Privacy notice

The short version

• We collect what it takes to run your account and the services, and nothing else.
• There are no advertising or analytics trackers, and no marketing email.
• Documents you send to the services are processed and then discarded, not stored.
• We never see or store your card details; Paddle handles payment.
• We do not sell your data or use it to train AI models.

Who is responsible for your data

The controller of your personal data is Qx Quantum Limited, a company registered in England and Wales with company number [COMPANY NUMBER], whose registered office is at [REGISTERED OFFICE ADDRESS]. It provides Halmos Editor's accounts and services and is registered with the Information Commissioner's Office under number [ICO REGISTRATION NUMBER]. For anything on this page, email hermeseditor@qxquantum.com.

When you pay, Paddle.com is our merchant of record and a separate controller of the data it needs to take payment, calculate tax and prevent fraud. Paddle's own privacy notice covers that.

What we collect and why

Your account

Your email address, a password if you choose to set one (stored only as a one-way hash), when you confirmed the address, and records of your sign-in sessions. We need these to create your account and let you sign in: the lawful basis is performing our contract with you.

Organisations and seats

The name of your organisation, who belongs to it and in what role, which seat each person holds, and the email addresses of people invited to join. Invitations name the person who sent them. If you were invited, we received your email address from the person who invited you. Lawful basis: contract.

Paired editors

When you pair the editor on a Mac with your account, we store the device name it reports (usually the computer's name), when it was paired, when it was last used, and the IP address it was last used from. We use them to show you your devices so you can spot one you do not recognise, and to detect a stolen credential. The editor can ask for your account's email address, to show you which account it is signed in to. Lawful basis: contract, and our legitimate interest in keeping accounts secure.

Subscriptions

From Paddle we receive and keep the subscription's status, plan, number of seats, billing period and Paddle's references for the customer, subscription and transactions — not card or bank details. Lawful basis: contract, and our legal obligation to keep financial records.

Documents and requests you send to the services

A document you convert, or a description you give the AI features, is processed to produce your result and then discarded. We record that a request was made, by which seat, when, how large it was and whether it succeeded, and for AI requests how much of the allowance it used, so allowances can be enforced and abuse spotted — not what the request said. Lawful basis: contract.

Security and server logs

Our servers log requests, including IP addresses, and we count requests per address and per seat to limit abuse. Lawful basis: our legitimate interest in keeping the services secure and available.

Email

We send email only about your account and the services: sign-in links, invitations, seat changes, security notices and billing notices. These are part of the service and are not marketing. Lawful basis: contract. Messages wait in a queue on our server for up to 7 days, so a failed delivery can be retried.

What you have to give us

An email address is the only thing you must give us, because it is how you sign in. Everything else is optional or created as you use the services.

Automated decisions

We make no decisions about you by automated means that have legal or similarly significant effects. Two automatic safeguards exist: an editor credential that is used twice is revoked, because that is how a stolen one shows itself, and requests over a rate limit are refused for a short time. If either affects you, email us and a person will look at it.

Cookies

We use two cookies, both strictly necessary, so there is no cookie banner: a session cookie that keeps you signed in and protects forms against forgery, and, if you choose to stay signed in, a cookie that remembers you for up to 14 days. There are no analytics, advertising or third-party cookies, and the site's fonts are served from our own server. Paddle's checkout sets its own cookies when you open it.

Who else handles your data

We use the following providers, each under a contract that restricts them to acting on our instructions:

• Hetzner Online GmbH (Germany) — hosts the servers and the database.
• Postmark (ActiveCampaign, LLC, United States) — delivers our email.
• Anthropic, PBC (United States) — runs the AI models behind the AI features. It receives the text of your AI requests, without your name or email address, and does not use them to train its models.
• Paddle.com (United Kingdom) — sells and bills subscriptions, as an independent controller.

We do not sell personal data or share it with anyone else, except where the law requires us to.

International transfers

Postmark and Anthropic are in the United States. Data sent to them is protected by the UK International Data Transfer Addendum and the EU Standard Contractual Clauses, or by the UK–US data bridge and the EU–US Data Privacy Framework where the provider is certified under them.

How long we keep it

• Account, organisation and seat data: while your account is open, and deleted within 30 days of you asking us to close it.
• Sign-in links: 15 minutes. Email-change links: 7 days. Sign-in sessions: 14 days.
• Invitations: until accepted, revoked or expired, then up to 90 days.
• Paired editors: while paired; a pairing lapses after 30 days unused and 90 days at most. Revoked and expired pairings, with their last IP address, are deleted after 12 months.
• Usage records: 12 months.
• Server logs: 30 days.
• Subscription records: six years after the subscription ends, as UK tax law requires.
• Documents and AI requests: not stored.

Your rights

You have the right to:

• get a copy of the personal data we hold about you;
• have inaccurate data corrected;
• have your data deleted;
• restrict or object to how we use it, where we rely on legitimate interests;
• receive the data you gave us in a portable, machine-readable form.

Email hermeseditor@qxquantum.com from the address on your account. We reply within one month and do not charge. Some records — subscription records in particular — must be kept for the period above even if you ask us to delete them.

You can also complain to the UK Information Commissioner's Office at ico.org.uk, or to the data protection authority where you live in the EU. We would appreciate the chance to put things right first.

Security

All traffic is encrypted in transit. Passwords and editor credentials are stored only as one-way hashes, editor credentials are replaced each time they are used so a stolen one is detected, and staff access is limited to the people who run the service.

Children

The services are not intended for anyone under 16, and we do not knowingly collect data from them.

Changes to this notice

We will post changes here with a new date, and email account holders about any change to what we collect or who we share it with before it takes effect.