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ReasonBlocks

YC X26

San Francisco, US · 2 employees · 8 known investors

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ReasonBlocks provides a runtime layer that optimizes AI agent performance by correcting reasoning processes and reducing token usage during execution, resulting in lower costs and improved reliability across repeated operations.

Enterprise SoftwareUnited States of AmericaAmerica / Canada

Founders & leadership· Y Combinator alumni (X26)

SMSajeev Magesh
Sajeev MageshCo-FounderSajeev Magesh studied computer science at Stanford and has published research in machine learning applications to agriculture. He has spent 11 years building products alongside co-founder Rohan and is now developing AI agents at ReasonBlocks.
RVRohan Vij
Rohan VijCo-FounderRohan Vij studied information systems and artificial intelligence at Carnegie Mellon University and has worked on molecular dynamics and AI research, as well as AI applications for distributed energy at ENGIE and IoT research at UC Davis. He is building ReasonBlocks with co-founder Sajeev, focusing on cost reduction and reliability improvements for large language models.

Investors · 8

Y Combinatorlisted by Y CombinatorSan Francisco · $500K

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

Amino CapitalreportedPalo Alto · $100K – $10M

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

Capitalize VCreportedChicago · $100K – $200K

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

Metsu Capitalreported

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

OurCrowdreportedJerusalem

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

Ritual CapitalreportedMenlo Park · $100K – $500K

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

RobinhoodreportedMenlo Park

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

Legal entities · 1

corporate structure
ReasonBlocks Inc.

In the news

ReasonBlocks - Stop your AI agents from burning money re-learning what they already know.ycombinator.com · Apr 2026

Frequently asked questions

What does ReasonBlocks do?
ReasonBlocks provides a runtime layer that optimizes AI agent performance by correcting reasoning processes and reducing token usage during execution, resulting in lower costs and improved reliability across repeated operations.
Who founded ReasonBlocks?
ReasonBlocks was founded by Sajeev Magesh, Rohan Vij.
Who are ReasonBlocks's investors?
ReasonBlocks's investors include 515 Ventures, Y Combinator, Amino Capital, Capitalize VC, Metsu Capital, OurCrowd, Ritual Capital, Robinhood.
Where is ReasonBlocks headquartered?
ReasonBlocks is headquartered in San Francisco, US.