--- id: 'functions' title: 'Edge Functions' description: 'Run TypeScript functions globally at the edge.' subtitle: 'Run TypeScript functions globally at the edge.' sidebar_label: 'Overview' tocVideo: 'za_loEtS4gs' --- Edge Functions are server-side TypeScript functions, distributed globally at the edge—close to your users. They can be used for listening to webhooks or integrating your Supabase project with third-parties [like Stripe](https://github.com/supabase/supabase/tree/master/examples/edge-functions/supabase/functions/stripe-webhooks). Edge Functions are developed using [Deno](https://deno.com), which offers a few benefits to you as a developer: - It is open source. - It is portable. Supabase Edge Functions run locally, and on any other Deno-compatible platform (including self-hosted infrastructure). - It is TypeScript first and supports WASM. - Edge Functions are globally distributed for low-latency. ## How it works - **Request enters an edge gateway (relay)** — the gateway routes traffic, handles auth headers/JWT validation, and applies routing/traffic rules. - **Auth & policies are applied** — the gateway (or your function) can validate Supabase JWTs, apply rate-limits, and centralize security checks before executing code. - **[Edge runtime](https://github.com/supabase/edge-runtime) executes your function** — the function runs on a regionally-distributed Edge Runtime node closest to the user for minimal latency. - **Integrations & data access** — functions commonly call Supabase APIs (Auth, Postgres, Storage) or third-party APIs. For Postgres, prefer connection strategies suited for edge/serverless environments (see the `connect-to-postgres` guide). - **Observability and logs** — invocations emit logs and metrics you can explore in the dashboard or downstream monitoring (Sentry, etc.). - **Response returns via the gateway** — the gateway forwards the response back to the client and records request metadata. ## Quick technical notes - **Runtime:** Supabase Edge Runtime (Deno compatible runtime with TypeScript first). Functions are `.ts` files that export a handler. - **Local dev parity:** Use Supabase CLI for a local runtime similar to production for faster iteration (`supabase functions serve` command). - **Global deployment:** Deploy your Edge Functions via Supabase Dashboard, CLI or MCP. - **Cold starts & concurrency:** cold starts are possible — design for short-lived, idempotent operations. Heavy long-running jobs should be moved to [background workers](/docs/guides/functions/background-tasks). - **Database connections:** treat Postgres like a remote, pooled service — use connection pools or serverless-friendly drivers. - **Secrets:** store credentials in Supabase [project secrets](/docs/reference/cli/supabase-secrets) and access them via environment variables. ## When to use Edge Functions - Authenticated or public HTTP endpoints that need low latency. - Webhook receivers (Stripe, GitHub, etc.). - On-demand image or Open Graph generation. - Small AI inference tasks or orchestrating calls to external LLM APIs (like OpenAI) - Sending transactional emails. - Building messaging bots for Slack, Discord, etc. ## Examples Check out [Supabase Edge Function Examples](https://github.com/supabase/supabase/tree/master/examples/edge-functions) in GitHub or try these examples: