ghm-template-sync

ghm-template-sync is a skill for Claude Code from mattgierhart/PRD-driven-context-engineering. It costs 82 tokens per session (1,121 once invoked), scanned A, original, MIT.

A tool for comparing a project with its starting template and moving it to a newer template version. It checks files and structure, then identifies safe updates while preserving project-specific content.

In plain words
What is it for?
Use it to check template drift, list missing or outdated files, and guide a repository migration to the latest template.
Why use it?
It helps find template changes that a project may have missed and reduces the risk of updating shared files incorrectly.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: reads .claude/ paths; mentions CLAUDE.md.

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/mattgierhart/prd-driven-context-engineering/ghm-template-sync
Any agent
npx skills add mattgierhart/PRD-driven-context-engineering --skill ghm-template-sync
Clone the repo
git clone --depth 1 https://github.com/mattgierhart/PRD-driven-context-engineering

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for ghm-template-sync

README.md
[![agentmods](https://agentmods.dev/badge/skills/mattgierhart/prd-driven-context-engineering/ghm-template-sync.svg)](https://agentmods.dev/skills/mattgierhart/prd-driven-context-engineering/ghm-template-sync)
Your own site
<a href="https://agentmods.dev/skills/mattgierhart/prd-driven-context-engineering/ghm-template-sync"><img src="https://agentmods.dev/badge/skills/mattgierhart/prd-driven-context-engineering/ghm-template-sync.svg" alt="Measured on agentmods" height="20"></a>
Per session 82 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,121 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00082 $0.01121
Opus 5 $0.00041 $0.00561
Sonnet 5 $0.00016 $0.00224
Haiku 4.5 $0.00008 $0.00112

Measured 6d ago against content hash 852eb2d1faf7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

ghm-template-sync scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/ghm-template-sync/SKILL.md · 119 lines

How it starts

The opening of the file, as written. The whole thing — 119 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Template Sync

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

Workflow

Phase 1: Detect Current State

  1. Read .claude/VERSION (if it exists) to get current template version
  2. If no VERSION file, check CLAUDE.md frontmatter for template_version
  3. If neither exists, assume v1.0.0 (pre-versioning)
  4. 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

Read the full file on GitHub · 119 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 6d ago First seen · 119 lines · 82 tokens per session scan A 852eb2d1faf7

Subscribe to this mod's changes

ghm-template-sync is a skill published in the GitHub repository mattgierhart/PRD-driven-context-engineering (182 stars, last pushed 6d ago), licensed MIT. It adds 82 tokens to every session and 1,121 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

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