/supabase

name: supabase
description: "Use when doing ANY task involving Supabase. Triggers: Supabase products (Database, Auth, Edge Functions, Realtime, Storage, Vectors, Cron, Queues); client libraries and SSR integrations (supabase-js, @supabase/ssr) in Next.js, React, SvelteKit, Astro, Remix; auth issues (login, logout, sessions, JWT, cookies, getSession, getUser, getClaims, RLS); Supabase CLI or MCP server; schema changes, migrations, declarative schemas, security audits, Postgres extensions (pg_graphql, pg_cron, pg_vector)."
metadata:
  author: supabase
  version: "0.1.2"

Supabase

Core Principles

**1. Supabase changes frequently — verify against changelog and current docs before implementing.** Do not rely on training data for Supabase features. Function signatures, config.toml settings, and API conventions change between versions.

First, fetch `https://supabase.com/changelog.md` (a lightweight summary index — not a heavy pull), scan for `breaking-change` tags relevant to your task, and follow the linked page for any that apply. Then look up the relevant topic using the documentation access methods below.

**2. Verify your work.** After implementing any fix, run a test query to confirm the change works. A fix without verification is incomplete.

**3. Recover from errors, don't loop.** If an approach fails after 2-3 attempts, stop and reconsider. Try a different method, check documentation, inspect the error more carefully, and review relevant logs when available. Supabase issues are not always solved by retrying the same command, and the answer is not always in the logs, but logs are often worth checking before proceeding.

**4. Exposing tables to the Data API:** Depending on the user's [Data API settings](https://supabase.com/dashboard/project/<ref>/integrations/data_api/settings), newly created tables may not be automatically exposed via the Data (REST) API. If this is the case, `anon` and `authenticated` roles will need to be explicitly granted access.

> Note that this is separate from RLS, which controls which _rows_ are visible once a table is accessible, not whether the table is accessible at all.

When a user reports a SQL-created table is unexpectedly inaccessible, check their Data API settings and whether the roles have been granted access via explicit `GRANT` SQL. When granting public (`anon`/`authenticated`) access, always enable RLS too. See [Exposing a Table to the Data API](https://supabase.com/docs/guides/api/securing-your-api.md) for the full setup workflow.

**5. RLS in exposed schemas.** Enable RLS on every table in any exposed schema, which includes `public` by default. This is critical in Supabase because tables in exposed schemas can be reachable through the Data API when the `anon`/`authenticated` roles have access (see [Exposing a Table to the Data API](https://supabase.com/docs/guides/api/securing-your-api.md)). For private schemas, prefer RLS as defense in depth. After enabling RLS, create policies that match the actual access model rather than defaulting every table to the same `auth.uid()` pattern.

**6. Security checklist.** When working on any Supabase task that touches auth, RLS, views, storage, or user data, run through this checklist. These are Supabase-specific security traps that silently create vulnerabilities:

• **Auth and session security**
• **Never use `user_metadata` claims in JWT-based authorization decisions.** In Supabase, `raw_user_meta_data` is user-editable and can appear in `auth.jwt()`, so it is unsafe for RLS policies or any other authorization logic. Store authorization data in `raw_app_meta_data` / `app_metadata` instead.
• **Deleting a user does not invalidate existing access tokens.** Sign out or revoke sessions first, keep JWT expiry short for sensitive apps, and for strict guarantees validate `session_id` against `auth.sessions` on sensitive operations.
• **If you use `app_metadata` or `auth.jwt()` for authorization, remember JWT claims are not always fresh until the user's token is refreshed.**

• **API key and client exposure**
• **Never expose the `service_role` or secret key in public clients.** Prefer publishable keys for frontend code. Legacy `anon` keys are only for compatibility. In Next.js, any `NEXT_PUBLIC_` env var is sent to the browser.

• **RLS, views, and privileged database code**
• **Views bypass RLS by default.** In Postgres 15 and above, use `CREATE VIEW ... WITH (security_invoker = true)`. In older versions of Postgres, protect your views by revoking access from the `anon` and `authenticated` roles, or by putting them in an unexposed schema.
• **UPDATE requires a SELECT policy.** In Postgres RLS, an UPDATE needs to first SELECT the row. Without a SELECT policy, updates silently return 0 rows — no error, just no change.
• **`auth.role()` is deprecated — use the `TO` clause instead.** Supabase has deprecated `auth.role()` in favour of specifying the target role directly on the policy with `TO authenticated` or `TO anon`. Beyond deprecation, `auth.role() = 'authenticated'` breaks silently when anonymous sign-ins are enabled, because anonymous users carry the `authenticated` Postgres role and pass the check regardless of whether the user is genuinely signed in.

    -- Deprecated (do not use)
    create policy "example" on table_name for select
    using ( auth.role() = 'authenticated' );

• **`TO authenticated` alone is authentication without authorization (BOLA / IDOR).** Using `TO authenticated` only checks the role — it does not restrict which rows a user can access. The correct pattern combines `TO authenticated` with an ownership predicate in `USING`:

    create policy "example" on table_name for select
    to authenticated
    using ( (select auth.uid()) = user_id );

• **UPDATE policies require both `USING` and `WITH CHECK`.** Without `WITH CHECK`, a user can reassign a row's `user_id` to another user:

    create policy "example" on