idle' | 'dnd' | 'offline' | null; deleted?: boolean | null },
 ): typeof schema.users.$inferSelect | null {
   const existing = findFederatedUser(homeUserId, homeInstance, db, hints);
   if (existing) return backfillHomeUserId(existing, homeUserId, db);
 
+  // A participant the sender marks as deleted must not materialize as a new
+  // stub — mirror of the local-tombstone skip below. An existing row still
+  // resolves above, so historical attribution is unaffected (spec §3.3).
+  if (hints?.deleted) {
+    console.log(`[federation] Skipping stub creation for remotely-deleted identity homeUserId=${homeUserId}`);
+    return null;
+  }
+
   // Check if this identity was previously deleted — don't resurrect a tombstoned
   // user by creating a new stub. The isDeleted=0 filter in findFederatedUser
   // already hides the deleted row, so we must query without that filter here.
@@ -3916,7 +3924,7 @@ async function processCreateEvent(
   }> = [];
 
   for (const p of event.participants) {
-    let localUser = resolveOrCreateReplicatedUser(p.homeUserId, p.homeInstance, db, { username: p.profile?.username, status: p.profile?.status });
+    let localUser = resolveOrCreateReplicatedUser(p.homeUserId, p.homeInstance, db, { username: p.profile?.username, status: p.profile?.status, deleted: p.profile?.deleted });
     // Skip deleted identities — don't include tombstoned users in the DM
     if (!localUser) continue;
     // Hydrate with profile data from the relay event (displayName, avatar, etc.)
@@ -4513,7 +4521,7 @@ export async function processMemberAddEvent(
     // Resolve owner — create a replicated stub if unknown
     let ownerId: string | null = null;
     if (event.group.owner) {
-      const ownerLocal = resolveOrCreateReplicatedUser(event.group.owner.homeUserId, event.group.owner.homeInstance, db, { username: event.group.owner.profile?.username, status: event.group.owner.profile?.status });
+      const ownerLocal = resolveOrCreateReplicatedUser(event.group.owner.homeUserId, event.group.owner.homeInstance, db, { username: event.group.owner.profile?.username, status: event.group.owner.profile?.status, deleted: event.group.owner.profile?.deleted });
       ownerId = ownerLocal?.id ?? null;
     }
 
@@ -4550,7 +4558,7 @@ export async function processMemberAddEvent(
     // Add all roster members — create replicated user stubs for any
     // participants from remote instances that haven't been seen before.
     for (const member of event.group.members) {
-      const rosterUser = resolveOrCreateReplicatedUser(member.homeUserId, member.homeInstance, db, { username: member.profile?.username, status: member.profile?.status });
+      const rosterUser = resolveOrCreateReplicatedUser(member.homeUserId, member.homeInstance, db, { username: member.profile?.username, status: member.profile?.status, deleted: member.profile?.deleted });
       // Skip deleted identities — tombstoned users can't be added to a DM
       if (!rosterUser) continue;
       const existing = db.select().from(schema.dmMembers)
@@ -4604,7 +4612,7 @@ export async function processMemberAddEvent(
     event.membership.user.homeUserId,
     event.membership.user.homeInstance,
     db,
-    { username: event.membership.user.profile?.username, status: event.membership.user.profile?.status },
+    { username: event.membership.user.profile?.username, status: event.membership.user.profile?.status, deleted: event.membership.user.profile?.deleted },
   );
   if (!localUser) {
     // The user's identity has been deleted — don't add a tombstoned user to the DM
@@ -4643,7 +4651,7 @@ export async function processMemberAddEvent(
   // would otherwise find the channel already present and fall through to the incremental path,
   // creating spurious system messages (the exact bug this fixes).
   const actorUser = event.membership.addedBy
-    ? resolveOrCreateReplicatedUser(event.membership.addedBy.homeUserId, event.membership.addedBy.homeInstance, db, { username: event.membership.addedBy.profile?.username, status: event.membership.addedBy.profile?.status })
+    ? resolveOrCreateReplicatedUser(event.membership.addedBy.homeUserId, event.membership.addedBy.homeInstance, db, { username: event.membership.addedBy.profile?.username, status: event.membership.addedBy.profile?.status, deleted: event.membership.addedBy.profile?.deleted })
     : null;
   const actorId = actorUser?.id ?? localUser.id;
   const addBaseName = localUser.username?.includes('@') ? localUser.username.split('@')[0] : (localUser.username ?? 'Unknown');
@@ -4952,7 +4960,7 @@ export function processOwnershipTransferEvent(
     event.ownership.newOwner.homeUserId,
     event.ownership.newOwner.homeInstance,
     db,
-    { username: event.ownership.newOwner.profile?.username, status: event.ownership.newOwner.profile?.status },
+    { username: event.ownership.newOwner.profile?.username, status: event.ownership.newOwner.profile?.status, deleted: event.ownership.newOwner.profile?.deleted },
   );
   if (!newOwnerLocal) {
     rejected.push({ messageId: event.messageId, reason: 'participant_not_found' });
@@ -5127,7 +5135,7 @@ async function processFriendRequestCreateEvent(
   }
 
   // Resolve the sender (create stub if needed — they're on a remote instance)
-  const fromUserResolved = resolveOrCreateReplicatedUser(from.homeUserId, from.homeInstance, db, { username: event.friendship.fromProfile?.username, status: event.friendship.fromProfile?.status });
+  const fromUserResolved = resolveOrCreateReplicatedUser(from.homeUserId, from.homeInstance, db, { username: event.friendship.fromProfile?.username, status: event.friendship.fromProfile?.status, deleted: event.friendship.fromProfile?.deleted });
   if (!fromUserResolved) {
     // Sender's identity has been deleted — silently accept to drop the event
     accepted.push(event.messageId);
@@ -5245,7 +5253,7 @@ function processFriendRequestUpdateEvent(
   }
 
   // Resolve the recipient (create stub if needed — they're on the remote instance)
-  const toUser = resolveOrCreateReplicatedUser(to.homeUserId, to.homeInstance, db, { username: event.friendship.toProfile?.username, status: event.friendship.toProfile?.status });
+  const toUser = resolveOrCreateReplicatedUser(to.homeUserId, to.homeInstance, db, { username: event.friendship.toProfile?.username, status: event.friendship.toProfile?.status, deleted: event.friendship.toProfile?.deleted });
   if (!toUser) {
     // Recipient's identity has been deleted — accept idempotently to drop the event
     accepted.push(event.messageId);
@@ -5385,14 +5393,14 @@ async function processFriendAddEvent(
   }
 
   // Resolve both users (create stubs if needed) and hydrate with profile data
-  const fromUserResolved = resolveOrCreateReplicatedUser(from.homeUserId, from.homeInstance, db, { username: event.friendship.fromProfile?.username, status: event.friendship.fromProfile?.status });
+  const fromUserResolved = resolveOrCreateReplicatedUser(from.homeUserId, from.homeInstance, db, { username: event.friendship.fromProfile?.username, status: event.friendship.fromProfile?.status, deleted: event.friendship.fromProfile?.deleted });
   if (!fromUserResolved) {
     // One party's identity is deleted — accept idempotently to drop the event
     accepted.push(event.messageId);
     return;
   }
   let fromUser = await hydrateReplicatedUserProfile(fromUserResolved, event.friendship.fromProfile, db);
-  const toUserResolved = resolveOrCreateReplicatedUser(to.homeUserId, to.homeInstance, db, { username: event.friendship.toProfile?.username, status: event.friendship.toProfile?.status });
+  const toUserResolved = resolveOrCreateReplicatedUser(to.homeUserId, to.homeInstance, db, { username: event.friendship.toProfile?.username, status: event.friendship.toProfile?.status, deleted: event.friendship.toProfile?.deleted });
   if (!toUserResolved) {
     accepted.push(event.messageId);
     return;
@@ -6479,7 +6487,7 @@ export async function processGroupMetadataUpdateEvent(
       actorParticipant.homeUserId,
       actorParticipant.homeInstance,
       db,
-      { username: actorParticipant.profile?.username, status: actorParticipant.profile?.status },
+      { username: actorParticipant.profile?.username, status: actorParticipant.profile?.status, deleted: actorParticipant.profile?.deleted },
     );
     actorUserId = actorUser?.id ?? null;
   }

packages/server/src/routes/social.snapshot.test.ts

@@ -0,0 +1,78 @@
+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';
+
+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,
+  getRawDb: () => sqlite,
+  schema,
+}));
+
+let _sf = 1;
+vi.mock('../utils/snowflake.js', () => ({
+  generateSnowflake: () => String(_sf++),
+  setWorkerId: vi.fn(),
+}));
+
+vi.mock('../utils/federationAuth.js', async (importActual) => {
+  const actual = await importActual<typeof import('../utils/federationAuth.js')>();
+  return { ...actual, getOurOrigin: () => 'https://home.test' };
+});
+
+// social.ts imports connectionManager from ws/handler.js — stub the minimal
+// surface so the route module loads at test time. buildProfileSnapshot doesn't
+// touch any of these.
+vi.mock('../ws/handler.js', () => ({
+  connectionManager: {
+    sendToUser: vi.fn(),
+    sendToSpace: vi.fn(),
+    sendToDmMembers: vi.fn(),
+    sendToAdmins: vi.fn(),
+    getAllOnlineUserIds: () => [],
+    evictFederatedCallsForHost: vi.fn(),
+    federatedCalls: new Map(),
+    isUserOnline: vi.fn(),
+    lateBindFederatedCall: 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');
+    for (const stmt of sql.split(/-->\s*statement-breakpoint/)) {
+      const clean = stmt.trim();
+      if (clean) db.exec(clean);
+    }
+  }
+}
+
+beforeEach(() => {
+  sqlite = new Database(':memory:');
+  testDb = drizzle(sqlite, { schema });
+  applyMigrations(sqlite);
+  _sf = 1;
+});
+
+describe('buildProfileSnapshot — deleted users', () => {
+  it('never ships the !deleted: tombstone marker', async () => {
+    const { buildProfileSnapshot } = await import('./social.js');
+    const row = {
+      username: '!deleted:12345', displayName: null, avatar: null, avatarColor: null,
+      banner: null, bio: null, status: 'offline', homeInstance: null, isDeleted: 1,
+    } as unknown as Parameters<typeof buildProfileSnapshot>[0];
+    const snap = buildProfileSnapshot(row);
+    expect(snap.deleted).toBe(true);
+    expect(snap.username ?? null).toBeNull();
+  });
+});

packages/server/src/routes/social.ts

@@ -20,7 +20,11 @@ import type {
 } from '@backspace/shared';
 import { sanitizeUser } from '../utils/sanitize.js';
 
-function buildProfileSnapshot(user: typeof schema.users.$inferSelect): FederationRelayProfileSnapshot {
+export function buildProfileSnapshot(user: typeof schema.users.$inferSelect): FederationRelayProfileSnapshot {
+  if (user.isDeleted) {
+    // Never ship the internal '!deleted:<id>' tombstone marker (spec §3.3).
+    return { deleted: true };
+  }
   // Only meaningful for native users (us). Replicated stubs carry stale status
   // their home owns — emitting it would flap remote UIs on relay receipt.
   const status = !user.homeInstance && user.status

packages/server/src/utils/federationOutbox.participants.test.ts

@@ -0,0 +1,89 @@
+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';
+
+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,
+  getRawDb: () => sqlite,
+  schema,
+}));
+
+let _sf = 1;
+vi.mock('./snowflake.js', () => ({
+  generateSnowflake: () => String(_sf++),
+  setWorkerId: vi.fn(),
+}));
+
+vi.mock('./federationAuth.js', async (importActual) => {
+  const actual = await importActual<typeof import('./federationAuth.js')>();
+  return { ...actual, getOurOrigin: () => 'https://home.test' };
+});
+
+// federationOutbox.ts imports extractDomain from routes/federation.js, which in
+// turn imports connectionManager/ws — stub the minimal surface so the module
+// graph loads at test time. getDmParticipants doesn't touch any of these.
+vi.mock('../ws/handler.js', () => ({
+  connectionManager: {
+    sendToUser: vi.fn(),
+    sendToSpace: vi.fn(),
+    sendToDmMembers: vi.fn(),
+    sendToAdmins: vi.fn(),
+    getAllOnlineUserIds: () => [],
+    evictFederatedCallsForHost: vi.fn(),
+    federatedCalls: new Map(),
+    isUserOnline: vi.fn(),
+    lateBindFederatedCall: 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');
+    for (const stmt of sql.split(/-->\s*statement-breakpoint/)) {
+      const clean = stmt.trim();
+      if (clean) db.exec(clean);
+    }
+  }
+}
+
+beforeEach(() => {
+  sqlite = new Database(':memory:');
+  testDb = drizzle(sqlite, { schema });
+  applyMigrations(sqlite);
+  _sf = 1;
+});
+
+describe('getDmParticipants — deleted members', () => {
+  it('ships deleted:true and NO username for tombstoned members', async () => {
+    testDb.insert(schema.users).values([
+      { id: 'alice', username: 'alice', passwordHash: 'h', homeInstance: null, createdAt: 1 },
+      { id: 'ghost', username: '!deleted:ghost', passwordHash: 'h', homeInstance: null, isDeleted: 1, createdAt: 1 },
+    ]).run();
+    testDb.insert(schema.dmChannels).values({ id: 'ch1', federatedId: 'fed-ch1', createdAt: 1 }).run();
+    testDb.insert(schema.dmMembers).values([
+      { dmChannelId: 'ch1', userId: 'alice', closed: 0 },
+      { dmChannelId: 'ch1', userId: 'ghost', closed: 0 },
+    ]).run();
+
+    const { getDmParticipants } = await import('./federationOutbox.js');
+    const participants = getDmParticipants('ch1');
+    const ghost = participants.find(p => p.homeUserId === 'ghost')!;
+    expect(ghost.profile?.deleted).toBe(true);
+    expect(ghost.profile?.username ?? null).toBeNull();
+    expect(ghost.profile?.displayName ?? null).toBeNull();
+    const alice = participants.find(p => p.homeUserId === 'alice')!;
+    expect(alice.profile?.deleted ?? undefined).toBeUndefined();
+    expect(alice.profile?.username).toBe('alice');
+  });
+});

packages/server/src/utils/federationOutbox.ts

@@ -364,6 +364,7 @@ export function getDmParticipants(dmChannelId: string): FederationRelayParticipa
       avatar: schema.users.avatar,
       avatarColor: schema.users.avatarColor,
       status: schema.users.status,
+      isDeleted: schema.users.isDeleted,
     })
     .from(schema.dmMembers)
     .innerJoin(schema.users, eq(schema.dmMembers.userId, schema.users.id))
@@ -372,7 +373,17 @@ export function getDmParticipants(dmChannelId: string): FederationRelayParticipa
 
   const domainOrigin = getOurOrigin();
 
-  return members.map(m => ({
+  return members.map(m => {
+    if (m.isDeleted) {
+      // Tombstoned member: ship the identity for attribution but no profile
+      // data — the internal '!deleted:<id>' marker never leaves this instance.
+      return {
+        homeUserId: m.homeUserId || m.id,
+        homeInstance: m.homeInstance || domainOrigin,
+        profile: { deleted: true },
+      };
+    }
+    return {
       homeUserId: m.homeUserId || m.id,
       homeInstance: m.homeInstance || domainOrigin,
       profile: {
@@ -384,7 +395,8 @@ export function getDmParticipants(dmChannelId: string): FederationRelayParticipa
         // stale status owned by their home; emitting it would flap remote UIs.
         status: !m.homeInstance ? (m.status as 'online' | 'idle' | 'dnd' | 'offline' | null) : null,
       },
-  }));
+    };
+  });
 }
 
 /**

packages/shared/src/types.ts

@@ -1046,6 +1046,12 @@ export interface FederationRelayProfileSnapshot {
   // already-online remote stays stuck at 'offline' on the receiver until they
   // next change status.
   status?: 'online' | 'idle' | 'dnd' | 'offline' | null;
+  /**
+   * The user is tombstoned on the instance that built this snapshot.
+   * Receivers must not create a new stub for this identity; internal
+   * '!deleted:<id>' usernames are never shipped (dead-incarnation spec §3.3).
+   */
+  deleted?: boolean | null;
 }
 
 export interface FederationProfileUpdatePayload {