Ring is a Clojure web applications library that provides an HTTP server abstraction.
Ring solves the problem of coupling web applications tightly to specific HTTP servers and frameworks by defining a simple, unified API for HTTP requests and responses. Inspired by Python's WSGI and Ruby's Rack, it abstracts HTTP details into a modular interface where handlers are functions that take a request map and return a response map. This design allows components to be reused across different applications, servers, and frameworks without modification.
The tool suits Clojure projects that need flexibility in choosing web servers or that want to build reusable middleware and handler components. Ring is distributed as several focused libraries: ring-core provides the core functions and middleware; ring-devel offers development and debugging utilities; ring-jetty-adapter supplies an embedded Jetty server; and ring-servlet and ring-jakarta-servlet enable integration with legacy Java Servlets and modern Jakarta Servlets respectively. The project also provides minimal protocol-only packages for building custom Ring responses and WebSocket support without pulling in unnecessary dependencies.
The project maintains active test coverage through continuous integration workflows. Development follows a structured contribution process documented in a dedicated contributing guide. The codebase acknowledges its intellectual debt to the Ruby and Python communities while building on contributions accumulated over many years.
