Supabase

Supabase describes itself as "the Postgres development platform": rather than one monolithic backend, it's a modular composition of open-source tools centered on PostgreSQL - Realtime (an Elixir server for streaming database changes over websockets), PostgREST (auto-generated REST API from your schema), GoTrue (JWT-based authentication), a Storage API for files backed by S3 with permissions enforced in Postgres, pg_graphql for a GraphQL API, and postgres-meta for managing the database itself. The stated goal is a Firebase-like developer experience built from open-source, permissively-licensed components, or original components Supabase builds and open-sources when no suitable one exists.

Core capabilities include a hosted Postgres database, authentication/authorization, auto-generated REST and GraphQL APIs, realtime subscriptions, database and edge functions, file storage, an AI/vector-embeddings toolkit, and a web dashboard. Client libraries are modular, so you can use just the pieces you need (e.g. only PostgREST or GoTrue) rather than the whole platform.

Supabase can be used as a hosted platform (sign up and go) or self-hosted/run locally, making it a fit for teams that want a Postgres-centric backend with Firebase-style developer experience but open-source components underneath.