LMStudio

Access 3 LMStudio models through Mastra's model router. Authentication is handled automatically using the LMSTUDIO_API_KEY environment variable.

Learn more in the LMStudio documentation.

LMSTUDIO_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: "lmstudio/openai/gpt-oss-20b"
});

// 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);
}

:::info

Mastra uses the OpenAI-compatible /chat/completions endpoint. Some provider-specific features may not be available. Check the LMStudio documentation for details.

:::

Models

<ProviderModelsTable models={[ { "model": "lmstudio/openai/gpt-oss-20b", "imageInput": false, "audioInput": false, "videoInput": false, "toolUsage": true, "reasoning": true, "contextWindow": 131072, "maxOutput": 32768, "inputCost": null, "outputCost": null }, { "model": "lmstudio/qwen/qwen3-30b-a3b-2507", "imageInput": false, "audioInput": false, "videoInput": false, "toolUsage": true, "reasoning": false, "contextWindow": 262144, "maxOutput": 16384, "inputCost": null, "outputCost": null }, { "model": "lmstudio/qwen/qwen3-coder-30b", "imageInput": false, "audioInput": false, "videoInput": false, "toolUsage": true, "reasoning": false, "contextWindow": 262144, "maxOutput": 65536, "inputCost": null, "outputCost": null } ]} />

Advanced configuration

Custom headers

const agent = new Agent({
  id: "custom-agent",
  name: "custom-agent",
  model: {
    url: "http://127.0.0.1:1234/v1",
    id: "lmstudio/openai/gpt-oss-20b",
    apiKey: process.env.LMSTUDIO_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
      ? "lmstudio/qwen/qwen3-coder-30b"
      : "lmstudio/openai/gpt-oss-20b";
  }
});