{"id":88086,"title":"Mastra: the open-source JavaScript framework for building agents","tagline":"If you hate Langchain, you'll love Mastra :) ","body":"Hey everyone 🙂 we’re Sam, Shane and Abhi.\n\n![mastra co-founders](https://mastra.ai/_next/image?url=%2Fabout%2Fmastra-founders.png\u0026w=1200\u0026q=75)\n\n**What we’re building:** Mastra (\u003chttps://mastra.ai\u003e) is an open-source JavaScript SDK for building agents on top of Vercel’s AI SDK.\n\n\u003chttps://www.youtube.com/watch?v=8o_Ejbcw5s8\u003e\n\n**Our backstory:** Previously, we built Gatsby, the open-source React web framework.\n\nWe noticed our friends building AI applications getting stuck debugging prompts, figuring out why their agents called (or didn’t call) tools, and writing lots of custom memory retrieval logic.\n\nIn October, we started building Mastra, and last week we went viral on Hacker News and Github and went from 1,500 to 7,500 stars.\n\n**Mastra use-cases:** Fireworks AI is using us to build agentic workflows. YC companies are using Mastra to automate support, build CAD diagrams, scrape the web for contact info, automate medical transcriptions, generate financial documents, and create code generation products.\n\nMastra allows you to create workflow graphs that can suspend/resume, build RAG pipelines, write evals, give agents memory, create multi-agent workflows, and test it all in a local playground.\n\nHere’s a weather agent and the agent playground (with tracing built in!):\n\n![uploaded image](/media/?type=post\u0026id=88086\u0026key=user_uploads/153911/2af3d557-eda5-4e84-9e3d-8ca9f89ba3b4)\n\nYou can deploy Mastra agents and workflows to a serverless platform like Vercel, Cloudflare, Netlify, any cloud service that can run Node.js, or our [own hosting platform](https://mastra.ai/waitlist) with evals and tracing.\n\n**How to get started:** Just head over to the command line and install:`npm create mastra`\n\nHappy building 🙂 \\\n\\\nPS: we’ve spent a lot of time this batch doing AI engineering whiteboarding sessions with other batch startups, walking through architecture and best practices, so we decided to write a book to help people get up to speed faster: [Principles of Building AI Agents](https://www.amazon.com/dp/B0DYH5GHDD/ref=tmm_pap_swatch_0?_encoding=UTF8\u0026dib_tag=se\u0026dib=eyJ2IjoiMSJ9.xOCgmaLViBdLwSFuscVMKTz0vTJBUua4OTJbmgz-H-ZCHIxUUBdjGogX4uyU7T6V.kAblDRv1ODXGF3V-QgC6-AVQCrcuYiDicC-BYx4cYXc\u0026qid=1740435997\u0026sr=8-1).\n\nFollow [@mastra_ai](https://twitter.com/mastra_ai) on Twitter/X and tweet at us and we’ll get you a physical copy!\n\n![uploaded image](/media/?type=post\u0026id=88086\u0026key=user_uploads/153911/3fe20638-050c-463d-b8cd-f23b7ce91592)\n\n","slug":"Muk-mastra-the-open-source-javascript-framework-for-building-agents","created_at":"2025-02-27T15:40:16.256Z","updated_at":"2026-04-23T06:05:02.283Z","total_vote_count":172,"url":"https://www.ycombinator.com/launches/Muk-mastra-the-open-source-javascript-framework-for-building-agents","share_image_url":"https://www.ycombinator.com/media/?type=post\u0026id=88086\u0026key=user_uploads/153911/3fe20638-050c-463d-b8cd-f23b7ce91592","company":{"id":30304,"name":"Mastra","slug":"mastra","url":"https://mastra.ai","logo":"https://bookface-images.s3.amazonaws.com/small_logos/a6e5f319cbd11b23e8938be90ed120209a914c0a.png","batch":"Winter 2025","industry":"B2B","tags":["Artificial Intelligence","Developer Tools","Open Source","AI"],"search_path":"https://bookface.ycombinator.com/company/30304"}}