opensrc

CLI tool to fetch source code for packages/repos, giving AI coding agents deeper implementation context.

When to Use

• Need to understand how a library/package works internally (not just its interface)
• Debugging issues where types alone are insufficient
• Exploring implementation patterns in dependencies
• Agent needs to reference actual source code of a package

Quick Start

# Install globally or use npx
npm install -g opensrc

# Fetch npm package (auto-detects installed version from lockfile)
npx opensrc zod

# Fetch from other registries
npx opensrc pypi:requests       # Python/PyPI
npx opensrc crates:serde        # Rust/crates.io

# Fetch GitHub repo directly
npx opensrc vercel/ai           # owner/repo shorthand
npx opensrc github:owner/repo   # explicit prefix
npx opensrc https://github.com/colinhacks/zod  # full URL

# Fetch specific version/ref
npx opensrc zod@3.22.0
npx opensrc owner/repo@v1.0.0

Commands

Output Structure

After fetching, sources stored in opensrc/ directory:

opensrc/
├── settings.json           # User preferences
├── sources.json            # Index of fetched packages/repos
└── repos/
    └── github.com/
        └── owner/
            └── repo/       # Cloned source code

File Modifications

On first run, opensrc prompts to modify:

• .gitignore – adds opensrc/ to ignore list
• tsconfig.json – excludes opensrc/ from compilation
• AGENTS.md – adds section pointing agents to source code

Use --modify or --modify=false to skip prompt.

Key Behaviors

1. Version Detection – For npm, auto-detects installed version from node_modules, package-lock.json, pnpm-lock.yaml, or yarn.lock
2. Repository Resolution – Resolves package to its git repo via registry API, clones at matching tag
3. Monorepo Support – Handles packages in monorepos via repository.directory field
4. Shallow Clone – Uses --depth 1 for efficient cloning, removes .git after clone
5. Tag Fallback – Tries v{version}, {version}, then default branch if tag not found

Common Workflows

Fetching a Package

# Agent needs to understand zod's implementation
npx opensrc zod
# → Detects version from lockfile
# → Finds repo URL from npm registry
# → Clones at matching git tag
# → Source available at opensrc/repos/github.com/colinhacks/zod/

Updating Sources

# Re-run same command to update to currently installed version
npx opensrc zod
# → Checks if version changed
# → Re-clones if needed

Multiple Sources

# Fetch multiple at once
npx opensrc react react-dom next
npx opensrc zod pypi:pydantic vercel/ai

References

For detailed information:

• CLI Usage & Options – Full command reference
• Architecture – Code structure and extension
• Registry Support – npm, PyPI, crates.io details