Modal — serverless Python & GPU as decorators

Modal runs your Python on remote containers without you ever writing a Dockerfile or a YAML file. The mental model: infrastructure is declared inline as Python decorators. A modal.App is the deployable unit; each @app.function runs in its own container built from a modal.Image you describe in code; you attach a GPU, a Volume, or a Secret as keyword arguments and the platform provisions, scales to zero, and tears down for you. There is no control plane to babysit — the source file is the infra.

Pinned stack: modal 1.4.3 (released 2026-05-18), Python 3.10–3.14 (>=3.10,<3.15). Install with pip install modal then modal setup to authenticate. Everything below uses the Modal 1.0+ API; several pre-1.0 forms were removed and are called out as Bad→Good.

Not this skill

Modal owns the serverless-container-as-decorators surface and its CLI lifecycle; the contents of your function belong elsewhere.