Prefect

Prefect is a Python framework for writing workflows as flows, which it runs on a schedule, on an external event or through its API. Projects install the Python package with pip or uv, as the install guide describes, and the Prefect server can also run from the official Docker image or from a Docker Compose setup.

The self-hosted server runs as its own process and serves a web UI. Its database is SQLite by default, and the server guide describes switching to PostgreSQL. A REST API on the server lets other programs create flow runs from a deployment.

Worth knowing

The server is a long-running process, and the guide shows it started with several worker processes for concurrent requests. Prefect Cloud is the hosted service beside the open-source framework and server, and the docs describe features such as SSO, roles and webhooks only for Prefect Cloud.