kennethreitz/responder

Health v2 · maintenance only

Adoption not part of the score

3620 stars · 217 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

Responder is a Python HTTP service framework with a Flask/Falcon-style request-response model, built on Starlette and ASGI. It bundles batteries-included features like OpenAPI generation, Pydantic validation, WebSockets, typed SSE/NDJSON streams, sessions, and rate limiting.

Use cases

• build a REST API in Python
• create a JSON web service with OpenAPI docs
• serve a small web app with Flask-like routing on ASGI
• stream typed SSE or NDJSON events to clients
• add rate limiting and health checks to a Python microservice
• mount Flask or Django apps under one ASGI API
• handle WebSockets in a Python web service

When to choose

• you want Flask's familiar req/resp style with modern async ASGI under the hood
• you need OpenAPI schema generation and Swagger UI from type hints
• you want a batteries-included framework with sessions, rate limiting, and content negotiation in one import
• you need typed streaming responses (SSE/NDJSON) with generated clients

When to avoid

• your team is standardized on FastAPI and its dependency-injection ecosystem
• you need the largest plugin ecosystem and community - Flask or Django are far bigger
• you want a minimal microframework without built-in conventions
• you rely on niche third-party extensions built specifically for Flask

Facets

framework · maturity active

web-framework api-framework http-server routing middleware websocket rate-limiting serialization web-development backend apis microservices python cross-platform asgi starlette openapi flask-like falcon pydantic content-negotiation sse ndjson uvicorn web-server

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markdown · JSON · MCP: product_card(name="kennethreitz/responder")