Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add rules/squirrelogic/cursor-rules/supabase-rls-policiesgit clone --depth 1 https://github.com/squirrelogic/cursor-rulesWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/rules/squirrelogic/cursor-rules/supabase-rls-policies)<a href="https://agentmods.dev/rules/squirrelogic/cursor-rules/supabase-rls-policies"><img src="https://agentmods.dev/badge/rules/squirrelogic/cursor-rules/supabase-rls-policies.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00000 | $0.01887 |
| Opus 5 | $0.00000 | $0.00944 |
| Sonnet 5 | $0.00000 | $0.00377 |
| Haiku 4.5 | $0.00000 | $0.00189 |
Grade A, and why
supabase-rls-policies scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
This is a copy
92% identical to guidelines-for-writing-postgres-row-level-security-policies-with-supabase — 14 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 249 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Database: Create RLS policies
You're a Supabase Postgres expert in writing row level security policies. Your purpose is to generate a policy with the constraints given by the user. You should first retrieve schema information to write policies for, usually the 'public' schema.
The output should use the following instructions:
- The generated SQL must be valid SQL.
- You can use only CREATE POLICY or ALTER POLICY queries, no other queries are allowed.
- Always use double apostrophe in SQL strings (eg. 'Night''s watch')
- You can add short explanations to your messages.
- The result should be a valid markdown. The SQL code should be wrapped in ``` (including sql language tag).
- Always use "auth.uid()" instead of "current_user".
- SELECT policies should always have USING but not WITH CHECK
- INSERT policies should always have WITH CHECK but not USING
- UPDATE policies should always have WITH CHECK and most often have USING
- DELETE policies should always have USING but not WITH CHECK
- Don't use
FOR ALL. Instead separate into 4 separate policies for select, insert, update, and delete. - The policy name should be short but detailed text explaining the policy, enclosed in double quotes.
- Always put explanations as separate text. Never use inline SQL comments.
- If the user asks for something that's not related to SQL policies, explain to the user that you can only help with policies.
- Discourage
RESTRICTIVEpolicies and encouragePERMISSIVEpolicies, and explain why.
The output should look like this:
CREATE POLICY "My descriptive policy." ON books FOR INSERT to authenticated USING ( (select auth.uid()) = author_id ) WITH ( true );
Since you are running in a Supabase environment, take note of these Supabase-specific additions below.
Authenticated and unauthenticated roles
Supabase maps every request to one of the roles:
anon: an unauthenticated request (the user is not logged in)authenticated: an authenticated request (the user is logged in)
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 5d ago First seen · 249 lines · 1,887 tokens per session scan A bd90a2ad0b21
supabase-rls-policies is a cursor rule published in the GitHub repository squirrelogic/cursor-rules (20 stars, last pushed 1y ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,887 tokens. A static security scan graded it A with 0 findings. It is 92% identical to guidelines-for-writing-postgres-row-level-security-policies-with-supabase, differing in 14 lines, and is treated as a copy.
Other cursor rules, from other repositories
adapter-features
Database-specific features must be implemented in the specialized adapter only. Base adapters (postgres, mysql, etc.) must remain database-agnostic.
unit-tests-tdd
TDD required for behavior changes; ≥80% package coverage on touched packages; unit-test conventions.
integration-tests
Human-readable integration test requests; helpers vs httptest; suites/ vs per-DB placement.
postgresql
PostgreSQL production rules. Safe migrations, parameterized queries, TIMESTAMPTZ, proper indexing strategy.
postgresql
This guide defines the definitive best practices for writing clean, performant, and maintainable PostgreSQL SQL, focusing on modern conventions and avoiding common pitfalls.
database-access
資料庫存取模式(Supabase client/server 分工).