Gemini

Happier integrates Gemini through the local Gemini CLI/runtime and ACP-compatible messaging.

Requirements

• Gemini CLI installed on your machine.
• CLI available on PATH (or set HAPPIER_GEMINI_PATH if needed).

Install Gemini

If you use hstack, you can install Gemini with the providers installer:

hstack providers install gemini
gemini --version

Or install manually:

npm install -g @google/gemini-cli
gemini --version

Local authentication in Happier

Gemini supports machine-local auth management in:

• Settings → AI provider settings → Gemini

From there you can:

• check Gemini’s local auth state on the selected machine
• open Gemini’s native CLI auth flow directly inside Happier
• refresh the auth state with Check now

Happier can detect Gemini auth from environment variables, local Gemini auth/config files, and supported Google ADC files.

For the shared user guide, see Provider authentication.

Start Gemini with Happier

happier gemini

Authentication (connected services)

Gemini auth is managed through Happier connected services (gemini):

• Settings → Connected services → Gemini
• Or CLI: happier connect gemini

For paste/redirect flows, Happier exchanges the OAuth code on the server and returns an encrypted bundle to the client (no Gemini OAuth secrets are bundled into the app UI).

Supported UI methods:

• paste redirect URL
• in-app browser on native

On web, Happier uses the paste flow.

If you are self-hosting and need to override OAuth client settings, see:

• Connected services

Model selection

Model selection is capability-driven and can be set from:

• CLI start options
• App session input settings (when exposed for the current runtime)

For cross-provider model behavior details, see Permissions.

Troubleshooting

• If Gemini is not detected, verify CLI installation and restart Happier.
• If needed, point to binary explicitly with HAPPIER_GEMINI_PATH.