GitHub’s SSH host keys are now published in the API

The GitHub metadata endpoint now contains our SSH host keys.
(We'll continue offering host key fingerprints as well.)

{
  // new entry
  "ssh_keys": [
    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOMqqnkVzrm0SdG6UOoqKLsabgH5C9okWi0dh2l9GKJl",
    "ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBEmKSENjQEezOmxkZMy7opKgwFB9nkt5YRrYMjNuG5N87uRgg6CLrbo5wAdT/y6v0mKV0U2w0WZ2YB/++Tpockg=",
    "ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ=="
  ],
  // existing entry
  "ssh_key_fingerprints": [
    "SHA256_RSA": "nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8",
    "SHA256_ECDSA": "p2QAMXNIC1TJYWeIOttrVc98/R1BUFWu3/LiyKgUfQM",
    "SHA256_ED25519": "+DiY3wvvV6TuJJhbpZisF/zLDA0zPMSvHdkr4UvCOqU"
  ],
  // ... rest of payload
}

These keys are in the OpenSSH known_hosts format for easy inclusion into existing known_hosts files.
This will make it easier to preconfigure systems which expect to connect via SSH.
For example, you can prime your CI runners with these keys before starting to fetch from GitHub.

The keys returned from the API include both SSH host keys that we're actively using, plus any that we're advertising via host key rotation for future use.
Currently, we're not offering any keys via rotation that aren't actively in use, but if we announce new host keys in the future, you can find them here as well during the rotation period.

See the meta API endpoint to learn more.