A skill that reverse engineers a detailed product and technical specification from a git branch's implementation.

Use it when:

• A branch has shipped or is in-progress and needs documentation
• You need to understand what a branch does at product and architecture level
• Onboarding to someone else's feature branch
• Creating PR descriptions or design docs after the fact

Produces a structured markdown spec covering problem statement, product requirements, architecture, technical design, file inventories, testing strategy, rollout plan, and risks.

git clone https://github.com/blader/schematic.git ~/.claude/skills/schematic

Restart Claude Code to pick up the new skill.

git clone https://github.com/blader/schematic.git ~/.codex/skills/schematic

Or use the built-in skill installer:

Install the skill from github.com/blader/schematic

Restart Codex to pick up the new skill.

In Claude Code or Codex, just ask:

• "Reverse engineer a spec from this branch"
• "Analyze this branch"
• "Write a spec from the code"
• "Document what this branch does"

The skill will systematically analyze every file changed on the branch and produce a comprehensive specification document.

1. Scope the branch - Gets the full diff stats and categorizes files
2. Parallel deep exploration - Launches 2-4 parallel agents to read file groups concurrently
3. Cross-check for gaps - Diffs analyzed files against the full file list to catch stragglers
4. Write the spec - Produces a structured 11-section markdown document
5. Verify completeness - Ensures every changed file is accounted for

MIT