Google

Google is natively supported in fast-agent using the Google GenAI libraries.

Google models have support for attaching YouTube URLs for video and transcript understanding. Gemini models that support Grounding with Google Search can also use provider-side web search via the standard web_search model-string option.

YAML Configuration:

google:
  api_key: "your_google_key"

Environment Variables:

• GOOGLE_API_KEY: Your Google API key

Reasoning, search, and multimodal input

Google models support model-dependent thinking controls, structured outputs, multimodal inputs, and Grounding with Google Search.

fast-agent --model gemini
fast-agent --model "gemini3?reasoning=auto"
fast-agent --model "google.gemini-3.1-pro-preview?reasoning=high"
fast-agent --model "gemini3?web_search=on"
fast-agent --model "google.gemini-3.5-flash?web_search=on"

Useful query parameters:

• reasoning=auto|minimal|low|medium|high|off where the selected Gemini model advertises thinking controls
• web_search=on|off for Grounding with Google Search on supported Gemini models
• structured=json for JSON schema structured outputs
• sampling controls such as temperature, top_p, and top_k where applicable

When web_search=on, fast-agent sends Google's native GoogleSearch tool and formats grounding metadata as citations in the text response when Google returns citation spans. Search can be toggled from the /model web_search command or the interactive model controls on models that advertise support.

Current fast-agent metadata marks Google Search as supported on Gemini 2.0 Flash, Gemini 2.5, and Gemini 3 / 3.5 aliases. Check Models Reference for the generated capability view.

Model Name Aliases:

OpenAI Mode

You can also access Google via the OpenAI-compatible provider. Use googleoai in the YAML file, or GOOGLEOAI_API_KEY for API key access; that path uses the Google OpenAI-compatible endpoint by default.