A Swagger UI alternative

Same spec. Way more swagger.

Paste a link to any OpenAPI or Swagger document and Specbook opens it as an explorer you can click through, send requests from, and share. Requests start on mock data, so there is something to try before you have set anything up. Nothing is uploaded.

Try one:

Specbook on a laptop with the Petstore spec open: a list of operations on the left, and on the right a mock request to POST /store/order that returned 200 and matches the spec. — Petstore, opened from a link, on a laptop and on a phone. The response is a mock that matches the spec. Set Environment to live and the same request goes to the real API.

The same operation on a phone: the request and the 200 response with its body, full width. — Petstore, opened from a link, on a laptop and on a phone. The response is a mock that matches the spec. Set Environment to live and the same request goes to the real API.

What you get

Try it before there is a backend. Mock responses come from your spec and follow what you send: posted fields come back, filters shape the list.
Reads well where people read docs. Phone, tablet, dark mode, and a link to any single operation.
One script tag. Serve it from your docs route and it runs on your origin: no CORS to configure, and your visitors' cookies are sent.

Add an "Open in Specbook" button to your README

Paste the address of your OpenAPI file. Anyone who clicks the button gets your API open and runnable, with nothing to install.