How do I make sure generated docs match the API spec exactly?

To make generated docs match the API spec exactly, the key rule is: make the spec the single source of truth and generate docs directly from it.

Practical checklist

1. Use one canonical spec

   • Keep OpenAPI/Swagger, AsyncAPI, or whatever spec you use as the authoritative source.
   • Don’t hand-edit published docs if you can avoid it.

2. Generate docs automatically

   • Use a doc generator wired to the spec in your CI/CD pipeline.
   • Regenerate docs on every spec change.

3. Version-control the spec

   • Store the spec in Git.
   • Review spec changes like code changes.

4. Validate the spec

   • Run schema validation and linting before docs are generated.
   • Catch missing fields, invalid types, broken refs, and formatting issues early.

5. Diff generated docs against expected output

   • In CI, generate docs and compare them to the committed/published version.
   • Fail the build if there’s drift.

6. Test examples and code samples

   • If docs include request/response examples, validate them against the spec.
   • Make sure examples are executable and schema-compliant.

7. Tie docs generation to release

   • Publish docs from the same build artifact/version as the API release.
   • That reduces mismatch caused by race conditions or stale deployments.

8. Avoid duplication

   • If descriptions, endpoint lists, parameters, and response models are duplicated in prose, they will drift.
   • Prefer generated tables/sections over manual copy-paste.

Common patterns that help

• OpenAPI + generated reference docs: Swagger UI, Redoc, Stoplight, etc.
• Contract-first development: update spec first, then implement API.
• Schema-driven examples: examples are generated or validated from the schema.

Best practice

If you want the docs to match exactly, treat the pipeline like this:

spec → validate/lint → generate docs → diff/check → publish

If you want, I can also give you:

• a CI example for OpenAPI,
• a workflow for keeping docs and SDKs in sync,
• or a checklist for preventing docs drift.