Requests for Startups | Y Combinator

Requests for Startups<br>RFS is our tradition of sharing ideas we'd like to see founders tackle. These represent just a fraction of what we fund — if one excites you, take it as extra validation to dive in, but you don't need to work on these ideas to apply to YC.

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Fall 2026<br>AI is moving into the physical world. We're excited about a new wave of startups rebuilding the systems that power the real world, from education and healthcare to defense, finance, infrastructure, and work itself. This batch's requests come from YC partners and founders building on the frontier, and include, for the first time, one from the sitting U.S. Secretary of the Army.

The Primer#<br>By Andrew Miklas

In Neal Stephenson's The Diamond Age, a young girl is given an interactive book called A Young Lady's Illustrated Primer. It looks like a tool for learning to read, but it's far more. It adapts to her completely, and through stories tuned to her life, it teaches her not just to read but to think, to reason, and eventually to grapple with the hardest questions of ethics, meaning, and character. She returns to it day after day for years, and as she grows, it grows too. Continually reshaping itself around who she is becoming and the life she is living.

For the first time in history, something like the Primer is starting to feel possible.

The best education has always come from one-on-one tutoring. Aristotle taught Alexander. But that privilege has been reserved for the few. AI can bring it to every child. And great tutors do more than drill facts. Over years, they learn a child's mind, and with it how to teach what can't be drilled at all: thinking, reasoning, even wisdom.

In Stephenson's story, the Primer is an AI tutor that never runs out of patience or time. We're a long way from building one, but we can start today. What we'd love to see now is a product that adaptively teaches young children to read, write, and do arithmetic, at the quality of a devoted private tutor and at consumer scale. Not a replacement for teachers, but a supplement that makes them more effective.

While we think this begins as something a parent buys to help their child learn basic skills, it is also the entry point to far greater ambitions. A company that gets it right could build toward something like the Primer, and even a fraction of that vision would have a profound effect on society.

If you're building this, we'd love to hear from you.

The Future of American Defense#<br>By Daniel P. Driscoll, US Secretary of the Army

Warfare is at an inflection point, and the old ways of Army acquisition simply don't keep pace with modern threats. Modern combat demands commercially developed, modular open-system solutions, and that's why we ripped up the old acquisition playbook.

We need hungry, innovative founders to build for the crucible of ground combat. The threats we face change daily, and the Army must dominate everywhere, from the Arctic to the archipelago and from space to subterranean environments. So here is our request for startups. We are actively funding low-cost interceptors or any component that helps us lower the cost per kill.

We need next-gen sensors, software, payloads, and other hardware that plugs directly into our open system architecture. We need cutting-edge drones, resilient logistics, and advanced manufacturing, and we need it all to survive the most extreme climates on Earth. Bring us your ideas, and we will give you the capital and the proving ground to scale.

There has never been a better time to build for the Army. The door is wide open, so let's get to work.

A Cloud for Small Software#<br>By Pete Koomen

Using agents to build personal software to solve your own problems is a lot of fun.

This is "Small Software". Purpose-built tools that will only ever have one or a small handful of users.

Small software is useful for teams too: Every team does things differently, and there's unlimited demand for bespoke tools for running workflows, tracking important numbers, managing sprints, sharing prototypes, and so on.

Software like this is now very easy to build, but still hard to deploy and share.

Incumbent clouds like Azure and AWS were designed for shipping Big Software that scales with many users… at the cost of complexity.

A cloud designed for small software could delete most of this complexity and unlock a big set of new use cases that agents have only recently made possible.

At the same time, there are other hard problems to solve: every company will want to customize the environment this software runs in, auth & permissions are hard, and allowing nontechnical users to share arbitrary code is tricky to do securely.

Small software should be as easy to share with your colleagues as a Google Doc.

If you're working on something like this, we'd love to hear from you.

Multiplayer AI#<br>By Aaron Epstein

The best work...