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assistant-ui

YC W25

San Francisco, US · Founded 2024 · 3 employees · 10 known investors

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Assistant-ui is an open-source React library that provides pre-built components and state management for building AI chat interfaces. It enables developers to integrate ChatGPT-style conversational UIs into applications with support for streaming, multi-turn conversations, and integration with LLM providers like LangChain and Vercel AI SDK.

Also known as AgentbaseAI Inc.

AI & Machine LearningData & InfrastructureDeveloper ToolsEnterprise SoftwareGenerative AIChatWeb DevelopmentAI AssistantUnited States of AmericaAmerica / Canada

Founders & leadership· Y Combinator alumni (W25)

assistant-ui was founded in 2024 by Simon Farshid.

SFSimon Farshid
Simon FarshidFounderSimon Farshid is founder and CEO of assistant-ui, and previously co-founded READO, a book recommendation platform that grew to 140k monthly active users. He has been developing software since childhood and has participated in hackathons internationally.

Investors · 10

Pioneerlisted by PioneerToronto, Ontario

How we know: Y Combinator's founder network · pioneerfund.vc · open dataset · 5k.vc investor directory · Not right? Tell us

SaaStr Fundlisted by SaaStr FundSan Francisco · $750K – $5M

How we know: SaaStr Fund's portfolio page · Y Combinator's founder network · Not right? Tell us

Y Combinatorlisted by Y CombinatorSan Francisco · $500K

How we know: the Y Combinator directory · funding news · open dataset · 5k.vc investor directory · Not right? Tell us

468 CapitalreportedBerlin

How we know: the VCSheet dataset · Y Combinator's founder network · Not right? Tell us

Andreessen HorowitzreportedMenlo Park · $500K – $50M

How we know: Y Combinator's founder network · Not right? Tell us

CRV (Charles River Ventures)reportedBay Area · $250K – $5M

How we know: Y Combinator's founder network · Not right? Tell us

Peak XV PartnersreportedBengaluru · $100K – $10M

How we know: Y Combinator's founder network · Not right? Tell us

Tekedia CapitalreportedLagos · $1K

How we know: Y Combinator's founder network · Not right? Tell us

Velocity Fundreported

How we know: Y Combinator's founder network · Not right? Tell us

Images

assistant-ui photo

Related companies · 10

LinzumiA tool that runs in the terminal and detects when interactive prompts stall execution in development workflows, providing visibility into file operations and enabling remote redirection without SSH access.
FigmaFigma is a collaborative design platform that enables teams to create apps, websites, and products through shared design tools integrated with development workflows and AI-powered design assistance.
OlarkOlark provides live chat software that enables businesses to communicate with customers in real time. The platform serves small to mid-market businesses seeking customer engagement and support tools.
VercelVercel is an infrastructure platform for building and deploying applications, with emerging support for agentic capabilities that allow AI agents and humans to collaborate in software development. The platform serves developers and agents building web applications and software.
RowFlowRowFlow converts traditional web forms into AI-driven conversational interfaces that operate via text, Slack, or embedded chat, enabling companies to collect structured data from users while improving response rates and reducing administrative overhead.
StreamStream provides infrastructure for building AI applications and real-time communication features including chat, video, feed, and moderation across multiple platforms. The company serves developers and enterprises building multi-modal AI applications and communication-enabled apps.
GuildedA group communication platform for gaming communities that includes built-in calendars, discussion boards, and additional collaboration tools.
LangChainLangChain provides an agent engineering platform and open source frameworks for developers to build, test, and deploy AI agents that can use data and take actions. The platform includes LangSmith for observability and evaluation, and serves enterprise customers including 35% of the Fortune 500.
PensilPensil is a community platform that provides live session hosting, webinar capabilities, and community management tools with integrated video streaming and recording features. The platform serves organizations building online communities across education, nonprofits, and freelancer networks.
OpenAIOpenAI is an AI research and deployment company focused on developing artificial general intelligence (AGI) with emphasis on safety and beneficial outcomes for humanity.

Companies working in the same space as assistant-ui.

Legal entities · 1

corporate structure
AgentbaseAI Inc.

In the news

💬 assistant-ui - Open Source Typescript/React Library for AI Chatycombinator.com · Feb 2025

Frequently asked questions

What does assistant-ui do?
Assistant-ui is an open-source React library that provides pre-built components and state management for building AI chat interfaces. It enables developers to integrate ChatGPT-style conversational UIs into applications with support for streaming, multi-turn conversations, and integration with LLM providers like LangChain and Vercel AI SDK.
Who founded assistant-ui?
assistant-ui was founded by Simon Farshid in 2024.
Who are assistant-ui's investors?
assistant-ui's investors include Eight Capital, Pioneer, SaaStr Fund, Y Combinator, 468 Capital, Andreessen Horowitz, CRV (Charles River Ventures), Peak XV Partners and 2 more.
Where is assistant-ui headquartered?
assistant-ui is headquartered in San Francisco, US.