Hermes Google Antigravity Plugin

What Hermes Google Antigravity Plugin does

This plugin adds a native Google Antigravity (Cloud Code PA) provider to Hermes Agent as an oauth_external provider. You sign in with a Google account through hermes auth add, hermes model and hermes chat, with no API key and no dummy token, because the access token lives in an auto-refreshed OAuth file. Requests go to the cloudcode-pa generateContent API, and a thin shim exposes them as OpenAI-style chat.completions, so Gemini, Claude and GPT-OSS models behave like other Hermes models, including tool calls, thinking and multi-turn chat.

Integration needs a core patch that touches nine Hermes files, covering runtime provider resolution, the auxiliary client, auth, the provider registry, auth commands, model setup flows and the model list. The provider plugin itself sits under plugins/model-providers/google-antigravity, outside the Hermes repo, so it survives hermes update, but the patch has to be re-applied afterwards. The README recommends deploying through hermes-patch-manager, which re-applies it automatically. Curated models include gemini-3.1-pro, gemini-3.5-flash, claude-opus-4-6-thinking, claude-sonnet-4-6-thinking and gpt-oss-120b, and an image_gen backend plugin is also included.

Key features

• Google account OAuth login with PKCE and automatic token refresh
• OpenAI-style chat.completions shim over the Cloud Code PA client
• Integration with hermes auth add, hermes model and hermes chat
• Curated Gemini, Claude and GPT-OSS model list
• Optional image_gen backend plugin
• Deployable as a mod through hermes-patch-manager

When to use it

• Running Hermes chat on Gemini or Claude models through an Antigravity subscription
• Avoiding a separate API key by signing in with Google
• Keeping the patch applied across hermes update with a patch manager

Who it is for: Hermes Agent users with a Google Antigravity subscription who are comfortable applying a patch to Hermes.

How it fits with Hermes Agent

A Hermes model provider that registers google-antigravity as an oauth_external provider, with a provider plugin and a core patch against Hermes source files.

Note: Installation patches nine files in Hermes Agent core, and the patch has to be re-applied after hermes update.

FAQ