npm provenance public beta

npm packages built on a cloud CI/CD system (like GitHub Actions) can now publish with provenance, meaning the package has verifiable links back to its source code and build instructions.

The cloud CI/CD system securely communicates this information by sending provenance information in a signed OIDC JWT to Sigstore's public-good servers, which returns a signing certificate that is sent to the registry along with your built package.

Here's an example of how to do a build with provenance in a GitHub Actions workflow:

name: Publish Package to npmjs
on:
 release:
   types: [created]
jobs:
 build:
   runs-on: ubuntu-latest
   permissions:
     contents: read
     id-token: write
   steps:
     - uses: actions/checkout@v3
     - uses: actions/setup-node@v3
       with:
         node-version: '18.x'
         registry-url: 'https://registry.npmjs.org'
     - run: npm install -g npm
     - run: npm ci
     - run: npm publish --provenance --access public
       env:
         NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}

Once published, packages display provenance on the registry website:

Dependencies with provenance can also be verified from the command line with npm audit signatures.

For more information, see generating provenance.