#ReflectionIRCd

ReflectionIRCd is an IRCd that bridges Matrix, allowing you to use an IRC client to chat on Matrix from any homeserver. See the support matrix (pun intended) for what it can do. The issue tracker is here: https://todo.sr.ht/~emerson/reflectionircd

#Why?

This is for people who want to use their existing IRC client to talk on Matrix channels, without needing a working bridge or existing IRC network. I also wanted to use it on all homeservers without needing special privileges. You'll probably always need another Matrix client on hand for doing administrative things, media uploading, and Element-specific things, but it works great for general chatting.

Also, I'm using it as an easy way to develop new IRCv3 features for both clients and servers

#Running

#1. Setup pantalaimon

The best way to run Reflection is using pantalaimon to provide end to end encryption support. You can run Reflection without it by using the access token from an existing Matrix connection, but you will not be able to see encrypted messages.

• Install pantalaimon. When you become sad about the lack of setup documentation, just know that I built this entire thing with a similar lack of documentation.
• Initialize your user by sending a POST request to the /login endpoint, for example curl -XPOST -d '{"type":"m.login.password", "user":"testing", "password":"secret"}' "http://127.0.0.1:8009/_matrix/client/r0/login"
• Save the access_token somewhere
• Verify the device using panctl

#2. Create config

Add a JSON file to configs/, and copy and edit the values from config.example.json:

• serverName is the name of the IRC server
• port is the listening port of the server
• certFile and keyFile are the SSL cert and key for Reflection to use. If you don't have one, self-signed is okay as long as your IRC client can handle it. Store them in the certs/ directory so they don't get in version control.
• lazyLoadLimit is the limit for "lazy load" mode. In lazy load mode, only room members with PL > 0 are shown right away, everyone else is joined once they send an event to the room. This prevents clients crashing or lagging on large rooms.
• syncTimeout is the number of milliseconds to ask the homeserver to hold the sync open. 15000 seems to be the de-facto number.
• lagWarningLimit is the number of milliseconds that will trigger a "Sync is lagging" message to warn of a lagging homeserver. If you run your own HS, setting it to 2000 more than syncTimeout will help you diagnose issues. Larger servers like matrix.org often have a 5-10 second lag time, so increase this to prevent your screen filling with lag warnings.
• mxid is the MXID of your Matrix user
• homeserver is the URL of your homeserver.
• accessToken is the access token to use.
• saslPassword is the SASL password to use when connecting to Reflection

If you're running multiple instances, use multiple config files, i.e. matrix.json or aria.json.

#3. Build and run

Then npm ci, npm run build, and node reflection.js configs/matrix.json (replace matrix.json if you named your config differently). You'll see a message about starting initial sync, and then "Synced to network!". Once it's synced, you can connect with your client, specifying the SASL password you put in the config (SASL username doesn't matter).

#Known issues

• You need to manually verify devices in encrypted rooms using Pantalaimon. You can also use the send-anyways panctl command to send without verifying everyone.
• You can't /join channels. However, if you join a channel via Element (other clients are available), it will auto-join your IRC client to it.
• You can't open a PM to individual users, since a "PM" in Matrix is just another room, and you can't join rooms from IRC.
• There's no IRC equivalent to Spaces (yet). Since they are just regular rooms, they show up in IRC as just regular rooms, however, you can't send messages to them.
• In order to highlight users, you need to prefix their nick with an @, so @emerson: hi. Reflection automatically expands this to the user's MXID, so even though it's annoying, it's needed to stop inadvertent highlights for now.
• Read receipts aren't synced to other clients

#Compatibility

Because Matrix and IRC are open protocols, there's no way for me to test every single implementation, so here's a list of what I test on. If you see a bug in a specific Matrix or IRC client, please join the support channel and report it. If it's a closed instance, please DM/PM me a login and I'll look into it.

#Matrix

Reflection implements features straight from the Client-Server spec, so any homeserver that conforms to the specification will be compatible. I only test Synapse right now, if you know of a Dendrite or Conduit homeserver I can create an account on, let me know!

#IRC

I regularly test on Weechat, Gamja (using Soju), and The Lounge. Any actively maintained IRC client will be able to have basic functionality, although no free IRC clients currently support things like reactions, message editing/deleting, and channel renaming. If you're using multiple clients, it's best to use a bouncer like Soju to connect to Reflection, and then connect your clients to Soju.

#FAQs

#Who is this for?

It's for people who want to use their IRC client to chat on Matrix. It's like Bitlbee or Matterbridge, but focused specifically on IRC <-> Matrix, as well as being a reference server for IRCv3 specifications.

#Why are there different channel prefixes?

Because matrix room names are often long and have characters that IRC channel names can't use, Reflection attempts to find a suitable IRC equivalent

# channels are channels that have a canonical alias to use. & channels are DMs. ! channels are the room IDs of channels whose names can't be converted into IRC-friendly names.

#Why do messages appear out of order?

If you have server-time enabled on your client, you might find messages arriving late or out of order. Similarly, if you're joined to the same channel from different homeservers, you may see messages appear on one several minutes/hours before the other(s). This is called "federation", and is considered a feature of Matrix.

#What does "Sync is lagging" mean?

The matrix sync is set with a timeout of 15 seconds (configurable in milliseconds as the syncTimeout value in the config file). The server is supposed to return an HTTP response after the timeout (if not sooner). If the server doesn't respond after 20 seconds (also configurable as lagWarningLimit), that message is printed to the console to warn you that the homeserver is lagging.

#Why is there a random JSON object in my console?

That means you were sent an event type that I didn't know existed. Please hop into the chat and tell me what the type value is.

#Support channel

#reflectionircd:matrix.org

I'm @emersonveenstra:matrix.org, feel free to ping me in the channel with any questions/bug reports/complaints.

#Feature support

✅ - Implemented
🟨 - Partially implemented, see notes
❌ - Not implemented

(IRCv3) denotes IRC features that might not be available in all clients