#4141st of 55 in Backend and cloud templates
connexion
Python framework that builds REST APIs from an OpenAPI specification
- Stars
- 4.6k
- License
- Apache-2.0
- Last commit
- Nov 2026
- Last release
- Oct 2025
- Language
- Python
Missed the latest GitHub check; these facts may be older.
Overview
Connexion is a Python web framework where the OpenAPI (or Swagger) spec drives the API. It registers routes from operationId, validates requests and responses, parses parameters into function arguments, serializes return values and serves a Swagger UI console. It runs standalone (AsyncApp or FlaskApp) or as middleware around an existing ASGI or WSGI app.
Who it is for: Python developers building spec-first REST APIs, such as ones serving models
Strengths
- Routes, parameter parsing and validation come from the OpenAPI spec, no route decorators
- Works standalone or as middleware over any ASGI or WSGI framework
- Authentication is handled separately from application logic
- CLI command `connexion run openapi.yaml` runs and mocks a spec
Weaknesses
- Not AI-specific; a general API framework with no model or agent integration
- The OpenAPI spec must be written before the code
- Swagger UI, uvicorn and Flask support need optional extras
- Connexion 3 changed the app model, so upgrading from 2.x takes work
What it needs
- Python
- Needs Python, OpenAPI specification, uvicorn (optional), Flask (optional)
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