Start a Gemini session with: 
happy gemini

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Prerequisites

Install the Gemini CLI. Connect your Google credentials through Happy: 
happy connect gemini

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Model configuration

Set the default Gemini model: 
happy gemini model set gemini-2.5-pro
happy gemini model get    # Show current model
Available models:
  • gemini-2.5-pro — Most capable
  • gemini-2.5-flash — Fast, balanced
  • gemini-2.5-flash-lite — Lightweight

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Google Workspace accounts

If you use a Google Workspace account, you need to set your Cloud Project ID: 
happy gemini project set my-project-id
happy gemini project get    # Show current project

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How it works

Happy spawns Gemini CLI with the Agent Client Protocol (ACP) and communicates through it. All Happy features (mobile control, voice, orchestration) work with Gemini sessions.