Grok Build

Grok Build is xAI's terminal-based coding agent. Point it at AI Gateway to:

• Use any model available through the gateway
• Monitor traffic and spend in your AI Gateway Overview
• View detailed traces in Vercel Observability under AI
• Switch models from the in-CLI picker without re-authenticating

Set two environment variables and every request routes through AI Gateway, with the model picker populated from the gateway's full catalog.

1. Install Grok Build

   Follow the installation instructions in the xAI documentation. Verify the install:

   grok --version

2. Point Grok Build at AI Gateway

   Set both variables in your shell configuration file, for example ~/.zshrc or ~/.bashrc:

   export GROK_MODELS_BASE_URL="https://ai-gateway.vercel.sh/v1"
   export GROK_CODE_XAI_API_KEY="your-ai-gateway-api-key"

   Replace your-ai-gateway-api-key with a key from the AI Gateway API Keys page. See API key authentication for details.

   Reload your shell:

   source ~/.zshrc  # or source ~/.bashrc

   When GROK_MODELS_BASE_URL is set, Grok Build sends the API key as Authorization: Bearer instead of session-based auth. If you've previously signed in with grok login, run grok logout first. An existing session takes precedence over the API key.

3. Run Grok Build

   Start a session:

   grok

   Press Ctrl+M to open the model picker. It lists every model AI Gateway exposes at /v1/models. To set a default model, add it to ~/.grok/config.toml:

   ~/.grok/config.toml

   [models]
   default = "xai/grok-4.3"
   # Or try other models:
   # default = "anthropic/claude-sonnet-4.6"
   # default = "openai/gpt-5.5"
   # default = "google/gemini-3.1-pro-preview"

   To confirm requests are flowing through the gateway, check your AI Gateway Overview in the Vercel dashboard.

Grok Build's web search tool requires a separate model configured to use the OpenAI Responses API.

1. Add a Responses-backed model entry

   Add the entry below to ~/.grok/config.toml:

   ~/.grok/config.toml

   [model.vercel-search]
   model = "xai/grok-4.3"
   base_url = "https://ai-gateway.vercel.sh/v1"
   api_backend = "responses"

2. Point web search at the new entry

   Set the env var in your shell configuration file:

   export GROK_WEB_SEARCH_MODEL="vercel-search"

   Reload your shell and restart Grok Build for the change to take effect.