MSC Support

MSCs (Matrix Spec Changes) are proposals to extend or modify the Matrix protocol. This page tracks the implementation status of notable MSCs in Zendrite.

Many MSCs listed here have since been merged into the Matrix specification proper. They are listed by their original MSC number and the first spec version which includes them.

Sync

MSC	Title	Spec	Status
MSC4186	Simplified Sliding Sync	N/A	Implemented (native, no proxy needed)
MSC3575	Sliding Sync (v1)	N/A	Implemented (legacy, superseded by MSC4186)

Messaging

MSC	Title	Spec	Status
MSC2675	Serverside aggregations of message relationships	1.3	Implemented
MSC2676	Message editing	1.4	Implemented
MSC2677	Reactions	1.7	Implemented
MSC2836	Threading	N/A	Opt-in (`msc2836`)
MSC2285	Private read receipts	1.4	Implemented

Rooms & Spaces

MSC	Title	Spec	Status
MSC1772	Spaces	1.2	Implemented
MSC2946	Spaces summary / room hierarchy	1.2	Implemented
MSC3083	Restricted rooms (space-based membership)	1.2	Implemented
MSC2403	Knocking	1.1	Implemented
MSC3266	Room summary API	1.15	Implemented
MSC3765	Rich text in room topics	1.15	Not implemented
MSC4267	Forget room on leave (`m.forget_forced_upon_leave` capability)	1.18	Implemented (opt-in via `auto_forget_on_leave`)

Encryption & Security

MSC	Title	Spec	Status
MSC3916	Authenticated media	1.11	Implemented
MSC2732	OLM fallback keys	1.2	Implemented
MSC3814	Dehydrated devices v2	N/A	Opt-in (`msc3814`)
MSC4115	Membership metadata on events	1.11	Opt-in (`msc4115`)

Federation

MSC	Title	Spec	Status
MSC3706	Partial state in `/send_join` (faster joins)	1.6	Implemented
MSC2444	Peeking over federation	N/A	Opt-in (`msc2444`)
MSC2753	Peeking via `/sync`	N/A	Opt-in (`msc2753`)

Authentication

MSC	Title	Spec	Status
MSC2918	Refresh tokens	1.3	Implemented
MSC3861	Next-gen auth (OIDC)	1.15	Opt-in (`msc3861`)

VoIP

MSC	Title	Spec	Status
MSC4143	MatrixRTC transport discovery	N/A	Implemented

Opt-in MSCs

The following MSCs are not enabled by default and must be activated in the mscs section of the config file:

mscs:
  mscs:
    - msc2836
    - msc2444
    - msc2753
    - msc3814
    - msc3861
    - msc4115

MSC3814: Dehydrated Devices v2

MSC3814 allows clients to store a “dehydrated” device on the server so that encrypted to-device messages (e.g. key shares) can be delivered while the user is offline. When the user signs in again, the client rehydrates the device and retrieves messages it missed.

What changes when MSC3814 is enabled:

PUT /_matrix/client/unstable/org.matrix.msc3814.v1/dehydrated_device — store a dehydrated device with its keys.
GET /_matrix/client/unstable/org.matrix.msc3814.v1/dehydrated_device — retrieve the current dehydrated device metadata.
DELETE /_matrix/client/unstable/org.matrix.msc3814.v1/dehydrated_device — remove the dehydrated device.
POST /_matrix/client/unstable/org.matrix.msc3814.v1/dehydrated_device/{deviceID}/events — retrieve to-device events addressed to the dehydrated device.

Configuration:

mscs:
  mscs:
    - msc3814

No additional configuration is needed beyond enabling the MSC.

MSC3861: OIDC Delegated Authentication

MSC3861 delegates authentication to an external OpenID Connect (OIDC) provider such as Matrix Authentication Service (MAS). When enabled, Zendrite validates access tokens via OAuth 2.0 token introspection instead of managing passwords directly, and provisions accounts and devices on demand.

This changes the behaviour of a large part of the client-server API: password login and registration are disabled, session management moves to the provider, and clients without native OIDC support go through a legacy SSO compatibility layer.

Configuration:

mscs:
  mscs:
    - msc3861
  msc3861:
    issuer: "https://auth.example.com/"
    client_id: "0000000000000000000ZENDRITE"
    client_secret: "secret"

See Delegated authentication (OIDC) for the full setup guide, the complete configuration reference, client support, account provisioning rules, migration caveats and troubleshooting.