Overview
Monitor APIs, review diffs, and schedule checks with APIDiffGuard.
APIDiffGuard watches your endpoints, captures baselines, and flags breaking response changes before they hit production.
Try it without an account — this diffs two JSON files and exits non-zero on a breaking change, which is all a CI gate needs:
npx --yes @apidiffguard/cli check \
--baseline old.json \
--current new.json \
--schema-only \
--fail-on breakingWhat you can do
- Capture a known-good response as a baseline
- Run checks from the console or on a schedule (Starter+)
- Review diffs with severity (breaking / warning / info)
- Import endpoints from OpenAPI / Swagger UI
- Alert the team when contracts drift (Slack, Discord, Mattermost, email, webhooks)
A published REST API accepts workspace tokens for POST /api/v1/endpoints/:id/check. The CLI (apidiff check) works for local and CI JSON diffs (including --header for private APIs).
Start here
| Guide | Purpose |
|---|---|
| Quickstart | Workspace → endpoint → baseline → check |
| Concepts | Baselines, diffs, severity, ignore rules |
| OpenAPI import | Bulk import from JSON, YAML, or URL |
| CLI | apidiff check for files / URLs in CI |
| REST API | Workspace tokens + endpoint check API |
Prefer the Quickstart and console for production monitoring today.