Scalar

Scalar takes an OpenAPI or Swagger document and renders it as an interactive API reference that does not look like it was designed in 2011. Next to it sits an API client for calling the endpoints, so reading a specification and trying it become the same activity.

Publishing a reference is a single HTML file: load the package from a script tag, point it at your document, and add a proxy address for the CORS problem that always turns up. Code examples are generated for many languages and frameworks from the same document.

The surrounding pieces are worth knowing about.

• API client: offline-first and open source, with environment variables and dynamic parameters, in the browser or downloaded for Windows, macOS and Linux.
• Watch mode: the client keeps itself in sync with your server framework as the specification changes.
• Framework integrations: ASP.NET Core, Django, Express, FastAPI, Fastify, Flask, Go, Spring Boot, SvelteKit, Vue and dozens more.
• Built-in adoption: Effect, ElysiaJS, Litestar, Nitro, oRPC and Platformatic ship Scalar as their default OpenAPI interface.
• Supporting tools: a registry for managing documents, an SDK generator, a CLI, a mock server and an online editor.

Everything here can be self-hosted straight from the repository. A managed service is offered alongside it, with a free tier that publishes references on a project subdomain with SSL, GitHub sync, free-form documentation, team collaboration and support for your own domain.