API Versioning Documentation Manager

The hard part of versioning an API is not cutting the new release — it is keeping documentation honest for everyone still on an older version while you move forward. A consumer pinned to v2 should be able to read docs that describe their endpoints, not a single page littered with “available since v3” footnotes. This manager keeps one self-contained document per version: its status, its servers, and every endpoint with parameters and responses — so the docs a developer reads always match the version they call.

Comparison is where the lifecycle becomes actionable. Matching endpoints by method and path, the tool reports what was added, removed and modified, and applies the heuristics that actually break clients: a removed endpoint or parameter is breaking, a newly required parameter is breaking, and a new optional parameter is a safe addition. Those buckets map straight onto SemVer — any breaking change implies a major bump, additions imply a minor, edits a patch — and the impact assessment lets you defend the version number in review.

From a comparison you can generate a migration guide that reads like a release plan: an overview, the breaking-change list doubling as a checklist, timed steps, before/after code, and a recommended timeline that stretches automatically when breakage is present. Deprecation is tracked the same way — versions and individual endpoints carry a deprecated flag, and the timeline shows each release alongside its successor so the sunset window is obvious to the people who need to move.

For sharper single-purpose views, diff two specs into Markdown with the API Changelog Generator, drill into structural deltas with the Schema Difference Analyzer, and turn a single spec into polished reference docs with the OpenAPI / Swagger Generator.