Everything you need to build AI agents in TypeScript

Mastra agents come with the primitives you need to get to production faster, all built in. Connect to more than 1,000 models through a unified model router, give agents tools to act on and share them across agents via MCP. Track the context that matters across sessions using observational memory that learns about your users automatically. Require a human or external system to approve or reject any tool call before it executes. Split complex work across specialized agents and coordinate them with a supervisor. Every capability is there from the start.

Mastra workflows let you orchestrate complex, multi-step processes by combining agents, tools and logic in a single type-safe flow. Define exactly what happens, when and in what order using sequential steps, parallel branches, conditional logic and loops. Call an agent or run deterministic code at each step, using models where you need reasoning and plain functions where you do not. Any step can suspend execution, hand control to a human and resume when input arrives. Persist workflow state automatically so you can suspend a workflow and resume whenever ready.

Mastra's unified model router supports more than 1,000 models across providers including OpenAI, Anthropic, Google and others. Set your provider API key as an environment variable and Mastra auto-detects it.

Mastra integrates with Next.js, React, Astro, Express, SvelteKit and Hono. Add Mastra to an existing project or create a new app with your preferred framework. For other frameworks, Mastra provides framework integration guides covering additional setup and configuration.

Mastra provides guardrails, scorers, evals and tracing to make agents production-ready. Scorers evaluate agent output using model-graded, rule-based and statistical methods. Built-in observability traces agent decisions and captures token usage, latency and costs. Input and output processors sanitize responses and prevent prompt injection before agents reach production.

Mastra Studio provides an interactive environment for testing agents, tracing execution and refining prompts before and after you ship. Run agents and workflows in Studio, switch models, tweak settings and see results instantly. Follow execution traces to see exactly where an agent stalled or made the wrong call. Edit prompts and create datasets directly in the UI without requiring code access, then hand it to your product manager, designer or data scientist.

Mastra Studio connects directly to your Mastra instance and lets you interact with your agents, workflows and tools in an interactive UI. Run agents locally during development at localhost:4111, then deploy Studio to production so your team can manage agents, monitor performance and inspect traces with no source code access required.

Mastra deploys to any Node.js-compatible environment including Bun, Deno and Cloudflare. Server adapters let you run Mastra with Express, Hono or your own HTTP server. Mastra is fully open source under the Apache 2.0 license, so you control your source code and infrastructure.