Mastra is an open source TypeScript framework for building AI agents and workflows, designed to feel natural for JavaScript/TypeScript developers who don't want to write Python. It provides first-class primitives for tool calling, memory management, workflow orchestration, and agent-to-agent communication, all with strong TypeScript types throughout. The framework ships with built-in integrations for common services (GitHub, Slack, PostgreSQL), a local development server with a browser-based agent playground for testing, and built-in evaluation tooling for testing agent behavior. Mastra agents can be deployed as serverless functions on Vercel, Cloudflare Workers, or any Node.js environment without needing a separate agent runtime. Mastra was created to fill the gap left by LangChain's Python-centric design. It gained significant traction in the TypeScript agent development community in early 2025, with over 7,000 GitHub stars within months of launch. It's particularly popular among Next.js developers building full-stack AI applications where the entire stack can stay in TypeScript.

What the community says

Mastra quickly became the most-discussed TypeScript agent framework in the Next.js and full-stack developer communities, filling a gap that LangChain.js never quite addressed. Developers praise the TypeScript ergonomics, the built-in playground for testing agents locally, and the clean mental model for tools and memory. Some early adopters note that the ecosystem is still young compared to LangChain's Python side and that documentation has gaps in more advanced use cases. The GitHub star growth rate is frequently cited as a signal of strong community interest.

See alternatives to Mastra →