@ -19,19 +19,17 @@ To propose a change to the Matrix Spec, see the explanations at
The specification consists of the following parts:
The specification consists of the following parts:
* [Client-Server API ](client-server-api )
* [Client-Server API ](/client-server-api )
* [Server-Server API ](server-server-api )
* [Server-Server API ](/server-server-api )
* [Application Service API ](application-service-api )
* [Application Service API ](/application-service-api )
* [Identity Service API ](identity-service-api )
* [Identity Service API ](/identity-service-api )
* [Push Gateway API ](push-gateway-api )
* [Push Gateway API ](/push-gateway-api )
* [Room Versions ](/rooms )
* [Appendices ](/appendices )
Additionally, this introduction page contains the key baseline
Additionally, this introduction page contains the key baseline
information required to understand the specific APIs, including the
information required to understand the specific APIs, including the
sections on [room versions ](#room-versions ) and [overall
section the [overall architecture ](#architecture ).
architecture](#architecture).
The [Appendices ](/appendices ) contain supplemental information not
specific to one of the above APIs.
The [Matrix Client-Server API Swagger
The [Matrix Client-Server API Swagger
Viewer](https://matrix.org/docs/api/client-server/) is useful for
Viewer](https://matrix.org/docs/api/client-server/) is useful for
@ -426,82 +424,6 @@ Unless otherwise stated, timestamps are measured as milliseconds since
the Unix epoch. Throughout the specification this may be referred to as
the Unix epoch. Throughout the specification this may be referred to as
POSIX, Unix, or just "time in milliseconds".
POSIX, Unix, or just "time in milliseconds".
## Room Versions
Rooms are central to how Matrix operates, and have strict rules for what
is allowed to be contained within them. Rooms can also have various
algorithms that handle different tasks, such as what to do when two or
more events collide in the underlying DAG. To allow rooms to be improved
upon through new algorithms or rules, "room versions" are employed to
manage a set of expectations for each room. New room versions are
assigned as needed.
There is no implicit ordering or hierarchy to room versions, and their
principles are immutable once placed in the specification. Although
there is a recommended set of versions, some rooms may benefit from
features introduced by other versions. Rooms move between different
versions by "upgrading" to the desired version. Due to versions not
being ordered or hierarchical, this means a room can "upgrade" from
version 2 to version 1, if it is so desired.
### Room version grammar
Room versions are used to change properties of rooms that may not be
compatible with other servers. For example, changing the rules for event
authorization would cause older servers to potentially end up in a
split-brain situation due to not understanding the new rules.
A room version is defined as a string of characters which MUST NOT
exceed 32 codepoints in length. Room versions MUST NOT be empty and
SHOULD contain only the characters `a-z` , `0-9` , `.` , and `-` .
Room versions are not intended to be parsed and should be treated as
opaque identifiers. Room versions consisting only of the characters
`0-9` and `.` are reserved for future versions of the Matrix protocol.
The complete grammar for a legal room version is:
room_version = 1*room_version_char
room_version_char = DIGIT
/ %x61-7A ; a-z
/ "-" / "."
Examples of valid room versions are:
- `1` (would be reserved by the Matrix protocol)
- `1.2` (would be reserved by the Matrix protocol)
- `1.2-beta`
- `com.example.version`
### Complete list of room versions
Room versions are divided into two distinct groups: stable and unstable.
Stable room versions may be used by rooms safely. Unstable room versions
are everything else which is either not listed in the specification or
flagged as unstable for some other reason. Versions can switch between
stable and unstable periodically for a variety of reasons, including
discovered security vulnerabilities and age.
Clients should not ask room administrators to upgrade their rooms if the
room is running a stable version. Servers SHOULD use **room version 6** as
the default room version when creating new rooms.
The available room versions are:
- [Version 1 ](/rooms/v1 ) - **Stable** . The current version of most
rooms.
- [Version 2 ](/rooms/v2 ) - **Stable** . Implements State Resolution
Version 2.
- [Version 3 ](/rooms/v3 ) - **Stable** . Introduces events whose IDs
are the event's hash.
- [Version 4 ](/rooms/v4 ) - **Stable** . Builds on v3 by using
URL-safe base64 for event IDs.
- [Version 5 ](/rooms/v5 ) - **Stable** . Introduces enforcement of
signing key validity periods.
- [Version 6 ](/rooms/v6 ) - **Stable** . Alters several
authorization rules for events.
- [Version 7 ](/rooms/v7 ) - **Stable** . Introduces knocking.
## Specification Versions
## Specification Versions
Matrix as a whole is released under a single specification number in the
Matrix as a whole is released under a single specification number in the