River was founded by Brian Joseff, Chandler Supple in 2026.

Who are River's investors?

River's investors include Y Combinator, Claypond Capital, Elev8 Venture Partners.

Where is River headquartered?

River is headquartered in San Francisco, US.

River

YC F26

San Francisco, US · Founded 2026 · 2 employees · 3 known investors

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River is developing an AI-powered desktop environment aimed at increasing the productivity of knowledge workers, applying to general office and information tasks the kind of AI assistance already used in software development.

AI & Machine Learning Enterprise Software Future of Work Artificial Intelligence ProductivityUnited States of AmericaAmerica / Canada

Founders & leadership· Y Combinator alumni (F26)

River was founded in 2026 by Brian Joseff and Chandler Supple.

Brian Joseff Co-FounderHe previously founded Bedrock (2020-2023), worked as a neuroscience researcher at Stanford School of Medicine, and was on the founding team of Progressly (acquired by Box). He holds a BA in Economics from Dartmouth.

Chandler Supple CEO & Co-FounderFounder and CEO of River, previously a software engineer at Roboflow and co-founder of Outwork, and a participant in Z Fellows. He studied computer science at UC Berkeley before leaving.

Investors · 3

Y Combinatorlisted by Y CombinatorSan Francisco · $500K

How we know: the Y Combinator directory · Not right? Tell us

Claypond CapitalreportedBengaluru

How we know: press coverage · Not right? Tell us

Elev8 Venture PartnersreportedBengaluru

How we know: press coverage · Not right? Tell us

Funding

SEC filings, press & company announcements

Undisclosed amountSeries Seed and Series AAug 2026
Source ↗
Undisclosed amountSeries CAug 2026
Source ↗

Source: company announcements and press reports — follow each round's link for the claim.

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Frequently asked questions

What does River do?: River is developing an AI-powered desktop environment aimed at increasing the productivity of knowledge workers, applying to general office and information tasks the kind of AI assistance already used in software development.
Who founded River?: River was founded by Brian Joseff, Chandler Supple in 2026.
Who are River's investors?: River's investors include Y Combinator, Claypond Capital, Elev8 Venture Partners.
Where is River headquartered?: River is headquartered in San Francisco, US.