Introducing hato, a Personal Journaling System
hato is a personal journaling system for deepening understanding, reflecting, and acting on your daily records through dialogue with AI. I built it for myself and use it every day. I grow it steadily by dogfooding — telling an agent whatever feature seems useful next.
It started on a morning walk
It began as a habit. During my morning walks, I’d journal the previous day by talking it through with ChatGPT.
What made it interesting was that ChatGPT would respond to my record with comments. Those comments nudged me to adjust my behavior a little, or pushed a thought one notch deeper. A plain diary doesn’t give back this kind of objective feedback. I don’t think AI is all-knowing. But simply externalizing my own thinking — getting it out of my head — brought back surprisingly on-point feedback, and with almost no effort. That feeling is what motivated me to build hato.
So hato isn’t a tool for “having the AI give you answers.” It’s a way to make a daily habit of externalizing your own thinking and getting a reflection back.
The name “hato”
There’s a thread of bird names here: karasu (crow), this blog’s fukurou (owl), and now hato (dove). I chose hato because I wanted it to bring a little peace into daily life — the dove is a symbol of peace. Written out like that it might sound like a cause for concern, but I mean it simply: I want to stack up calm days, one at a time.
A day with hato
The core is very simple:
- Each morning, open hato and journal the previous day.
- Get feedback on that record.
That single round trip is the center of it. And to make the feedback better, a few mechanisms run underneath:
- Distilling persistent memory — every day, hato distills a “persistent memory” of your context and who you are from the records so far, sharpening the feedback.
- Weekly and monthly feedback — it aggregates daily records to generate reflection over longer time horizons.
- A morning brief — it delivers a summary of the day’s events and newsletter digests each morning.
- Catching the seeds of goals — when something that looks like a goal you’d want to set surfaces in your records, it turns that into a goal.
- Admiring the flowers of accomplishment — when it spots words in your records that count as something achieved, it tells you you’ve reached it.
Picture a small loop that keeps turning: record → feedback → distill → even better feedback.
Not chasing differentiation
To be honest, I’m not trying to differentiate hato from other journaling tools. That’s because it’s a tool for myself. When I think “a feature like this would probably help me,” I implement it, dogfooding as I go. The accumulation of that is what hato is today.
Where hato is now, and what’s next
After about 40 days of running it personally, I’ve reached the point of getting monthly feedback.
Soon, I plan to release it as open source — because I want to share the fun of growing a journaling tool with your own hands.
One honest note: dialogue with AI incurs API costs, and how much you can spend will differ from person to person. hato runs once you deploy it to Cloudflare, so you can customize the usage model yourself — which model to use, how far to automate.
Externalize your own thinking, and reflect on it, steadily. Why not grow that habit with your own hands?