Request proxying

Proxy requests to the EAS Update server through your own server.

EAS Update supports request proxying, which allows you to proxy requests to the EAS Update server through your own server. This can be useful for various reasons, such as adding custom headers, logging requests, or implementing additional security or request IP anonymization measures.

Enabling request proxying

1. Create two proxy servers that will handle the requests:

   • One for the update asset requests (JavaScript bundles, images, and so on).
     • This must forward requests to assets.eascdn.net, the EAS Update asset server.
     • This must pass-through all URL contents (path, query parameters, and so on).
     • This must pass-through all headers prefixed with expo- or eas-.
   • One for the update manifest requests.
     • This must forward requests to u.expo.dev, the EAS Update server.
     • This must pass-through all URL contents (path, query parameters, and so on).
     • This must pass-through all headers prefixed with expo- or eas-.

2. Add the following fields to your eas.json configuration file, replacing the placeholders with your actual proxy server URLs:

   eas.json

   Copy

   {
     "cli": {
       %%placeholder-start%%... %%placeholder-end%%
       "updateAssetHostOverride": "updates-asset-proxy.example.com",
       "updateManifestHostOverride": "updates-manifest-proxy.example.com"
     }
   }
   

3. Run the following command to apply the changes:

   Terminal

   Copy

   - eas update:configure

4. Publish an update to test the proxying:

   Terminal

   Copy

   - eas update

5. Verify by navigating to the update group on the EAS Update dashboard and clicking "View Metadata" for one of the platforms.

   • manifest.json should show the overridden manifestHostOverride.
   • Other assets should show the overridden assetHostOverride.