nodu: hypnosis for habits

Changing a habit can be hard. Drinking, doomscrolling, pornography, anything. With nodu, you chat with an AI coach, then it generates a custom hypnosis session. Each one builds on the last.

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Inspiration

I've done some hard things. I went to a top-tier law school, practiced in Big Law, worked on human rights cases including death penalty and child slavery litigation, and finished an Ironman. But some of the hardest things I've ever done were changing my own habits: skin picking that started when I was a teenager, and habitual substance use through high school and college.

While I was practicing law, I saw a hypnosis practitioner for my skin picking. It helped me enormously, but a handful of sessions cost thousands of dollars. nodu is my attempt to make something in that spirit available to anyone, for $29.99 a month.

As a lawyer, I studied democracy in Paris, and it left me convinced that what our societies need is not just better systems, but people able to make the choices they actually want to make. Changing a habit is one of the most personal versions of that.

What it does

You name a habit in your own words: drinking, doomscrolling, pornography, skin picking, anything. You talk it through with an AI coach in a short, private chat. From that conversation, nodu writes a hypnosis session just for you, drawing on guided relaxation, visualization and hypnosis, and reads it aloud.

  • Written new every time. There is no library of recordings. Each session comes from what you shared that day.
  • Each one builds on the last. nodu remembers what you've told it, and you can see what it remembers in the app.
  • Quick relief. A short session for the moment an urge hits.
  • Your way. About 10, 15 or 20 minutes, a male or female voice, rain, ocean or deep noise behind it, and an Awake or Asleep ending.

The first three sessions are free, no card needed. After that it's $29.99 a month, with an annual plan in App Review now. nodu is self-help and general wellness, not therapy, and it's for adults 18 and older.

How we built it

I built nodu on my own.

  • App: iOS, in React Native with Expo.
  • Server: TypeScript on Node, hosted on Railway, with Supabase for sign-in and the database.
  • The coach and the writing: Anthropic's Claude runs the coach chat and writes each session from the conversation and from what nodu remembers about you.
  • The voice: ElevenLabs reads the script, with the background sound you picked.
  • Subscriptions: RevenueCat runs the monthly and annual plans through Apple in-app purchase. Its webhooks keep the server's record of who is subscribed up to date, and the server checks that record before starting any paid session, so the three free sessions are counted on the server, not the phone. A running subscription stays with the account that bought it.
  • Safety: what people type and what the model writes are both screened for crisis language, and a match puts crisis resources in front of the person.

Challenges we ran into

  • Getting a voice to take its time. Hypnosis lives in the pauses. Getting the pacing right in text-to-speech took a lot of listening, and some early sessions opened with a stray syllable before the first word, which I finally fixed at the source.
  • Waiting. Writing and voicing a 10 to 20 minute session takes time, and the first session is when people are least patient. The app shows the session being written while you wait, and making the first one faster is what I'm working on next.
  • Handling personal data properly as a solo founder. What people tell nodu is personal. Consent is built into sign-up, there are no ad trackers in the app, data is never sold or used to train nodu's models, and anyone can delete their account and data from Settings.
  • App Review. Apple sent nodu back once before approving it. It went live on September 23.

Accomplishments that we're proud of

  • Taking nodu from an idea to a live App Store app as a solo founder, with real subscriptions running through RevenueCat.
  • Every session is written for one person. Nothing comes from a library.
  • Sessions that remember: each one picks up from what you've shared before.
  • Building safety and privacy in from day one rather than adding them later.
  • Submitting a 1.0.1 update a week after launch, with Home rebuilt as a chat and a new annual plan.

What we learned

  • Building is no longer the hardest part. Distribution is. Making something good is only half the work; getting it in front of the people it's for is the other half.
  • What people hear matters more than what they see. A pause in the wrong place breaks the experience in a way no screen bug does.
  • Privacy and safety are cheaper to build in early than to bolt on later.
  • Testers shape the product. Some of the best changes came straight from early testers' reports.

What's next for nodu: hypnosis for habits

  • A faster first session.
  • The annual plan, now in App Review.
  • Going beyond habits, toward goals and the beliefs that sit underneath them.
  • Getting nodu in front of the people it's for, starting with creators who talk about these habits, and then more countries beyond the US.

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