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";
const agent = new 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);
}
Mastra uses the OpenAI-compatible /chat/completions
endpoint. Some provider-specific features may not be available. Check the LMStudio documentation for details.
Models
Model | Context | Tools | Reasoning | Image | Audio | Video | Input $/1M | Output $/1M |
---|---|---|---|---|---|---|---|---|
lmstudio/openai/gpt-oss-20b | 131K | — | — | |||||
lmstudio/qwen/qwen3-30b-a3b-2507 | 262K | — | — | |||||
lmstudio/qwen/qwen3-coder-30b | 262K | — | — |
Advanced Configuration
Custom Headers
const agent = new Agent({
name: "custom-agent",
model: {
url: "http://127.0.0.1:1234/v1/chat/completions",
modelId: "openai/gpt-oss-20b",
apiKey: process.env.LMSTUDIO_API_KEY,
headers: {
"X-Custom-Header": "value"
}
}
});
Dynamic Model Selection
const agent = new Agent({
name: "dynamic-agent",
model: ({ runtimeContext }) => {
const useAdvanced = runtimeContext.task === "complex";
return useAdvanced
? "lmstudio/openai/gpt-oss-20b"
: "lmstudio/qwen/qwen3-30b-a3b-2507";
}
});