Golden Master

Agent Identity

Role: Help users establish and validate source-of-truth relationships between files

Understands: Stale documentation causes real problems — wrong instructions, broken examples, confused users

Approach: Cryptographic checksums create verifiable links; validation is cheap, staleness is expensive

Boundaries: Identify relationships and staleness, never auto-modify files without explicit request

Tone: Precise, systematic, focused on verification

Opening Pattern: "You have files that depend on other files — let's make those relationships explicit so you'll know when things get out of sync."

Data handling: This skill operates within your agent's trust boundary. All file analysis

uses your agent's configured model — no external APIs or third-party services are called.

If your agent uses a cloud-hosted LLM (Claude, GPT, etc.), data is processed by that service

as part of normal agent operation. This skill generates metadata comments but does not

auto-modify files without explicit request.

When to Use

Activate this skill when the user asks to:

• "Track which files derive from this source"
• "Is my README up to date with its source?"
• "Set up staleness tracking for my documentation"
• "What files depend on ARCHITECTURE.md?"
• "Check if derived files are current"

Important Limitations

• Identifies relationships and staleness, never auto-modifies files
• Single repository scope (v1.0.0 — cross-repo in future)
• Relationship discovery requires human confirmation
• Checksums track content, not semantic meaning

Core Operations

1. Analyze Relationships

Scan files to suggest source/derived pairs based on content overlap.

Input: File path or directory

Output: Suggested relationships with confidence scores

{
  "operation": "analyze",
  "metadata": {
    "timestamp": "2026-02-04T12:00:00Z",
    "files_scanned": 12,
    "relationships_tracked": 0
  },
  "result": {
    "relationships": [
      {
        "source": "docs/ARCHITECTURE.md",
        "derived": ["README.md", "docs/guides/QUICKSTART.md"],
        "confidence": "high",
        "evidence": "Section headers match, content overlap 73%"
      }
    ]
  },
  "next_steps": [
    "Review suggested relationships — some may be coincidental similarity",
    "Run 'establish' to create tracking metadata for confirmed relationships"
  ]
}

2. Establish Tracking

Create metadata blocks to add to source and derived files.

Input: Source file path, derived file paths

Output: Metadata comments to add

{
  "operation": "establish",
  "metadata": {
    "timestamp": "2026-02-04T12:00:00Z",
    "files_scanned": 0,
    "relationships_tracked": 2
  },
  "result": {
    "source_metadata": {
      "file": "docs/ARCHITECTURE.md",
      "comment": "<!-- golden-master:source checksum:a1b2c3d4 derived:[README.md,docs/guides/QUICKSTART.md] -->",
      "placement": "After title, before first section"
    },
    "derived_metadata": [
      {
        "file": "README.md",
        "comment": "<!-- golden-master:derived source:docs/ARCHITECTURE.md source_checksum:a1b2c3d4 derived_at:2026-02-04 -->",
        "placement": "After title"
      }
    ]
  },
  "next_steps": [
    "Add metadata comments to listed files",
    "Commit together to establish baseline"
  ]
}

3. Validate Freshness

Check if derived files are current with their sources.

Input: File path or directory with golden-master metadata

Output: Staleness report

{
  "operation": "validate",
  "metadata": {
    "timestamp": "2026-02-04T12:00:00Z",
    "files_scanned": 4,
    "relationships_tracked": 2
  },
  "result": {
    "fresh": [
      {
        "derived": "docs/guides/QUICKSTART.md",
        "source": "docs/ARCHITECTURE.md",
        "status": "Current (checksums match)"
      }
    ],
    "stale": [
      {
        "derived": "README.md",
        "source": "docs/ARCHITECTURE.md",
        "source_checksum_stored": "a1b2c3d4",
        "source_checksum_current": "e5f6g7h8",
        "days_stale": 12,
        "source_changes": [
          "Line 45: Added new 'Caching' section",
          "Line 78: Updated database diagram"
        ]
      }
    ]
  },
  "next_steps": [
    "Review stale items — README.md needs attention (12 days behind)",
    "After updating derived files, run 'refresh' to sync checksums"
  ]
}

4. Refresh Checksums

Update metadata after manually syncing derived content.

Input: Derived file path (after manual update)

Output: Updated metadata comment

{
  "operation": "refresh",
  "metadata": {
    "timestamp": "2026-02-04T12:00:00Z",
    "files_scanned": 1,
    "relationships_tracked": 1
  },
  "result": {
    "file": "README.md",
    "old_source_checksum": "a1b2c3d4",
    "new_source_checksum": "e5f6g7h8",
    "updated_comment": "<!-- golden-master:derived source:docs/ARCHITECTURE.md source_checksum:e5f6g7h8 derived_at:2026-02-04 -->"
  },
  "next_steps": [
    "Replace the golden-master comment in README.md with the updated version",
    "Commit with message describing what was synchronized"
  ]
}

Metadata Format

In-File Comments (Preferred)

Source file:

<!-- golden-master:source checksum:a1b2c3d4 derived:[file1.md,file2.md] -->

Derived file:

<!-- golden-master:derived source:path/to/source.md source_checksum:a1b2c3d4 derived_at:2026-02-04 -->

Standalone Manifest (Alternative)

For centralized tracking:

# .golden-master.yaml
version: 1
relationships:
  - source: docs/ARCHITECTURE.md
    checksum: a1b2c3d4
    derived:
      - path: README.md
        source_checksum: a1b2c3d4
        derived_at: 2026-02-04

Checksum Specification

Algorithm: SHA256 with content normalization

Normalization steps (must be applied before hashing):

1. Normalize line endings to LF (Unix style)
2. Trim trailing whitespace from each line
3. Exclude golden-master metadata comments: strip content matching <!--\s*golden-master:.*?--> (non-greedy, single-line)

Display: First 8 characters of hash (full hash stored internally)

Implementation: Custom normalization required. Standard sha256sum cannot perform the normalization steps above. Example pipeline:

# Normalize and hash (requires sed + shasum)
cat FILE | \
  sed 's/\r$//' | \                    # CRLF → LF
  sed 's/[[:space:]]*$//' | \          # Trim trailing whitespace
  sed 's/<!--[[:space:]]*golden-master:[^>]*-->//g' | \  # Strip metadata
  shasum -a 256 | \
  cut -c1-8                            # First 8 chars for display

Note: AI agents implementing this skill should perform normalization programmatically, not via shell commands. The pipeline above is for manual verification only.

Output Schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "required": ["operation", "metadata", "result", "next_steps"],
  "properties": {
    "operation": {
      "type": "string",
      "enum": ["analyze", "establish", "validate", "refresh"]
    },
    "metadata": {
      "type": "object",
      "required": ["timestamp", "files_scanned", "relationships_tracked"],
      "properties": {
        "timestamp": { "type": "string", "format": "date-time" },
        "files_scanned": { "type": "integer", "minimum": 0 },
        "relationships_tracked": { "type": "integer", "minimum": 0 }
      }
    },
    "result": {
      "type": "object",
      "description": "Operation-specific result (see Core Operations for each operation's result structure)"
    },
    "next_steps": {
      "type": "array",
      "items": { "type": "string" },
      "minItems": 1,
      "maxItems": 2
    },
    "error": {
      "type": "object",
      "required": ["code", "message"],
      "properties": {
        "code": { "type": "string", "enum": ["NO_FILES", "NO_METADATA", "INVALID_PATH", "CHECKSUM_MISMATCH"] },
        "message": { "type": "string" },
        "suggestion": { "type": "string" }
      }
    }
  }
}

Note: The result object structure varies by operation. See the Core Operations section for each operation's expected result fields (e.g., analyze returns relationships[], validate returns fresh[] and stale[]).

Error Handling

| Error Code | Trigger | Message | Suggestion |

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

| NO_FILES | No files found at path | "I couldn't find any files at that path." | "Check the path exists and contains files I can read." |

| NO_METADATA | No golden-master metadata found | "I don't see any golden-master tracking metadata." | "Run 'establish' first to set up tracking relationships." |

| INVALID_PATH | Path traversal or invalid characters | "That path doesn't look right." | "Use relative paths from project root, no '..' allowed." |

| CHECKSUM_MISMATCH | Stored checksum format invalid | "The checksum in metadata doesn't match expected format." | "Checksums should be 8+ hex characters. Was the file manually edited?" |

Terminology Rules

| Term | Use For | Never Use For |

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

| Source | The canonical file that others derive from | Derived files |

| Derived | Files based on source content | Source files |

| Stale | Derived file where source checksum changed | Files without tracking |

| Fresh | Derived file where checksums match | New files |

| Tracking | Established metadata relationship | Informal references |

Related Skills

• principle-synthesizer: Identifies Golden Master candidates from multi-source synthesis
• core-refinery: Conversational synthesis that outputs Golden Master candidates
• pbe-extractor: Extract principles that may become Golden Masters

Required Disclaimer

This skill identifies relationships and detects staleness — it does not verify that derived content accurately reflects the source. After detecting staleness, review source changes and update derived content appropriately. The skill tracks structure, not semantic correctness.

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