End-user documentation


When a user joins an IRC channel on an IRC server (see Join an IRC channel), biboumi connects to the remote IRC server, sets the user’s nick as requested, and then tries to join the specified channel. If the same user subsequently tries to connect to an other channel on the same server, the same IRC connection is used. If, however, an other user wants to join an IRC channel on that same IRC server, biboumi opens a new connection to that server. Biboumi connects once to each IRC servner, for each user on it.

Additionally, if one user is using more than one clients (with the same bare JID), they can join the same IRC channel (on the same server) behind one single nickname. Biboumi will forward all the messages (the channel ones and the private ones) and the presences to all the resources behind that nick. There is no need to have multiple nicknames and multiple connections to be able to take part in a conversation (or idle) in a channel from a mobile client while the desktop client is still connected, for example.


If you use a biboumi that you have no control on: remember that the administrator of the gateway you use is able to view all your IRC conversations, whether you’re using encryption or not. This is exactly as if you were running your IRC client on someone else’s server. Only use biboumi if you trust its administrator (or, better, if you are the administrator) or if you don’t intend to have any private conversation.


IRC entities are represented by XMPP JIDs. The domain part of the JID is the domain served by biboumi (the part after the @, biboumi.example.com in the examples), and the local part (the part before the @) depends on the concerned entity.

IRC channels and IRC users have a local part formed like this: name % irc_server.

name can be a channel name or an user nickname. The distinction between the two is based on the first character: by default, if the name starts with '#' or '&' (but this can be overridden by the server, using the ISUPPORT extension) then it’s a channel name, otherwise this is a nickname.

There is two ways to address an IRC user, using a local part like this: nickname % irc_server or by using the in-room address of the participant, like this: channel_name % irc_server @ biboumi.example.com / Nickname

The second JID is available only to be compatible with XMPP clients when the user wants to send a private message to the participant Nickname in the room channel_name%irc_server@biboumi.example.com.

On XMPP, the node part of the JID can only be lowercase. On the other hand, IRC nicknames are case-insensitive, this means that the nicknames toto, Toto, tOtO and TOTO all represent the same IRC user. This means you can talk to the user toto, and this will work.

Also note that some IRC nicknames or channels may contain characters that are not allowed in the local part of a JID (for example ‘@’). If you need to send a message to a nick containing such a character, you can use a jid like %irc.example.com@biboumi.example.com/AnnoyingNickn@me, because the JID AnnoyingNickn@me%irc.example.com@biboumi.example.com would not work. This “weird” JID is just using the fact that you can send a private message through any room (even a room with an empty name) because, on IRC, a query does not go through any room at all, it’s just server-wide. So, sending a message to #doesnotexist%irc@biboumi/User is exactly the same as sending one to %irc@biboumi/User.

And if you need to address a channel that contains such invalid characters, you have to use jid-escaping, and replace each of these characters with their escaped version, for example to join the channel #b@byfoot, you need to use the following JID: #b\40byfoot%irc.example.com@biboumi.example.com.


  • #foo%irc.example.com@biboumi.example.com is the #foo IRC channel, on the irc.example.com IRC server, and this is served by the biboumi instance on biboumi.example.com

  • toto%irc.example.com@biboumi.example.com is the IRC user named toto, or TotO, etc.

  • irc.example.com@biboumi.example.com is the IRC server irc.example.com.

Note: Some JIDs are valid but make no sense in the context of biboumi:

  • #test%@biboumi.example.com, or any other JID that does not contain an IRC server is invalid. Any message to that kind of JID will trigger an error, or will be ignored.

If compiled with Libidn, an IRC channel participant has a bare JID representing the “hostname” provided by the IRC server. This JID can only be used to set IRC modes (for example to ban a user based on its IP), or to identify user. It cannot be used to contact that user using biboumi.

Join an IRC channel

To join an IRC channel #foo on the IRC server irc.example.com, join the XMPP MUC #foo%irc.example.com@biboumi.example.com.

Connect to an IRC server

The connection to the IRC server is automatically made when the user tries to join any channel on that IRC server. The connection is closed whenever the last channel on that server is left by the user.


You can add some JIDs provided by biboumi into your own roster, to receive presence from them. Biboumi will always automatically accept your requests.

Biboumi’s JID

By adding the component JID into your roster, the user will receive an available presence whenever it is started, and an unavailable presence whenever it is being shutdown. This is useful to quickly view if that biboumi instance is started or not.

IRC server JID

These presence will appear online in the user’s roster whenever they are connected to that IRC server (see Connect to an IRC server for more details). This is useful to keep track of which server an user is connected to: this is sometimes hard to remember, when they have many clients, or if they are using persistent channels.

Channel messages

On XMPP, unlike on IRC, the displayed order of the messages is the same for all participants of a MUC. Biboumi can not however provide this feature, as it cannot know whether the IRC server has received and forwarded the messages to other users. This means that the order of the messages displayed in your XMPP client may not be the same as the order on other IRC users’.


Public channel messages are saved into archives, inside the database, unless the record_history option is set to false by that user (see Ad-hoc commands). Private messages (messages that are sent directly to a nickname, not a channel) are never stored in the database.

A channel history can be retrieved by using Message archive management (MAM) on the channel JID. The results can be filtered by start and end dates.

When a channel is joined, if the client doesn’t specify any limit, biboumi sends the max_history_length last messages found in the database as the MUC history. If a client wants to only use MAM for the archives (because it’s more convenient and powerful), it should request to receive no history by using an attribute maxchars=’0’ or maxstanzas=’0’ as defined in XEP 0045, and do a proper MAM request instead.

Note: the maxchars attribute is ignored unless its value is exactly 0. Supporting it properly would be very hard and would introduce a lot of complexity for almost no benefit.

For a given channel, each user has her or his own archive. The content of the archives are never shared, and thus a user can not use someone else’s archive to get the messages that they didn’t receive when they were offline. Although this feature would be very convenient, this would introduce a very important privacy issue: for example if a biboumi gateway is used by two users, by querying the archive one user would be able to know whether or not the other user was in a room at a given time.

List channels

You can list the IRC channels on a given IRC server by sending an XMPP disco items request on the IRC server JID. The number of channels on some servers is huge so the result stanza may be very big, unless your client supports result set management (XEP 0059)


On IRC, nicknames are server-wide. This means that one user only has one single nickname at one given time on all the channels of a server. This is different from XMPP where a user can have a different nick on each MUC, even if these MUCs are on the same server.

This means that the nick you choose when joining your first IRC channel on a given IRC server will be your nickname in all other channels that you join on that same IRC server.

If you explicitely change your nickname on one channel, your nickname will be changed on all channels on the same server as well. Joining a new channel with a different nick, however, will not change your nick. The provided nick will be ignored, in order to avoid changing your nick on the whole server by mistake. If you want to have a different nickname in the channel you’re going to join, you need to do it explicitly with the NICK command before joining the channel.


There are multiple different ways to authenticate to an IRC service. The most commonly used is to send some command with your password to some special user on the server, often called NickServ. This can be done manually by talking to this user in private and sending the appropriate messages, or this can be done automatically using the `After-connection IRC commands`_. The biggest issue with this method is that you need to first be connected and logged (nick and username selected) to the server before you can start this authentication method, and this often creates a race condition if you need to be authenticated before joining a channel.

A new method has been introduced to improve this: SASL authentication. You just need to configure your password into the “Sasl password” field of the IRC server, and biboumi will automatically authenticate when you connect to that server. If the authentication fails, the connection to the server is aborted. To fix this, check the error message and fix your nick and/or password, or remove your password entirely (empty that field) if you don’t want to use SASL at all.

Private messages

Private messages are handled differently on IRC and on XMPP. On IRC, you talk directly to one server-user: toto on the channel #foo is the same user as toto on the channel #bar (as long as these two channels are on the same IRC server). By default you will receive private messages from the “global” user (aka nickname%irc.example.com@biboumi.example.com), unless you previously sent a message to an in-room participant (something like #test%irc.example.com@biboumi.example.com/nickname), in which case future messages from that same user will be received from that same “in-room” JID.


Notices are received exactly like private messages. It is not possible to send a notice.


The topic can be set and retrieved seemlessly. The unique difference is that if an XMPP user tries to set a multiline topic, every line return (\n) will be replaced by a space, because the IRC server wouldn’t accept it.


If the invited JID is a user JID served by this biboumi instance, it will forward the invitation to the target nick, over IRC. Otherwise, the mediated instance will directly be sent to the invited JID, over XMPP.

Example: if the user wishes to invite the IRC user “FooBar” into a room, they can invite one of the following “JIDs” (one of them is not a JID, actually):

(Note that the “anything” parts are simply ignored because they carry no additional meaning for biboumi: we already know which IRC server is targeted using the JID of the target channel.)

Otherwise, any valid JID can be used, to invite any XMPP user.

Kicks and bans

Kicks are transparently translated from one protocol to another. However banning an XMPP participant has no effect. To ban an user you need to set a mode +b on that user nick or host (see IRC modes) and then kick it.


On XMPP, the encoding is always UTF-8, whereas on IRC the encoding of each message can be anything.

This means that biboumi has to convert everything coming from IRC into UTF-8 without knowing the encoding of the received messages. To do so, it checks if each message is UTF-8 valid, if not it tries to convert from iso_8859-1 (because this appears to be the most common case, at least on the channels I visit) to UTF-8. If that conversion fails at some point, a placeholder character '�' is inserted to indicate this decoding error.

Messages are always sent in UTF-8 over IRC, no conversion is done in that direction.

IRC modes

One feature that doesn’t exist on XMPP but does on IRC is the modes. Although some of these modes have a correspondance in the XMPP world (for example the +o mode on a user corresponds to the moderator role in XMPP), it is impossible to map all these modes to an XMPP feature. To circumvent this problem, biboumi provides a raw notification when modes are changed, and lets the user change the modes directly.

To change modes, simply send a message starting with “/mode” followed by the modes and the arguments you want to send to the IRC server. For example “/mode +aho louiz”. Note that your XMPP client may interprete messages begining with “/” like a command. To actually send a message starting with a slash, you may need to start your message with “//mode” or “/say /mode”, depending on your client.

When a mode is changed, the user is notified by a message coming from the MUC bare JID, looking like “Mode #foo [+ov] [toto tutu]”. In addition, if the mode change can be translated to an XMPP feature, the user will be notified of this XMPP event as well. For example if a mode “+o toto” is received, then toto’s role will be changed to moderator. The mapping between IRC modes and XMPP features is as follow:


Sets the participant’s role to moderator and its affiliation to owner.


Sets the participant’s role to moderator and its affiliation to owner.


Sets the participant’s role to moderator and its affiliation to admin.


Sets the participant’s role to moderator and its affiliation to member.


Sets the participant’s role to participant and its affiliation to member.

Similarly, when a biboumi user changes some participant’s affiliation or role, biboumi translates that in an IRC mode change.

Affiliation set to none

Sets mode to -vhoaq

Affiliation set to member

Sets mode to +v-hoaq

Role set to moderator

Sets mode to +h-oaq

Affiliation set to admin

Sets mode to +o-aq

Affiliation set to owner

Sets mode to +a-q

Ad-hoc commands

Biboumi supports a few ad-hoc commands, as described in the XEP 0050. Different ad-hoc commands are available for each JID type.

On the gateway itself


For example on the JID biboumi.example.com


Just respond “pong”


Provide a form, where the user enters their name, and biboumi responds with a nice greeting.


Only available to the administrator. The user provides a list of JIDs, and a quit message. All the selected users are disconnected from all the IRC servers to which they were connected, using the provided quit message.


Disconnect a single user from one or more IRC server. The user is immediately disconnected by closing the socket, no message is sent to the IRC server, but the user is of course notified with an XMPP message. The administrator can disconnect any user, while the other users can only disconnect themselves.


Lets each user configure some options that apply globally. The provided configuration form contains these fields:

  • Record History: whether or not history messages should be saved in the database.

  • Max history length: The maximum number of lines in the history that the server is allowed to send when joining a channel.

  • Persistent: Overrides the value specified in each individual channel. If this option is set to true, all channels are persistent, whether or not their specific value is true or false. This option is true by default for everyone if the persistent_by_default configuration option is true, otherwise it’s false. See below for more details on what a persistent channel is.

On a server JID


For example on the JID chat.freenode.org@biboumi.example.com


Lets each user configure some options that applies to the concerned IRC server. The provided configuration form contains these fields:

  • Address: This address (IPv4, IPv6 or hostname) will be used, when biboumi connects to this server. This is a very handy way to have a custom name for a network, and be able to edit the address to use if one endpoint for that server is dead, but continue using the same JID. For example, a user could configure the server “freenode@biboumi.example.com”, set “chat.freenode.net” in its “Address” field, and then they would be able to use “freenode” as the network name forever: if “chat.freenode.net” breaks for some reason, it can be changed to “irc.freenode.org” instead, and the user would not need to change all their bookmarks and settings.

  • Realname: The customized “real name” as it will appear on the user’s whois. This option is not available if biboumi is configured with realname_customization to false.

  • Username: The “user” part in your user@host. This option is not available if biboumi is configured with realname_customization to false.

  • In encoding: The incoming encoding. Any received message that is not proper UTF-8 will be converted from the configured In encoding into UTF-8. If the conversion fails at some point, some characters will be replaced by the placeholders.

  • Out encoding: Currently ignored.

  • After-connection IRC commands: Raw IRC commands that will be sent one by one to the server immediately after the connection has been successful. It can for example be used to identify yourself using NickServ, with a command like this: PRIVMSG NickServ :identify PASSWORD.

  • Ports: The list of TCP ports to use when connecting to this IRC server. This list will be tried in sequence, until the connection succeeds for one of them. The connection made on these ports will not use TLS, the communication will be insecure. The default list contains 6697 and 6670.

  • TLS ports: A second list of ports to try when connecting to the IRC server. The only difference is that TLS will be used if the connection is established on one of these ports. All the ports in this list will be tried before using the other plain-text ports list. To entirely disable any non-TLS connection, just remove all the values from the “normal” ports list. The default list contains 6697.

  • Verify certificate: If set to true (the default value), when connecting on a TLS port, the connection will be aborted if the certificate is not valid (for example if it’s not signed by a known authority, or if the domain name doesn’t match, etc). Set it to false if you want to connect on a server with a self-signed certificate.

  • SHA-1 fingerprint of the TLS certificate to trust: if you know the hash of the certificate that the server is supposed to use, and you only want to accept this one, set its SHA-1 hash in this field.

  • SASL Password: The password to authenticate with your nickname, on that server. Authentication will be tried with the nick that is used when connecting to the server. This is the Nickname_ field if it is set, otherwise it’s simply the nickname specified in the first room you join.

  • Nickname: A nickname that will be used instead of the nickname provided in the initial presence sent to join a channel. This can be used if the user always wants to have the same nickname on a given server, and not have to bother with setting that nick in all the bookmarks on that server. The nickname can still manually be changed with a standard nick change presence.

  • Server password: A password that will be sent just after the connection, in a PASS command. This is usually used in private servers, where you’re only allowed to connect if you have the password. Note that, although this is NOT a password that will be sent to NickServ (or some other authentication service), some server (notably Freenode) use it as if it was sent to NickServ to identify your nickname. See SASL password if you need to authenticate.

  • Throttle limit: specifies a number of messages that can be sent without a limit, before the throttling takes place. When messages are throttled, only one command per second is sent to the server. The default is 10. You can lower this value if you are ever kicked for excess flood. If the value is 0, all messages are throttled. To disable this feature, set it to a negative number, or an empty string.


Returns some information about the IRC server, for the executing user. It lets the user know if they are connected to this server, from what port, with or without TLS, and it gives the list of joined IRC channel, with a detailed list of which resource is in which channel.

On a channel JID


For example on the JID #test%chat.freenode.org@biboumi.example.com


Lets each user configure some options that applies to the concerned IRC channel. Some of these options, if not configured for a specific channel, defaults to the value configured at the IRC server level. For example the encoding can be specified for both the channel and the server. If an encoding is not specified for a channel, the encoding configured in the server applies. The provided configuration form contains these fields:

  • In encoding: see the option with the same name in the server configuration form.

  • Out encoding: Currently ignored.

  • Persistent: If set to true, biboumi will stay in this channel even when all the XMPP resources have left the room. I.e. it will not send a PART command, and will stay idle in the channel until the connection is forcibly closed. If a resource comes back in the room again, and if the archiving of messages is enabled for this room, the client will receive the messages that where sent in this channel. This option can be used to make biboumi act as an IRC bouncer.

  • Record History: whether or not history messages should be saved in the database, for this specific channel. If the value is “unset” (the default), then the value configured globally is used. This option is there, for example, to be able to enable history recording globally while disabling it for a few specific “private” channels.

Raw IRC messages

Biboumi tries to support as many IRC features as possible, but doesn’t handle everything yet (or ever). In order to let the user send any arbitrary IRC message, biboumi forwards any XMPP message received on an IRC Server JID (see Addressing) as a raw command to that IRC server.

For example, to WHOIS the user Foo on the server irc.example.com, a user can send the message “WHOIS Foo” to irc.example.com@biboumi.example.com.

The message will be forwarded as is, without any modification appart from adding \r\n at the end (to make it a valid IRC message). You need to have a little bit of understanding of the IRC protocol to use this feature.