How it works
The 30-second version
Map Alerts is a real Telegram client wrapped around a map. You sign into your own Telegram account inside the app, pick a few public channels you already follow, and Map Alerts pulls their messages, ships only the text to our server for analysis, and gets back coordinates so the events show up as pins on your map.
The Telegram session lives on your phone, never on our server. Channel selection lives on your phone, never on our server. The only thing that ever reaches our server is the text of messages from the channels you explicitly added, and it leaves the server again immediately as coordinates.
The data flow, in one picture
1. You log in with your real Telegram account
Map Alerts is a Telegram client. Inside the app, we run TDLib — the same official library Telegram themselves publish for third-party clients. Logging in is the same flow you'd see in Telegram Desktop or any third-party Telegram client:
- You enter your phone number.
- Telegram sends you a code (in the Telegram app or by SMS).
- You enter the code. If you have 2FA, you enter your cloud password.
Everything that comes out of that handshake — the auth token, the chat keys, the list of your chats — lives in TDLib's local database, on your phone, in {App Sandbox}/Documents/tdlib/. None of it is uploaded to our server. We literally have no place to put it: there's no user account, no Telegram-credentials table, nothing.
2. You pick which channels to watch
Inside the app, the Sources tab shows the public channels you've already joined on Telegram. You select up to 3 of them on the free plan, or up to 100 on a paid plan. That's the entire input.
The list of channels you picked is saved locally in the app's database (SwiftData), not on our server. If you uninstall the app, the list disappears with it.
3. What actually reaches our server
When a new message arrives in one of your selected channels, the app forwards just the message body to our server:
- The message text.
- The channel name (so the pin can show its source).
- The post timestamp.
- The author's display name, if the channel exposes one.
That's it. No phone numbers, no contacts, no photos, no archive of your other chats, no analytics. Messages from channels you didn't add never touch our server — the app physically skips them at the point of arrival.
4. What we do with that text
The server reads the text, tries to find a place name, address, neighbourhood or coordinates inside it, picks an emoji and a category, and replies with:
- Latitude / longitude.
- Approximate accuracy radius.
- An emoji and a one-line summary for the pin.
The reply goes straight back to your app. The map renders the pin. The server does not keep the message.
5. What stays on your phone, and for how long
- Telegram session — kept by TDLib until you log out or uninstall.
- Your channel picks — kept until you remove them or uninstall.
- Analyzed events on the map — auto-deleted after 24 hours. The cleanup job runs on launch and periodically; it removes both successfully-located events and messages that we couldn't locate.
6. Why a Telegram login is required at all
The most reasonable question we get is: Why can't I just paste a public channel link, and you read it on your side?
We thought about that for a long time. The blocker is Telegram's own policy:
- Running a server-side Telegram client that joins arbitrary channels on behalf of users isn't something Telegram permits — the bot/client TOS doesn't allow it, and accounts that do this get banned.
- Even if we accepted the ban risk, a single Telegram account has hard limits on how many channels it can join. We'd be back to square one within a few hundred users.
So the practical option that doesn't get us banned is: each user runs their own Telegram session, on their own device. Your TDLib instance, your channels, your messages.
If you have an idea for getting around this in a way Telegram is OK with — we genuinely want to hear it. Drop us a line at help.mapalerts@gmail.com.
7. If you're still nervous, this is what we recommend
Because there's no way for us to prove we don't quietly store anything — any cloud service is, in the end, a trust exercise — we'd rather be honest about it and tell you how to reduce the leap of faith:
- Use a secondary Telegram account. Get a second SIM or a virtual number, log into that account on Telegram, subscribe to the channels you care about from that account, and use it inside Map Alerts. Your primary account stays untouched.
- Add only the channels you need. Map Alerts can only see what you tell it to see. Three channels on the free plan is plenty for most people.
- Log out from inside the app in Account Settings whenever you want — TDLib clears its local session immediately.
- Uninstall if you ever want a hard reset. Everything Map Alerts kept on your phone goes with the app.
8. The disclaimer we'd want to read
We're a small team, and Map Alerts is a paid app. We have an obvious commercial reason not to scrape your data — getting caught would end the business overnight. That's not the same as a mathematical proof, and we're not going to pretend otherwise.
What we can say is in the Privacy Policy: what we collect, what we don't, what's stored where, and how long it lives. If anything on this page contradicts what you see when you actually use the app — please tell us, we'll fix it.