Postgres

SQLite is the default and is single-writer, which is fine for one instance. To scale out to many workers or instances, point WHOOK_DATABASE_URL at Postgres.

WHOOK_DATABASE_URL=postgres://whook:whook@localhost:5432/whook?sslmode=disable

A DSN starting with postgres:// or postgresql:// selects the Postgres backend automatically; anything else is SQLite.

How it works

The gateway applies its Postgres migrations on startup, the same way it does for SQLite, so there is no separate migrate step. The delivery queue is claimed with:

SELECT ... FOR UPDATE SKIP LOCKED

so many workers and many instances can share one queue without ever delivering the same event twice. SQLite achieves the same guarantee with a single-writer lease; Postgres uses row-level locking, which scales horizontally.

With Docker Compose

The bundled compose file ships an optional Postgres service under a profile. Start it and set the DSN with host postgres:

docker compose --profile postgres up

WHOOK_DATABASE_URL=postgres://whook:whook@postgres:5432/whook?sslmode=disable