Mastra

What is Mastra?

Mastra is an open-source framework for building AI agents in TypeScript. The core framework is licensed under Apache 2.0, with enterprise features under a separate Mastra Enterprise License. It lets developers connect language models to tools, workflows and memory.

Key capabilities of Mastra

• Agents: connect LLMs to tools so they act autonomously until reaching a conclusion
• Workflows: graph-based orchestration with branching, parallelization and human-in-the-loop steps
• Memory: conversation history, semantic recall and external data retrieval
• Observability: tracing, evals, metrics and datasets for measuring performance
• MCP support: author Model Context Protocol servers
• Harness: manages long-running work with persistent sessions and approvals

How Mastra works

Developers write agent instructions in TypeScript, attach tools, and deploy the app. Workflows define typed steps, branches and retries for processes that need structure, while agents iterate using tools on their own. Models come through one interface covering more than 90 providers such as OpenAI, Anthropic and Gemini. Human-in-the-loop steps allow approval before actions.

Who uses Mastra?

TypeScript and JavaScript developers building agent products use Mastra, including teams on React, Next.js or Node.js. It can also be deployed standalone through Hono, Express or Fastify.

Mastra pricing

The open-source framework is free under Apache 2.0, with no usage tiers. Enterprise features use a separate license, and Mastra Cloud pricing was not published on the pages reviewed.

Mastra alternatives

Mastra is compared with LangChain and LangGraph, CrewAI and the Vercel AI SDK. LangChain has Python and JavaScript versions, whereas Mastra is TypeScript first with built-in workflows, memory and evals.