What it is
Mastra is an open-source TypeScript framework for building AI agents and workflows, with memory, tools, MCP, RAG, suspend-and-resume workflows, evals and observability built in. It includes a local environment for testing agents and deploys to Node servers or platforms like Vercel. It's the natural pick for JavaScript teams that don't want to switch to Python.
How to use it
- Start a project with the CLI and test your agents in the local dev environment.
- Define agents with instructions, tools and conversation memory.
- Orchestrate workflows with steps, branches and pauses for human approval.
- Connect tools over MCP or expose your agents as an MCP server.
- Measure quality with scorers and traces for every run.
What it's good for
- A startup adding a support agent to its Next.js app without switching languages.
- A Node backend team orchestrating long-running processes with steps that wait for human approval.
- An AI team comparing agent versions with evals before shipping them.
Pros
- All TypeScript: agents, workflows, memory, RAG and evals
- Open source under Apache 2.0, except the enterprise modules
- Local environment to test agents and inspect traces while you build
- Native MCP support, as both client and server
Cons
- Requires coding; it's not a no-code tool
- Younger ecosystem than LangChain's, with fewer examples and a smaller community
- The managed platform jumps from free to about US$250 a month
