{"id":87644,"title":"💬 assistant-ui - Open Source Typescript/React Library for AI Chat","tagline":"The UX of ChatGPT in your own app, connected to your own AI agents.","body":"Hi YC! I’m Simon, building **assistant-ui**, an open source Typescript/React library for AI chat.\n\nHundreds of projects use assistant-ui to build in-app AI assistants, including companies like:\n\n![Logos of LangChain, AthenaIntelligence, Browser Use, Stack AI](https://bookface.ycombinator.com/media/?type=post\u0026id=87644\u0026key=user_uploads/1152943/d3eda556-de8c-4404-b4be-c0295f9aeb8e)\n\nWith \u003e50k+ monthly downloads, assistant-ui is the most popular UI library for AI chat.\n\n## **Getting Started**\n\nYou can get started by running **\\`npx assistant-ui create\\`** (new project) or **\\`npx assistant-ui init\\`** (existing project) in your terminal.\n\n![Gif showing the setup process, which takes under 30 seconds](https://bookface.ycombinator.com/media/?type=post\u0026id=87644\u0026key=user_uploads/1152943/17c78ae1-d8cf-4fc4-a8aa-056fe449da02)\n\n## **Features**\n\n* **Pre-built components**, fully customizable\n* **Connects to your backend**\n  * We have first class integration for **AI SDK** and **LangGraph** or build your own\n* **Generative UI**: Map LLM tool calls and JSONs to custom UI components\n* **Frontend Tool Calls:** Let LLMs take action in your frontend app\n* **Human Tool Calls:** Human approvals and input collection\n* **Chat history and analytics** via assistant-cloud (the hosted offering)\n\n## **Customization**\n\nThe API of assistant-ui is inspired by libraries like **Radix UI** and **cmdk**. Instead of a single monolithic chat component, we give you composable primitives and a great starter configuration. You have full control over the look and feel of every pixel while leaving auto-scrolling, LLM streaming and accessibility to us.\n\n![Photo showing the modular component structure. ComposerPrimitive.Input is the chat input field, ComposerPrimitive.Send is the send button.](/media/?type=post\u0026id=87644\u0026key=user_uploads/1152943/d8eacc69-2d94-4c43-8fab-2dcac5e7f029)\n\nSample customization to make a perplexity lookalike:\n\n![Perplexity lookalike Chat UI](/media/?type=post\u0026id=87644\u0026key=user_uploads/1152943/16e96ae2-d563-4f6c-9047-6c3485a1cb3d)\n\n## **Demo Video**\n\n[Demo Video](https://youtu.be/9eLKs9AM4tU?si=jm9GzoFAcyM_tPT-)\n\n## **About**\n\nI’ve wanted to build my own dev tool company since high school. Last year, I built the first version of assistant-ui because I needed the UX of ChatGPT in my own app. The app I was building didn’t work out, but few friends asked me about the chat UI. Since then, AI chat has became increasingly popular as a means for delegating tasks to AI agents. My focus is on enabling human \u003c\u003e agent collaboration through better UX and AX (agent experience).\n\n![Photo of Simon, the founder](https://bookface.ycombinator.com/media/?type=post\u0026id=87644\u0026key=user_uploads/1152943/d43c8332-b160-40d8-8f27-849bd82806e3)\n\n## **Ask**\n\n* [Check out example demos](https://www.assistant-ui.com/)\n* [Star us on GitHub](https://github.com/assistant-ui/assistant-ui)\n* [Join our Discord](https://discord.com/invite/S9dwgCNEFs)\n* [Book a sales call](https://cal.com/simon-farshid/assistant-ui)","slug":"Mnc-assistant-ui-open-source-typescript-react-library-for-ai-chat","created_at":"2025-02-13T15:37:24.704Z","updated_at":"2026-04-23T06:25:01.841Z","total_vote_count":30,"url":"https://www.ycombinator.com/launches/Mnc-assistant-ui-open-source-typescript-react-library-for-ai-chat","share_image_url":"https://bookface.ycombinator.com/media/?type=post\u0026id=87644\u0026key=user_uploads/1152943/17c78ae1-d8cf-4fc4-a8aa-056fe449da02","company":{"id":30355,"name":"assistant-ui","slug":"assistant-ui","url":"https://assistant-ui.com","logo":"https://bookface-images.s3.amazonaws.com/small_logos/11f41b527f94c63e7d0ee1e19db038344f713a8f.png","batch":"Winter 2025","industry":"B2B","tags":["Developer Tools","Generative AI","Chat","Web Development","AI Assistant"],"search_path":"https://bookface.ycombinator.com/company/30355"}}