Why this is needed
When a computer connects to an Android phone over ADB, it proves its identity with a private key. The first time, the phone asks “Allow USB debugging?” and remembers the computer’s public key. Phone farm boards have no screen to tap, so they only accept the key of the computer the seller or a previous tool used — typically the one stored next to CXT Group Control, Total Control or adb on that PC.
First: try the built-in keys
PhoneFarm tries the public keys that box sellers publish (such as the CXT authorization file) automatically. Plug the box in and add the phones; if they go online, you are done. You only need the steps below when your seller uses a private key.
1. Find the adbkey file
| Computer | Location |
|---|---|
| Windows | C:\Users\<your name>\.android\adbkey |
| macOS | ~/.android/adbkey — in Finder press ⌘⇧G and type ~/.android |
| Linux | ~/.android/adbkey |
There are two files: adbkey (private) and adbkey.pub (public). You need adbkey, the one without “.pub”. Some box sellers include it on a USB stick or in the download that came with the box — the manual often calls it the “ADB authorization file”.
2. Import it in PhoneFarm
- Open PhoneFarm and click ADB key & access in the sidebar.
- Drop the
adbkeyfile on the drop zone, or click it to choose the file. - PhoneFarm checks the key and reconnects your phones. Boards that trusted the old computer now trust this browser too.
The key is stored only in this browser’s local storage and is used only to sign the ADB handshake with your own phones. It is never uploaded. Remove it at any time from the same dialog.
No key? Authorize the boards once
If you don’t have the original key, ask the box seller for the “ADB authorization file” — most include it. Otherwise each board must approve PhoneFarm once: boards with a display connector or a screen show the prompt when PhoneFarm connects; tap “Always allow from this computer”. After that the board remembers PhoneFarm’s own key.
Keep a backup
Copy your adbkey to a safe place. If you lose it and reset your browser, screenless boards won’t connect until they’re authorized again.
Ready? Open PhoneFarm — or try the 40-phone demo first.