##  Project Analysis (Recap) - **Frontend:** React (Vite), no current auth logic. - **Backend:** Rust, currently uses Supabase service key for backend operations. - **Goal:** Use Clerk for authentication, integrate with Supabase for secure, user-aware data access. --- ## 2. Clerk + Supabase Integration Plan (with Latest Docs) ### Step 1: Set Up Clerk in the Frontend - **Install Clerk:** - `npm install @clerk/clerk-react` - **Initialize ClerkProvider:** - Wrap your app in`<ClerkProvider publishableKey={process.env.CLERK_PUBLISHABLE_KEY}>` in `main.js` - **Add Auth UI:** Use Clerk components `SignIn`, `SignUp`, `UserButton` in your React pages. - **Protect Routes:** Use Clerk hooks `useUser`, `SignedIn`, `SignedOut` to guard routes/components. ### Step 2: Configure Clerk to Issue JWTs - **Enable JWT Templates:** In the Clerk dashboard, create a JWT template. - Include the user’s external ID as a claim: `{ "userId": "{{user.external_id || user.id}}" }` - Add custom claims if you need group/role-based access: `{ "groups": ["org:admin", "org:member"] }` - **Frontend: Get JWT for API Requests:** Use Clerk’s session API to get the JWT: `const token = await clerk.session.getToken({ template: 'YOUR_TEMPLATE' });` Attach this token as a Bearer token in requests to your backend. ### Step 3: Backend — Verify Clerk JWT - **Fetch Clerk’s JWKS:** Your backend must verify JWTs using Clerk’s public keys (JWKS endpoint). - **Rust JWT Verification:** - Use a crate like `jsonwebtoken`  to verify the token’s signature and claims. - Validate standard claims (`exp`, `nbf`) and custom claims (e.g., `userId`) - Optionally, check the `azp` (Authorized Party) claim for allowed origins. - **Example (from Clerk docs, TypeScript, adapt to Rust):** - Retrieve token from `Authorization`header. - Verify with Clerk’s public key. - Check claims and expiration. ### Step 4: Backend — Connect to Supabase - **Option 1: Backend as Proxy (Recommended for Rust):** - Backend receives requests with Clerk JWT. - After verifying, use Supabase service key for privileged actions, but enforce access control based on the verified Clerk user ID. - (Optional) Map Clerk user ID to Supabase user or roles for RLS. - **Option 2: Direct Supabase Access from Frontend (Advanced):** - Configure Supabase to trust Clerk JWTs for Row Level Security (RLS). - Supabase policies use the Clerk user ID claim for access control. - This requires setting up Supabase JWT secrets and policies accordingly. ### Step 5: (Optional) Supabase RLS with Clerk JWT - **Supabase JWT Secret:** If using direct access, set up Supabase to accept Clerk JWTs by configuring the JWT secret or JWKS URL in Supabase settings. - **RLS Policies:** Write policies that use the `userId` claim from Clerk JWT for row-level access. --- ## 3. Key Implementation Notes - **Frontend:** - Always retrieve and attach the latest Clerk JWT to API requests. - Use Clerk hooks for session state. - **Backend:** - Fetch and cache Clerk JWKS for JWT verification. - Use a robust JWT validation library. - Enforce all sensitive logic on the backend, using the verified user identity. - **Supabase:** - If using RLS, ensure policies reference the correct claim (e.g., `userId`) - If not using RLS, restrict all access through backend logic. --- ## 4. References (from Docs) - Clerk JWT verification: - [Manual JWT Verification Example](https://github.com/clerk/clerk-docs/blob/main/docs/backend-requests/manual-jwt.mdx) - Clerk React integration: - [ClerkProvider Example](https://github.com/clerk/javascript/blob/main/packages/expo/CHANGELOG.md) - Supabase JWT/RLS: - [Custom JWT Claims in Supabase](https://github.com/supabase/supabase/blob/master/apps/docs/content/guides/auth/third-party/auth0.mdx) - [Supabase RLS Policies](https://github.com/supabase/supabase/blob/master/apps/docs/content/guides/auth/auth-hooks/custom-access-token-hook.mdx) --- ## 5. Review Points - Do you want your frontend to access Supabase directly (with RLS), or should all DB access go through your backend? - Should user roles/groups be encoded in Clerk JWTs for use in Supabase policies? - Is your backend ready to fetch and cache JWKS for JWT verification? ---