Derive ADRs, rules, PRDs from git commit history. Use when finding doc gaps, detecting unrecorded decisions, deriving conventions from commits, or generating skeleton docs.
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Derive ADRs, rules, PRDs from git commit history. Use when finding doc gaps, detecting unrecorded decisions, deriving conventions from commits, or generating skeleton docs.
name
git-derive-docs
When to Use This Skill
Use this skill when...
Use the alternative when...
Mining git history for undocumented rules, PRDs, ADRs, or PRPs
Use git-cli-agentic for one-shot porcelain queries against the history
Generating skeleton documentation from commit-message patterns
Use git-commit-workflow to set conventions BEFORE the history accrues
Detecting architectural decisions or feature work that was never recorded
Use github-issue-writing to file fresh issues from the gaps you find
Auditing whether .claude/rules/ and docs/{prds,adrs,prps}/ reflect actual practice
Use git-triage to triage the open issues and PRs surfaced during the audit
--rules: Derive .claude/rules/ from commit patterns (conventions, naming, tooling)
--prd: Detect features implemented without requirements documentation
--adr: Detect architecture decisions made without decision records
--prp: Detect implementation work done without planning documentation
--all: Run all detection categories (default if no flags specified)
--since=<date>: Limit analysis to commits after date (e.g., --since=2025-01-01)
--depth=<N>: Number of commits to analyze (default: 200)
--dry-run: Report findings without creating files
--refinements: Focus on plan refinement detection (approach changes, reverts, rework)
Your task
Analyze git commit history to identify documentation gaps.
Step 1: Determine Scope and gather history signals
Parse flags to determine which categories to analyze. Default to --all if no category flags provided.
Run the data-gathering script once. It aggregates file-naming patterns
(top directories + added-file extensions), tallies commit-convention frequency
(CONV_<type>=<count>), and detects dependency/migration signals
(DEP_MANIFEST_COMMITS, MIGRATION_COMMITS, REFACTOR_COMMITS), plus existing
doc coverage (DOCS_*):
Parse STATUS= and ISSUES: from the output. Pass --since (precedence) or
--depth (default 200). The structured rollup replaces the raw git log
pipes the rest of this skill used to run inline.
Step 2: Rules Detection (if --rules or --all)
The script already aggregated the convention signals: read the CONV_<type>
frequency tally (commit-message conventions), the DIR_<n>=<path> /
EXT_<name>=<count> entries (file-naming patterns), and DOCS_* (existing
coverage). Cross-reference with existing .claude/rules/ to avoid duplicates —
the script reports current rule-file counts under DOCS__CLAUDE_RULES.
Step 3: PRD Detection (if --prd or --all)
Find features built without requirements documentation:
# Feature commits without PRD references
git log --format='%H %s' -$DEPTH | grep -iE '^[a-f0-9]+ feat' | head -20
# Large additions (new feature directories)
git log --diff-filter=A --name-only --format='%H---' -$DEPTH | awk '/^[a-f0-9]+---/{hash=$0;next}{if(hash)print hash,$0}'# Cluster commits by directory to find feature groups
git log --format='' --name-only -$DEPTH | grep -oP '^[^/]+/[^/]+' | sort | uniq -c | sort -rn | head -15
Cross-reference with existing docs/prds/ to avoid duplicates.
Step 4: ADR Detection (if --adr or --all)
Find architecture decisions without documentation. The script already detected
the deterministic dependency/migration signals — read DEP_MANIFEST_COMMITS
(commits touching dependency manifests), MIGRATION_COMMITS (migrate/switch/
replace/upgrade language), and REFACTOR_COMMITS (restructure/reorganize/
redesign language) from Step 1's output. For the specific commit subjects behind
a non-zero count, drill in with a targeted log:
# Infrastructure-change commits (for context behind the signal counts)
git log --oneline -$DEPTH -- 'docker*''Dockerfile*''.github/workflows/*''terraform/*''k8s/*'
Cross-reference with existing docs/adrs/ (the script reports the count under
DOCS__DOCS_ADRS) to avoid duplicates. Judging whether a flagged commit
represents a real architectural decision worth an ADR stays with you.
## Documentation Gaps Report
Generated: <date>
Commits analyzed: <N>
Period: <first> to <last>### High Priority
[Items with strong evidence and high impact]
### Medium Priority
[Items with moderate evidence]
### Low Priority
[Minor patterns or old history items]
