Privacy Policy

For the Twain iOS app and thetwain.app · Last updated 29 August 2026

Twain is local-first. Your journal lives on your phone, not on our servers. We never receive your pages, we cannot read them, and there is no account holding them.

This policy explains what that means precisely: what stays on your device, what leaves it, who receives it, and what you can do about it. It covers the Twain iOS app and the website at thetwain.app.

Who we are

xVentures Global Ltd is the data controller for the personal data described here.

xVentures Global Ltd
Registered in England and Wales, company number 12298947
Registered office: 124 City Road, London, England, EC1V 2NX
Privacy contact: hello@thetwain.app

What stays on your device

Everything that is actually your journal:

The photographs you take of your pages, and the thumbnails made from them
The transcription of each page, and any corrections you make
Tags for people, places and topics, moods, and the lines you choose to keep
Twain's writing about your pages: what it noticed, weekly and monthly notes, stories, your record
Your chats with Twain
The semantic index that makes search work, which is built on your device using Apple's on-device language models

All of it is stored inside the app's own container on your iPhone. None of it is uploaded to us. We hold no copy, no backup, and no account containing it. If your device backs itself up to iCloud, that backup is covered by Apple's terms, not ours.

What leaves your device, and when

Reading handwriting and writing reflections need models that do not fit on a phone. So when you ask Twain to read a page or to answer a question, the material needed for that request is sent to an AI provider, used to answer, and returned. This happens because you asked for it, and only then.

Who	What they receive	Why
Anthropic api.anthropic.com	The photograph of the page you are preserving, and its text, tags and day summaries when Twain is reflecting	To read your handwriting, extract tags and dates, and write Twain's reflections
OpenAI api.openai.com	Text only: day summaries, notes and your chat messages. Never the photograph of a page.	Optional. Only if you choose OpenAI as the voice that writes Twain's reflections. Reading handwriting always stays with Anthropic.
Twain's relay duo-relay.twain-app.workers.dev	The same request as above, passed through	Beta builds only, so testers do not need their own API key. Operated by us on Cloudflare Workers. It adds the API key on the far side and forwards the request. It does not store your pages.
Apple	Place names only, for example "Regent's Canal"	To turn a place you wrote about into a pin on the Atlas. Twain never asks for or uses your device location, which is why the app requests no location permission.
PostHog eu.i.posthog.com	Anonymous product events, for example "a page was preserved". Never journal text.	To know which parts of the app are used. Hosted in the EU. See below.

Your API key. If you use your own Anthropic or OpenAI key, it is held in your device's Keychain and sent only to that provider. We never see it.

Training. These requests are made through the providers' commercial APIs. Anthropic and OpenAI both state that data submitted through their APIs is not used to train their models by default. We do not opt in to any such use, and we do not license, sell or share your journal with anyone.

Analytics

Twain records a small number of anonymous product events, sent directly to PostHog's EU servers by Twain's own code. There is no PostHog SDK in the app, no session replay, no autocapture and no advertising identifier.

Events are types, not text. The event system cannot carry free text, so a journal entry cannot end up in one.
They are attached to a random identifier generated on your device, which is destroyed when you delete the app. It is not linked to your name, email or any account.
We do not track you across other apps or websites, and we do not use this data for advertising.

The website

If you ask for an invite at thetwain.app, we store the email address you type, along with the date and a note of which page you came from. It is kept in a Cloudflare D1 database in the UK/EU, and a notification is sent to us by email through Resend.

We use it for one thing: to tell you when Twain is ready for you. We do not add you to a marketing list, and we do not pass it to anyone else. Ask us at hello@thetwain.app and we will delete it.

The site sets no advertising or analytics cookies, which is why you were not asked to accept any.

Why we are allowed to do this

Under the UK GDPR we rely on:

Performance of a contract, for sending a page to an AI provider so it can be transcribed. That is the service you asked for and the app cannot do it otherwise.
Legitimate interests, for anonymous product analytics and for keeping the service secure and working. Our interest is understanding whether the app functions; the impact on you is minimal because the data is anonymous.
Consent, for the waitlist email, which you give by submitting the form and can withdraw at any time.

How long anything is kept

Your journal: for as long as you keep it. It is on your device and under your control. Deleting the app deletes it.
AI requests: we retain nothing. Providers may retain requests briefly for abuse monitoring under their own policies.
Analytics events: no more than 12 months.
Waitlist email: until Twain launches and we have contacted you, or until you ask us to delete it.

Deleting your data

In the app: Settings has "Erase everything in Twain", which removes every preserved page, transcription, note and chat from the device. Individual pages can be deleted from the entry itself.
Everything at once: delete the app. Because there is no server-side copy, that is a complete deletion. There is no account for us to close.
Waitlist: email hello@thetwain.app.

Your rights

You have the right to ask us for a copy of the personal data we hold about you, to have it corrected or deleted, to object to or restrict how we use it, and to receive it in a portable form. In practice the only personal data we hold is a waitlist email address and anonymous analytics that are not linked to you, so most requests resolve quickly.

Write to hello@thetwain.app. If you are unhappy with our response you can complain to the UK Information Commissioner's Office at ico.org.uk, or to your local supervisory authority in the EEA.

Sending data outside the UK

Anthropic, OpenAI and Resend process data in the United States. Where personal data is involved, those transfers rely on the UK International Data Transfer Addendum and the EU Standard Contractual Clauses in our agreements with them. PostHog data is held in the EU, and Cloudflare stores the waitlist in the UK/EU.

Security

Your journal never leaves your device except for the requests described above, which travel over HTTPS. API keys and beta tokens are stored in the iOS Keychain, not in ordinary storage. The app has no login, so there is no password to be stolen and no server holding your pages to be breached.

Children

Twain is not directed at children. You must be at least 16 to use it, or 13 with the consent of a parent or guardian where local law allows. We do not knowingly collect personal data from children. If you believe a child has provided us with personal data, contact us and we will delete it.

Changes

If we change how Twain handles your data we will update this page and the date at the top. Material changes will be announced in the app before they take effect.

Contact

xVentures Global Ltd, hello@thetwain.app.