librarian

name: librarian description: Research open-source libraries with evidence-backed answers and GitHub permalinks. Use when the user asks about library internals, implementation details, source code references, change history, or authoritative answers backed by actual code.

Research open-source libraries by finding evidence in code, docs, issues, pull requests, and history. Back code-related claims with GitHub permalinks.

When needed, load and follow the web-search, web-fetch, and github skills.

Choose the workflow

Source workflow

1. Use github to clone or inspect the repo.
2. Search locally with find and grep; read relevant files with read.
3. For history, use git log, git blame, and git show in the clone.
4. For issues and pull requests, use gh issue, gh pr, or gh search.
5. Use web-search or web-fetch for non-GitHub docs, articles, and discussions when useful.

Common commands:

cd /tmp/pi-github-repos/owner/repo

# Get the exact commit for permalinks
git rev-parse HEAD

# Find recent changes to a file
git log --oneline -n 20 -- path/to/file.ts

# See who last changed specific lines
git blame -L 10,30 path/to/file.ts

# Inspect a commit's changes to a file
git show <sha> -- path/to/file.ts

# Search related GitHub issues and merged PRs
gh search issues "keyword" --repo owner/repo --state all --limit 10
gh search prs "keyword" --repo owner/repo --state merged --limit 10

Permalinks

Use full commit SHAs, not branch names:

https://github.com/<owner>/<repo>/blob/<commit-sha>/<filepath>#L<start>-L<end>

Get the current clone SHA:

cd /tmp/pi-github-repos/owner/repo && git rev-parse HEAD

Get a tag SHA when answering version-specific questions:

gh api repos/owner/repo/git/refs/tags/v1.0.0 --jq '.object.sha'

Answer rules

• Cite every code-related claim with a permalink.
• Prefer official docs and source code over articles.
• State uncertainty when evidence is incomplete.
• If search fails, broaden terms from exact names to concepts.
• Reuse existing clones in /tmp/pi-github-repos/owner/repo.