Ghm Template Sync Skill for Claude

Template Sync

Detect template version drift and migrate to the latest template version.

Workflow

Phase 1: Detect Current State

• Read .claude/VERSION (if it exists) to get current template version
• If no VERSION file, check CLAUDE.md frontmatter for template_version
• If neither exists, assume v1.0.0 (pre-versioning)
• Report: "Your repo is on template v{X}. Latest is v{Y}."

Phase 2: Diff Against Template

Compare your repo structure against what the current template version expects:

Check for missing files:

• .claude/VERSION
• .claude/domain-profile.yaml
• .claude/hooks/HOOK_CONTRACT.md
• .claude/hooks/context-validation.sh
• .claude/hooks/context-density-gate.sh
• .claude/hooks/sot-update-trigger.sh
• CHANGELOG.md
• MIGRATION.md

Check for stale files (should be removed):

• .claude/hooks/context-validation.py
• .claude/hooks/context-density-gate.py
• .claude/hooks/sot-update-trigger.py
• .claude/agents/HORIZON.md (replaced by subdirectory)
• .claude/agents/STUDIO.md
• .claude/agents/DEVLAB.md
• .claude/agents/METRO.md

Check for structure issues:

• settings.json: Does it use 3-level nesting? Are timeouts in seconds?
• Agent directories: Do horizon/, studio/, devlab/, metro/ subdirectories exist with AGENT.md + MEMORY.md?
• EPIC template: Does it use semantic headers (not numbered)?
• Frontmatter: Do key files have template_version?

Phase 3: Generate Migration Plan

Output a table:

| File | Status | Action | Risk |

|------|--------|--------|------|

| .claude/VERSION | Missing | Copy from template | None |

| .claude/hooks/*.py | Stale | Delete (replaced by .sh) | None |

| .claude/agents/HORIZON.md | Stale | Split into horizon/AGENT.md + MEMORY.md | Preserve MEMORY.md content |

| settings.json | Outdated | Update hook nesting + commands | Check for custom hooks |

| CLAUDE.md | Missing frontmatter | Add template_version: "3.0.0" | None |

Phase 4: Execute Safe Updates

Auto-safe (do without asking):

• Create .claude/VERSION with current template version
• Add template_version frontmatter to files that lack it
• Report what was done

Confirm first (show diff, ask user):

• Update settings.json hook configuration
• Restructure agent files (must preserve MEMORY.md)
• Delete stale Python hooks
• Update EPIC template headers

Never touch (product-specific):

• PRD.md content (only add frontmatter)
• SoT/*.md content
• epics/EPIC-*.md content (only update headers on closed EPICs)
• .claude/agents/*/MEMORY.md content
• README.md content

Phase 5: Verify

After all changes:

• Test all shell hooks produce valid JSON
• Verify no Python hooks remain
• Confirm settings.json uses correct nesting
• Check agent subdirectories have both AGENT.md and MEMORY.md
• Report summary of changes made

Version Migration Matrix

| From | To | Key Changes |

|------|----|-------------|

| v1.0.0 | v2.0.0 | Add skills, hooks, agents, SoT standardization |

| v2.0.0 | v3.0.0 | Shell hooks, agent subdirs, semantic EPICs, versioning, domain-profile |

| v1.0.0 | v3.0.0 | All of the above (cumulative) |

Safety Rules

• NEVER overwrite MEMORY.md -- these contain product-specific agent memory
• NEVER modify SoT content -- only add section markers or frontmatter
• NEVER modify PRD.md content -- only add frontmatter version
• ALWAYS show diff before destructive changes (deletes, restructures)
• ALWAYS verify hooks work after updating settings.json
• Commit changes incrementally -- one commit per phase, not one giant commit