A NOTEBOOK THAT ACTS, NOT JUST STORES

Write it down.
Let it get done.

Zen is a calm study notebook with an AI agent built in — one that creates notes, manages your calendar, cites your PDFs, and quizzes you back, instead of waiting for you to do it yourself.

Start with Zen See what it can do
Assistant · live conversation
Everyday tools

Everything you'd want in a study notebook, quietly in one place.

No tab-switching between five apps. Zen keeps your notes, math, reading, and schedule together — so focus doesn't get interrupted by logistics.

✎

Fast, flexible notes

Link ideas together, drag them into shape, and find anything again in seconds.

∑

Math that renders live

Type an equation and watch it become beautiful as you go — graphs and diagrams too.

◧

One source library

Drive, Zotero, GitHub, Canvas, and clipped web pages — all searchable in one place.

⏳

Deep Work sessions

A focus timer plus a real study plan that tracks what you actually know.

✉

Calendar & inbox

See and manage your schedule and email without ever leaving your notebook.

⟲

Synced everywhere

Sign in once and your notes, plans, and progress follow you to every device.

Pricing

Bring your own model.
Pick the one that fits.

Start free with your own model key, or choose a managed model subscription. Paid plans use Stripe Checkout.

Sign in for a paid plan

The free download needs no account. For DeepSeek or Claude, sign in with Google so your Stripe subscription can be linked to your Zen account.

Not signed in yet.
Bring your own key
Free
€0/ forever

Run Zen with a model API key you already have. No subscription and no checkout.

  • The full Zen desktop app
  • Notes, lessons, quizzes, and Deep Work
  • Connect your own supported model provider
  • Download immediately
Choose Free
Fast & light
DeepSeek Agent
€7/ month

A capable, budget-friendly agent for day-to-day notes, scheduling, and quizzing.

  • Full tool access — notes, calendar, email, PDFs
  • Deep Work sessions, lessons, and quizzes
  • Connected source search across Drive, Canvas, Zotero, GitHub
  • Great for routine studying and staying organized
Connect DeepSeek
Best reasoning
Claude Agent
€30/ month

Anthropic's Claude behind the wheel — stronger reasoning for harder material and more nuanced tool use.

  • Everything in the DeepSeek plan
  • Better judgment on ambiguous, multi-step requests
  • More reliable lesson walkthroughs and grading
  • Best for dense coursework and exam prep
Connect Claude

Paid plans renew monthly through Stripe. Switch plans anytime from Settings — your notes stay exactly where they are.