---
name: Doc Sync
slug: doc-sync
category: Writing
description: Doc Sync keeps linked project documents synchronized when a source file changes. Use it to review reports, extract updates, and propose edits for PRDs, decks, and notes before applying them.
github: "https://github.com/coco-research/coco/tree/main/skills/doc-sync"
language: HTML
stars: 218
forks: 11
install: "npx degit https://github.com/coco-research/coco/tree/main/skills/doc-sync ~/.claude/skills/doc-sync"
installs_to: ~/.claude/skills/doc-sync
source_path: skills/doc-sync/SKILL.md
collection_size: 25
category_size: 1144
collection_url: "https://dirskills.com/collections/coco-research/coco"
added: 2026-09-04T05:25:20.207Z
last_synced: 2026-09-04T05:25:20.207Z
canonical_url: "https://dirskills.com/skills/doc-sync"
---

# Doc Sync

Doc Sync keeps linked project documents synchronized when a source file changes. Use it to review reports, extract updates, and propose edits for PRDs, decks, and notes before applying them.

**Install:**

```bash
npx degit https://github.com/coco-research/coco/tree/main/skills/doc-sync ~/.claude/skills/doc-sync
```

## README

# Doc Sync — Cascading Document Updater

## What This Skill Does

Maintains consistency across a documentation ecosystem where one source change (e.g., a new meeting note) should cascade updates to multiple downstream documents (PRD, presentation, project memory).

**This is NOT a background watcher.** This skill is the Claude-side processor that:
1. Reads a sync report or detects changes directly
2. Extracts actionable content from new/modified source files
3. Proposes specific edits to each downstream target
4. Applies changes only after user approval

## Prerequisites

### Infrastructure (one-time setup)

The persistent detection layer runs outside Claude Code via `/project-sync init`:

| Component | Path | Purpose |
|-----------|------|---------|
| Orchestrator | `~/.claude/scripts/project-sync-orchestrator.sh` | Email search + file detection + report generation |
| launchd agent | `~/Library/LaunchAgents/com.claude.project-sync.<name>.plist` | Background scheduler (every 2 hours) |
| State dir | `~/.claude/state/<project-name>/` | Logs, timestamps, cached config (outside OneDrive) |

### Per-Project Config

Each project needs `.sync-watch.json` in its root:

```json
{
  "project_name": "My Project",
  "watch_dirs": ["docs/meeting-notes", "docs/research"],
  "target_docs": {
    "tier1": [
      {
        "path": "docs/PRD.html",
        "name": "Product Requirements",
        "update_from": ["meeting-notes", "research"],
        "what": "Requirements, user stories, decisions"
      }
    ],
    "tier2": [
      {
        "path": "docs/presentation.html",
        "name": "Stakeholder Deck",
        "update_from": ["meeting-notes"],
        "what": "Stakeholder updates, timeline changes"
      }
    ]
  },
  "ignore_patterns": [".*", "*.tmp", "~$*"],
  "file_types": [".md", ".html", ".docx", ".xlsx", ".pdf"]
}
```

## Invocation

### Automatic (via session hook)
When you start a Claude Code session in a watched project with pending changes:
```
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 SYNC WATCHER ► 3 new/modified file(s) detected
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Say "process sync report" to review and apply updates.
```

### Manual
- `/doc-sync` — check for changes now and process
- `/doc-sync path/to/new-file.md` — process a specific source file
- `process sync report` — process a pending `.sync-report.md`

## Process

### Step 1: Detect Changes

**If `.sync-report.md` exists:** Read it — it lists all changed files with timestamps.

**If no report (manual invocation):**
```bash
!`bash ~/.claude/scripts/project-sync-orchestrator.sh "$(pwd)"`
```
Then read the generated `.sync-report.md` (written to project root or `~/.claude/state/<project-name>/sync-report.md`).

**If a specific file was passed as `$ARGUMENTS`:** Use that file as the sole source.

**If no changes detected:** Report "All documents are in sync." and stop.

### Step 2: Read Source Files

For each new/modified file detected:

1. **Skip binaries** (`.docx`, `.xlsx`, `.pptx`, `.pdf`) — note them but don't read. Tell user: "Binary file detected — paste key content or convert to text."
2. **Read text files** (`.md`, `.html`) in full
3. **Extract structured data** from each:

```
For each source file, extract:
- NEW STAKEHOLDERS: Name, Role, Email, Group
- NEW DECISIONS: What was decided, by whom, date, impact
- NEW REQUIREMENTS: Functional/non-functional, priority, acceptance criteria
- NEW ACTION ITEMS: Owner, deadline, status
- NEW ARCHITECTURE: Design changes, module updates, integration changes
- NEW RISKS: Description, impact, mitigation
- VERSION CHANGES: What changed from previous version
```

### Step 3: Read Config & Map Dependencies

Read `.sync-watch.json` to determine which target docs need which types of updates.

For each target doc in `tier1` and `tier2`:
- Check if any source file matches its `update_from` patterns
- If yes → read the target doc to understand current state
- Identify exactly WHERE in the target doc the new content should go

### Step 4: Propose Updates

Present a structured proposal — DO NOT edit anything yet:

```markdown
## Sync Proposal

### Source: Meeting-Notes-2026-03-17.md
**New content extracted:**
- 2 new stakeholders (Jane Doe, John Smith)
- 1 decision (moved go-live to Q4)
- 3 action items

### Updates Needed:

**1. PRD.html** (Tier 1)
- Section 05 Stakeholders: Add Jane Doe (Tax Director), John Smith (IT Lead)
- Section 12 Timeline: Update go-live from Q3 → Q4
- Change log: Add v1.1 entry
- [Show exact diff preview for each change]

**2. Presentation.html** (Tier 1)
- Slide 7 (Team): Add 2 stakeholder cards
- Slide 12 (Timeline): Update milestone date
- [Show exact diff preview]

**3. CLAUDE.local.md** (Tier 1)
- Recent Changes: Add dated entry
- [Show exact content to append]

**4. Stakeholder-Directory.xlsx** (Tier 2)
- SKIP — binary file, manual update needed
```

### Step 5: Get Approval

Ask user:
- "Apply all updates?" → proceed with all
- "Apply selectively?" → let user pick which targets
- "Skip for now?" → clean up report, do nothing
- User may also request modifications to the proposal

### Step 6: Apply Updates

For each approved target:
1. **Read the target file** (always re-read before editing — it may have changed)
2. **Apply edits** using the Edit tool (not Write — preserve unchanged content)
3. **Verify** the edit was applied correctly
4. **Log** what was changed

### Step 7: Clean Up & Update Memory

After all edits applied:
1. **Delete `.sync-report.md`** (consumed)
2. **Update `_temp/.last-sync-check`** timestamp
3. **Update `CLAUDE.local.md`** Recent Changes section with a dated entry summarizing what was synced
4. **Report** summary to user:

```
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 DOC SYNC ► COMPLETE ✓
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Source files processed: 3
Documents updated: 4
  ✓ PRD.html — 3 edits (stakeholders, timeline, changelog)
  ✓ Presentation.html — 2 edits (team slide, timeline)
  ✓ CLAUDE.local.md — 1 edit (recent changes)
  ⚠ Stakeholder-Directory.xlsx — skipped (binary)

Manual follow-up needed:
  - Update Stakeholder-Directory.xlsx with 2 new contacts
```

## Critical Rules

1. **NEVER edit without approval.** Always show the proposal first. The user must explicitly approve.
2. **NEVER fabricate content.** Only extract what's actually written in source files. If a meeting note doesn't mention a stakeholder's email, don't guess it.
3. **NEVER overwrite — always append/insert.** Use Edit tool with precise `old_string` matching. Never rewrite entire files.
4. **ALWAYS read target docs before editing.** They may have been modified since the report was generated.
5. **ALWAYS preserve existing formatting.** Match the target doc's style (HTML structure, CSS classes, indentation patterns).
6. **Binary files are report-only.** Flag them for manual update, don't attempt to modify.
7. **Version bumps:** If the target doc has a version badge/number, increment it and add a changelog entry.

## Adding This to a New Project

1. Create `.sync-watch.json` in the project root (use template above)
2. Run `/project-sync init` to set up the launchd cron job
3. Done — the background orchestrator runs every 2 hours and generates `.sync-report.md` when changes are detected

## Dependency Graph Pattern

For complex projects, document the update cascade in `.sync-watch.json`:

```
Meeting Notes ──→ PRD ──→ PRD Presentation
       │                         │
       ├──→ Main Presentation ←──┘
       │
       └──→ CLAUDE.local.md ←── (all changes)
```

This ensures that when a meeting note creates a PRD change, and that PRD change should also update the presentation, the full cascade is handled in one sync pass.