supabase-rls

A set of Supabase database security rules based on Row Level Security, which controls which rows each user can read or change. It requires user operations to use limited-access clients and keeps the administrator key on the server.

In plain words
What is it for?
Use it when writing Supabase policies and queries for private records, public read-only data, user operations, webhooks, and scheduled server jobs.
Why use it?
It reduces the risk of exposing another user’s data or accidentally giving browser code administrator access.

Cursor rule for Cursor

Install

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.

agentmods
npx agentmods add rules/vibestackdev/vibe-stack/supabase-rls
Clone the repo
git clone --depth 1 https://github.com/vibestackdev/vibe-stack

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 188 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00188
Opus 5 $0.00000 $0.00094
Sonnet 5 $0.00000 $0.00038
Haiku 4.5 $0.00000 $0.00019

Measured 2d ago against content hash ed44abc31c3c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

supabase-rls 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 2d 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.

.cursor/rules/supabase-rls.mdc · 28 lines

What it actually says

Supabase Row Level Security (RLS)

ALWAYS assume RLS is enabled. NEVER generate queries that assume admin access by default.

RLS Policy Patterns: -- Own record only:

create policy "Users own data" on todos
  for all using (auth.uid() = user_id);

-- Read-only public:

create policy "Public read" on posts  
  for select using (published = true);

Code rules:

  • ALWAYS use anon/authenticated clients (not service_role) for user operations
  • Service role client: ONLY use in server-to-server operations (webhooks, cron jobs)
  • NEVER pass service_role key to the browser
  • Use select('specific, columns') not select('*') for performance
Changes

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.

  1. 2d ago First seen · 28 lines · 0 tokens per session scan A ed44abc31c3c

Subscribe to this mod's changes

supabase-rls is a cursor rule published in the GitHub repository vibestackdev/vibe-stack (7 stars, last pushed 2d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 188 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.