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GBrain

YC X26

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

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gbrain.io offers a cloud-based AI assistant that retains user-provided information and executes assigned tasks over time, delivering results asynchronously. It is designed for individuals and teams to delegate work.

Also known as gbrain.io · Gbrain.io · The Overton Window Company · The Overton Window Company, Gbrain.io, gbrain.io

AI & Machine LearningEnterprise SoftwareFuture of WorkWorkflow AutomationAutomationAI AssistantUnited States of AmericaAmerica / Canada

Founders & leadership· Y Combinator alumni (X26)

GBrain was founded in 2026 by Brad Gessler and Jamison Mercurio.

BGBrad Gessler
Brad GesslerCEOFounder and CEO of gbrain.io, a cloud-based multiplayer AI agent platform. He was previously co-founder and CTO of Poll Everywhere.
JMJamison Mercurio
Jamison MercurioFounderJamison Mercurio is co-founder of gbrain.io and previously co-founded and served as CEO of Mango Health, an AI mental health company. He earlier worked as an iOS and web engineer at Meta on Messenger Video Chat and Facebook News, and studied computer science at Princeton, graduating in 2020.
GTGarry Tan
Garry TanPresident & CEO of Y Combinator

Investors · 2

Transpose Platform ManagementreportedSan Francisco

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

The YC application· Spring 2026 batch

Alumni Q&A

How did your company get started? (i.e., How did the founders meet? How did you come up with the idea? How did you decide to be a founder?)
The three founders met while building Garry's List and were frustrated by having to re-enter API keys and re-explain their work each time they switched between AI tools, none of which supported team use. They built an agent setup with shared memory, skills, and external integrations for themselves and friends, then turned it into gbrain.io, a cloud, multiplayer version that configures itself in one click.

Summarized from the founders' answers on their Y Combinator profile.

Images

GBrain photo

Founder mafia

2 people who came through GBrain went on to found or lead other companies.

Garry TanFounded Posterous +2Jamison MercurioFounderFounded Mango Health

Related companies · 4

loopfourLoopfour provides finance automation software that enables organizations to automate workflows such as invoicing, contracts, payments, and reconciliations while maintaining control through triggers, integrations, and approval mechanisms.
Decisional AIDecisional provides AI agents that automate operational tasks within existing business software, handling workflows such as expense reconciliation, preventive maintenance, and field service management. The platform pairs general AI capabilities with custom automation agents that build, run, and repair workflows across connected applications.
Integration LabsIntegration Labs provides an API that connects B2B software companies to multiple accounting, payments, and e-commerce platforms, allowing them to access customer financial data for applications like invoice financing, lending, and automated reconciliation.
KeystrokeKeystroke is a platform for building specialized agents and workflow automations that integrate with coding agents like Claude Code and Cursor, allowing users to build actual TypeScript code that lives in their repository and deploy to the Keystroke platform for credential management, logging, and access control.

Companies working in the same space as GBrain.

Legal entities · 1

corporate structure
The Overton Window Company

Frequently asked questions

What does GBrain do?
gbrain.io offers a cloud-based AI assistant that retains user-provided information and executes assigned tasks over time, delivering results asynchronously. It is designed for individuals and teams to delegate work.
Who founded GBrain?
GBrain was founded by Brad Gessler, Jamison Mercurio in 2026.
Who are GBrain's investors?
GBrain's investors include Y Combinator, Transpose Platform Management.
Where is GBrain headquartered?
GBrain is headquartered in San Francisco, US.