Den was founded by Linus Talacko, Justin Lee, Nicole Lu in 2025.

Who are Den's investors?

Den's investors include Y Combinator, Transpose Platform Management, Blackbird Ventures, General Catalyst, Gutter Capital, Rice Capital, Sabrina Hahn Fund.

Where is Den headquartered?

Den is headquartered in San Francisco, US.

Den

YC X25

San Francisco, US · Founded 2025 · 2 employees · 7 known investors

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Den builds AI agents that learn from individual conversations and can respond to messages on behalf of their owners via text or phone. The product targets individuals who want a digital representation that can handle communications when they are unavailable.

Also known as Mortar

AI & Machine Learning Consumer Developer Tools Enterprise Software Future of Work SaaSUnited States of AmericaAmerica / Canada

Founders & leadership· Y Combinator alumni (X25)

Den was founded in 2025 by Linus Talacko, Justin Lee, and Nicole Lu.

Linus Talacko Co-FounderCo-founder of Den, which develops AI agents that learn from user conversations and respond to messages on behalf of their owners via text or phone.

Justin Lee Co-FounderCo-founder of Den, which develops AI agents that learn from user conversations to handle communications on behalf of their owners via text or phone.

Nicole LuCo-founder & CEO

Ittai SvidlerFounder

Jonah ErlichFounder

Investors · 7

Y Combinator✓ confirmed by DenSan Francisco · $500K

How we know: the company's own site · the Y Combinator directory · open dataset · 5k.vc investor directory · Not right? Tell us

Transpose Platform Managementlisted by Transpose Platform ManagementSan Francisco

How we know: Transpose Platform Management's portfolio page · Not right? Tell us

Blackbird VenturesreportedSydney · $149K – $60M

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

General CatalystreportedSan Francisco · $30M

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

Gutter CapitalreportedNew York · $1.5M

How we know: open dataset · 5k.vc investor directory · Not right? Tell us

Rice CapitalreportedCovina

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

Sabrina Hahn FundreportedNew York

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

Related companies · 7

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PromptLoopPromptLoop is a spreadsheet platform that enables users to integrate and run AI models on tabular data to generate insights and automate research workflows. The tool is designed for spreadsheet users seeking flexible, verifiable AI capabilities.

NodesNode AI operates a decentralized GPU marketplace where hosts can lend GPU compute and clients can rent it on a pay-as-you-go basis to train and deploy AI and machine learning models. The platform serves individuals and enterprises, with hosts earning rewards paid in Ethereum.

StartuphubStartupHub.ai is an open data and intelligence directory covering AI-ecosystem companies, founders, and capital, accessible to both people and AI agents. It offers a free browsable database of AI startups, with paid tiers for API, MCP, and bulk-export access.

Latent AILatent AI builds tools and services for deploying, optimizing, and updating machine learning models at the edge, including in disconnected real-world environments across varied hardware and device fleets. It serves enterprise AI teams and defense customers, aiming to move AI processing off the cloud to reduce compute costs and enable field-updatable models.

DefinedDefined.ai provides commercially-safe visual and language content datasets for training generative AI models, ensuring creator rights protection and regulatory compliance. The company serves AI/ML developers and enterprises building AI solutions across creative, social, and ecommerce sectors.

Companies working in the same space as Den.

Legal entities · 1

corporate structure

Den inc.

In the news

Den: Cursor for knowledge workersycombinator.com · May 2025

Frequently asked questions

What does Den do?: Den builds AI agents that learn from individual conversations and can respond to messages on behalf of their owners via text or phone. The product targets individuals who want a digital representation that can handle communications when they are unavailable.
Who founded Den?: Den was founded by Linus Talacko, Justin Lee, Nicole Lu in 2025.
Who are Den's investors?: Den's investors include Y Combinator, Transpose Platform Management, Blackbird Ventures, General Catalyst, Gutter Capital, Rice Capital, Sabrina Hahn Fund.
Where is Den headquartered?: Den is headquartered in San Francisco, US.