# Mastra

> Open-source TypeScript framework for building agents and workflows with memory, evals and observability

Source: https://dontaskagain.com/mastra
Website: https://mastra.ai/?utm_source=dontaskagain
Pricing: Freemium
Categories: [Agent frameworks](https://dontaskagain.com/categories/agent-frameworks.md), [Open source](https://dontaskagain.com/categories/open-source.md)
Listed: 2026-10-19
Updated: 2026-10-19

Mastra is an open-source TypeScript framework for building, observing and improving AI agents, including agents that run for days. Developers define typed agents with instructions, models and tools in code, compose them into workflows and serve them from a built-in server.

**Key features:**

- Define typed agents with models, tools, memory and runtime behavior in one place.
- Compose durable multi-step workflows with typed steps, retries and control flow.
- Control agents through a harness with modes such as plan and build.
- Give agents message history, semantic recall and observational memory.
- Collect traces, metrics and logs, and run evals with scorers, datasets and experiments.
- Iterate in Studio and deploy agents into products or tools such as Slack.

The framework is free and Apache 2.0 licensed for self-hosting anywhere, with an enterprise license for RBAC, SSO and VPC-only data. The hosted Mastra Platform has a free Starter plan with 100K observability events and 24 CPU hours a month; Teams is $250/month, and Enterprise is custom.

## More agent frameworks

- [Browser Use](https://dontaskagain.com/browser-use.md): Open-source browser agent and cloud browsers that complete web tasks like form filling, checkout and data extraction
- [Stagehand](https://dontaskagain.com/stagehand.md): Open-source SDK for building browser agents with Playwright-style APIs plus natural-language act, observe and extract
- [LangGraph](https://dontaskagain.com/langgraph.md): Open-source, low-level orchestration framework and runtime for building stateful, controllable agents
- [CrewAI](https://dontaskagain.com/crewai.md): Multi-agent framework and enterprise platform for building, running and governing teams of role-based agents
- [OpenAI Agents SDK](https://dontaskagain.com/openai-agents-sdk.md): OpenAI's lightweight Python framework for building agents with tools, handoffs, guardrails, sessions and tracing
- [Pydantic AI](https://dontaskagain.com/pydantic-ai.md): Type-safe Python agent framework from the Pydantic team with model-agnostic agents, tools and evals
- [Agno](https://dontaskagain.com/agno.md): Open-source agent framework and self-hosted runtime for building agents, teams and workflows in your own cloud
- [LlamaIndex](https://dontaskagain.com/llamaindex.md): Document parsing and extraction platform (LlamaParse) plus the open-source LlamaIndex framework for document agents
- [AI SDK](https://dontaskagain.com/ai-sdk.md): Open-source TypeScript toolkit from Vercel for building AI apps and agents with streaming and multi-model support
- [Letta](https://dontaskagain.com/letta.md): Research lab behind MemGPT building stateful agents with persistent, self-improving memory