supabase

supabase is a skill for Claude Code, Codex from G1Joshi/Agent-Skills. It costs 21 tokens per session (489 once invoked), scanned A, original, MIT.

A Supabase guide for building a backend around PostgreSQL, with user sign-in, file storage, live database updates, and server-side functions.

In plain words
What is it for?
Use it to create application backends, expose database data through APIs, handle authentication, receive real-time updates, store files, and support vector-based AI features.
Why use it?
It brings common backend services together so an application can use a database and user accounts without building each service separately.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to create application backends, expose database data through APIs, handle…

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Install with agentmods
npx agentmods add skills/g1joshi/agent-skills/supabase
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.

Any agent
npx skills add G1Joshi/Agent-Skills --skill supabase
Clone the repo
git clone --depth 1 https://github.com/G1Joshi/Agent-Skills

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for supabase

README.md
[![agentmods](https://agentmods.dev/badge/skills/g1joshi/agent-skills/supabase.svg)](https://agentmods.dev/skills/g1joshi/agent-skills/supabase)
Your own site
<a href="https://agentmods.dev/skills/g1joshi/agent-skills/supabase"><img src="https://agentmods.dev/badge/skills/g1joshi/agent-skills/supabase.svg" alt="Measured on agentmods" height="20"></a>
Per session 21 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 489 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00021 $0.00489
Opus 5 $0.00010 $0.00244
Sonnet 5 $0.00004 $0.00098
Haiku 4.5 $0.00002 $0.00049

Measured 3d ago against content hash 5c205aea5555, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

supabase 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 3d 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.

skills/databases/supabase/SKILL.md · 72 lines

What it actually says

Supabase

Supabase is an open source Firebase alternative. It provides a dedicated PostgreSQL database, packaged with Authentication, Realtime subscriptions, Storage, and Edge Functions.

When to Use

  • Rapid Application Development: Get Auth + DB + APIs in 5 minutes.
  • Postgres Power: Unlike Firebase, you have full SQL power (JOINs, aggregation).
  • Realtime: Subscribe to DB changes via WebSockets.
  • Vector/AI: Highly integrated pgvector support for AI apps.

Quick Start (JS)

import { createClient } from "@supabase/supabase-js";

const supabase = createClient("https://xyz.supabase.co", "public-anon-key");

// Listen to changes
const subscription = supabase
  .channel("public:messages")
  .on(
    "postgres_changes",
    { event: "INSERT", schema: "public", table: "messages" },
    (payload) => {
      console.log("New message:", payload);
    },
  )
  .subscribe();

Core Concepts

Row Level Security (RLS)

Supabase exposes the DB directly to the frontend (via PostgREST). RLS is critical to secure data.

CREATE POLICY "Users can see own data" ON "profiles"
FOR SELECT USING (auth.uid() = user_id);

PostgREST

Automatically turns your Database Tables into RESTful APIs.

Extensions

Supabase makes enabling Postgres extensions easy (PostGIS, pgvector, pg_cron).

Best Practices (2025)

Do:

  • Enable RLS immediately: Never launch without RLS policies.
  • Use Supabase CLI: For local development and migrations. Develop locally, push to prod.
  • Use Generated Types: supabase gen types typescript generates accurate TS definitions from your DB schema.

Don't:

  • Don't access service_role key in client: Allows bypassing RLS. Server-side only.
  • Don't put business logic in triggers: Hard to debug. Use Database Webhooks or Edge Functions.

References

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. 3d ago First seen · 72 lines · 21 tokens per session scan A 5c205aea5555

Subscribe to this mod's changes

supabase is a skill published in the GitHub repository G1Joshi/Agent-Skills (12 stars, last pushed 6mo ago), licensed MIT. It adds 21 tokens to every session and 489 once invoked, about $0.0001 per session on Opus 5. 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 2026-09-03.