diff --git a/apps/app/src/components/collaboration/CollaborativeDocContext.tsx b/apps/app/src/components/collaboration/CollaborativeDocContext.tsx
index 596cfb545..edc4706c1 100644
--- a/apps/app/src/components/collaboration/CollaborativeDocContext.tsx
+++ b/apps/app/src/components/collaboration/CollaborativeDocContext.tsx
@@ -32,6 +32,8 @@ const CollaborativeDocContext =
 interface CollaborativeDocProviderProps {
   /** Unique document identifier for collaboration */
   docId: string;
+  /** JWT token for Tiptap Cloud authentication */
+  token: string | null;
   /** User's display name for collaboration cursors */
   userName?: string;
   /** Loading state to show while the collaboration provider initializes */
@@ -46,7 +48,7 @@ interface CollaborativeDocProviderProps {
  *
  * @example
  * ```tsx
- * <CollaborativeDocProvider docId="proposal-123" userName="Alice" fallback={<Skeleton />}>
+ * <CollaborativeDocProvider docId="proposal-123" token={collabToken} userName="Alice" fallback={<Skeleton />}>
  *   <CollaborativeTitleField />
  *   <CollaborativeEditor />
  * </CollaborativeDocProvider>
@@ -54,6 +56,7 @@ interface CollaborativeDocProviderProps {
  */
 export function CollaborativeDocProvider({
   docId,
+  token,
   userName = 'Anonymous',
   fallback = null,
   children,
@@ -61,6 +64,7 @@ export function CollaborativeDocProvider({
   const { ydoc, provider, status, isSynced, user } = useTiptapCollab({
     docId,
     enabled: true,
+    token,
     userName,
   });
 
diff --git a/apps/app/src/components/decisions/proposalEditor/ProposalEditor.tsx b/apps/app/src/components/decisions/proposalEditor/ProposalEditor.tsx
index 9da5ad0bb..a235ef671 100644
--- a/apps/app/src/components/decisions/proposalEditor/ProposalEditor.tsx
+++ b/apps/app/src/components/decisions/proposalEditor/ProposalEditor.tsx
@@ -240,6 +240,13 @@ export function ProposalEditor({
     draftRef,
   ]);
 
+  // -- Collaboration token ---------------------------------------------------
+
+  const { data: collabTokenData } = trpc.decision.getCollabToken.useQuery(
+    { proposalProfileId: proposal.profileId },
+    { staleTime: 1000 * 60 * 60 },
+  );
+
   // -- Render ----------------------------------------------------------------
 
   const userName = user.profile?.name ?? t('Anonymous');
@@ -247,6 +254,7 @@ export function ProposalEditor({
   return (
     <CollaborativeDocProvider
       docId={collaborationDocId}
+      token={collabTokenData?.token ?? null}
       userName={userName}
       fallback={<ProposalEditorSkeleton />}
     >
diff --git a/apps/app/src/hooks/useTiptapCollab.ts b/apps/app/src/hooks/useTiptapCollab.ts
index 22ac217b0..01e87d080 100644
--- a/apps/app/src/hooks/useTiptapCollab.ts
+++ b/apps/app/src/hooks/useTiptapCollab.ts
@@ -15,6 +15,8 @@ export interface CollabUser {
 export interface UseTiptapCollabOptions {
   docId: string | null;
   enabled?: boolean;
+  /** JWT token for Tiptap Cloud authentication */
+  token: string | null;
   /** User's display name for the collaboration cursor */
   userName?: string;
 }
@@ -33,6 +35,7 @@ export interface UseTiptapCollabReturn {
 export function useTiptapCollab({
   docId,
   enabled = true,
+  token,
   userName = 'Anonymous',
 }: UseTiptapCollabOptions): UseTiptapCollabReturn {
   const [status, setStatus] = useState<CollabStatus>('connecting');
@@ -48,7 +51,7 @@ export function useTiptapCollab({
   }, [userName]);
 
   useEffect(() => {
-    if (!enabled || !docId) {
+    if (!enabled || !docId || !token) {
       setStatus('disconnected');
       return;
     }
@@ -63,7 +66,7 @@ export function useTiptapCollab({
     const newProvider = new TiptapCollabProvider({
       name: docId,
       appId,
-      token: 'notoken', // TODO: proper JWT auth
+      token,
       document: ydoc,
       onConnect: () => {
         setStatus('connected');
@@ -82,7 +85,7 @@ export function useTiptapCollab({
       newProvider.destroy();
       setProvider(null);
     };
-  }, [docId, enabled, ydoc]);
+  }, [docId, enabled, token, ydoc]);
 
   // Update awareness when user info changes
   useEffect(() => {
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index ac4fc4122..3995e875b 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -1319,6 +1319,9 @@ importers:
 
   services/collab:
     dependencies:
+      jsonwebtoken:
+        specifier: ^9.0.2
+        version: 9.0.2
       ky:
         specifier: ^1.8.1
         version: 1.14.2
@@ -1326,6 +1329,9 @@ importers:
       '@op/typescript-config':
         specifier: workspace:*
         version: link:../../configs/typescript-config
+      '@types/jsonwebtoken':
+        specifier: ^9.0.10
+        version: 9.0.10
 
   services/db:
     dependencies:
diff --git a/services/api/src/routers/decision/proposals/getCollabToken.ts b/services/api/src/routers/decision/proposals/getCollabToken.ts
new file mode 100644
index 000000000..f1147f1fb
--- /dev/null
+++ b/services/api/src/routers/decision/proposals/getCollabToken.ts
@@ -0,0 +1,73 @@
+import { generateCollabToken } from '@op/collab/server';
+import { getProfileAccessUser, parseProposalData } from '@op/common';
+import { db } from '@op/db/client';
+import { TRPCError } from '@trpc/server';
+import { checkPermission, permission } from 'access-zones';
+import { z } from 'zod';
+
+import { commonAuthedProcedure, router } from '../../../trpcFactory';
+
+export const getCollabTokenRouter = router({
+  getCollabToken: commonAuthedProcedure({
+    rateLimit: { windowSize: 60, maxRequests: 30 },
+  })
+    .input(
+      z.object({
+        proposalProfileId: z.uuid(),
+      }),
+    )
+    .output(z.object({ token: z.string() }))
+    .query(async ({ ctx, input }) => {
+      const { user } = ctx;
+      const { proposalProfileId } = input;
+
+      // Look up the proposal by its profile ID
+      const proposal = await db.query.proposals.findFirst({
+        where: { profileId: proposalProfileId },
+        columns: {
+          id: true,
+          proposalData: true,
+          profileId: true,
+        },
+      });
+
+      if (!proposal) {
+        throw new TRPCError({
+          code: 'NOT_FOUND',
+          message: 'Proposal not found',
+        });
+      }
+
+      // Verify user has access to the proposal's profile
+      const profileAccessUser = await getProfileAccessUser({
+        user,
+        profileId: proposalProfileId,
+      });
+
+      const hasAccess = checkPermission(
+        { profile: permission.READ },
+        profileAccessUser?.roles ?? [],
+      );
+
+      if (!hasAccess) {
+        throw new TRPCError({
+          code: 'FORBIDDEN',
+          message: 'You do not have access to this proposal',
+        });
+      }
+
+      // Extract the collaboration doc ID from the proposal data
+      const { collaborationDocId } = parseProposalData(proposal.proposalData);
+
+      if (!collaborationDocId) {
+        throw new TRPCError({
+          code: 'BAD_REQUEST',
+          message: 'Proposal does not have a collaboration document',
+        });
+      }
+
+      const token = generateCollabToken(user.id, [collaborationDocId]);
+
+      return { token };
+    }),
+});
diff --git a/services/api/src/routers/decision/proposals/index.ts b/services/api/src/routers/decision/proposals/index.ts
index 0d99bd11a..6832020a8 100644
--- a/services/api/src/routers/decision/proposals/index.ts
+++ b/services/api/src/routers/decision/proposals/index.ts
@@ -4,6 +4,7 @@ import { createProposalRouter } from './create';
 import { deleteProposalRouter } from './delete';
 import { exportProposalsRouter } from './export';
 import { getProposalRouter } from './get';
+import { getCollabTokenRouter } from './getCollabToken';
 import { getExportStatusRouter } from './getExportStatus';
 import { listProposalsRouter } from './list';
 import { submitProposalRouter } from './submit';
@@ -13,6 +14,7 @@ export const proposalsRouter = mergeRouters(
   acceptProposalInviteRouter,
   createProposalRouter,
   getProposalRouter,
+  getCollabTokenRouter,
   listProposalsRouter,
   submitProposalRouter,
   updateProposalRouter,
diff --git a/services/collab/package.json b/services/collab/package.json
index d3c34cced..78c9fc8eb 100644
--- a/services/collab/package.json
+++ b/services/collab/package.json
@@ -5,6 +5,7 @@
   "type": "module",
   "exports": {
     ".": "./src/index.ts",
+    "./server": "./src/server/index.ts",
     "./testing": "./__mocks__/index.ts"
   },
   "main": "./src/index.ts",
@@ -14,9 +15,11 @@
     "typecheck": "tsgo --noEmit"
   },
   "dependencies": {
+    "jsonwebtoken": "^9.0.2",
     "ky": "^1.8.1"
   },
   "devDependencies": {
-    "@op/typescript-config": "workspace:*"
+    "@op/typescript-config": "workspace:*",
+    "@types/jsonwebtoken": "^9.0.10"
   }
 }
diff --git a/services/collab/src/server/index.ts b/services/collab/src/server/index.ts
new file mode 100644
index 000000000..09e397986
--- /dev/null
+++ b/services/collab/src/server/index.ts
@@ -0,0 +1 @@
+export { generateCollabToken } from './token';
diff --git a/services/collab/src/server/token.ts b/services/collab/src/server/token.ts
new file mode 100644
index 000000000..1cd0bd886
--- /dev/null
+++ b/services/collab/src/server/token.ts
@@ -0,0 +1,41 @@
+import jwt from 'jsonwebtoken';
+
+function getTiptapSecret(): string {
+  const secret = process.env.TIPTAP_SECRET;
+
+  if (!secret) {
+    throw new Error('Missing required environment variable: TIPTAP_SECRET');
+  }
+
+  return secret;
+}
+
+/**
+ * Generate a Tiptap Cloud collaboration JWT for a user.
+ *
+ * The token restricts the user to only the specified document names.
+ *
+ * @see https://tiptap.dev/docs/collaboration/getting-started/authenticate
+ *
+ * @param userId - The authenticated user's identifier
+ * @param allowedDocumentNames - Document names the user may access (supports trailing wildcards)
+ * @returns Signed JWT string
+ */
+export function generateCollabToken(
+  userId: string,
+  allowedDocumentNames: string[],
+): string {
+  const secret = getTiptapSecret();
+
+  return jwt.sign(
+    {
+      sub: userId,
+      allowedDocumentNames,
+    },
+    secret,
+    {
+      algorithm: 'HS256',
+      expiresIn: 60 * 60 * 24, // 24 hours
+    },
+  );
+}