Write API documentation from code

This prompt writes API documentation from the routes, handlers or OpenAPI snippet you paste in.

text-api-docs-from-code — chatgpt — 44 words

Write API documentation for these endpoints:

[PASTE ROUTES, HANDLERS OR OPENAPI SNIPPET]

For each endpoint include purpose, method and path, parameters, request body, example request, example response, error codes and authentication requirements. Organise them into sections and start with a short "getting started" guide.

Edit in the builder Copy & open ChatGPT ↗Copy & open Gemini ↗Copy & open Claude ↗

Generate a working curl example for each endpoint and test it before publishing.

Get a better result

What you will get

Documentation for each endpoint with purpose, method and path, parameters, body, example request and response, error codes and authentication, in sections with a short getting-started guide at the start.

Common mistake

The docs describe behaviour that the code does not have.

Fix: Paste the real handler code, not only the route names, and ask “mark anything you are inferring from names alone”.

Also watch for

Example responses use made-up field names. Paste an actual response or the schema, and say “use these exact field names”. Run each example request before publishing.
Authentication is described vaguely. State the scheme, such as a bearer token in the Authorization header, and ask for a table of which endpoints need it.

Try a variation: add a changelog stub

Ask for “a short changelog section with a date, a version and breaking changes noted”. Developers who rely on your API will look for it first.

Still not right? Reply with this

Rewrite the error section as a table with status code, when it happens and the body returned, using only errors found in the code I pasted.