---

name: exploring-packages description: Explore npm package source code locally. Use when needing to understand a library's API, types, or implementation.

Exploring Packages

Goal

Get npm package source code locally for reading, stored globally to amortize across projects.

Location

All packages stored in: ~/.claude/package-sources/<package-name>/

Steps

1. Check if already exists

Copyls ~/.claude/package-sources/<package-name>/ 2>/dev/null

If exists, check if update needed:

Copycd ~/.claude/package-sources/<package-name> && npm outdated 2>/dev/null

2. Get package (prefer npm pack over git clone)

CRITICAL: Use npm pack + extract, NOT git clone. This gets the actual published package (post-build) matching what's installed in projects, not raw source that may need complex builds.

Copymkdir -p ~/.claude/package-sources/<package-name>
cd ~/.claude/package-sources/<package-name>
npm pack <package-name> && tar -xzf *.tgz --strip-components=1 && rm *.tgz

This gives you:

• Built/transpiled code (what projects actually import)
• Published types (.d.ts files)
• package.json with exports map

3. For source code (when published package isn't enough)

Only if you need original TypeScript source or tests:

Copy# Get repo URL from package.json
npm view <package-name> repository.url

# Clone to separate directory
git clone --depth 1 <repo-url> ~/.claude/package-sources/<package-name>-src

4. Read the code

Start with:

• package.json - exports map, main entry
• Type definitions (.d.ts files)
• Actual implementation files

Use Serena MCP's symbolic tools for efficient navigation.

Update existing package

Copycd ~/.claude/package-sources/<package-name>
rm -rf * && npm pack <package-name> && tar -xzf *.tgz --strip-components=1 && rm *.tgz

Version-specific package

For specific version matching your project:

Copynpm pack <package-name>@<version>

Check project's version:

Copycat package.json | grep '"<package-name>"'
# or
pnpm list <package-name>

Notes

• Prefer npm pack over git clone - gets published output, not complex source
• Global location (~/.claude/package-sources/) amortizes across all projects
• Check existing before fetching - avoid re-downloading
• Match project version when debugging specific issues