Rex was founded by Lewis Blackwood, Merlin Kafka in 2026.

Who are Rex's investors?

Rex's investors include Y Combinator, Vela Partners, Zero Index, Accel, Calm/Storm VC, Capnamic, Founders Fund, Kadan Capital and 8 more.

Where is Rex headquartered?

Rex is headquartered in San Francisco, US.

Rex

YC S26

San Francisco, US · Founded 2026 · 2 employees · 16 known investors

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Rex is an agentic finance platform that connects to existing enterprise financial systems and automates manual operational finance work like collections, reconciliation, and portal uploads using AI agents. The product is designed for finance teams at scaled technology companies seeking to delegate repetitive tasks while maintaining governance and audit compliance.

Also known as Rex AI Inc.

AI & Machine Learning Enterprise Software Fintech B2B Enterprise AIUnited States of AmericaAmerica / Canada

Founders & leadership· Y Combinator alumni (S26)

Rex was founded in 2026 by Lewis Blackwood and Merlin Kafka.

Lewis Blackwood Co-FounderHe was a founding engineer at Sequence, a venture-backed company, and cofounded Personably; earlier he was part of the initial team at GoCardless, a payments startup backed by Y Combinator, and studied economics at Cambridge University.

Merlin Kafka Co-founder & CEOMerlin spent four years as Chief Product Officer at Sequence, an order-to-cash platform, before founding Rex. He previously held a product management role at Tessian and studied Industrial Engineering at Cambridge and Product Design at Glasgow.

Aliza RosenFounder

Jonathan LoesingFounder

Julian LechnerFounder

Investors · 16

Y Combinator✓ confirmed by RexSan Francisco · $500K

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

Vela Partnerslisted by Vela PartnersSan Francisco · $100K – $500K

Zero Indexlisted by Zero Index

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

AccelreportedPalo Alto · $500K – $100M

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

Calm/Storm VCreportedVienna

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CapnamicreportedCologne · $540K – $3.2M

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

Founders FundreportedSan Francisco · $500K – $5M

How we know: funding news · Not right? Tell us

Kadan Capitalreported

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

Maiora Rebel Venturesreported

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MischiefreportedSan Francisco · $1M – $5M

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Myriad Venture Partnersreported

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RobinhoodreportedMenlo Park

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Stage 2 CapitalreportedLincoln · $200K – $4M

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TechstarsreportedBoulder · $220K

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

Transpose Platform ManagementreportedSan Francisco

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Vercelreported

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Related companies · 4

superglueSuperglue provides AI agents that automate enterprise system integration, data migration, and implementation work across cloud or on-premises infrastructure. The platform connects disparate systems and performs data synchronization tasks that typically require manual engineering coordination.

Visibl SemiconductorsVisibl Semiconductors handles end-to-end custom chip design, verification, and manufacturing for hardware companies in robotics, drones, industrial, and IoT sectors that cannot afford traditional semiconductor development costs.

screenpipeScreenpipe is a local-first context layer that captures screen activity for enterprise AI agents, enabling them to act on real user behavior. The platform serves enterprise organizations building or deploying AI agents.

AdaptionalAdaptional is an AI-powered claims quality review platform that audits insurance claims in real time to identify compliance gaps, leakage, and reserve issues. It connects to claims systems and continuously evaluates claims against customizable scorecards covering compliance, coverage, reserves, and subrogation.

Companies working in the same space as Rex.

Legal entities · 1

corporate structure

Rex AI Inc.

Frequently asked questions

What does Rex do?: Rex is an agentic finance platform that connects to existing enterprise financial systems and automates manual operational finance work like collections, reconciliation, and portal uploads using AI agents. The product is designed for finance teams at scaled technology companies seeking to delegate repetitive tasks while maintaining governance and audit compliance.
Who founded Rex?: Rex was founded by Lewis Blackwood, Merlin Kafka in 2026.
Who are Rex's investors?: Rex's investors include Y Combinator, Vela Partners, Zero Index, Accel, Calm/Storm VC, Capnamic, Founders Fund, Kadan Capital and 8 more.
Where is Rex headquartered?: Rex is headquartered in San Francisco, US.