Privacy Policy

Last updated 4 November 2026. Draft — under review.

This policy explains what personal data KerfCraft holds, why, who else handles it, and your rights under UK data protection law (UK GDPR and the Data Protection Act 2018).

Who we are

The controller is Goldealers Ltd (trading as KerfCraft), 11 De Grey Square, De Grey Road, Colchester, CO4 5YQ, company number 07689632, ICO registration number ZB840298. Contact us about your data at hello@kerfcraft.app.

For data protection requests, email hello@kerfcraft.app, or write to Goldealers Ltd (not "KerfCraft", which is a trading name) at 11 De Grey Square, De Grey Road, Colchester, CO4 5YQ.

What we hold

  • Your account: your Google account's email address, the user id Firebase gives you, when you first signed in, and whether you have access or are on the waitlist.
  • Waitlist answers (all optional): your name, your country, the projects you want to build first and anything you tell us about them, whether it's for home or work, how much you want the AI to do (from "I like to draw" to "Autopilot"), and the design tools you use now.
  • Your credit ledger: credit granted, top-ups, the cost of each AI call, and when each happened.
  • Founding Maker invites: the invite, the email address it was sent to, its number, any credit it carried, and when it was redeemed.
  • Rate limits: counts of your recent AI calls, kept only until each time window ends.
  • Product analytics and error reports (PostHog): pages you open in the app, errors the app hits, and for each AI step the model, tokens, cost, time taken and whether it failed, plus any Good/Bad rating you give a reply. Tied to your Firebase user id, never your email address, and never the content of your conversations or designs.
  • Logs: server and error logs (Cloudflare Workers observability), which can include your user id, IP address and details of the request.

We don't hold your designs. Your projects stay in your browser and in the files you save (see "Storage in your browser").

What is sent when you use the AI

When you use the assistant or AI images, we send what the model needs to produce the result: your prompts and messages, the relevant parts of your design, and images (such as a view of your model you ask to restyle). These go through our server to Vercel's AI Gateway and on to a provider that runs the model. Before an AI image is made, your restyle prompt is checked by an AI safety model, which may refuse it. Nothing is decided about you by these checks beyond whether that one image is made.

We don't train AI models, and we tell the AI Gateway to send the assistant's requests and the restyle prompt check only to providers that have agreed not to train on them. AI images go to the image providers below under their own terms. Some providers may keep requests for a limited time, for example to detect abuse.

Who processes it

  • Google (Firebase Authentication): Google sign-in. Google also serves the fonts these pages use (Google Fonts), which means your browser sends it your IP address.
  • Cloudflare: hosting, Workers (our server), the D1 database that holds the data above, and logs.
  • Vercel (AI Gateway): routes AI requests to the model providers and reports their cost.
  • AI model providers, reached through the AI Gateway. By default:
    • OpenAI: the assistant, and high-quality AI images;
    • Anthropic: the assistant, if you pick a Claude model;
    • Black Forest Labs: draft AI images;
    • Topaz Labs: image upscaling, when you ask for it;
    • the restyle prompt check, which uses an OpenAI open-weight model.
    If you pick a different model, your request goes to that model's provider instead, named at the start of the model's id (for example google/… for Google). The AI Gateway can also send a request to another cloud that hosts the same model, such as Amazon Bedrock or Google Vertex AI for Claude models, or to a hosting company for open-weight models. For the assistant and the prompt check, it only uses hosts that have agreed not to train on your requests.
  • PostHog (EU Cloud, Frankfurt): product analytics and error reports, as above.
  • Stripe: payments for top-ups, once they are switched on. Stripe handles your card details; we never see your card number. Stripe also uses payment data for its own fraud prevention and legal obligations, as a separate controller under its privacy policy.

International transfers

Several of these providers are based in the US or process data there. Where the recipient is certified to the UK Extension to the EU–US Data Privacy Framework, we rely on the UK's adequacy regulations for it (the "UK–US data bridge"). Otherwise we rely on the International Data Transfer Agreement or the UK Addendum to the EU standard contractual clauses in the provider's data processing terms. Black Forest Labs is in Germany, which the UK treats as adequate. Ask us for details of the safeguard for any provider.

Why we use it (lawful bases)

  • Contract: to run your account, your credit and the AI features you ask for.
  • Legitimate interests: to keep KerfCraft secure, find and fix errors, understand how the assistant performs and is rated, apply rate limits, check restyle prompts and prevent misuse, and to choose who to invite from the waitlist using your answers. You can object to this (see "Your rights").
  • Legal obligation: to keep payment and accounting records.

You need to give us your email address (through Google sign-in) to have an account. Waitlist answers are optional.

How long we keep it

  • On the waitlist: if you don't accept an invite or sign in for 6 months, we delete your account, your waitlist answers and the invite.
  • Your account: if you don't sign in for 12 months, we delete it, with its credit history and Terms acceptances. Any paid credit has expired by then (it lasts 90 days from your last top-up). If you ever paid, we keep the payment records as below and delete the rest, including your waitlist answers.
  • You can ask us to delete your account at any time.
  • Your sign-in record at Firebase (Google): until you ask us to delete it.
  • Payment records (your top-ups and refunds, the credit history that goes with them, and the Terms you agreed to when paying): 7 years from your last payment, which covers the 6 years from the end of the financial year that HMRC requires.
  • Rate-limit counts: until their time window ends (at most a day).
  • Logs: up to 7 days (Cloudflare Workers Logs).
  • Product analytics and error reports: 30 days (PostHog).

Your rights

You have the right to access your data, correct it, have it deleted, restrict how we use it, and take it with you (portability). You have the right to object to anything we do on the basis of legitimate interests; we'll stop unless we have compelling grounds. Send requests to hello@kerfcraft.app. We will answer within one month.

If you're unhappy with how we've used your data, tell us at hello@kerfcraft.app and we'll acknowledge your complaint within 30 days. You can also complain to the Information Commissioner's Office (ICO) at ico.org.uk.

Storage in your browser

KerfCraft uses no advertising or analytics cookies. Its analytics (PostHog, above) set no cookies and remember nothing about you between visits. Your browser stores:

  • your Firebase sign-in session;
  • your projects, their version history and your model library (IndexedDB);
  • choices you make, such as the last project you opened and your chosen AI model (localStorage).

These are strictly necessary to provide what you ask for, or remember a choice you made, so they don't need your consent. They stay on your device; clearing your browser's data removes them.

Children

Accounts are for adults (18 or over). A younger person may use KerfCraft under a parent's or guardian's account and with their supervision; we don't knowingly create accounts for, or collect sign-up details from, anyone under 18. If you think a child has an account of their own, tell us and we'll delete it.

Changes

We may update this policy. The date at the top shows the latest version. If a change affects how we use data you've already given us, we'll email you before it takes effect.