Your eSIM as an agent backhaul: the Agent Relay Hub
The Agent Relay turns your LTE.app eSIM into a private message channel that any automation tool, AI agent, or script can reach β with push notifications the instant a message arrives.
By LTE.app Editorial Team
Your eSIM as a private agent backhaul
Most people think of an eSIM as a replacement for a physical SIM card. That's true β but the Agent Relay turns your LTE.app eSIM into something more unusual: a private, always-on message channel that any automation tool, AI agent, or script in the world can reach.
What is the Agent Relay?
Every LTE.app device gets two private endpoints β a webhook URL and an MQTT topic β both tied to your anonymous device ID. Your anon ID is long, random, and unguessable. It acts as your write token. No account, no API key, no OAuth dance required.
The relay uses DTN (Delay-Tolerant Networking) queuing. Messages sent while you're on a flight, underground, or off-grid don't disappear β they're stored and delivered the moment your connection returns.
Send messages from anything
The simplest integration is a single line:
`
curl -X POST https://lte.app/api/relay/anon_YOUR_ID/message \
-H "Content-Type: application/json" \
-d '{"text": "Server deployed successfully", "agent": "ci-bot"}'
`
From there, the integrations expand quickly:
- IFTTT / Zapier β connect any trigger (calendar event, weather alert, stock price, smart home sensor) to a Webhooks action pointed at your relay URL
- Amazon Alexa β say "trigger send LTE message: the laundry is done" and it appears in your inbox
- Google Home β same pattern via IFTTT's Google Assistant trigger
- Home Assistant β add a REST Command service in your automations YAML and trigger it from any rule
- iOS Shortcuts β tap "Open Shortcuts" in the app; your webhook URL is already on the clipboard, ready to paste
Inside the app, each integration has a setup guide that shows you the exact JSON body to use β with a one-tap copy button so there's nothing to guess.
Push notifications β no polling needed
When a message lands in your relay, LTE.app sends a push notification instantly. You don't need to open the app to check. This makes the relay useful for time-sensitive alerts: a CI pipeline finishing, a smart home sensor firing, a price drop you've been waiting for.
The relay respects your notification preferences. If you'd rather not be interrupted, turn off Relay Alerts in Settings β Notifications.
Your inbox
The inbox is built for quick triage:
- Source badges β every message shows a colour-coded pill (IFTTT, Home Assistant, Alexa, mqtt, your own script) so you can tell at a glance where it came from
- Time-ago timestamps β "2m ago", "1h ago" rather than raw datetimes
- Expandable messages β long messages collapse to two lines; tap to read the full text
- Swipe to delete β swipe left on any message to remove it immediately
- Clear all β one tap wipes the whole inbox
- Pull to refresh β pull down any time to check for new messages
Test it in seconds
Tap Send test in the relay endpoints card. A test message lands in your inbox within seconds β and you'll get a push notification β confirming the full pipeline (webhook β backend β FCM β your device) is working.
Completely anonymous
The relay is built on LTE.app's privacy-first design. Your anon ID is never tied to an email address or name. Messages exist only for inbox delivery β nothing is sold, indexed, or shared. There is no login, no tracking, no profile.
Try it now
Open LTE.app β Relay tab. Your webhook URL and MQTT topic are ready. Pick an integration that fits your workflow, tap the setup guide, and send your first message.
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