Doc Sync

Maintains the CLAUDE.md navigation hierarchy and README.md invisible knowledge docs across a repository. This skill is self-contained and performs all documentation work directly.

Documentation Conventions

For authoritative CLAUDE.md and README.md format specification:

The conventions/ directory contains all universal documentation standards.

Scope Resolution

Determine scope FIRST:

For REPOSITORY-WIDE scope, perform a full audit. For narrower scopes, operate only within the specified boundary.

Workflow

Phase 1: Discovery

Map directories requiring CLAUDE.md verification:

# Find all directories (excluding .git, node_modules, __pycache__, etc.)
find . -type d \( -name .git -o -name node_modules -o -name __pycache__ -o -name .venv -o -name target -o -name dist -o -name build \) -prune -o -type d -print

For each directory in scope, record:

1. Does CLAUDE.md exist?
2. If yes, does it have the required table-based index structure?
3. What files/subdirectories exist that need indexing?

Phase 2: Audit

For each directory, check for drift and misplaced content:

<audit_check dir="[path]">
CLAUDE.md exists: [YES/NO]
Has table-based index: [YES/NO]
Files in directory: [list]
Files in index: [list]
Missing from index: [list]
Stale in index (file deleted): [list]
Triggers are task-oriented: [YES/NO/PARTIAL]
Contains misplaced content: [YES/NO] (architecture/design docs that belong in README.md)
README.md exists: [YES/NO]
README.md warranted: [YES/NO] (invisible knowledge present?)
</audit_check>

Phase 3: Content Migration

Critical: If CLAUDE.md contains content that does NOT belong there, migrate it:

Content that MUST be moved from CLAUDE.md to README.md:

• Architecture explanations or diagrams
• Design decision documentation
• Component interaction descriptions
• Overview sections with prose (beyond one sentence)
• Invariants or rules documentation
• Any "why" explanations beyond simple triggers
• Key Invariants sections
• Dependencies sections (explanatory -- index can note dependencies exist)
• Constraints sections
• Purpose sections with prose (beyond one sentence)
• Any bullet-point lists explaining rationale

Content that MAY stay in CLAUDE.md (operational sections):

• Build commands specific to this directory
• Test commands specific to this directory
• Regeneration/sync commands (e.g., protobuf regeneration)
• Deploy commands
• Other copy-pasteable procedural commands

Test: Ask "is this explaining WHY or telling HOW?" Explanatory content (architecture, decisions, rationale) goes to README.md. Operational content (commands, procedures) stays in CLAUDE.md.

Migration process:

1. Identify misplaced content in CLAUDE.md
2. Create or update README.md with the architectural content
3. Strip CLAUDE.md down to pure index format
4. Add README.md to the CLAUDE.md index table

Phase 4: Index Updates

For each directory needing work:

Creating/Updating CLAUDE.md:

1. Use the appropriate template (ROOT or SUBDIRECTORY)
2. Populate tables with all files and subdirectories
3. Write "What" column: factual content description
4. Write "When to read" column: action-oriented triggers
5. If README.md exists, include it in the Files table

Creating README.md (when invisible knowledge exists):

1. Verify invisible knowledge exists (semantic trigger, not structural)
2. Document architecture, design decisions, invariants, tradeoffs
3. Apply the content test: remove anything visible from code
4. Keep as concise as possible while capturing all invisible knowledge
5. Must be self-contained: do not reference external authoritative sources

Phase 5: Verification

After all updates complete, verify:

1. Every directory in scope has CLAUDE.md
2. All CLAUDE.md files use table-based index format (pure navigation)
3. No drift remains (files <-> index entries match)
4. No misplaced content in CLAUDE.md (explanatory prose moved to README.md)
5. README.md files are indexed in their parent CLAUDE.md
6. CLAUDE.md contains only: one-sentence overview + tabular index + operational sections
7. README.md exists wherever invisible knowledge was identified
8. README.md files are self-contained (no external authoritative references)

Output Format

## Doc Sync Report

### Scope: [REPOSITORY-WIDE | directory path]

### Changes Made
- CREATED: [list of new CLAUDE.md files]
- UPDATED: [list of modified CLAUDE.md files]
- MIGRATED: [list of content moved from CLAUDE.md to README.md]
- CREATED: [list of new README.md files]
- FLAGGED: [any issues requiring human decision]

### Verification
- Directories audited: [count]
- CLAUDE.md coverage: [count]/[total] (100%)
- CLAUDE.md format: [count] pure index / [count] needed migration
- Drift detected: [count] entries fixed
- Content migrations: [count] (prose moved to README.md)
- README.md files: [count] (wherever invisible knowledge exists)
- Self-contained: [YES/NO] (no external authoritative references)

Exclusions

DO NOT create CLAUDE.md for:

• Generated files directories (dist/, build/, compiled outputs)
• Vendored dependencies (node_modules/, vendor/, third_party/)
• Git internals (.git/)
• IDE/editor configs (.idea/, .vscode/ unless project-specific settings)
• Stub directories (contain only .gitkeep or no code files) - these do not require CLAUDE.md until code is added

DO NOT index (skip these files in CLAUDE.md):

• Generated files (.generated., compiled outputs)
• Vendored dependency files

DO index:

• Hidden config files that affect development (.eslintrc, .env.example, .gitignore)
• Test files and test directories
• Documentation files (including README.md)

Anti-Patterns

Index Anti-Patterns

Too vague (matches everything):

| `config/` | Configuration | Working with configuration |

Content description instead of trigger:

| `cache.rs` | Contains the LRU cache implementation | - |

Missing action verb:

| `parser.py` | Input parsing | Input parsing and format handling |

Correct Examples

| `cache.rs` | LRU cache with O(1) get/set | Implementing caching, debugging misses, tuning eviction |
| `config/` | YAML config parsing, env overrides | Adding config options, changing defaults, debugging config loading |

When NOT to Use This Skill

• Single file documentation (inline comments, docstrings) - handle directly
• Code comments - handle directly
• Function/module docstrings - handle directly
• This skill is for CLAUDE.md/README.md synchronization specifically

Reference

For additional trigger pattern examples, see references/trigger-patterns.md.