The answer is 42.
The question is what to do today?
Connect Claude or ChatGPT and name your goal. Your AI assistant will build a personal path, and 42day will show you one next step every day, with a clear explanation of why it matters.
What is 42day
An app where your AI assistant guides you to your goal, and every day you do one clear thing.
How it works under the hood
- You name a goal, and the assistant builds stages, steps and tasks for your deadline and starting point
- 42day shows “Do it now” and a queue of tasks for today, each with its own explanation of why and how
- Questions arrive as quizzes in the app, and the result of a task is recorded in your own words
- A 42-day cycle, then a fresh start from next Monday or the first of the month
Facts
- Works in the browser and on Android
- Works with Claude, ChatGPT and other assistants that support MCP
- Free: up to 3 active goals. 42-day pass: $7 one-time, no subscription
- Friends: sharing goals and tasks is free
Turn a goal into action.
Your AI assistant will plan the route, and 42day will remind you of the next step.
An ordinary to-do list
- An empty list you fill in yourself
- Ready-made courses, the same for everyone
- The assistant asks ten questions in chat
- You miss a day and drop everything
42day
- The path is built around your goal, deadline and starting point
- Your own Claude or ChatGPT writes the content and remembers past goals and results
- All questions come as short quizzes in the app
- The assistant picks the time, the first missed day is forgiven, and you can come back with one light task
From wish to done in 5 steps
The assistant leads you through a clear cycle. The server makes sure stages can’t be skipped.
Goal breakdown
A starting quiz: where you are now, how much time you have, what got in the way. The goal gets a number, a deadline and a definition of “achieved”.
Stages and steps
The big parts of the path and the steps inside them. Built for you, not taken from a template.
Quiz
Short questions with options, “I don’t know” and “Other”. Your answers decide what to do next.
Task
One action per sitting: when and where, why, how, steps, a 2-minute version, a starter template and a deadline.
Step complete
The assistant assesses your work and skills. A check before moving to the next stage.
Everything you need to see it through
Game mechanics keep your rhythm, but rewards are given only for real actions.
Today’s tasks: reschedule with one tap
The app builds your day by goal importance: “Do it now” on top, a queue below. Running out of time? Tap “Later” and the task moves on. The assistant picks the time and the reminder itself. If it didn’t work out, choose a reason with one button and it will suggest an easier version.
A 42-day cycle
Day N of 42 and your charge. The first missed day is forgiven, after that the charge drops, and one light task brings it back. XP and achievements are never taken away.
Goal priorities and pause
Rank your goals by importance. Put extras on pause: they get no tasks until you bring them back.
Quizzes instead of interrogations
3 to 10 questions, one per screen. There are no questions in chat; all the context is gathered here.
XP, levels and skills
Tasks, steps and quizzes give XP. Skills grow from 1 to 5 based on real work and carry over between linked goals.
Linked goals
The apartment depends on income, and income on English. The assistant sees the results of linked goals and doesn’t ask twice.
The assistant edits the plan
It creates, changes and removes tasks and goals when you ask. The assistant awards XP itself based on your report. Permanent deletion only with explicit confirmation.
Personal achievements
The assistant invents rewards for your real actions: “Three banks with mortgage numbers”, “10 games reviewed”. They are awarded only on proof from your report.
Friends
Copy your link and send it to a friend. Share goals with chosen people, hand tasks to each other and send a “Well done”. Personal quizzes and answers stay private.
Goal ideas from the assistant
Not sure where to start? The assistant suggests goals based on your tasks and results, and you accept or hide each one.
A ready-made prompt with context
One tap copies a ready request: what to do, why, by what method and what happened last time. Paste it into Claude or ChatGPT and carry on.
Any goal: language, work, product, health, money
The path is built for your field, language and deadline. Task texts are always in your language.
Connect Claude or ChatGPT in a couple of minutes
The app doesn’t replace Claude or ChatGPT; it gives them a memory of your goals and a place to ask questions. Connecting takes a couple of minutes and is done once.
Create an account and your first goal
Describe what you want in one sentence.
Add the 42day connector
In Claude or ChatGPT, add a custom connector with the server address and sign in with the same email and password. No tokens to copy.
Say “Next in 42day”
The assistant will build the path and send a quiz to the app.
// Connector address (MCP) https://mcp.42day.app/mcp // What you tell the assistant “Next in 42day” // What it does on its own get_product_state → get_next_step → quiz in the app → tasks → step complete
You need an assistant that can connect custom MCP connectors. Availability depends on your plan and the version of Claude or ChatGPT.
Start free, no subscription
You only need the paid pass when you have more than three active goals. It’s one-time: no auto-renewal.
Free
- 3 active goals, the rest on pause
- Quizzes, tasks, XP, skills, achievements
- 42-day cycle and charge
- Web and Android
42-day pass
- No limit on active goals for 42 days
- Afterwards you can take another 42 days or not
- Your data and achievements stay whatever you choose
- Everything from the free plan
420-day pack
- 10 passes of 42 days
- You save $28: $0.10 a day instead of $0.17
- One-time, no subscription or auto-renewal
- Everything from the free plan
Friends
- A personal invite link
- Shared goals with chosen friends
- Hand tasks to each other
- A “Well done” in one tap
What’s ready and what’s coming
Core and friends
Goals, stages, steps, quizzes, tasks with a trigger and a 2-minute version, skills, XP, charge, a 42-day cycle with a fresh start, priorities and pause, achievements, goal ideas, friends with shared goals and tasks, plan management through the assistant.
Payments
Connecting payments for the 42-day pass ($7) and the 420-day pack ($42). There is no in-app payment yet: the pass is enabled manually, so write to support@42day.app.
Marketplace of paths
Paths that other people have already completed, adapted for you. The author anonymizes the path and earns a share of sales.
Your data stays yours
Quizzes and answers are private
Only you and your assistant see them. Friends see only what you shared: goal progress and their own tasks, but not answers.
You can delete everything
A goal, or the whole account with all its data, can be deleted in the app. Details in the instructions.
Honest rewards
XP and achievements only for real actions. The result of a task is recorded in the user’s own words, with no swapping of the outcome.
Frequently asked questions about 42day
What is 42day?
42day is an app for achieving goals. You name a goal, your AI assistant (Claude, ChatGPT or another one that supports MCP) builds a route of stages, steps and tasks, and the app shows what to do today, reschedules tasks with one tap and collects your answers to short quizzes. A cycle lasts 42 days.
Who is 42day for?
For people who need not a to-do list but a clear path to a goal: learning a language, finding a job, launching a product, buying an apartment, getting healthier, preparing to move. You need an assistant that can connect custom connectors (MCP).
How is 42day different from an ordinary to-do list?
You fill in a list yourself. Here the path is written by an assistant that knows your goals and past results, and each task comes with an explanation of why it matters, how to do it and a 2-minute version. Overdue items don’t pile up: whatever isn’t done can be rescheduled or simplified.
Why does a cycle last 42 days?
42 days is a convenient horizon for getting a goal moving: long enough for a visible result and short enough not to lose interest. It is not a promise to form a habit in 42 days: habits usually take longer. After a cycle you can start the next one with a fresh start, from Monday or from the first of the month.
How much does 42day cost?
The free plan includes up to three active goals, quizzes, tasks, XP, skills and achievements. The 42-day pass costs $7 one-time, with no subscription or auto-renewal; afterwards you can take another one or not. The 420-day pack costs $42 instead of $70: 40% off, a saving of $28. Friends and sharing goals and tasks are free.
Do I need a Claude or ChatGPT subscription?
You need an assistant that can connect custom connectors (MCP). Availability depends on the plan and version of the assistant, so check it on your side first. Connecting takes a couple of minutes, once: you add the connector with the server address and sign in with the same email and password.
How do I connect 42day to ChatGPT or Claude?
Create an account on 42day.app, then in your assistant’s settings add a custom connector with the address https://mcp.42day.app/mcp and sign in with your account. After that tell the assistant “Next in 42day”: it will build the path and send a quiz to the app.
What happens if I miss a day?
The first missed day is forgiven. After that your charge drops: it shows how much the goal has “cooled down”, and comes back with one light task. XP, levels and achievements are never taken away, and while a goal is paused the charge doesn’t drop. In that case the assistant will say “It happens” and suggest a smaller step.
Why doesn’t the assistant ask questions in chat?
That’s by design: all questions arrive as short quizzes in the app, one per screen. Answers are saved and the assistant doesn’t ask the same thing twice. It’s also handy on free versions of assistants, where messages are limited.
Can I work on several goals at once?
Yes. Rank your goals by importance and pause the extras. From all your goals the app builds today’s tasks by goal importance. The free plan allows up to three active goals.
How do friends work in 42day?
Copy your link on the “Friends” tab and send it to a friend. When they open the link and sign in to 42day, you become friends: you can share goals with chosen people, hand tasks to each other and send a short “Well done”. Personal quizzes and answers stay private. Friends are free.
Where do achievements come from?
The assistant invents them for your real actions and awards them only on proof from your report. No more than two per step, and legendary ones only for a real-world result.
Where is my data stored and how do I delete it?
Data is stored on the 42day server. A goal or the whole account can be deleted in the app; details are in the privacy policy and in the account deletion instructions.
Ready to reach your goal?
Free, in the browser and on Android. The first step takes five minutes: name your goal, connect the assistant and find out what to do today.
Open 42day →