API Versioning Skill
Design and manage API versioning strategies for backward-compatible evolution.
Trigger Conditions
- •Breaking API change is proposed
- •New API endpoint is created
- •User invokes with "version API" or "API deprecation plan"
Input Contract
- •Required: Current API spec and proposed change
- •Required: Consumer list (who calls this endpoint)
- •Optional: Sunset timeline, migration support level
Output Contract
- •Versioning recommendation (strategy + implementation)
- •Breaking change analysis with consumer impact
- •Migration guide for consumers
- •Deprecation timeline with Sunset headers
Tool Permissions
- •Read: API specs, route definitions, consumer registry
- •Write: API specs, migration guides, deprecation notices
- •Search: Codebase for endpoint usage
Execution Steps
- •Analyze proposed change for breaking vs. non-breaking
- •If breaking: determine versioning strategy (URL path, header, content negotiation)
- •Assess consumer impact using consumer registry
- •Draft migration guide for affected consumers
- •Configure Sunset and Warning headers on deprecated endpoints
- •Set deprecation timeline (minimum 3 months)
- •Create monitoring for deprecated endpoint usage
Success Criteria
- •Breaking changes identified and versioned correctly
- •All affected consumers notified with migration guide
- •Sunset headers configured on deprecated endpoints
- •Monitoring in place to track deprecated endpoint usage
Escalation Rules
- •Escalate if >10 consumers are affected by breaking change
- •Escalate if deprecation timeline conflicts with consumer contracts
- •Escalate if no versioning strategy exists yet
Example Invocations
Input: "We need to change the /users response from {name: string} to {first_name: string, last_name: string}"
Output: Breaking change: field removal (name) + field addition (first_name, last_name). Strategy: v2 endpoint at /api/v2/users. v1 maintained with computed 'name' field for 6 months. Migration guide: update client SDK, map first_name+last_name. Sunset header on v1: 2026-08-01. Monitor v1 usage weekly.