/breaking-changes

name: breaking-changes
description: "Use when checking whether a Claude Code update breaks our plugin ecosystem — hooks, agent frontmatter, manifest schema, or skill format."
argument-hint: "[version]"
user-invocable: true

<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](references/api-surface.md)
• [Migration Guide Template](references/templates/migration-guide.md)