How to create your config

Step 1

Create an empty matterbridge.toml file.

Step 2

Choose the protocols you want to bridge below, and copy paste those into your config file.
You can select as many different protocols as you'd like.
In the example we only use 2 protocols.

Section-Discord-(basic)
Section-Gitter-(basic)
Section-Harmony-(basic)
Section-IRC-(basic)
Section-Keybase-(basic)
Section-Matrix-(basic)
Section-Mattermost-(basic) (use this if you don't have SSL/https enabled)
Section-Mattermost-(basic) https
Section-MSteams-(basic)
Section-Mumble-(basic)
Section Nextcloud-Talk-(basic)
Section-RocketChat-(basic)
Section-Sshchat-(basic)
Section-Slack-(basic)
Section-Steam-(basic)
Section-Telegram-(basic)
Section-Twitch-(basic)
Section-VK-(basic)
Section-Whatsapp-(basic)
Section-XMPP-(basic)
Section-Zulip-(basic)

In the example below we want messages from channel #general on discord to be sent to channel 42wim/mygreatproject on gitter.
(and messages from channel 42wim/mygreatproject on gitter to channel #general on discord

Just add below to the config

[discord.mydiscord]
#You can get your token by following the instructions on
#https://github.com/42wim/matterbridge/wiki/Discord-bot-setup
#If you want roles/groups mentions to be shown with names instead of ID, 
#you'll need to give your bot the "Manage Roles" permission.
Token="Yourtokenhere"
Server="yourservername"
RemoteNickFormat="[{PROTOCOL}] <{NICK}> "

[gitter.mygitter]
#You can get your token by going to https://developer.gitter.im/docs/welcome and #
Token="Yourtokenhere"
RemoteNickFormat="[{PROTOCOL}] <{NICK}> "

Step 3

Change the Token and Server keys above to actual working ones

Step 4

Add the gateway configuration to your config file.
Copy paste the config from Gateway-config-(basic)

Step 5

Modify the gateway config matching the protocols you selected above.
For the correct channel=mychannel settings, look at Gateway-config-(channel-rules)
And save your matterbridge.toml file

# this must always be [[gateway]], don't use anything else
[[gateway]]
name="gateway1"
enable=true

[[gateway.inout]]
account="discord.mydiscord"
channel="ID:0118999881999"

[[gateway.inout]]
account="gitter.mygitter"
channel="42wim/mygreatproject"

The .inout key will forward messages in both directions. You can use .in and .out to forward in one direction e.g. from (in) discord to (out) gitter.

Step 6

Full configuration looks now like this:

[discord.mydiscord]
Token="MTk4NjIyNDgzNDcdOTI1MjQ4.Cl2FMZ.ZnCjm1XVW7vRze4b7Cq4se7kKWs-abD"
Server="myserver"
RemoteNickFormat="[{PROTOCOL}] <{NICK}> "

[gitter.mygitter]
Token="319fda1761c6875739a489b6772daf2ace4b95d0"
RemoteNickFormat="[{PROTOCOL}] <{NICK}> "

[[gateway]]
name="gateway1"
enable=true

[[gateway.inout]]
account="discord.mydiscord"
channel="general"

[[gateway.inout]]
account="gitter.mygitter"
channel="42wim/mygreatproject"