Breaking changes are inevitable. What separates reliable platforms from chaotic ones is how you communicate, schedule, and enforce version transitions.
Start with a published policy
Before you ship v2 of anything, document your rules: how long deprecated endpoints remain available, what counts as a breaking change, and how partners subscribe to change notifications.
Use contract tests as gates
Automated contract tests against your OpenAPI specification catch accidental breaking changes in CI. Treat a failing contract test with the same urgency as a failing unit test.
Deprecation is a product feature
Give partners at least 90 days for non-critical endpoints and 180 days for widely adopted ones. Surface deprecation banners in your developer portal and include sunset dates in response headers.
Deprecation: true
Sunset: Sat, 15 Jun 2026 00:00:00 GMT
Link: </v2/orders>; rel="successor-version"Measure adoption before you cut
Track traffic to deprecated routes daily. Do not sunset an endpoint until usage drops below an agreed threshold — and notify the remaining consumers individually.