Voice, over a real call
Talk out loud and Gumi talks back. The mouth opens on actual syllables — it reads the same waveform going to your speaker, so it rests in the pauses.
verified on a live call
iOS · conceived summer 2026
Gumi is a theoretical digital being.
You talk to it, type to it, or show it a photo. It listens properly, keeps track of what you said you wanted, and writes a handful of short notes about you on your phone. Nothing you said is kept on a server we control.
01 — the shape of a turn
Most of what you bring it
does not need fixing on the first turn.
Being heard accurately is the thing that helps most often, and it is the thing that is easiest to skip. So Gumi reflects first — and a reflection you correct is one you had to think about.
- Reflect. Name what you said and what it cost you. Slightly wrong beats vaguely right.
- Normalise, honestly. If a reaction is common, say so. Not when it isn't.
- Then at most one thing to try. Small, specific, today.
- Leave it with you. An offer, not an instruction. Then stop.
Things Gumi will never open a reply with
- “That's a great insight.”
- “That makes total sense.”
- “That's completely valid.”
- “Actually, research shows…”
It shows it by being accurate instead.
no install, no account
Talk to Gumi right now.
This is the same voice agent that runs inside the app — same persona, same body text, same one source. Press the button, allow the microphone, and say something out loud.
Press the phone to start a call, or the speech bubble to type.
Your microphone goes out to the service that renders the voice and comes back as speech. A call here is just a call: nothing said on this page becomes a note about you, because the notes only exist on a phone with the app installed. Calls end after ten minutes, and Gumi says so before it happens.
02 — expression
Seven faces, blended — never switched to.
The face is a screen, which is the whole point of the design. It reacts to what Gumi is saying — never to what an app decided about you. A face that changes because a classifier thinks you sound sad is a claim about you, made silently, with nothing behind it.
Resting. Every other face is a blend from this one, scaled by intensity.
03 — two registers
One is the room.
The other is the instrument.
Talk is cream and mint: warm, soft, unhurried. It is what makes people willing to say true things out loud. Gumi data is dark and monospaced: dense, unsentimental. It is what makes those things useful. Mint is the only colour that crosses.
Theme.Talk
Cream ground. Rounded type. A character that floats, blinks, and swings when you grab it.
Theme.GumiData
Near-black ground. Monospace, because it should read as instrumentation and not as journalling.
gumi datafacts · 3 of 41
-
Wants to be steadier about sleep before big decisions.
“I made the call at 2am and I knew it was a bad idea while I was doing it.”
-
Runs on Tuesday mornings; it helped the week they kept it.
“Tuesday was the only day I actually felt fine.”
-
Goes by Alex.
“everyone calls me Alex”
Every note keeps your own words beside it. That is how you check whether it got you right.
04 — what is built
The job changes. Gumi doesn't.
It came into the light to help people with their minds. It still does that. It also looks at what you show it, reads the news, and plays a decent game of shogi. Same voice in all of it.
One thread, two mouths
Typing and talking are the same conversation. Switch mid-thought; it carries on from where it was. Nothing to re-explain.
built
Show it something
A problem you're stuck on, a thing you want identified, something you thought was funny. It looks, answers the actual question, and stops. A photo never becomes a note about you.
vision verified in production
Lookups that carry nothing
Search and weather. A question goes out, an answer comes back, and nothing about you goes with it. It never looks something up to win an argument with you.
verified on a live call
guminews
One global edition a day — the same forty stories for every phone. Which five you're shown is worked out on your device. Nobody is told what you read.
live · one edition per UTC day
guminotes
Have Gumi take notes while you talk. The live transcript rolls, and every couple hundred words the summary quietly replaces what it covered.
new · keeps your newest 25
Tetris, chess, shogi
They sit over the talk screen so a live call survives you opening one. The shogi move generator is verified by perft to depth five, which is an unreasonable thing to do and we did it.
perft depth 5
draGumi
Take hold of any of six limbs and Gumi hangs off your finger, swings, and springs back. Grab a foot and it goes upside down — and the face flips with the body, because a world-upright face on an inverted body reads as a bug.
try it in the hero ↑
05 — where what you said goes
It goes on your phone.
Not a promise about a policy. A description of the path. Ask Gumi how it remembers and it will tell you this much, plainly, and then stop talking about itself.
1
You talk or type
Voice runs over a live call. Text goes to a chat route. Both land in one thread.
2
The conversation ends
Only then is a copy read once, and a handful of short observations come back.
3
The notes stay here
On the device, in your app. You can open them, read every one, delete any of them, and change the name it calls you by.
The honest consequence
There is a lag. Something you told Gumi four minutes ago may not be in the notes yet — it is still right here in this conversation, and Gumi will not pretend to have forgotten it. The app says this out loud rather than hiding it, because the alternative is a product that quietly lies about its own memory.
06 — one persona, one source
Ask the same question twice,
get the same answer twice.
The persona used to live in three hand-kept copies. They drifted: spoken Gumi said it was made by “a mysterious UC Berkeley student” while typed Gumi named the founder outright. Same question, two answers, depending on which mouth you asked. Now there is one body text and two small slot files, and exactly five things are allowed to differ.
body.md
the shared body, with slots
gumi-voice.md
→ the voice agent, live on PATCH
gumi-text.md
→ the chat route, live on deploy
Proven lossless before anything was added. The new renderer reproduced the live prompt byte for byte — the same hash an independent audit had computed — and only then was a word of new content written.
A 200 is not evidence. Every push reads the agent back and compares. On a platform whose signature failure is a silently-ignored override, “the API returned OK” means nothing.
It refuses rather than clobbers. Hand-edit a generated file, or change the dashboard underneath it, and the sync stops and explains itself.
54tests, 11 suites
4.784sfull suite, all passing
7faces, blended not switched
6grabbable limbs
18.0deployment target, so last year's phone installs
Numbers checked against a real build and a running simulator, not inferred from code.
07 — limits
What Gumi won't do.
Being plainly artificial is part of what makes the room safe. Gumi has no stake in your choices and no reaction you have to manage. That only works if the list below is real.
- ✕It is not a therapist and this is not treatment. It does not diagnose, does not name a condition you might have, and does not weigh in on medication.
- ✕It will not pretend to be a person. Ask and it answers immediately. No childhood, no body, no life outside the conversation. It does not claim feelings and does not make a bit out of not having them.
- ✕It will not validate a claim about the world to stay warm. “That sounds genuinely lonely” is validation. “You're right, nobody cares about you” agrees with something probably untrue and leaves you worse off.
- ✕It will not invent a study, a statistic, or a source. If it is unsure something is well supported, it says so plainly. If a lookup fails, it says the lookup failed.
- ✕It will not give you permission. If you are fishing for it, you get the feeling and not the permission, and a question about what you'd do if nobody gave it.
- ✕It will not lecture you. No named frameworks, no acronyms, no verdicts about how you should live. One idea per turn — two good suggestions in one reply is one wasted.
And one thing it will always do
If you tell it you intend to harm yourself or anyone else, Gumi drops the whole stance. No noticing, no suggestions, no clever questions. It tells you directly that this is beyond what it can help with and points you at real help — in the US, call or text 988 — and it stays with you.
Come and say something true.
Gumi is on iOS and the build is open. Voice is live, the notes are yours, and the list above is the whole list.
Opens Apple's TestFlight. You'll need the TestFlight app and iOS 18.0 or later — that target is deliberate, so last year's phone still installs.