This is a Matrix.org Application Service (AS) that bridges SMS messages to Matrix, using a USB 3G modem plugged into a server. Crucially, it only works for one user - obviously, if you only have one 3G modem, it doesn't really make sense to support more than one user...

• an instance of PostgreSQL
• a Huawei USB 3G modem, like the Huawei E3531, or Huawei E169
  • Other models of 3G modem are available. Essentially, if it uses the AT/Hayes command set, and implements a bunch of common commands, it'll probably work.
  • This has been tested working with the Huawei E3531, though.
• a nightly version of Rust; see below for details
• a decent amount of patience ;p

You may also be interested in sms-irc, which is in many ways the successor to this project. This project isn't that maintained at the moment, with work mainly being focused on sms-irc, but PRs and issues are still very much welcome and will receive attention!

Oh, man.

• Firstly, ensure that your 3G modem presents itself as a serial port - usually with a path like /dev/ttyUSBX.
  • Advice is available on the Arch Wiki, and varies from model to model. You might need to do a bit of googling to figure out how to poke your modem into appearing as a serial device, as many appear as mass storage devices with software by default.
  • For the Huawei E3531, try sudo usb_modeswitch -v 12d1 -p 15cd -M '55534243123456780000000000000011062000000100000000000000000000'.
    • If that doesn't work, try changing the 12d1 and 15cd above with whatever VID:PID combo appears next to the device in lsusb.
    • For example, if your device presents itself as a ID 12d1:1506 Huawei Technologies Co., Ltd. Modem/Networkcard when lsusb is run, you'd use -v 12d1 and -p 1506.
    • Again, this stuff is really dependent on your modem. Google is your friend, if the above device didn't work for you!
  • Some modems (like the E3531) present three serial ports: /dev/ttyUSB0-2. You want /dev/ttyUSB2 in this case.
  • Once you've found the device path for your modem, try connecting to it with sudo minicom -D /dev/ttyUSB2 (replacing /dev/ttyUSB2 with the path for your modem if different), and typing AT<Enter>. If you get OK back, you've found the right path!
• Also ensure that the user you're going to run the AS as can read and write to this serial port. (sudo chmod 777 /dev/ttyUSB2 does the job, but is pretty bad security-wise; it's better to configure users and groups correctly.)

• You need the latest nightly version of Rust installed; check out their install page. If you install with rustup, change the default configuration when prompted to install the nightly toolchain.
  • NB: As of 2018-05-24, this project only works with rustc 1.27.0-nightly (e5f80f2a4 2018-05-09) - override your toolchain to use that nightly!
  • This can be done with $ rustup override set nightly-2018-05-10.
• Build the project with cargo build.
• Then, install diesel_cli with cargo install diesel_cli.

• Run DATABASE_URL=[url] diesel migration run, substituting [url] for your database URL (e.g. postgresql://localhost/database).

• Replace the placeholders in sms-registration.yaml with sane values (for the tokens and id, generate some random crap, but make sure all of the values are different; for the URL, put the URL of where you're going to put your matrix-appservice-sms instance).
• Copy this somewhere (usually /etc/synapse) readable by synapse.
• Edit app_service_config_files in your synapse homeserver.yaml, and add the path to your sms-registration.yaml file. e.g.:

app_service_config_files: ["/etc/synapse/sms-registration.yaml"]

• (Hold off on restarting synapse for now; we want to make sure that the AS is reachable first.)

• Replace the placeholders in Rocket.example.toml, following the guidance therein, and rename it to Rocket.toml.
• Run the AS with cargo run.
• Now, restart synapse.

• Invite @_sms_bot:[your HS] to a 1-1 chat.
• Issue !sms [phone number] in that chatroom to start texting! (You'll get invited to a private chat with that phone number.) Make sure the number is in international format (e.g. +440123456789) for best results.

• Yell at me on Matrix, then: @eta:theta.eu.org.

• This is GPLv3-licensed software.