Phone connection

What you can do on your phone

On a phone connected to your PC, you can:

• View the projects and session list of the connected PC
• View and type into in-app terminals
• Read Switcher chats, send messages, and respond to approval requests
• Open new sessions, resume past sessions, and rename or archive sessions
• Change per-project tool, connection, and model settings
• View usage statistics across multiple PCs

Creating multiple accounts for a tool and starting sign-in for those accounts can only be done on the PC.

Choosing a phone app

Web app

Open https://app.switchboard.twentyoz.kr in your phone's browser. You can use it right away without installing anything. To keep it like an app, use Add to Home screen in the browser menu.

Android app

1. On the download page, choose the Android tab and download Agent-Switchboard-Android-<version>.apk.
2. Open the downloaded file to install it. If the browser or file app asks for permission to install, allow it.

If you previously installed an APK built with a different signature, the new APK cannot be installed over it. In that case, uninstall the existing app, install the new APK, and then connect to your PC and sign in with Google again.

Turning on phone connection on the PC

Phone connection is off by default.

1. On the PC, open 환경 설정 › 휴대폰 (Settings › Phone).
2. Turn on 휴대폰 연결 켜기 (Turn on phone connection).

When it is on, the PC only makes outbound connections to the relay server. No ports are opened on the PC. If the PC cannot use the operating system's secure storage, phone connection cannot be turned on.

Method 1: QR code

This method works without a Google account.

1. On the PC, go to 환경 설정 › 휴대폰 › 새 휴대폰 연결 (Settings › Phone › Connect a new phone) and click 연결 QR 만들기 (Create connection QR). A QR code can be created only after the PC is connected to the relay server.
2. In the phone app, go to PC 연결 (Connect PC), tap QR 코드 스캔 (Scan QR code), and scan the QR code on the PC screen. If you cannot use the camera, click 주소 복사 (Copy address) on the PC and use 연결 링크 붙여넣기 (Paste connection link) on the phone.
3. A 6-digit number appears on the phone. Confirm that it matches the number in the approval dialog on the PC, then approve.

A QR code is valid for 5 minutes only and can be used only once. If it has expired or has already been used, create a new one.

Method 2: Google account

If the PC and the phone are signed in to the same Google account, you can connect without a QR code.

1. On the PC, sign in with Google from the account menu at the bottom left or from 내 컴퓨터 (My computers) in the rail. You can also check the status under Google 계정 · PC 목록 동기화 (Google account · PC list sync) in Settings › Phone.
2. On the phone app, sign in with the same Google account.
3. The phone shows the list of PCs for that account, including PCs that are turned off. Tap a PC to connect to it without a QR code.

Choosing whether to accept without approval

Set this under 환경 설정 › 휴대폰 › 대시보드·세션 접근 권한 (Settings › Phone › Dashboard and session access).

• 같은 계정 휴대폰·웹 자동 허용 (Automatically allow phones and web on the same account): When on, a new phone authenticated with the same Google account connects without number confirmation. When off, you must approve it on the PC the first time it connects.
• 같은 계정 다른 PC 자동 허용 (Automatically allow other PCs on the same account): Sets whether to skip the approval dialog when another PC on the same account opens this PC from My computers in the rail. A connected PC can type into this PC's terminals. Turn this on only if you use PCs you manage yourself.

Even with automatic approval on, the PC's approval dialog (number confirmation) is required in the following cases:

• When a device that was disconnected or signed out from this PC tries to connect again
• When more than 3 different devices try to register automatically within 1 hour

When a new device on the account connects, you are informed through a PC notification and the activity log.

The PC verifies connections itself

The account server only stores the list of PCs and does not authorize connections. The PC itself verifies the Google sign-in proof sent by the phone. Even if the list on the account server were tampered with, access to the PC's terminals would not be handed over.

Receiving notifications

The Android app can receive notifications for pending approvals, completed tasks, and errors. After registering for notifications in the phone app, turn 작업 완료 알림 (Task completion notifications) on or off for each device under 환경 설정 › 휴대폰 › 연결한 휴대폰 (Settings › Phone › Connected phones) on the PC. Notifications for approval requests, new device connections, and errors are always sent.

The PC encrypts notification content with a per-device key created by the phone before sending it. The relay server and the Apple and Google push services see only the push token and ciphertext. If the phone cannot decrypt a notification, a fixed message, "There is something to check", is shown. Notifications are not sent to devices that currently have the app open and connected.

What the relay server can see

Content between the phone and the PC is end-to-end encrypted. The relay server only forwards ciphertext.

What the server cannot see

• Terminal input and output
• Switcher chat content
• Pairing secrets and session keys
• API keys and OAuth tokens
• Email addresses and Google tokens (received when verifying sign-in, but not stored)

What the server handles

• Connecting IP addresses (for abuse prevention and access logs)
• PC room identifiers (derived from the PC's public key), and the size and timing of encrypted data
• When using a Google account: the account identifier, PC public keys, names, and last connection times, phone device IDs, names, and platforms, and session hashes
• When usage sync is on: encrypted monthly usage bundles

How encryption works

• The one-time secret in the QR code is in the fragment of the address, so it is not sent to the server.
• Both sides create a new session key on every connection. If the relay server tries to intercept, the keys do not match and the connection fails.
• The relay server does not store or accumulate messages.

For details on how data is processed, see the Privacy Policy.

Managing connected devices

Under Settings › Phone › Connected phones, you can do the following for each device:

• 이름 바꾸기 (Rename): Changes the name in this PC's list only.
• 연결 끊기 (Disconnect): Disconnects from this PC only. To connect again, the device must connect anew with a QR code or go through this PC's approval dialog.
• 로그아웃 (Sign out) (devices that joined with a Google account): Signs that phone out of the account and disconnects it from all PCs on the same account.
• 모두 끊기 (Disconnect all): Disconnects all phones connected to this PC.

데스크톱 신원을 새로 만들면 (If you create a new desktop identity), all connected phones are disconnected and the desktop fingerprint changes. The PC is also signed out of the Google account.

Combined usage across PCs

When you turn on 여러 PC 사용량 합쳐 보기 (Combine usage across PCs) under Settings › Phone, token counts by date, tool, model, and project are encrypted with a key known only to the devices on the account and stored on the account server. Chat content is not uploaded. View the combined totals in the phone's statistics and under 모든 PC (All PCs) in the PC overview.

Stored records remain until you delete them. Delete them with 서버에서 이 PC 기록 지우기 (Delete this PC's records from the server) or 계정 사용량 기록 모두 지우기 (Delete all account usage records).

Self-hosted relay server

Initially, the official relay server and the official phone app address are used. Under 환경 설정 › 휴대폰 › 주소 (Settings › Phone › Addresses), you can switch to a relay server you run yourself (wss:// address) and a phone app you host yourself (https:// address). Clear the fields and save to return to the official addresses. Enter only trusted addresses for the phone app. The app at that address will be able to type into this PC's terminals.

If you cannot connect, see Troubleshooting.