Supabase Edge Functions
Supabase Edge Functions are server-side TypeScript functions, built on the Deno runtime, that run close to users on a global edge network and are deployed as part of the Supabase backend-as-a-service platform to handle custom logic that…
Definition
Supabase Edge Functions are server-side TypeScript functions, built on the Deno runtime, that run close to users on a global edge network and are deployed as part of the Supabase backend-as-a-service platform to handle custom logic that doesn't fit cleanly into database queries or auto-generated APIs.
Overview
Supabase provides a backend-as-a-service platform built primarily around a managed PostgreSQL database, offering auto-generated REST and GraphQL APIs, authentication, storage, and realtime subscriptions out of the box. Edge Functions fill the gap for logic that doesn't map neatly onto database queries or row-level security policies — things like calling third-party APIs, processing webhooks, running custom business logic, or performing operations that need to happen server-side with elevated privileges. Built on Deno rather than Node.js, Supabase Edge Functions benefit from Deno's fast startup times, native TypeScript support, and secure-by-default permission model, and they are deployed globally so functions execute close to the requesting user for lower latency. Functions are written as standard TypeScript files using Deno's `serve()` API (or a compatible framework like Oak), stored in a `supabase/functions` directory within a project, and deployed via the Supabase CLI, which also supports local development and testing using the Deno runtime directly. Edge Functions commonly integrate with the rest of the Supabase stack: they can use the Supabase client library (with a service-role key for elevated access) to read and write to the database, verify Supabase Auth JWTs to authenticate callers, listen to Database Webhooks triggered by table changes, and process file uploads coordinated with Supabase Storage. This makes them a natural place to implement logic like sending transactional emails after a signup, processing payments via Stripe webhooks, or running AI inference calls that shouldn't be exposed directly to the client. Because they run in a restricted Deno edge runtime rather than a full server environment, Edge Functions are best suited for relatively short-lived, stateless request handling rather than long-running background jobs, which Supabase generally recommends handling through database functions, external queues, or scheduled triggers instead.
Key Features
- Built on Deno, offering fast cold starts and native TypeScript support
- Deployed globally on an edge network for low-latency execution
- Deployed and managed via the Supabase CLI from a `supabase/functions` directory
- Commonly used to handle webhooks, third-party API calls, and custom logic
- Integrates with Supabase Auth, Database, and Storage via the Supabase client
- Can use a service-role key for elevated, server-side database access
- Supports local development and testing with the Deno runtime
- Best suited for short-lived, stateless request handling, not long background jobs
Use Cases
Alternatives
Frequently Asked Questions
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