Matrix2051

Join Matrix from your favorite IRC client

Matrix2051 (or M51 for short) is an IRC server backed by Matrix. You can also see it as an IRC bouncer that connects to Matrix homeservers instead of IRC servers. In other words:

         IRC client
  (eg. weechat or hexchat)
             |
             |     IRC protocol
             v
         Matrix2051
             |
             |     Matrix protocol
             v
     Your Homeserver
     (eg. matrix.org)

Goals:

Make it easy for IRC users to join Matrix seamlessly
Support existing relay bots, to allows relays that behave better on IRC than existing IRC/Matrix bridges
Bleeding-edge IRCv3 implementation
Very easy to install. This means:
1. as little configuration and database as possible (ideally zero)
2. small set of depenencies.

Non-goals:

Being a hosted service (it would require spam countermeasures, and that's a lot of work).
TLS support (see previous point). Just run it on localhost. If you really need it to be remote, access it via a VPN or a reverse proxy.
Connecting to multiple accounts per IRC connection or to other protocols (à la Bitlbee). This conflicts with goals 1 and 4.
Implementing any features not natively by both protocols (ie. no need for service bots that you interract with using PRIVMSG)

Major features

Registration and password authentication
Joining rooms
Sending and receiving messages (supports formatting, multiline, highlights, replying, reacting to messages)
Partial IRCv3 ChatHistory support; enough for Gamja to work. open chathistory issues
Partial display name support

Shortcomings

Direct chats are shown as regular channels, with random names
Does not "feel" like a real IRC network (yet?)
User IDs and room names are uncomfortably long
Loading the nick list of huge rooms like #matrix:matrix.org overloads some IRC clients
IRC clients without hex color support will see some garbage instead of colors. (Though colored text seems very uncommon on Matrix)
IRC clients without advanced IRCv3 support work miss out on many features: quote replies, reacts, display names.

Screenshot

Two notes on this screenshot:

Message edits are rendered with a fallback, as message edits are not yet supported by IRC,
Replies on IRCCloud are rendered with colored icons, and clicking these icons opens a column showing the whole thread. Other clients may render replies differently.

Usage

Install system dependencies. For example, on Debian: sudo apt install elixir erlang erlang-dev erlang-inets erlang-xmerl
Install Elixir dependencies: mix deps.get
Run tests to make sure everything is working: mix test
Run: mix run matrix2051.exs
Connect a client to localhost:2051, with the following config:
- no SSL/TLS
- SASL username: your full matrix ID (user:homeserver.example.org)
- SASL password: your matrix password

See below for extra instructions to work with web clients.

See INSTALL.md for a more production-oriented guide.

Architecture

matrix2051.exs starts M51.Application, which starts M51.Supervisor, which supervises:
- config.ex: global config agent
- irc_server.ex: a DynamicSupervisor that receives connections from IRC clients.

Every time irc_server.ex receives a connection, it spawns irc_conn/supervisor.ex, which supervises:

irc_conn/state.ex: stores the state of the connection
irc_conn/writer.ex: genserver holding the socket and allowing to write lines to it (and batches of lines in the future)
irc_conn/handler.ex: task busy-waiting on the incoming commands from the reader, answers to the simple ones, and dispatches more complex commands
matrix_client/state.ex: keeps the state of the connection to a Matrix homeserver
matrix_client/client.ex: handles one connection to a Matrix homeserver, as a single user
matrix_client/sender.ex: sends events to the Matrix homeserver and with retries on failure
matrix_client/poller.ex: repeatedly asks the Matrix homeserver for new events (including the initial sync)
irc_conn/reader.ex: task busy-waiting on the incoming lines, and sends them to the handler

Utilities:

matrix/raw_client.ex: low-level Matrix client / thin wrapper around HTTP requests
irc/command.ex: IRC line manipulation, including "downgrading" them for clients that don't support some capabilities.
irc/word_wrap.ex: generic line wrapping
format/: Convert between IRC's formatting and org.matrix.custom.html
matrix_client/chat_history.ex: fetches message history from Matrix, when requested by the IRC client

Questions

Why?

There are many great IRC clients, but I can't find a Matrix client I like. Yet, some communities are moving from IRC to Matrix, so I wrote this so I can join them with a comfortable client.

This is also a way to prototype the latest IRCv3 features easily, and for me to learn the Matrix protocol.

What IRC clients are supported?

In theory, any IRC client should work. In particular, I test it with Gamja, IRCCloud, The Lounge, and WeeChat.

Please open an issue if your client has any issue.

What Matrix homeservers are supported?

In theory, any, as I wrote this by reading the Matrix specs. In practice, this is only tested with Synapse.

A notable exception is registration, which uses a Synapse-specific API as Matrix itself does not specify registration.

Please open an issue if you have any issue with your homeserver (a dummy login/password I can use to connect to it would be appreciated).

Are you planning to support features X, Y, ...?

At the time of writing, if both Matrix and IRC/IRCv3 support them, Matrix2051 likely will. Take a look at the list of open 'enhancement' issues.

A notable exception is direct messages, because Matrix's model differs significantly from IRC's.

Can I connect with a web client?

To connect web clients, you need a websocket gateway. Matrix2051 was tested with KiwiIRC's webircgateway (try this patch if you need to run it on old Go versions).

Here is how you can configure it to connect to Matrix2051 with Gamja:

[fileserving]
enabled = true
webroot = "/path/to/gamja"


[upstream.1]
hostname = "localhost"
port = 2051
tls = false
# Connection timeout in seconds
timeout = 20
# Throttle the lines being written by X per second
throttle = 100
webirc = ""
serverpassword = ""

What's with the name?

This is a reference to xkcd 1782:

I still have a question, how can I contact you?

Join #matrix2051 at irc.interlinked.me. (No I am not eating my own dogfood, I still prefer "native" IRC.)

progval/matrix2051