Mastra — TypeScript AI Agent Framework

Core Features

Agents with Tools

import { Agent, Tool } from "@mastra/core";

const weatherTool = new Tool({
  name: "get_weather",
  description: "Get current weather for a location",
  parameters: z.object({ city: z.string() }),
  execute: async ({ city }) => {
    const res = await fetch(`https://api.weather.com/${city}`);
    return res.json();
  },
});

const agent = new Agent({
  model: "claude-sonnet-4-20250514",
  tools: [weatherTool],
});

First-Class MCP Support

import { MCPClient } from "@mastra/mcp";

const github = new MCPClient({
  command: "npx",
  args: ["-y", "@modelcontextprotocol/server-github"],
  env: { GITHUB_TOKEN: process.env.GITHUB_TOKEN },
});

const agent = new Agent({
  tools: [...github.getTools()],  // All MCP tools available
});

Workflows

Multi-step workflows with branching and error handling:

import { Workflow, Step } from "@mastra/core";

const workflow = new Workflow("deploy-pipeline")
  .step(analyzeCode)
  .step(runTests, { dependsOn: [analyzeCode] })
  .step(deploy, { dependsOn: [runTests], condition: "tests.passed" })
  .step(notify, { dependsOn: [deploy] });

await workflow.execute({ repo: "my-app" });

RAG Pipeline

import { RAG } from "@mastra/rag";

const rag = new RAG({
  embedder: "openai/text-embedding-3-small",
  vectorStore: "pinecone",
  chunker: { strategy: "recursive", size: 512 },
});

await rag.index("./docs");
const context = await rag.retrieve("How does auth work?");

Persistent Memory

const agent = new Agent({
  memory: {
    provider: "postgres",
    connectionString: process.env.DATABASE_URL,
  },
});
// Agent remembers conversations across sessions

Key Stats

• 9,000+ GitHub stars
• TypeScript-first (full type safety)
• Native MCP support
• Workflow orchestration
• RAG + memory built-in

FAQ

Q: What is Mastra? A: Mastra is a TypeScript framework for building production AI agents with tool use, MCP integration, workflows, RAG, and persistent memory.

Q: Is Mastra free? A: Yes, fully open-source under Apache 2.0 license.

Q: How is Mastra different from LangChain.js? A: Mastra is TypeScript-native with first-class MCP support, built-in workflows, and a CLI scaffolding tool. LangChain.js is a port of the Python library.