plugin-librarian

Plugin Librarian

A similarity-aware index for the Claude Code plugin ecosystem. Scans all installed marketplaces, computes MinHash signatures for every skill and agent file, and answers questions about overlap, duplication, and coverage before you install anything.

Installation

# Add the marketplace and install the plugin
claude plugin marketplace add galeep/plugin-librarian
claude plugin install librarian

# One-time setup (creates venv, installs deps, builds index)
/librarian init

Requires Python 3.10+. The init step scans every marketplace you have registered and builds a similarity index at ~/.librarian/similarity_report.json. Takes about a minute for a typical setup.

Commands

Command	What it does
/librarian init	One-time setup: venv, dependencies, initial scan
/librarian find <query>	Search plugins by what they do, not just by name
/librarian where <file>	Show every location where similar content appears
/librarian compare <target>	Compare a marketplace or plugin against what you have installed
/librarian impact <target>	Estimate what's new vs. redundant before installing
/librarian installed	List currently installed plugins
/librarian stats	Show index statistics (file counts, cluster counts, coverage)
/librarian scan	Rebuild the similarity index

Examples

/librarian find code review
/librarian where backend-architect.md
/librarian compare claude-code-templates
/librarian impact claude-code-workflows/backend-development

How it works

The scanner reads every .md file across all registered marketplaces, computes word-level MinHash signatures (128 permutations, 3-shingle), and indexes them in a locality-sensitive hash. Queries against this index run in milliseconds. Two files are considered similar at 70%+ estimated Jaccard similarity.

The tool reports observable facts about content similarity and location. It does not make claims about provenance or authorship.