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Using xAI (Grok) With Roo Code

xAI is the company behind Grok, a large language model known for its conversational abilities and large context window. Grok models are designed to provide helpful, informative, and contextually relevant responses.

Website: https://x.ai/

Getting an API Key​

  1. Sign Up/Sign In: Go to the xAI Console. Create an account or sign in.
  2. Navigate to API Keys: Go to the API keys section in your dashboard.
  3. Create a Key: Click to create a new API key. Give your key a descriptive name (e.g., "Roo Code").
  4. Copy the Key: Important: Copy the API key immediately. You will not be able to see it again. Store it securely.

Supported Models​

Roo Code supports the following xAI Grok models:

Current Models​

  • grok-code-fast-1 (Default) - xAI's Grok Code Fast model with 262K context window and prompt caching, optimized for reasoning and coding tasks
  • grok-4 - xAI's Grok-4 model with 262K context window, image support, and prompt caching
  • grok-3 - xAI's Grok-3 model with 128K context window and prompt caching
  • grok-3-fast - xAI's Grok-3 fast model with 128K context window and prompt caching
  • grok-3-mini - xAI's Grok-3 mini model with 128K context window, reasoning support, and prompt caching
  • grok-3-mini-fast - xAI's Grok-3 mini fast model with 128K context window, reasoning support, and prompt caching
  • grok-2-1212 - xAI's Grok-2 model (version 1212) with 128K context window
  • grok-2-vision-1212 - xAI's Grok-2 Vision model (version 1212) with image support and 32K context window
Grok Code Fast - Free Access in Roo Code

grok-code-fast-1 is available for free through the Roo Code Cloud provider during the promotional period. When using the xAI provider directly in Roo Code, standard pricing will apply once established. This model was previously known as "roo/sonic" and has been renamed. For free access within Roo Code, use the Roo Code Cloud provider instead of the xAI provider.

Configuration in Roo Code​

  1. Open Roo Code Settings: Click the gear icon () in the Roo Code panel.
  2. Select Provider: Choose "xAI" from the "API Provider" dropdown.
  3. Enter API Key: Paste your xAI API key into the "xAI API Key" field.
  4. Select Model: Choose your desired Grok model from the "Model" dropdown.

Reasoning Capabilities​

Grok 3 Mini models feature specialized reasoning capabilities, allowing them to "think before responding" - particularly useful for complex problem-solving tasks.

Reasoning-Enabled Models​

Reasoning is only supported by:

  • grok-3-mini - Supports reasoning effort control
  • grok-3-mini-fast - Supports reasoning effort control

The standard Grok 3 models (grok-3 and grok-3-fast) and Grok 4 do not support reasoning effort parameters.

Controlling Reasoning Effort​

When using reasoning-enabled models, you can control how hard the model thinks with the reasoning_effort parameter:

  • low: Minimal thinking time, using fewer tokens for quick responses
  • high: Maximum thinking time, leveraging more tokens for complex problems

Choose low for simple queries that should complete quickly, and high for harder problems where response latency is less important.

Key Features​

  • Step-by-Step Problem Solving: The model thinks through problems methodically before delivering an answer
  • Math & Quantitative Strength: Excels at numerical challenges and logic puzzles
  • Reasoning Trace Access: The model's thinking process is available via the reasoning_content field in the response completion object

Prompt Caching​

Prompt caching is available for select Grok models including grok-code-fast-1, grok-4, grok-3, grok-3-fast, grok-3-mini, and grok-3-mini-fast. This feature can reduce costs and improve response times.

Pricing​

Pricing varies by model. Refer to the xAI documentation for current pricing information.

Note: grok-code-fast-1 is available for free through the Roo Code Cloud provider during the promotional period. Standard pricing will apply when using the xAI provider directly in Roo Code.