A bedtime story that gets to know your kid.
On custom AI bedtime stories, and what one actually looks like in practice.
It is 7:42 on a Tuesday. The kid has had a long day - a tooth came out at lunch, there was a problem at recess, the bath was negotiated rather than given. On the way upstairs she picks a topic out of the air: a fox who can't find their den.
You open Cosmonaut on your phone. You type four words. By the time the lamp is on and the covers are turned down, the story is waiting.
Here is what one of those stories sounds like.
From the story
The Fox Who Couldn't Find Their Den
The snow had been falling since just after lunch, and by the time the small fox realized she could no longer see the shape of the cedar tree she usually turned at, the world had become a single soft, white room with no walls.
She sat down. The snow was the cold kind that did not melt under her, only got colder.
"I'll just wait," she said out loud, mostly so she would have a voice nearby. The wind did not answer. A wren did, somewhere overhead, but the wren did not know where her den was either.
After a while, the fox stood up. She decided she would walk - not because she knew which way to walk, but because sitting down had not been useful, and sometimes you have to try the next thing.
She walked until she came to a place where the snow had been disturbed. Tracks - but not her own. They were larger than hers. They were shaped a little like hers. They led in two different directions.
What does the fox do?
- › Follow the larger tracks deeper into the woods.
- › Call out, in case someone is nearby.
- › Turn around and look for her own tracks under the new snow.
Three things are quietly happening on that page.
The first is that the story knows your child. You typed four words, but Cosmonaut also knows the reading level you set, the kinds of stories your family tends toward, and the content filters you've turned on. A six-year-old gets the prose you just read. A nine-year-old gets a richer version with longer sentences and more weather in it. The hook is the same; the cloth is different.
The second is that the choices matter. They are not three flavors of the same outcome. Following the larger tracks goes somewhere; calling out goes somewhere else; turning back goes somewhere else again. Cosmonaut remembers what your child picked, so a choice made on page three is still true on page seven. That is the difference between a branching story and a chat transcript.
The third is harder to put in a feature list. Bedtime stories work when they have a shape - when there is a problem and a search and an ending. We tune Cosmonaut for that shape, so the story your kid hears tonight is the kind of story you would have wanted someone to tell you.
A few practical notes
The free tier is enough to try a bedtime story or two; the Explorer tier opens up more stories per month; the top Cosmonaut tier adds audio narration, with warm, natural voices that can carry a chapter while you sit alongside your child. Vocabulary level and content filters are settings, not paid features - they're available from the moment you sign up.
A note on how we mean this to be used
Cosmonaut is built to be used together. It is a thing parents and kids do side by side at bedtime, not a thing a child uses alone with a screen. Children under 13 should always read on Cosmonaut with a parent or guardian. We don't autoplay the next chapter, we don't push notifications, and there's no feed to scroll past your kid's choice. The story waits. That is on purpose.