Den
YC X25San Francisco, US · Founded 2025 · 2 employees · 2 known investors
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 LearningConsumerDeveloper ToolsEnterprise SoftwareFuture of WorkSaaSUnited States of AmericaAmerica / Canada
Founders & leadership· Y Combinator alumni (X25)
Den was founded in 2025 by Linus Talacko, Justin Lee, and Nicole Lu.
LT
Linus Talackoin𝕏Co-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.
JL
Justin Leein𝕏Co-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.
NL
Nicole LuCo-founder & CEO
Investors · 2
Competitors · 7
by search overlapDensity7 shared keywordsDensity AI designs custom AI accelerators optimized for frontier-scale large language model inference, combining near-memory compute architecture with high-bandwidth memory density. The company builds silicon-to-software solutions tailored for production inference workloads.
Density7 shared keywordsDensity makes radar-based sensors that measure workplace occupancy and space utilization without cameras, avoiding the capture of personally identifiable information. It serves enterprises, including Fortune 500 companies, that want to track workplace performance while complying with privacy laws.
PromptLoop5 shared keywordsPromptLoop 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.
Nodes4 shared keywordsNode 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.
Startuphub4 shared keywordsStartupHub is a searchable directory and intelligence platform that tracks startups, investors, founders, funding rounds, patents, and research across the AI ecosystem, using AI agents to detect signals like funding, hiring, launches, and stealth-company activity. It serves investors, founders, sales teams, competitive intelligence, recruiting, and corporate development users, offering watchlists, alerts, market maps, email finding, and a developer API.
Latent AI4 shared keywordsLatent AI builds tools for developing and deploying edge AI, processing data closer to the source rather than in the cloud to enable real-time decision-making and reduce infrastructure costs. Its solutions are aimed at organizations and developers integrating AI across diverse devices.
Defined4 shared keywordsDefined.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 competing with Den for the same Google search keywords, organic and paid, via search-intersection analysis.
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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.
- Where is Den headquartered?
- Den is headquartered in San Francisco, US.