Connexion

aid: connexion
url: https://raw.githubusercontent.com/api-evangelist/connexion/refs/heads/main/apis.yml
name: Connexion
kind: opensource
description: 'Connexion is an open source Python framework that automatically handles HTTP requests based on OpenAPI specifications.
  Connexion 3 provides AsyncApp, FlaskApp, and ConnexionMiddleware as primary entry points, with built-in routing, request
  and response validation, parameter parsing, security enforcement, content negotiation, error handling, lifespan, and Swagger
  UI integration. Connexion takes a contract-first, design-first approach: the OpenAPI specification is the source of truth
  and Python handlers are resolved from operationId or via configurable resolvers.'
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
tags:
- API Design
- ASGI
- Design-First
- Flask
- OpenAPI
- Python
- Validation
- WSGI
created: '2026-03-25'
modified: '2026-04-28'
specificationVersion: '0.19'
apis:
- aid: connexion:framework
  name: Connexion Python Framework
  description: Connexion is a contract-first Python web framework that loads an OpenAPI specification and routes requests
    to Python handlers based on operationId. It performs request validation, parameter parsing, and response validation against
    the specification, with first-class support for security schemes and Swagger UI.
  humanURL: https://connexion.readthedocs.io/en/latest/
  baseURL: https://connexion.readthedocs.io
  tags:
  - Framework
  - OpenAPI
  - Python
  - Validation
  properties:
  - type: Documentation
    url: https://connexion.readthedocs.io/en/latest/
  - type: Documentation
    url: https://connexion.readthedocs.io/en/latest/quickstart.html
  - type: GitHubRepository
    url: https://github.com/spec-first/connexion
  - type: License
    url: https://github.com/spec-first/connexion/blob/main/LICENSE
  - type: Issue Tracker
    url: https://github.com/spec-first/connexion/issues
  x-features:
  - AsyncApp, FlaskApp, and ConnexionMiddleware entry points
  - Native ASGI server support and Flask compatibility
  - Automatic routing from operationId via RestyResolver
  - Request and response validation against OpenAPI
  - Security middleware honoring OpenAPI security schemes
  - Swagger UI mounted from the framework
  - Pythonic snake_case parameter conversion
  - Strict parameter validation modes
  x-useCases:
  - Build Python APIs from an OpenAPI 3.x specification
  - Migrate Flask applications to a contract-first model
  - Add request and response validation to an existing ASGI app
  - Generate Swagger UI alongside your API automatically
  - Compose multiple OpenAPI specifications under a single app
- aid: connexion:middleware
  name: Connexion Middleware Stack
  description: Connexion 3 introduces a stack of pluggable ASGI middlewares that handle exceptions, server errors, lifespan,
    security, routing, request validation, response validation, Swagger UI, and context propagation. The middleware stack
    can be applied to any ASGI or WSGI application via ConnexionMiddleware.
  humanURL: https://connexion.readthedocs.io/en/latest/middleware.html
  baseURL: https://connexion.readthedocs.io
  tags:
  - ASGI
  - Middleware
  - WSGI
  properties:
  - type: Documentation
    url: https://connexion.readthedocs.io/en/latest/middleware.html
  - type: Reference
    url: https://github.com/spec-first/connexion/tree/main/connexion/middleware
  x-features:
  - Routing, security, request, and response validation middleware
  - SwaggerUIMiddleware for interactive docs
  - LifespanMiddleware for startup and shutdown hooks
  - ContextMiddleware to propagate request context
  x-useCases:
  - Add Connexion validation to FastAPI or Starlette
  - Wrap an existing WSGI application without rewriting handlers
  - Customize the middleware stack for a specific deployment
common:
- type: Website
  url: https://connexion.readthedocs.io/
- type: Documentation
  url: https://connexion.readthedocs.io/en/latest/quickstart.html
- type: GitHubRepository
  url: https://github.com/spec-first/connexion
- type: GitHubOrganization
  url: https://github.com/spec-first
- type: Issue Tracker
  url: https://github.com/spec-first/connexion/issues
- type: ChangeLog
  url: https://github.com/spec-first/connexion/releases
- type: License
  url: https://github.com/spec-first/connexion/blob/main/LICENSE
- type: PyPI
  url: https://pypi.org/project/connexion/
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com