This is a more "how" to the "what": https://paragonie.com/blog/2016/10/guide-automatic-security-updates-for-php-developers
This is a minimalistic secure auto update approach.
- Make an API call to a server to get the latest version information. This should be delivered over HTTPS, possibly with HPKP.
- If an update is available, the client software should download the update file.
- An Ed25519 signature should be available, either as a separate API call or as an HTTP header with the downloaded file.
- Verify that the signature is valid for one of the hard-coded Ed25519 public keys.