spring

Redoc in Spring Boot

A Spring Boot 4 (Java 21) app that serves its API reference at /. One controller returns the page; the Redoc bundle comes from the jsDelivr CDN and the API description from a URL.

Run

mvn spring-boot:run

Then open http://localhost:8080.

Use it in your app

• RedocController.java — returns the page: a <redoc spec-url> tag plus one script tag.
• application.properties — redoc.url is where the bundle is loaded from. Override it with the REDOC_URL environment variable to self-host the bundle or pin another version.
• The <redoc spec-url> in that page is where your API description lives — any URL the browser can fetch, for example the OpenAPI document springdoc already serves at /v3/api-docs.

Docker

docker build -f docker/Dockerfile -t redoc-spring .
docker run --rm -p 8080:8080 redoc-spring