The Relay Monitor & AppRelay Mobile
Control your computer from your phone: start the local companion server, pair by scanning a QR code over an encrypted connection, manage connected devices, and watch live traffic in the Relay Monitor. The companion also shows run history, sends a push when a run finishes, and holds your signed-in Studio account.
Last updated 2026-07-25
The Relay Monitor is the desktop window behind AppRelay's mobile companion. It puts everything about the connection to AppRelay Mobile in one place: whether the local server is running, the QR code you pair with, which devices have connected, and a live console of every request going back and forth. Think of it as the control room for letting your phone drive builds, runs, and tests on your computer — and, once paired, follow their run history and get a push the moment one finishes.
Opening the Relay Monitor
- The sidebar → Relay Monitor. This is the embedded version; it has an Open in Window button if you'd rather float it.
- The Window menu → Relay Monitor (on macOS, ⌘0).
- Settings → Remote → the Relay Monitor… button.
- The menu bar (macOS) or system tray (Windows) icon.
What you'll see
- Remote Server
- A status pill — Stopped, Starting…, or Running — the address on your network (
host:port), the service it advertises for discovery, uptime, and how many requests it has served. This is where you start or stop the server, reveal and copy the pairing token, and mint a New token. - The pairing QR
- Appears once the server is running, captioned Scan to pair. This is the fast path — see below.
- Devices
- Every device that has connected, each with a status badge (Connected, Active, Disconnected, or Blocked) and quick actions.
- Traffic log
- A live, scrolling console of the requests flowing between the phone and your computer, newest at the bottom, with filters and an auto-scroll toggle.
Pairing a phone
There are two ways to pair. Scanning the QR is the one to use — it carries the address and the security details the typed token can't.
With the QR code (recommended)
- Start the server. Click Start server in the Relay Monitor. The status turns to Running, the address goes live, and the QR appears.
- Open the companion. In AppRelay Mobile, tap Scan QR code and point the camera at the Relay Monitor. (Your phone's system camera works too — the QR is a link the app knows how to open.)
- That's it. The phone fills in the address, verifies your computer's certificate, swaps the code for a real token, and connects — one scan, nothing typed.
By typing the token
If the phone can't scan — no camera access, an awkward angle, a desktop too old to show a QR — pairing by hand still works:
- Reveal the token. Click the eye beside PAIRING TOKEN, or the copy button to put it on the clipboard.
- Enter it on the phone. In AppRelay Mobile, expand or enter manually and fill in Host, Port, and Pairing token, then tap Connect.
How the connection is secured
- The traffic is encrypted
- The server speaks TLS using a self-signed certificate it generates and keeps to itself. Nobody else on the café Wi-Fi can read what your phone and your computer say to each other.
- The phone pins your certificate
- Your phone remembers the exact certificate your computer presented and refuses anything else later — so another machine can't impersonate yours. Pairing by QR is stronger still: the QR carries the certificate's fingerprint, so even the first handshake is checked rather than trusted blindly.
- Guessing is throttled
- A handful of wrong tokens locks that device out for about a minute, so a token can't be brute-forced.
- Rotating the token rotates everything
- New token invalidates the old token and the current QR at once. Paired devices are dropped and must pair again.
Managing connected devices
Each row in the Devices area has actions for the device it represents:
- Logs
- Isolate the traffic log to just that device, so you can watch one phone's activity without noise from the others. The pill reads Showing while the filter is on; clear it to see everything again.
- Disconnect
- Ends the session and returns the device to its pairing screen. It can reconnect on its own — no re-scan needed — so use Block if you want it to stay out.
- Block
- Disconnects the device and refuses it even with a valid token until you Allow it again. Blocks are remembered across restarts.
A phone that backgrounds itself tells your computer it's going, and one that vanishes without saying goodbye — force-quit, flat battery, carried off the network — is cleaned up by an idle sweep. Either way the list reflects what's actually connected rather than growing forever.
The same right-click actions are on the connected-device card in the sidebar, so you don't have to open the Relay Monitor just to disconnect or block a phone.
Reading the traffic log
Every request the phone makes shows up as one line: a timestamp, the HTTP method (color-coded), the path, the response status, how long it took in milliseconds, and the device's address. Lifecycle events — the server starting and stopping, a device pairing — appear inline too. You can filter the stream by device, method, status, or address, toggle auto-scroll, and clear the console at any time.
When pairing won't work
- “Couldn't reach your computer” — on Windows
- Almost always Windows Firewall. Discovery is outbound so the phone finds your PC, then can't open a connection back to it. Go to Settings → Remote and use Allow through Windows Firewall (Windows will ask you to confirm), then try again. The installer normally adds this rule for you.
- “That pairing code has expired”
- The code rotated or was already used. Scan the QR again — it's always showing a live one.
- “That pairing token doesn't match this computer”
- The token was mistyped, or it's from a different machine. Re-copy it from the Relay Monitor.
- “This QR needs a newer version of AppRelay Remote”
- Your desktop is newer than your phone app. Update the companion, then scan again.
- “Too many attempts”
- The lockout. Wait about a minute and try again with the correct token.
- Pairing is refused over an unencrypted server
- Your computer couldn't build its security certificate, so it started without encryption and the phone won't pair. Reinstalling AppRelay restores the certificate.
Beyond pairing: the AppRelay Mobile app
Once your phone is paired, the companion is more than a pairing screen — it's a window on the work happening on your computer, plus your AppRelay account in your pocket.
- Drive and watch
- Kick off a build, run, or test, deploy, and roll back — with the log streaming live to the phone, exactly as it appears on the desktop.
- Run history
- Browse recent runs from the phone — each marked succeeded or failed, with its phases — whether it was started here or straight from your computer.
- Push notifications
- When a build, run, or test finishes on your computer, it can push a notification to your paired phone — even when the app is closed — that opens straight to that run. (Like driving your computer, finished-run alerts are part of the AppRelay Studio experience.)
Tucked behind the account icon is an optional, free AppRelay Studio sign-in — the same account as studio.apprelay.io, on your phone. Sign in to see your Licenses (keys, renewals, and seats), the Computers a license is activated on, your open Support tickets and replies, and the Help Center. It's never required to pair or to drive your computer — see Your AppRelay account & the Studio dashboard.
Next steps
- Running, debugging & the Test Console — what the phone is driving
- Your AppRelay account & the Studio dashboard — licenses, computers & tickets
- Pricing & licensing — the Studio unlock this needs
- Security & privacy — the full trust model