A room is a set of events. State events define properties of the room such as name, topic, user rights and visibility. Message events handle content such as text, media and redactions. It can be identified by a room ID or, if set, a room alias.
A room ID can be identified by the sigil
! at the beginning. It's identifier body is made up of 18 random ASCII letters which are automatically generated on room creation.
The domain is the server name of the homeserver that created the room. It is only used to avoid equal identifiers and does not implicate that the room is owned by or even available on this homeserver.
!yNaeAYXXLCFZcXvzXn:matrix.org |\________________/ \_______/ | | | sigil indentifier domain
A room alias can be identified by the sigil
# at the beginning.
It's identifier body is user-defined, case-sensitive and must not exceed 255 bytes, including the sigil and the domain.
#matrix-wiki:matrix.org |\_________/ \_______/ | | | sigil identifier domain
- Version 1: Base version.
- Version 2: Improves State Resolution.
- Version 3: Introduces events whose IDs are the event's hash.
- Version 4: Replaces event IDs with URL-safe event IDs.