Mastra: A TypeScript Framework for Building AI Agents, Workflows, and MCP Servers

If you've been playing with AI agents lately, you've probably hit the same wall I have: stitching together LLM calls, tool integrations, and state management gets messy fast. Mastra is a TypeScript framework that tries to solve that by giving you a structured way to build agents, define workflows, and serve them over MCP (Model Context Protocol).

It's not trying to be everything to everyone. It's just a clean, composable toolkit for developers who want to build AI-powered features without reinventing the orchestration layer every time.

What It Does

Mastra is a TypeScript framework that helps you build three things:

1. Agents – Define LLM-based agents with tools, memory, and system prompts. You can run them locally or as a server.
2. Workflows – Chain steps together (think DAGs of async operations) with built-in retries, parallel execution, and state passing.
3. MCP Servers – Expose your agents or workflows as MCP-compatible servers so other tools (like IDEs or chat UIs) can call them.

Under the hood, it handles the boring stuff like tool registration, context injection, and error handling so you can focus on the logic.

Why It’s Cool

A few things stand out about Mastra:

• It’s just TypeScript. No DSLs, no weird config files. You write plain functions and classes. If you know TS, you're already set.
• Workflows handle parallelism. You can run tasks concurrently without manually managing promises and race conditions.
• MCP built-in. Instead of bolting on API endpoints later, you can ship your agent as a proper MCP server that any MCP client can talk to.
• Memory and context management. Mastra gives you built-in ways to handle conversation history and tool contexts, which is one of the hardest parts of agent development.
• Logging and observability. It ships with structured logging so you can actually debug what your agent is thinking.

The whole thing feels like someone took the patterns from Express and applied them to agent orchestration. It's refreshingly pragmatic.

How to Try It

The quickest way to get started is via npm:

npm create mastra@latest

That'll scaffold a project with examples. Or you can clone the repo and check out the /examples folder.

Here's a minimal agent:

import { Agent } from '@mastra/core';

const agent = new Agent({
  model: 'gpt-4',
  systemPrompt: 'You are a helpful assistant.',
  tools: [myCustomTool],
});

const response = await agent.run('What's the weather in Tokyo?');

You can define workflows as classes that extend Workflow and then run them step by step. The MCP server setup is similarly clean.

Full docs and examples are on the GitHub repo.

Final Thoughts

Mastra isn't trying to replace LangChain or anything like that. It's a lighter, more TypeScript-native alternative that feels like it was designed by someone who actually builds agents for a living. The MCP support is a smart bet since that protocol is gaining traction quickly.

If you're building anything with AI agents and want something that doesn't fight you, give Mastra a look. It's early days, but the core is solid and the API is clean. I'm keeping an eye on this one.

Found via @githubprojects