Free to use. Here’s how.

Modus Ordo costs nothing to use, with no paid plan and no ads. The one part that can cost money is the AI, and that runs on your own key, so you stay in control of it. Or switch it off.

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The short version

The app: Free
Ads: None
The AI: Your own key, from Anthropic, OpenAI, Google (18+) or OpenRouter (18+)
Who you pay: The provider, for what you use
A usual month: Roughly US$10 to 18, or US$1 to 3 on Lowest cost
Without a key: Still a full planner and notebook

What’s free, and what might cost money

What each part costs
Part	Cost	Notes
The app: Today, Plan, Tasks, Sessions, Goals, Library, Progress	Free	No paid plan, no ads
Your account and everything you store	Free
The preview	Free	No account needed
The AI (the cast’s thinking)	Charged by your AI provider, by use	Paid to them, not to us, at their prices. Roughly US$10 to 18 in a usual month on the defaults, or US$1 to 3 on Lowest cost
Using it with AI off	Free	Planner, tasks, notes and the study timer keep working

Why bring your own key?

The expensive part of an AI app is the AI. Most apps pay for it and pass the cost on as a subscription. Here, the AI is billed to your own key at the provider’s price, with nothing added, so the app itself can stay free.

It also keeps the cast careful. Screens open without calling the AI at all: it only works when something changes, like a new task sheet or a plan that needs repairing. Fewer calls means a smaller bill on your key.

Getting a key, step by step

It takes 10 to 15 minutes, usually with a parent or carer. Do it during setup (it’s step 1, and you can skip it) or any time later in You › AI and spending.

Four steps

Pick a provider: Anthropic, OpenAI, Google or OpenRouter (Google and OpenRouter are 18+ under their terms). If nobody at home has an account with one, start with Anthropic.
At the provider, add US$20 to 25 of credit and leave automatic top-up off. That credit is the most that can be spent.
Set a monthly limit at the provider too, a little above the app’s own US$20, such as US$25.
Make a key, copy it (providers show it only once) and paste it into the app. It’s kept locked away, and you only ever see its last 4 characters.

Your card is entered on the provider’s own website. Modus Ordo never sees it and takes no cut.

Setup, step 1: adding an AI key, or continuing without one — Setup, step 1: the key, the provider and a monthly limit, or Skip for now.

The steps at each provider

Anthropic (Claude): about 10 minutes

Go to platform.claude.com (the Claude Console) and sign in, or make an account with the account holder’s email.
Add credit: Settings › Billing › Buy credits, US$20 to 25. Leave Auto-reload off, so spending stops when the credit runs out.
Set a limit: on the same page, Spend limits › Set limit, about US$25 a month.
Make the key: Settings › API keys › Create key. Name it Modus Ordo, and for Expiration choose Never.
Copy the key straight away. It starts with sk-ant- and is shown only once. Paste it into Modus Ordo.

Anthropic’s terms say the account holder must be 18 or over. Check the provider’s current terms.

OpenAI: about 15 minutes

Go to platform.openai.com and sign up or sign in. It texts a code to a mobile number (not a landline).
Make a project named Modus Ordo: the project menu at the top left, then Create project. Its limit then covers only Modus Ordo.
Add credit: Settings › Billing, US$20 to 25. Switch Auto recharge off: it starts on.
Set a limit: Project settings › Limits › Spend, about US$25 a month, and turn on the hard limit. Without it you only get an alert.
Make the key: the project’s API keys › Create new secret key. Name it Modus Ordo and leave Permissions on All.
Copy the key straight away. It starts with sk-proj- and is shown only once. Paste it into Modus Ordo.

OpenAI’s terms allow under-18s only with a parent’s or guardian’s permission. Check the provider’s current terms.

Google (Gemini), 18+ under Google’s terms: about 15 minutes

Go to aistudio.google.com and sign in with the account holder’s own Google account, not a school one.
Make the key: API keys › Create API key, in a project named Modus Ordo. If it says Unrestricted, choose Add restrictions › Restrict to Gemini API only.
Switch on billing before you use the key: Set up billing on that project and prepay at least US$10. Leave automatic reload off.
Set a limit: Spend › Monthly spend cap › Edit spend cap, about US$25. It takes about 10 minutes to start working.
Copy the key (newer keys start AQ., older ones AIza) and paste it into Modus Ordo.

Google’s terms say the account holder must be 18 or over, so a parent or carer usually holds the account. They also say Google’s free plan can use what’s typed to improve its products, which is why step 3 switches billing on. Check the provider’s current terms.

OpenRouter, 18+ under OpenRouter’s terms: about 10 minutes

Go to openrouter.ai and sign in, or make an account with the account holder’s details.
Add credit: Credits › Add credits, US$20 to 25. A fee of about 5.5% is added each time. Leave auto top-up off.
Make the key: API Keys › Create API Key. Name it Modus Ordo and set its credit limit to about US$25, resetting monthly.
In Settings › Privacy, leave the switches that allow providers that train on your data turned off.
Copy the key straight away. It starts with sk-or-v1- and is shown only once. Paste it into Modus Ordo.

OpenRouter’s terms say account holders must be 18 or over, so a parent or carer usually holds the account. Unused credit can be refunded only within 24 hours of buying it. Check the provider’s current terms.

Capping what it can cost

Three things stop the spending: the credit you add with automatic top-up off, the monthly limit you set at the provider, and Modus Ordo’s own monthly limit, which starts at US$20. At 80% of that, replies get shorter and extras pause; at 97%, only what you ask for runs.

Where the monthly limit lives at each provider
Provider	Monthly limit	Automatic top-up (leave it off)
Anthropic	Settings › Billing › Spend limits › Set limit	Auto-reload, on the Billing page
OpenAI	Project settings › Limits › Spend, with the hard limit on	Auto recharge, in Settings › Billing (it starts on)
Google	AI Studio › Spend › Monthly spend cap › Edit spend cap	Automatic reload, on the Billing page
OpenRouter	The key’s own credit limit, set when you make it	Auto top-up, on the Credits page

Under 18? A parent or carer usually holds the account

Most providers need the account holder to be 18 or over, and adding credit needs a card. These are each provider’s own terms, in short. Check the provider’s current terms before you sign up.

What each provider’s terms say
Provider	Who can hold the account	What happens to what’s typed
Anthropic	18 or over	Its business terms say it may not train its AI on what customers send.
OpenAI	Under 18 only with a parent’s or guardian’s permission	Its terms for this kind of use say what’s sent isn’t used for training. Leave its optional data-sharing program off.
Google	18+ under Google’s terms	Its free plan can use what’s typed to improve Google’s products; the paid plan doesn’t. Switch billing on.
OpenRouter	18+ under OpenRouter’s terms	It doesn’t keep what’s typed unless you opt in. Leave providers that train on your data switched off.

For a parent or carer. In setup, your student chooses “A parent will add it” and sends you a one-time link. It opens a page with the same steps, where you paste the key and set Modus Ordo’s monthly limit. You don’t see your student’s notes, plans or chats, and they don’t see the key or your card. Please don’t send the key in a message or an email.

Taking it away. Delete the key at the provider whenever you like, or let the credit run down. The AI then pauses, and nothing your student made is lost.

With the AI off, it’s still a planner

The app’s own table from setup says exactly what changes without a key.

What a key unlocks, with a key and without one
Part	With a key	Without one
Manager	Chats with you and changes things when you ask	No chat: you change things with buttons
Planner	Builds your week and repairs it when things move	A basic plan from fixed rules
Tutor	Hints, explanations and worked steps in sessions	Sessions run, but with no help in them
Marking	Marks checks, drafts and photos of working	You mark against the answers yourself
Your files	Reads task sheets and sorts everything you drop in	You type dates and topics in yourself

One switch, and the cast can’t touch it

You › AI and spending has Turn AI off. Turning the AI off or back on is in the “never the AI” band: you do it yourself, and the cast can’t change this setting. The same page shows your key, this month’s spending against your limit, and which model does which job.

AI and spending: turn AI on or off, the key, a monthly limit and the provider and models

In this early build

See it for yourself

The preview opens the real app in your browser, on a fictional student’s school week. No account needed, and nothing is saved. When you’re ready, join the beta list and we’ll email you when it starts.