Aleph Lab builds an AI language buddy embedded in the games children already love, such as Minecraft and Roblox, to help them learn new languages through interactive gameplay. Its AI companions prompt kids to speak vocabulary, absorb new words and receive real-time grammar correction, letting parents convert gaming time into productive learning. The company reports that many children improved by more than a grade level in just five sessions. Aleph Lab is based in San Francisco and is part of Y Combinator's Fall 2025 batch.