Set up the phone
The phone is the line. It needs Android 11 or newer, a SIM that can make calls, and the OpenLine app. Use a spare phone if you can: the app becomes its default phone app.
Setup steps in the app
Section titled “Setup steps in the app”- Default phone app. Lets the app place, answer and end calls.
- Connect to your gateway. Scan the QR code from the console’s Connection page. The app
exchanges the one-time code for its own credentials and connects to
wss://<public address>/v1/device-channel. - Call audio. A one-time pairing with Android’s Wireless debugging. The app uses it to start a small helper with the permissions needed to capture and play call audio, so no root or PC is needed. Tap Set up, turn on Wireless debugging, tap Pair device with pairing code, and type the 6-digit code into the app’s notification.
- Stay online in the background. Allow the app to ignore battery optimisation. On Vivo, also set Battery → Background power consumption → Allow for OpenLine.
Wi-Fi and mobile data
Section titled “Wi-Fi and mobile data”Android only runs Wireless debugging while the phone is connected to a Wi-Fi network. The call-audio helper is started through it, so:
- The first start needs Wi-Fi (any network, including another phone’s hotspot). The app shows a Connect to a Wi-Fi network prompt when it needs it.
- On that first start the app also switches Android’s debugging to a mode that works on any network. After that, calls and call audio work on mobile data until the phone restarts.
- After a reboot, connect to Wi-Fi once more.
The connection to the server itself works on any network, and the app reconnects by itself when the phone switches between Wi-Fi and mobile data.
Silent by design
Section titled “Silent by design”During calls the phone puts the call in “audio processing” mode: the caller hears your agent, your agent hears the caller, and nothing plays through the phone’s speaker or earpiece.
Health
Section titled “Health”The console’s Connection page shows, for each phone: online state, response time, network,
signal and carrier, battery, and whether call audio is ready. The same data is in
GET /v1/devices under health and latencyMs.
Vendor notes
Section titled “Vendor notes”Call audio depends on Android behaviour that differs between manufacturers. It’s tested on a Vivo V40 with Android 16. Other phones may need tweaks; check Troubleshooting.