Charlie is a chat app by Little Mesters, made for one person: its owner. It talks to a server the owner runs, and nobody else uses it. This page says what it does with data.
Last updated: 2026-10-05
Charlie asks for the microphone so you can talk instead of typing. - Talking in a chat, and Hands-free. Android's own speech recognition turns your speech into text on the phone, using the on-device recogniser where the phone has one. Charlie sends the server only the text, as a message. It never uploads a recording. On a phone with no on-device recogniser, Android uses its default speech service, which is the phone's, not Charlie's: its privacy terms apply to that audio. - In the car and on calls (test screens). Charlie has experimental test screens for Android Auto and phone calls. They listen through the car's or phone's microphone while you run a test, then measure and play back a short recording on the phone itself. What they heard goes into a log file on the phone. Nothing is sent anywhere unless you tap Export log and share it yourself. - Charlie doesn't record in the background. While a call test runs, Android shows a notification, because the microphone is in use.
The server is run by the owner of the app. It receives, and keeps until it is deleted: - Chat text: your messages and the replies, in threads, with a search index over them. - Attachments: files you attach to a message, stored with that thread. - Push tokens: a notification token for each phone (and each browser, for the web page), so the server can tell you a reply has finished. - The sign-in: the server checks a Cloudflare Access sign-in (Microsoft Azure) that allows only the owner's email address. Cloudflare and Microsoft handle that sign-in under their own terms. - Reply audio cache: when Charlie's voice reads a reply aloud, the audio is kept on the server so replaying it is free. It is stored under a hash, not the text, up to 100 MB, with the least recently played removed first.
Your messages are answered by Claude, run by the server through Anthropic's Claude Code, so message text and attachments go to Anthropic to get a reply, under Anthropic's terms.
Charlie's voice is made by OpenAI's text-to-speech service. When you play a reply aloud in that voice, the server sends OpenAI the spoken text of that reply, and the same for a few short fixed phrases. It does not send your messages, tool output or recordings. OpenAI says API data isn't used to train its models, and may keep abuse-monitoring logs for up to 30 days (OpenAI's data controls). If the voice is off or unavailable, the phone reads the reply in its own voice and nothing goes to OpenAI.
Deleting a thread in the app removes its messages and attachments from the server. Signing out of a phone removes its push token. To have everything deleted, or to ask any question about this page, contact: Little Mesters, privacy@littlemesters.uk. Little Mesters will reply and delete what you ask for.