Privacy

In effect from 16 October 2026

Who is responsible for your data

Will Percey, trading as Moonlight Software, a sole trader, is the controller of the personal data described here. Address: Devenish Grange, Devenish Lane, Ascot, SL5 9QU, United Kingdom. Email: [email protected].

This website

Fonts and icons are served from this site. Optional Google Analytics is described below; rejecting it does not affect access to the site or editor. Our hosting provider may keep standard server logs (IP address, time, page requested, browser) for a short period to keep the site running and secure.

Optional usage analytics and cookies

With your consent, we use Google Analytics 4, provided by Google, to understand which public pages and product features people use and improve Gnomon. Before you accept, we do not load Google's analytics script or send Google analytics requests, including consent-denied pings. The website, web editor and desktop app ask separately.

Analytics records page or screen categories, selected feature actions, the product surface and version, a randomly generated identifier, and technical information such as browser, operating system, screen size and language. Google receives your IP address when your device connects and may derive an approximate location; Google says it discards the IP address before logging it. These records are pseudonymous, not anonymous. We do not send diagram source, document contents, file or project names, local paths, prompts, licence keys, email addresses, or page query strings and fragments.

Advertising storage, ad personalisation, Google Signals and automatic enhanced measurement are disabled. We do not link this property to advertising accounts, set a User ID, or join analytics identifiers between the website, editor and desktop app.

On the website and web editor, the necessary analytics preference is kept in local storage for up to 180 days. Accepting allows Google's _ga and _ga_* first-party cookies, which recognise the consenting browser and its sessions, for up to 180 days. Rejecting sets no analytics cookies. Other local settings, such as your chosen editor theme, remain on your device to provide the features you request.

Use Analytics preferences in the website footer, or the web editor's Settings, to accept or reject later. Withdrawing consent stops analytics and removes analytics cookies. It does not affect processing that took place before withdrawal. Clearing browser storage removes your saved choice, so you may be asked again.

The desktop app asks once on first launch after this feature is installed, in the same prompt that asks about crash reports: crash reports on their own, both together, or neither. Closing the prompt, pressing Escape or choosing Neither saves a refusal of both, and the prompt does not automatically return. You can change the choice in Settings → Privacy. An analytics request that fails or is blocked, including an HTTP 403, disables analytics without retries. Only a deliberate change in Settings can enable it again. Your choice and any consenting installation identifier remain locally until you change the setting or reset the app's data; withdrawing consent removes the analytics identifier.

Google Analytics event and user data retention is set to two months. Aggregated standard reports may be retained longer by Google Analytics. See Google's privacy policy and how Google uses information from sites and apps.

The web editor

The web editor runs entirely in your browser. Files you open stay on your computer, and diagrams are drawn in the browser. Your settings are kept in your browser's local storage, on your device. Nothing you write is sent to us.

One exception you control: the editor can be pointed at a PlantUML server of your choosing. If you set that up, your diagram source goes to that server, under whatever terms it has. It is off unless you turn it on.

The desktop app

The app keeps your files, boards, notes and history on your own computer. It connects out only for the following.

Licence checks

When you activate a licence key, the app sends the key and your computer's name to Lemon Squeezy. The name is there so you can tell your computers apart when moving a licence between them. After that, about once a day, the app sends the key and an identifier for this activation to confirm the subscription is still active. Your 30-day trial is tracked on your computer and nothing about it is sent anywhere.

Update checks

The app checks our website for new versions and downloads them from it. As with any web request, the server sees your IP address, which may appear in its logs.

Crash reports, only if you switch them on

Crash reporting is off by default. The app asks on first launch, where you can choose crash reports on their own, crash reports and analytics together, or neither; closing that window means neither. You can change it afterwards in Settings → Privacy. When it is on, the app sends a report when something goes wrong to Sentry, a crash-reporting service, stored in its EU region. A report contains the error, where in Gnomon's code it happened, the app version, and your operating system and its version. Before anything is sent, the app removes file paths (which can reveal project and client names) and your computer's name, and it never attaches your diagrams or your identity. Sentry is also configured not to store the IP address the report arrives from. Turning the setting off stops reports.

Claude

Gnomon can work with Claude through your own Claude Code installation, on your computer. Anything a Claude session sends to Anthropic is between you and Anthropic, under your agreement with them. Gnomon sends nothing to Anthropic itself.

When you buy

Subscriptions are sold by Lemon Squeezy as merchant of record. It collects your payment details, processes payment, charges tax and sends receipts, under its own privacy policy. We never see your card. We receive your name, email address, country, and the details of your order, subscription and licence activations, which we use to provide your licence, support you, and keep the records the law requires.

When you email us

We use what you send us to answer you, and keep it for as long as that conversation needs.

Why we are allowed to use it

• To provide what you bought or asked for: licence checks, purchases and support.
• Our legitimate interests: update checks, and keeping the site and app secure.
• Your consent: optional usage analytics and crash reports, which you can withdraw using their separate privacy controls.
• Legal obligation: purchase records we must keep for tax.

How long we keep it

Purchase records are kept for as long as UK tax law requires, currently up to six years. Crash reports are deleted automatically by Sentry after its retention period. Support emails are kept for as long as the conversation needs, and then deleted.

Where it goes

Lemon Squeezy is based in the United States, and processing there is covered by appropriate safeguards under UK data protection law. Crash reports are stored in Sentry's EU region. If you accept analytics, Google processes analytics data, including outside the UK. Google describes its applicable transfer safeguards, including the UK Extension to the EU–US Data Privacy Framework and contractual safeguards, in its data transfer frameworks. We do not sell your data. The services described in this policy process it for their stated purposes.

Your rights

You can ask us for a copy of your personal data, to correct it, to delete it, to restrict or object to how we use it, or to have it in a portable form. Email us and we will reply within a month. If you are unhappy with how we handle your data, you can complain to the Information Commissioner's Office at ico.org.uk.

Changes

If this policy changes in a way that matters, we will say so here and, where we can, tell you directly. The date at the top shows when the current version took effect.