Agents & frameworks · A-tier

Mastra

TypeScript agent framework with workflows, tools, and evals, aimed at JS product teams.

Best for

TypeScript teams who want agents, workflows, and evals in one library.

What it is

Mastra is a TypeScript framework for agents, workflows, and tools. It is aimed at JavaScript product teams who want more structure than a thin SDK and less Python than LangChain. The framework is open source.

typescriptopen-sourceworkflowsAgents & frameworks

Score breakdown

Capability 40%82
Ease 25%80
Value 20%92
Momentum 15%84

Pricing

Free

Starting price: $0

The framework is open source. Hosted Mastra features, if you use them, are priced separately. Check the site.

Dates

Released 2024 (year precision).

Added to StackPick 14 Oct 2026.

Alternatives

A-tier · 89

Vercel AI SDK

TypeScript apps that need streaming chat or a small tool-calling agent.

A-tier · 81

Pydantic AI

Python services that want typed tool-calling agents.

A-tier · 83

LangChain

Application code that needs tools, retrieval, and a large example ecosystem.

Questions

What is Mastra best for?

TypeScript teams who want agents, workflows, and evals in one library.

How much does Mastra cost?

Free. Starting price: $0. The framework is open source. Hosted Mastra features, if you use them, are priced separately. Check the site.

What are alternatives to Mastra?

Vercel AI SDK, Pydantic AI, LangChain are the alternatives we file next to it. Open a comparison when one exists.