Fetch source code for npm packages to give coding agents deeper context than types alone.
When working with AI coding agents, types and documentation often aren't enough. Sometimes the agent needs to understand the implementation - how something works internally, not just its interface.
opensrc automates the process of fetching package source code so your agent can reference it when needed.
npm install -g opensrcOr use with npx:
npx opensrc <package># Fetch source for a package (auto-detects version from lockfile)
opensrc zod
# Fetch specific version
opensrc zod@3.22.0
# Fetch multiple packages
opensrc react react-dom nextRe-running opensrc <package> automatically updates to match your installed version—no flags needed.
You can also fetch source code directly from any public GitHub repository:
# Using github: prefix
opensrc github:owner/repo
# Using owner/repo shorthand
opensrc facebook/react
# Using full GitHub URL
opensrc https://github.com/colinhacks/zod
# Fetch a specific branch or tag
opensrc owner/repo@v1.0.0
opensrc owner/repo#main
# Mix packages and repos
opensrc zod facebook/reactGitHub repos are stored as opensrc/owner--repo/.
# List fetched sources
opensrc list
# Remove a source (package or repo)
opensrc remove zod
opensrc remove owner--repoOn first run, opensrc will ask for permission to modify these files:
.gitignore— addsopensrc/to ignore listtsconfig.json— excludesopensrc/from compilationAGENTS.md— adds a section pointing agents to the source code
Your choice is saved to opensrc/settings.json so you won't be prompted again.
To skip the prompt, use the --modify flag:
# Allow file modifications
opensrc zod --modify
# Deny file modifications
opensrc zod --modify=false- Queries the npm registry to find the package's repository URL
- Detects the installed version from your lockfile (
package-lock.json,pnpm-lock.yaml,yarn.lock) - Clones the repository at the matching git tag
- Stores the source in
opensrc/<package-name>/ - If permitted: adds
opensrc/to.gitignore, excludes fromtsconfig.json, updatesAGENTS.md
After running opensrc zod:
opensrc/
├── settings.json # Your modification preferences
├── sources.json # Index of fetched packages
└── zod/
├── src/
├── package.json
└── ...
The sources.json file lists all fetched packages with their versions, so agents know what's available:
{
"packages": [
{ "name": "zod", "version": "3.22.0", "path": "opensrc/zod" }
]
}The settings.json file stores your preferences:
{
"allowFileModifications": true
}Apache-2.0