Cerebras

Access 4 Cerebras models through Mastra's model router. Authentication is handled automatically using the CEREBRAS_API_KEY environment variable.

Learn more in the Cerebras documentation.

CEREBRAS_API_KEY=your-api-key

import { Agent } from "@mastra/core/agent";

const agent = new Agent({
  id: "my-agent",
  name: "My Agent",
  instructions: "You are a helpful assistant",
  model: "cerebras/gpt-oss-120b"
});

// Generate a response
const response = await agent.generate("Hello!");

// Stream a response
const stream = await agent.stream("Tell me a story");
for await (const chunk of stream) {
  console.log(chunk);
}

Models

<ProviderModelsTable models={[ { "model": "cerebras/gpt-oss-120b", "imageInput": false, "audioInput": false, "videoInput": false, "toolUsage": true, "reasoning": true, "contextWindow": 131072, "maxOutput": 32768, "inputCost": 0.25, "outputCost": 0.69 }, { "model": "cerebras/llama3.1-8b", "imageInput": false, "audioInput": false, "videoInput": false, "toolUsage": true, "reasoning": false, "contextWindow": 32000, "maxOutput": 8000, "inputCost": 0.1, "outputCost": 0.1 }, { "model": "cerebras/qwen-3-235b-a22b-instruct-2507", "imageInput": false, "audioInput": false, "videoInput": false, "toolUsage": true, "reasoning": false, "contextWindow": 131000, "maxOutput": 32000, "inputCost": 0.6, "outputCost": 1.2 }, { "model": "cerebras/zai-glm-4.7", "imageInput": false, "audioInput": false, "videoInput": false, "toolUsage": true, "reasoning": false, "contextWindow": 131072, "maxOutput": 40000, "inputCost": 2.25, "outputCost": 2.75 } ]} />

Advanced configuration

Custom headers

const agent = new Agent({
  id: "custom-agent",
  name: "custom-agent",
  model: {
    id: "cerebras/gpt-oss-120b",
    apiKey: process.env.CEREBRAS_API_KEY,
    headers: {
      "X-Custom-Header": "value"
    }
  }
});

Dynamic model selection

const agent = new Agent({
  id: "dynamic-agent",
  name: "Dynamic Agent",
  model: ({ requestContext }) => {
    const useAdvanced = requestContext.task === "complex";
    return useAdvanced
      ? "cerebras/zai-glm-4.7"
      : "cerebras/gpt-oss-120b";
  }
});

Direct provider installation

This provider can also be installed directly as a standalone package, which can be used instead of the Mastra model router string. View the package documentation for more details.

npm install @ai-sdk/cerebras

For detailed provider-specific documentation, see the AI SDK Cerebras provider docs.