Anthropic

ANTHROPIC_API_KEY=your-api-key

import { Agent } from "@mastra/core";
 
const agent = new Agent({
  name: "my-agent",
  instructions: "You are a helpful assistant",
  model: "anthropic/claude-3-5-haiku-20241022"
});
 
// 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);
}

const agent = new Agent({
  name: "custom-agent",
  model: {
    id: "anthropic/claude-3-5-haiku-20241022",
    apiKey: process.env.ANTHROPIC_API_KEY,
    headers: {
      "X-Custom-Header": "value"
    }
  }
});

const agent = new Agent({
  name: "dynamic-agent",
  model: ({ runtimeContext }) => {
    const useAdvanced = runtimeContext.task === "complex";
    return useAdvanced 
      ? "anthropic/claude-sonnet-4-5-20250929"
      : "anthropic/claude-3-5-haiku-20241022";
  }
});

const response = await agent.generate("Hello!", {
  providerOptions: {
    anthropic: {
      // See available options in the table below
    }
  }
});