Google Limited-Use Disclosure

Effective date: 17 July 2026 · Castellum

Google API Services User Data Policy — Limited Use compliance

Castellum, provided by Joan Marc Riera (sole trader), trading via riera.co.uk, uses Google APIs to give you an email client for your own Gmail account. Castellum's use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.

Scopes requested and why

• https://www.googleapis.com/auth/gmail.readonly — read your messages and metadata to

display your mailbox, thread conversations, and build the local search index.

• https://www.googleapis.com/auth/gmail.modify — organise your mail: mark read/unread,

label, archive, move, and flag messages, as you direct in the app.

• https://www.googleapis.com/auth/gmail.send — send and reply to messages on your behalf.

Each scope maps directly to a core, user-visible email-client feature. No scope is used for any purpose beyond operating the app on your device.

The four Limited-Use commitments

1. In-app use only. We use Google user data solely to provide and improve the

user-facing features of Castellum. We do not use it for any unrelated purpose.

1. No transfer. We do not transfer Google user data to third parties, except as necessary

to provide or improve the app's features, to comply with applicable law, or as part of a merger/acquisition with your consent. Castellum stores your data locally on your device and, by default, is not sent to us or to any AI provider (AI runs locally via Ollama with a hard egress guard). If you enable the optional, off-by-default cloud-AI mode, the specific content you act on is transferred to a third-party cloud AI provider that you explicitly select and enable in the app solely to provide the in-app feature you requested (e.g. a summary or draft reply), under terms that prohibit using your content to train or improve generalised AI models. We do not transfer Google user data for advertising.

1. No advertising. We do not use Google user data for serving advertisements, including

retargeting, personalised, or interest-based advertising.

1. No human reading. We do not allow humans to read Google user data, unless:

(a) we have your explicit consent to read specific messages (e.g. to debug an issue you report to support); (b) it is necessary for security purposes such as investigating abuse; or (c) it is required to comply with applicable law; or (d) our use is limited to internal operations and the data has been aggregated and anonymised.

Selling data

We do not sell Google user data.

Contact

Questions about this disclosure: info@castellummail.com — Joan Marc Riera (sole trader), trading via riera.co.uk.