<objective> Detects breaking changes in Claude Code updates by diffing the current API surface (hook types and matchers, agent frontmatter fields, plugin manifest schema, SKILL.md format, script CLI flags — tracked in `references/api-surface.md`) against the official changelog. Greps our plugins for each changed API and reports impact mapped to specific file:line locations, classified by severity (BREAKING / DEPRECATED / NEW). </objective>

Breaking Changes Detection Skill

Overview

Compares Claude Code API changes against our plugin ecosystem to detect compatibility issues.

API Surface File

The api-surface.md reference contains our current known API:

• Hook types and their matchers
• Agent frontmatter fields
• Plugin manifest schema
• Skill SKILL.md format
• Script CLI flags used

Detection Workflow

1. Load current api-surface.md
2. Fetch latest Claude Code API docs
3. Diff for added/changed/removed APIs
4. Grep our plugins for each changed API
5. Report with file:line impact mapping

Impact Assessment

| Change Type | Severity | Example | |-------------|----------|---------| | Removed API | BREAKING | Hook type deleted | | Changed schema | BREAKING | Frontmatter field renamed | | New required field | BREAKING | Mandatory new param | | Deprecated API | DEPRECATED | Old hook still works | | New optional API | NEW | New hook type added |

References

• API Surface
• Migration Guide Template