What is knife4j?

Knife4j is a tool for Java developers who build web APIs and need to generate readable API documentation automatically. It started as a project called swagger-bootstrap-ui and was later renamed knife4j (the name is meant to evoke something sharp and light, like a small knife). The core job it does is take the Swagger or OpenAPI annotations in a Java project and turn them into a browsable, interactive documentation page. The README is written in Chinese and targets Java developers. The short version for a non-technical reader: when a backend team builds an API, other developers need to know what endpoints exist, what data each one accepts, and what it returns. Knife4j generates that reference automatically from the code, so no one has to write and maintain a separate document by hand. It works with the two main API specification standards in common use, Swagger 2 and OpenAPI 3, and has integrations for popular Java web frameworks. Once installed, you visit a page at the address /doc.html on your server and get the full interactive API browser. That entry point has been kept constant and the README notes it will not change. The project is organized into several modules. The main knife4j module provides the Java middleware layer. knife4j-insight is a standalone ready-to-run version distributed as a Docker image. There is also a documentation module, a Vue 2 frontend, and a Vue 3 frontend contributed by the community. The project is actively maintained and has its own documentation site. A QR code in the README leads to a community chat group.