Action0-Client-OpenAPI

Generate fully typed action0-client API clients from an OpenAPI schema: one typed operation class per endpoint, plus the model classes their results are parsed into. The generated code is plain, readable action0-client code — it depends on action0-client only, not on this package — so it runs synchronously, on asyncio, on Twisted or on an execution model of your own, decided by the backend you plug in.

uv add --dev action0-client-openapi     # or: pip install action0-client-openapi
action0-openapi petstore.json -o src/   # YAML schemas: install the "yaml" extra

src/petstore_client/__init__.py
src/petstore_client/client.py
src/petstore_client/models.py
src/petstore_client/operations.py
src/petstore_client/py.typed

Using the generated client — the backend decides the execution model, and the static types follow it:

from action0.client.backends.requests import RequestsBackend
from petstore_client import GetPet, PetstoreClient

client = PetstoreClient(RequestsBackend(), token="...")
pet = client.send(GetPet(pet_id=42))  # Pet

from action0.client.backends.httpx import AsyncHttpxBackend

client = PetstoreClient(AsyncHttpxBackend(), token="...")
pet = await client.send(GetPet(pet_id=42))  # Awaitable[Pet]

Generated code is meant to be checked in and reviewed like hand-written code: it is readable, ruff-clean and fully typed — mypy strict, pyright and ty pass on it. Models become plain dataclasses with generated JSON converters, endpoints become Operation subclasses, security schemes become client constructor credentials — with the schema's descriptions carried along as docstrings and #: doc-comments. The schema support matrix lists exactly which OpenAPI 3.0/3.1 constructs are covered — schemas split over several files are bundled automatically, straight from a URL too (referenced files download after a per-file confirmation, or with --download) — and what is deliberately deferred (typed multipart bodies, per-status response typing, ...).

Requires Python 3.11 or newer.

Full documentation including the API reference: https://laughinjar.github.io/action0-client-openapi/

Development

The project is managed with uv; uv run syncs the environment automatically:

uv run pytest          # tests (incl. doctests in the sources)
uv run ruff check      # lint
uv run ruff format     # format
uv run mypy            # type-check (strict)
uv run pyright         # type-check
uv run ty check        # type-check

AI disclosure

This library is developed with heavy use of AI coding tools: the code, tests, and documentation are largely written by Claude Code, working from the author's design brief and reviewed by the author. If that changes how much you want to rely on this package, that's a fair call — read the source, it's small.

License

MIT — see LICENSE.