fix(permissions): deny space permissions to non-members (invite-bypass)

computePermissions() returned the space @everyone role's permissions without
verifying the caller had joined the space. Because CREATE_INVITE is in
DEFAULT_EVERYONE_PERMISSIONS, any authenticated user could mint an invite code
for a request-only space — whose id is listed by /api/spaces/explore — and then
self-join via /api/spaces/:id/join, bypassing the join-request approval flow.
The same gap let non-members read message history and search default channels.

Root cause:
- computePermissions now returns 0n for non-members (space owner and instance
  admin still short-circuit first, so they are unaffected).

Defense in depth (request-only spaces are approval-gated, never invite-joinable):
- both invite-code join endpoints reject visibility='request' (private stays
  invite-joinable — its only entry path; public too).
- POST /api/spaces/:id/invite refuses to hand out a code for request spaces.
- POST /api/dm/space-invite refuses to card a local request space, checked by
  space id against the local table so a spoofed spaceInstanceOrigin can't slip
  past it.
- InviteModal hides the invite affordances for request spaces.

Also removes the unused computeCategoryPermissions(), which duplicated the
resolution algorithm without the membership gate.

Adds unit + route + component tests covering non-member/member/owner/admin
resolution and the request/private/public visibility matrix.

Reported-by: BadAtCaptchas (#2)

packages/server/src/routes/dm.spaceInvite.test.ts

@@ -200,6 +200,57 @@ describe('POST /api/dm/space-invite', () => {
     expect(messageCount).toBe(0);
   });
 
+  it('rejects a space invite for a local request-only space (approval required)', async () => {
+    // Real local space with request visibility; the snapshot is mocked to match.
+    testDb.insert(schema.spaces).values({
+      id: 'S-REQ', name: 'Req', ownerId: 'alice', inviteCode: 'reqcode',
+      visibility: 'request', createdAt: 1,
+    }).run();
+    (getLocalInviteSnapshot as unknown as ReturnType<typeof vi.fn>).mockReturnValueOnce({
+      spaceId: 'S-REQ', spaceName: 'Req', description: null, icon: null,
+      avatarColor: null, memberCount: 1, instanceName: 'Backspace',
+    });
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/dm/space-invite',
+      payload: {
+        target: { userId: 'bob' },
+        spaceId: 'S-REQ',
+        spaceInstanceOrigin: '',
+        inviteCode: 'reqcode',
+      },
+    });
+    expect(res.statusCode).toBe(403);
+    // No DM card should be inserted for a request-only space.
+    expect(testDb.select().from(schema.dmMessages).all().length).toBe(0);
+  });
+
+  it('rejects a local request-only space even when spaceInstanceOrigin is spoofed to look remote', async () => {
+    // A caller can send an origin variant (trailing slash / different case) so
+    // `isLocal` is false and the fetch path is taken, but the space is genuinely
+    // local + request. The guard must not depend on the claimed origin.
+    testDb.insert(schema.spaces).values({
+      id: 'S-REQ2', name: 'Req2', ownerId: 'alice', inviteCode: 'reqcode2',
+      visibility: 'request', createdAt: 1,
+    }).run();
+    (fetchSpaceInviteSnapshot as unknown as ReturnType<typeof vi.fn>).mockResolvedValueOnce({
+      spaceId: 'S-REQ2', spaceName: 'Req2', description: null, icon: null,
+      avatarColor: null, memberCount: 1, instanceName: 'Backspace',
+    });
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/dm/space-invite',
+      payload: {
+        target: { userId: 'bob' },
+        spaceId: 'S-REQ2',
+        spaceInstanceOrigin: 'https://local.test/', // trailing slash defeats strict isLocal compare
+        inviteCode: 'reqcode2',
+      },
+    });
+    expect(res.statusCode).toBe(403);
+    expect(testDb.select().from(schema.dmMessages).all().length).toBe(0);
+  });
+
   it('inserts a type=system message with parseable space_invite content on success', async () => {
     (getLocalInviteSnapshot as unknown as ReturnType<typeof vi.fn>).mockReturnValueOnce({
       spaceId: 'S1',

packages/server/src/routes/dm.ts

@@ -2393,6 +2393,19 @@ export async function dmRoutes(app: FastifyInstance): Promise<void> {
       return reply.code(400).send({ error: 'invite_invalid', statusCode: 400 });
     }
 
+    // Request-only spaces are approval-gated and have no usable invite links, so
+    // refuse to send an invite card that would dead-end at the recipient's join
+    // guard. This is checked against our LOCAL spaces table by id, independent of
+    // the caller-supplied spaceInstanceOrigin: if the space is genuinely local and
+    // request-only we reject even when the origin is spoofed to look remote. A
+    // truly remote space is absent from this table (undefined → allowed); its own
+    // home instance enforces the same rule when the recipient tries to join.
+    const localSpace = db.select({ visibility: schema.spaces.visibility })
+      .from(schema.spaces).where(eq(schema.spaces.id, body.spaceId)).get();
+    if (localSpace?.visibility === 'request') {
+      return reply.code(403).send({ error: 'space_requires_approval', statusCode: 403 });
+    }
+
     // 4. Resolve / create the 1-on-1 DM (delegate to dedup helper).
     const dmChannelId = ensureOneOnOneDmChannel(callerId, targetUser, db);
 

packages/server/src/routes/spaces.joinVisibility.test.ts

@@ -0,0 +1,178 @@
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+import Fastify, { type FastifyInstance } from 'fastify';
+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 { setWorkerId } from '../utils/snowflake.js';
+
+setWorkerId(1);
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+
+type TestDb = ReturnType<typeof drizzle<typeof schema>>;
+let sqlite: Database.Database;
+let testDb: TestDb;
+let currentUserId = 'joiner';
+
+vi.mock('../db/index.js', () => ({
+  getDb: () => testDb,
+  getRawDb: () => sqlite,
+  schema,
+}));
+
+vi.mock('../utils/auth.js', () => ({
+  authenticate: async (req: { userId?: string }) => {
+    req.userId = currentUserId;
+  },
+}));
+
+vi.mock('../ws/handler.js', () => ({
+  connectionManager: {
+    addUserSpace: vi.fn(),
+    sendToSpace: 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 sqlText = fs.readFileSync(path.join(migrationsDir, f), 'utf8');
+    for (const stmt of sqlText.split(/-->\s*statement-breakpoint/)) {
+      const clean = stmt.trim();
+      if (clean) db.exec(clean);
+    }
+  }
+}
+
+const OWNER_ID = 'owner';
+const now = 1_700_000_000_000;
+
+async function buildApp(): Promise<FastifyInstance> {
+  const { spaceRoutes } = await import('./spaces.js');
+  const f = Fastify();
+  await f.register(spaceRoutes);
+  return f;
+}
+
+let app: FastifyInstance;
+
+function makeSpace(id: string, visibility: 'public' | 'request' | 'private', inviteCode: string): void {
+  testDb.insert(schema.spaces).values({
+    id,
+    name: `space-${visibility}`,
+    ownerId: OWNER_ID,
+    inviteCode,
+    visibility,
+    createdAt: now,
+  }).run();
+}
+
+beforeEach(async () => {
+  sqlite = new Database(':memory:');
+  sqlite.pragma('foreign_keys = ON');
+  applyMigrations(sqlite);
+  testDb = drizzle(sqlite, { schema });
+  currentUserId = 'joiner';
+
+  for (const id of [OWNER_ID, 'joiner']) {
+    testDb.insert(schema.users).values({
+      id, username: id, passwordHash: 'x', createdAt: now,
+    }).run();
+  }
+
+  app = await buildApp();
+});
+
+function isMember(spaceId: string, userId: string): boolean {
+  return testDb.select().from(schema.spaceMembers).all()
+    .some(m => m.spaceId === spaceId && m.userId === userId);
+}
+
+describe('POST /api/spaces/:id/join — visibility guard', () => {
+  it('rejects an invite-code join for a request-only space (approval required)', async () => {
+    makeSpace('s-req', 'request', 'code-req');
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/spaces/s-req/join',
+      payload: { inviteCode: 'code-req' },
+    });
+    expect(res.statusCode).toBe(403);
+    expect(isMember('s-req', 'joiner')).toBe(false);
+  });
+
+  it('allows an invite-code join for a private space (invite is the only entry path)', async () => {
+    makeSpace('s-priv', 'private', 'code-priv');
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/spaces/s-priv/join',
+      payload: { inviteCode: 'code-priv' },
+    });
+    expect(res.statusCode).toBe(200);
+    expect(isMember('s-priv', 'joiner')).toBe(true);
+  });
+
+  it('allows an invite-code join for a public space', async () => {
+    makeSpace('s-pub', 'public', 'code-pub');
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/spaces/s-pub/join',
+      payload: { inviteCode: 'code-pub' },
+    });
+    expect(res.statusCode).toBe(200);
+    expect(isMember('s-pub', 'joiner')).toBe(true);
+  });
+});
+
+describe('POST /api/spaces/join (codeless) — visibility guard', () => {
+  it('rejects an invite-code join for a request-only space', async () => {
+    makeSpace('s-req2', 'request', 'code-req2');
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/spaces/join',
+      payload: { inviteCode: 'code-req2' },
+    });
+    expect(res.statusCode).toBe(403);
+    expect(isMember('s-req2', 'joiner')).toBe(false);
+  });
+
+  it('allows an invite-code join for a private space', async () => {
+    makeSpace('s-priv2', 'private', 'code-priv2');
+    const res = await app.inject({
+      method: 'POST',
+      url: '/api/spaces/join',
+      payload: { inviteCode: 'code-priv2' },
+    });
+    expect(res.statusCode).toBe(200);
+    expect(isMember('s-priv2', 'joiner')).toBe(true);
+  });
+});
+
+describe('POST /api/spaces/:id/invite — visibility guard', () => {
+  // Caller is the owner (a member with CREATE_INVITE) so we exercise the
+  // visibility guard, not the permission/membership gate.
+  it('refuses to mint/return an invite code for a request-only space', async () => {
+    currentUserId = OWNER_ID;
+    makeSpace('s-req-inv', 'request', 'code-req-inv');
+    const res = await app.inject({ method: 'POST', url: '/api/spaces/s-req-inv/invite' });
+    expect(res.statusCode).toBe(403);
+  });
+
+  it('returns an invite code for a private space', async () => {
+    currentUserId = OWNER_ID;
+    makeSpace('s-priv-inv', 'private', 'code-priv-inv');
+    const res = await app.inject({ method: 'POST', url: '/api/spaces/s-priv-inv/invite' });
+    expect(res.statusCode).toBe(200);
+    expect(res.json().inviteCode).toBe('code-priv-inv');
+  });
+
+  it('returns an invite code for a public space', async () => {
+    currentUserId = OWNER_ID;
+    makeSpace('s-pub-inv', 'public', 'code-pub-inv');
+    const res = await app.inject({ method: 'POST', url: '/api/spaces/s-pub-inv/invite' });
+    expect(res.statusCode).toBe(200);
+    expect(res.json().inviteCode).toBe('code-pub-inv');
+  });
+});

packages/server/src/routes/spaces.ts

@@ -564,6 +564,13 @@ export async function spaceRoutes(app: FastifyInstance): Promise<void> {
       return reply.code(403).send({ error: 'Missing CREATE_INVITE permission', statusCode: 403 });
     }
 
+    // Request-only spaces are approval-gated and never joinable by invite code
+    // (see the join endpoints), so they have no usable invite links. Refuse to
+    // hand one out rather than mint a code that would dead-end at the join guard.
+    if (server.visibility === 'request') {
+      return reply.code(403).send({ error: 'Request-only spaces do not use invite links; entry is by join request', statusCode: 403 });
+    }
+
     // Return existing invite code if one exists, otherwise generate a new one
     if (server.inviteCode) {
       return reply.code(200).send({ inviteCode: server.inviteCode });
@@ -605,6 +612,13 @@ export async function spaceRoutes(app: FastifyInstance): Promise<void> {
       return reply.code(409).send({ error: 'You are already a member of this space', statusCode: 409 });
     }
 
+    // Request-only spaces are gated by manager approval: entry must go through
+    // POST /request-join + approval, never a bearer invite code. (Private spaces
+    // remain invite-joinable — that is their only entry path; public too.)
+    if (server.visibility === 'request') {
+      return reply.code(403).send({ error: 'This space requires an approved join request', statusCode: 403 });
+    }
+
     const now = Date.now();
     db.insert(schema.spaceMembers).values({
       spaceId: id,
@@ -661,6 +675,11 @@ export async function spaceRoutes(app: FastifyInstance): Promise<void> {
       return reply.code(409).send({ error: 'You are already a member of this space', statusCode: 409 });
     }
 
+    // Request-only spaces are gated by manager approval (see POST /:id/join).
+    if (server.visibility === 'request') {
+      return reply.code(403).send({ error: 'This space requires an approved join request', statusCode: 403 });
+    }
+
     const now = Date.now();
     db.insert(schema.spaceMembers).values({
       spaceId: server.id,

packages/server/src/utils/permissions.test.ts

@@ -0,0 +1,127 @@
+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 {
+  PermissionBits,
+  ALL_PERMISSIONS,
+  DEFAULT_EVERYONE_PERMISSIONS,
+  permissionsToString,
+} from '@backspace/shared/src/permissions.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,
+}));
+
+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 sqlText = fs.readFileSync(path.join(migrationsDir, f), 'utf8');
+    const statements = sqlText.split(/-->\s*statement-breakpoint/);
+    for (const stmt of statements) {
+      const clean = stmt.trim();
+      if (clean) db.exec(clean);
+    }
+  }
+}
+
+const OWNER_ID = 'owner-1';
+const MEMBER_ID = 'member-1';
+const OUTSIDER_ID = 'outsider-1';
+const ADMIN_ID = 'admin-1';
+const SPACE_ID = 'space-1';
+const now = 1_700_000_000_000;
+
+function seed(): void {
+  for (const [id, isAdmin] of [
+    [OWNER_ID, 0],
+    [MEMBER_ID, 0],
+    [OUTSIDER_ID, 0],
+    [ADMIN_ID, 1],
+  ] as const) {
+    testDb.insert(schema.users).values({
+      id,
+      username: id,
+      passwordHash: 'x',
+      isAdmin,
+      createdAt: now,
+    }).run();
+  }
+
+  testDb.insert(schema.spaces).values({
+    id: SPACE_ID,
+    name: 'Test Space',
+    ownerId: OWNER_ID,
+    inviteCode: 'code-1',
+    visibility: 'request',
+    createdAt: now,
+  }).run();
+
+  // @everyone role (id === spaceId) carries the default member permissions.
+  testDb.insert(schema.roles).values({
+    id: SPACE_ID,
+    spaceId: SPACE_ID,
+    name: '@everyone',
+    permissions: permissionsToString(DEFAULT_EVERYONE_PERMISSIONS),
+    createdAt: now,
+  }).run();
+
+  // Owner and one ordinary member are enrolled; OUTSIDER and ADMIN are not.
+  testDb.insert(schema.spaceMembers).values({ spaceId: SPACE_ID, userId: OWNER_ID, joinedAt: now }).run();
+  testDb.insert(schema.spaceMembers).values({ spaceId: SPACE_ID, userId: MEMBER_ID, joinedAt: now }).run();
+}
+
+beforeEach(() => {
+  sqlite = new Database(':memory:');
+  sqlite.pragma('foreign_keys = ON');
+  applyMigrations(sqlite);
+  testDb = drizzle(sqlite, { schema });
+  seed();
+});
+
+describe('computePermissions', () => {
+  it('returns 0n for a user who is not a member of the space', async () => {
+    const { computePermissions } = await import('./permissions.js');
+    expect(computePermissions(OUTSIDER_ID, SPACE_ID)).toBe(0n);
+  });
+
+  it('does not grant CREATE_INVITE to a non-member via @everyone', async () => {
+    const { hasPermission } = await import('./permissions.js');
+    expect(hasPermission(OUTSIDER_ID, SPACE_ID, PermissionBits.CREATE_INVITE)).toBe(false);
+  });
+
+  it('does not grant read access to a non-member via @everyone', async () => {
+    const { hasPermission } = await import('./permissions.js');
+    const read = PermissionBits.VIEW_CHANNEL | PermissionBits.READ_MESSAGE_HISTORY;
+    expect(hasPermission(OUTSIDER_ID, SPACE_ID, read)).toBe(false);
+  });
+
+  it('grants @everyone permissions to an enrolled member', async () => {
+    const { computePermissions } = await import('./permissions.js');
+    const perms = computePermissions(MEMBER_ID, SPACE_ID);
+    expect(perms).toBe(DEFAULT_EVERYONE_PERMISSIONS);
+    expect(perms & PermissionBits.CREATE_INVITE).toBe(PermissionBits.CREATE_INVITE);
+  });
+
+  it('grants ALL_PERMISSIONS to the space owner', async () => {
+    const { computePermissions } = await import('./permissions.js');
+    expect(computePermissions(OWNER_ID, SPACE_ID)).toBe(ALL_PERMISSIONS);
+  });
+
+  it('grants ALL_PERMISSIONS to an instance admin even when not a member', async () => {
+    const { computePermissions } = await import('./permissions.js');
+    expect(computePermissions(ADMIN_ID, SPACE_ID)).toBe(ALL_PERMISSIONS);
+  });
+});

packages/server/src/utils/permissions.ts

@@ -36,6 +36,13 @@ export function computePermissions(userId: string, spaceId: string, channelId?:
   const userRow = db.select().from(schema.users).where(eq(schema.users.id, userId)).get();
   if (userRow?.isAdmin === 1) return ALL_PERMISSIONS;
 
+  // 1c. Membership gate — a user who has not joined the space has NO permissions
+  // in it. Without this, the @everyone role below leaks default member rights
+  // (VIEW_CHANNEL, READ_MESSAGE_HISTORY, CREATE_INVITE, …) to any authenticated
+  // non-member, which allowed reading channels and minting invite codes for
+  // spaces the caller never joined. Owner and instance admin are handled above.
+  if (!getMember(spaceId, userId)) return 0n;
+
   // 2. Base permissions from @everyone role (id === spaceId)
   const everyoneRole = db.select().from(schema.roles)
     .where(and(eq(schema.roles.id, spaceId), eq(schema.roles.spaceId, spaceId)))
@@ -146,67 +153,6 @@ export function computePermissions(userId: string, spaceId: string, channelId?:
   return base;
 }
 
-/**
- * Compute permissions at the category level (no channel step).
- * Used for determining if a category is "private" for a user.
- */
-export function computeCategoryPermissions(userId: string, spaceId: string, categoryId: string): bigint {
-  const db = getDb();
-
-  const space = db.select().from(schema.spaces).where(eq(schema.spaces.id, spaceId)).get();
-  if (!space) return 0n;
-  if (space.ownerId === userId) return ALL_PERMISSIONS;
-
-  const userRow = db.select().from(schema.users).where(eq(schema.users.id, userId)).get();
-  if (userRow?.isAdmin === 1) return ALL_PERMISSIONS;
-
-  const everyoneRole = db.select().from(schema.roles)
-    .where(and(eq(schema.roles.id, spaceId), eq(schema.roles.spaceId, spaceId)))
-    .get();
-  let base = everyoneRole ? stringToPermissions(everyoneRole.permissions) : 0n;
-
-  const memberRoleRows = db.select().from(schema.memberRoles)
-    .where(and(eq(schema.memberRoles.spaceId, spaceId), eq(schema.memberRoles.userId, userId)))
-    .all();
-  const assignedRoleIds = memberRoleRows.map(mr => mr.roleId);
-
-  for (const roleId of assignedRoleIds) {
-    const role = db.select().from(schema.roles).where(eq(schema.roles.id, roleId)).get();
-    if (role) base |= stringToPermissions(role.permissions);
-  }
-
-  if ((base & PermissionBits.ADMINISTRATOR) !== 0n) return ALL_PERMISSIONS;
-
-  const catOverrides = db.select().from(schema.categoryOverrides)
-    .where(eq(schema.categoryOverrides.categoryId, categoryId))
-    .all();
-
-  if (catOverrides.length === 0) return base;
-
-  const everyoneOverride = catOverrides.find(o => o.targetType === 'role' && o.targetId === spaceId);
-  if (everyoneOverride) {
-    base = (base & ~stringToPermissions(everyoneOverride.deny)) | stringToPermissions(everyoneOverride.allow);
-  }
-
-  let combinedAllow = 0n;
-  let combinedDeny = 0n;
-  for (const roleId of assignedRoleIds) {
-    const roleOverride = catOverrides.find(o => o.targetType === 'role' && o.targetId === roleId);
-    if (roleOverride) {
-      combinedAllow |= stringToPermissions(roleOverride.allow);
-      combinedDeny |= stringToPermissions(roleOverride.deny);
-    }
-  }
-  base = (base & ~combinedDeny) | combinedAllow;
-
-  const memberOverride = catOverrides.find(o => o.targetType === 'member' && o.targetId === userId);
-  if (memberOverride) {
-    base = (base & ~stringToPermissions(memberOverride.deny)) | stringToPermissions(memberOverride.allow);
-  }
-
-  return base;
-}
-
 /**
  * Check if a user has a specific permission in a space/channel.
  */

packages/server/src/ws/spaceVoiceState.test.ts

@@ -54,6 +54,18 @@ function seedSpace(spaceId: string): void {
   }).run();
 }
 
+// Enroll a user as a space member. computePermissions grants @everyone
+// permissions only to actual members, and every real join path inserts this row
+// before voice state is built/pushed — so visibility tests must seed it too.
+function seedMember(spaceId: string, userId: string): void {
+  seedUser(userId);
+  testDb.insert(schema.spaceMembers).values({
+    spaceId,
+    userId,
+    joinedAt: Date.now(),
+  }).run();
+}
+
 function seedChannel(id: string, spaceId: string, type: 'text' | 'voice'): void {
   testDb.insert(schema.channels).values({
     id,
@@ -178,6 +190,7 @@ describe('connectionManager.buildSpaceVoiceState', () => {
     const privateCh = 'vc-private-1';
     seedSpace(spaceId);
     seedEveryoneRole(spaceId);
+    seedMember(spaceId, 'u-viewer');
     seedChannel(publicCh, spaceId, 'voice');
     seedChannel(privateCh, spaceId, 'voice');
     seedDenyViewOverride(privateCh, spaceId);
@@ -204,6 +217,7 @@ describe('connectionManager.addUserSpace voice-state push', () => {
     const voiceCh = 'vc-push-1';
     seedSpace(spaceId);
     seedEveryoneRole(spaceId);
+    seedMember(spaceId, 'u-joiner');
     seedChannel(voiceCh, spaceId, 'voice');
 
     cm.createRoom(voiceCh, 'space', { type: 'space', spaceId });

packages/web/src/components/modals/InviteModal.test.tsx

@@ -425,6 +425,32 @@ describe('InviteModal', () => {
     expect(screen.getByText('Sam')).toBeInTheDocument();
   });
 
+  it('shows an approval-required notice and hides invite affordances for request-only spaces', async () => {
+    const generateInvite = vi.fn().mockResolvedValue('should-not-be-used');
+    useUIStore.setState({ activeModal: 'invite', modalData: {} });
+    useSpaceStore.setState({
+      currentSpaceId: 'space-1',
+      spaces: [makeSpace({ visibility: 'request' })] as any,
+      members: [],
+      generateInvite,
+    } as any);
+    useSocialStore.setState({
+      friends: [makeFriend({ id: 'f1', username: 'alex', displayName: 'Alex' })],
+    } as any);
+    useAuthStore.setState({ user: { id: 'me', username: 'me' } } as any);
+
+    render(<InviteModal />);
+
+    // Explanatory copy replaces the invite UI.
+    expect(screen.getByText(/join request/i)).toBeInTheDocument();
+    // None of the invite affordances render.
+    expect(screen.queryByPlaceholderText('Search friends...')).not.toBeInTheDocument();
+    expect(screen.queryByText('Or share a link')).not.toBeInTheDocument();
+    expect(screen.queryByText('Alex')).not.toBeInTheDocument();
+    // No invite code is requested for a request-only space (the endpoint 403s).
+    expect(generateInvite).not.toHaveBeenCalled();
+  });
+
   it('passes federated target shape for remote friends', async () => {
     const user = userEvent.setup();
     mockSpaceInvite.mockResolvedValue({});

packages/web/src/components/modals/InviteModal.tsx

@@ -149,6 +149,10 @@ export function InviteModal() {
   const isOpen = activeModal === 'invite';
   const currentSpace = spaces.find((s) => s.id === currentSpaceId);
   const instanceOrigin = currentSpace?._instanceOrigin ?? '';
+  // Request-only spaces are approval-gated: they have no usable invite link and
+  // the /invite endpoint 403s. Show an explanatory notice instead of the invite
+  // affordances, and skip the invite-code fetch entirely.
+  const isRequestOnly = currentSpace?.visibility === 'request';
 
   const [inviteCode, setInviteCode] = useState('');
   const [codeError, setCodeError] = useState('');
@@ -167,7 +171,7 @@ export function InviteModal() {
 
   // Fetch / generate the per-space invite code on open.
   useEffect(() => {
-    if (!isOpen || !currentSpaceId) return;
+    if (!isOpen || !currentSpaceId || isRequestOnly) return;
     setCodeLoading(true);
     setCodeError('');
     generateInvite(currentSpaceId).then(
@@ -180,7 +184,7 @@ export function InviteModal() {
         setCodeLoading(false);
       },
     );
-  }, [isOpen, currentSpaceId, generateInvite]);
+  }, [isOpen, currentSpaceId, generateInvite, isRequestOnly]);
 
   // Reset modal state on open.
   useEffect(() => {
@@ -333,6 +337,20 @@ export function InviteModal() {
       title="Invite Friends"
       mobileStyle="sheet"
     >
+      {isRequestOnly ? (
+        <div className="space-y-3">
+          <p className="text-[13px] text-txt-tertiary">
+            This space uses join requests — people join by requesting approval
+            from a manager, so it has no invite link to share.
+          </p>
+          <button
+            onClick={closeModal}
+            className="w-full py-2 rounded-md text-[13px] font-semibold glass-pill text-txt-primary"
+          >
+            Got it
+          </button>
+        </div>
+      ) : (
       <div className="space-y-3">
         <p className="text-[13px] text-txt-tertiary">
           Send to friends, or share a link.
@@ -460,6 +478,7 @@ export function InviteModal() {
           </div>
         </div>
       </div>
+      )}
     </Modal>
   );
 }