title: How do I share Protocol Buffer .proto files between multiple repositories
body: <p>We are considering using <a href="https://developers.google.com/protocol-buffers/" rel="noreferrer">Protocol Buffers</a> for communicating between a python &amp; a node.js service that each live in their own repos. </p>
  
  <p>Since the <code>.proto</code> files must be accessible to both repos, how should we share the <code>.proto</code> files? </p>
  
  <p>We are currently considering:</p>
  
  <ol>
  <li>Creating a repo for all our <code>.proto</code> files, and making it a git subtree of all our services</li>
  <li>Creating a repo for all our <code>.proto</code> files, publishing both a private python module and private node module on push, and requiring the modules from the respective services</li>
  <li>Creating a repo for all our <code>.proto</code> files, and specifying the repository as the destination of a <code>pip</code> / <code>npm</code> package</li>
  </ol>
  
  <p>What is the standard way to share <code>.proto</code> files between repositories?</p>