A bridge lets you read and write your Signal or WhatsApp chats directly in Matrix. This guide shows you how to connect your account. The bridge has to be set up on your Matrix server already. You need your phone with the app in question.
How it works
You control the bridge through a bot, sending it commands as normal chat messages. Your phone stays the main device, and the bridge is simply added as another linked device.
| Service | Bot |
|---|---|
| Signal | @signalbot:example.com |
@whatsappbot:example.com |
Replace example.com with the domain of your Matrix account. If your server uses different names, ask whoever runs it.
Good to know: Signal and WhatsApp are end-to-end encrypted, but the bridge has to decrypt your messages to pass them on. Only connect your account on a server you trust.
Connect Signal
- Start a new chat in Matrix with
@signalbot:example.com. - Send the bot the message
login. It replies with a QR code. - Open Signal on your phone, go to Linked Devices in the settings and add a new device.
- Scan the QR code.
- If Signal asks about transferring your history, either choice is fine. Without a transfer, chats appear once a new message arrives.
- The bot confirms the login.
Connect WhatsApp
- Start a new chat in Matrix with
@whatsappbot:example.com. - Send the bot
login qr. It replies with a QR code. - Open WhatsApp on your phone, go to Linked devices and tap Link a device.
- Scan the QR code. If it expires, just start again.
- The bot confirms the login. About a minute later, your chats appear as new rooms.
Without a camera, for example if you use Matrix on the same phone: Send login phone and then your phone number. The bot gives you an eight-character code. When linking in WhatsApp, tap Link with a phone number instead and enter it.
Important: Open WhatsApp on your phone regularly. If it stays offline for more than two weeks, WhatsApp disconnects all linked devices, including the bridge.
Disconnect
Send the bot list-logins to see your logins. Use logout with the login ID shown to disconnect. help shows all commands.
You can also remove the bridge on your phone under Linked devices.
If it does not work
- The bot does not respond: Check the spelling of the address. If the invite stays unanswered, the bridge is not active on your server or not enabled for your account.
- No chats after logging in: Wait a few minutes. On Signal, without a history transfer, chats appear with the next message.
- WhatsApp asks for a passkey: This affects some accounts. Follow the bot’s instructions or contact whoever runs your server.
- The connection suddenly drops: Check under Linked devices on your phone whether the bridge is still listed, and log in again if it is not.
No bridge yet?
I run Matrix servers with bridges for Signal and WhatsApp in Germany.