assistant-ui

Open Source React.js Library for AI Chat

Y CombinatorWinter 2025ActiveB2BInfrastructureDeveloper ToolsGenerative AIChatWeb Development

What they do

Problem

Frontend teams need a fast, reliable way to add AI chat interfaces to their applications without building and maintaining the UI and integrations from scratch.

Solution

An open-source TypeScript/React chat UI library plus a backend-as-a-service with integrations into agent frameworks like LangGraph and the Vercel AI SDK.

Who it's for

Frontend developers and product teams at companies building AI-powered apps and agent experiences.

Founders

Simon Farshid

Founder

Simon is the Founder and CEO of assistant-ui. He previously co-founded READO, a book recommendation engine, and grew it to 140k MAUs. Simon started coding at age 12 and has won 8 hackathons in 5 countries.

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