Run sessions on Gemini or Anti-Gravity

Yardmaster can run sessions on Google's models in two ways: Gemini, which runs Google's Gemini program with an API key, and Anti-Gravity, which runs Google's Anti-Gravity program on your Google AI plan.

Set up Gemini with an API key#

1. 1

   Open Settings > Accounts, turn on Show alternative AI providers, and open Gemini (CLI provider) under Other AI tools.

2. 2

   If the card says the Gemini program is not installed, install it with the command the card shows (it runs in a terminal), then reopen Settings.

3. 3

   Paste a key from Google AI Studio into Gemini API Key.

4. 4

   Turn on Allow Gemini sessions in any project.

Set up Anti-Gravity with your Google AI plan#

1. 1

   In the same list, open Anti-Gravity. If its program is missing, the card links to the download.

2. 2

   Click Sign in with Anti-Gravity. A terminal window opens: finish the Google sign-in there.

3. 3

   Turn on Allow Anti-Gravity sessions in any project.

Anti-Gravity sessions use your Google AI plan's allowance. The models you can pick depend on the account you signed in with.

Start a session#

Start a session and, before your first message, pick Gemini or Antigravity from the engine name next to the session title. See Choose your AI engine.

Your Claude rules come along#

Yardmaster gives Anti-Gravity sessions the same rules you wrote for Claude: your own CLAUDE.md file (and the files it pulls in), your House Rules, and the project's CLAUDE.md. A short note explains Claude-only words, such as "Skill tool", so Anti-Gravity knows what to do with them.

Common key, token and password formats in these files are removed before the rules are sent. This is a safety net, not a guarantee, so do not keep secrets in these files.

Yardmaster writes them into two files, in the places where Anti-Gravity looks for rules. A live check that Anti-Gravity picks them up is still to come.

• Your own rules go in ~/.gemini/config/rules/yardmaster-rules.md in your home folder, while Anti-Gravity sessions are allowed in Yardmaster. An Anti-Gravity you run yourself, outside Yardmaster, may read this file too.

• The project's rules go in .agents/rules/yardmaster-project.md inside the session's working copy. Yardmaster tells git to ignore this file first, so it is never committed. If it cannot, the rules go to a file in Yardmaster's own data folder instead.

On Windows, Anti-Gravity starts in your home folder, so the first message of each conversation also tells it where the project's rules file is.

Long rules are split into numbered files (yardmaster-rules-2.md, ...). Do not edit these files: Yardmaster rewrites them. Edit your CLAUDE.md or House Rules instead. Yardmaster never reads secret files, such as keys or passwords, into these rules, even when a rules file points at one.

To keep your own rules to Claude, turn off Give Codex and Anti-Gravity my Claude rules in Settings > Accounts under Other AI tools. Yardmaster then removes your own rules file. The project's rules still come along.

An Anti-Gravity session works in its own copy. In a project that uses git, each new Anti-Gravity session gets its own working copy and branch, so several can run at once without changing your main copy or each other. Like a Claude session, it follows Yardmaster's instructions: it can start and message other sessions and publish Shares. It also remembers the conversation from one message to the next.

If a reply says "Antigravity couldn't reach Google", your internet connection is down. Reconnect, then send the message again. A real sign-in problem says Antigravity isn't signed in instead, with a button that opens the sign-in.