The TypeScript Agent Framework
From the team that brought you Gatsby: prototype and productionize AI features with a modern JavaScript stack.
1const chefAgent = new Agent({2name: 'Chef Agent',3instructions:4"You are Michel, a practical and experienced home chef" +5"who helps people cook great meals."6model: openai('gpt-4o-mini'),7memory,8workflow: { chefWorkflow }9});
/workflows
*ops
/agents
/rag
Loved by builders
It's the easiest & most dev-friendly SDK for building AI agents I've seen.
/agents
Build intelligent agents that execute tasks, access your data sources, and maintain
memory persistently.
1const chefAgent = new Agent({2name: 'Chef Agent',3instructions:4"You are Michel, a practical and experienced home chef" +5"who helps people cook great meals."6model: openai('gpt-4o-mini'),7memory,8workflow: { chefWorkflow }9});
Switch between AI providers by changing a single line of code using the AI SDK
Combine long-term memory with recent messages for more robust agent recall
Bootstrap, iterate, and eval prompts in a local playground with LLM assistance.
Allow agents to call your functions, interact with other systems, and trigger real-world actions
/workflows
Durable graph-based state machines with built-in tracing, designed to execute complex
sequences of LLM operations.
1workflow2.step(llm)3.then(decider)4.after(decider)5.step(success)6.step(retry)7.after([8success,9retry10])11.step(finalize)12.commit();
.step()
llm
.then()
decider
when:
.then()
success
when:
.then()
retry
.after()
finalize

Simple semantics for branching, chaining, merging, and conditional execution, built on XState.
Pause execution at any step, persist state, and continue when triggered by a human-in-the-loop.
Stream step completion events to users for visibility into long-running tasks.
Create flexible architectures: embed your agents in a workflow; pass workflows as tools to your agents.
*rag
Equip agents with the right context. Sync data from SaaS tools. Scrape the web.
Pipe it into a knowledge base and embed, query, and rerank.
*ops
Track inputs and outputs for every step of every workflow run. See each agent tool call
and decision. Measure context, output, and accuracy in evals, or write your own.
Measure and track accuracy, relevance, token costs, latency, and other metrics.
Test agent and workflow outputs using rule-based and statistical evaluation methods.
Agents emit OpenTelemetry traces for faster debugging and application performance monitoring.
Keep tabs on what we're shipping
Announcing Mastra’s Agent Studio
We've renamed Playground to Studio and it's now shareable with your team.Sam Bhagwat
Oct 30, 2025
HITL: Ask Before Acting
Learn how to use HITL (Human-in-the-Loop) to safely build tools that require human approval.Shane Thomas
Oct 28, 2025
Mastra Changelog 2025-10-23
Workflow state management, unified streaming, AI tracing updates, and more..Shane Thomas
Oct 23, 2025
You can suspend/resume workflows in playground
Mastra workflows now support suspend and resume in Playground. You can also use the new resumeStream API to close streams on suspend and resume them later.Sam Bhagwat
Oct 22, 2025
Workflow State: Share Data Across Steps
Workflow state lets you share values across steps without threading them through every `inputSchema` and `outputSchema`.Sam Bhagwat
Oct 22, 2025
