From 5b13e1da812d6bc60508b777d0f375b9c38e743c Mon Sep 17 00:00:00 2001
From: "Timo K." <toger5@hotmail.de>
Date: Mon, 5 Oct 2026 10:29:37 +0200
Subject: [PATCH] renames and restructure  - session -> matrixrtc (folder)  -
 move MatrixRtcClient to top level of sdk  - RtcTransport -> Transport  -
 backend -> media-backend

---
 eslint/SdkImportBoundary.js                   | 10 ++--
 sdk/README.md                                 |  2 +-
 sdk/SdkArchitecture.md                        | 48 ++++++++++---------
 sdk/SdkMigration.md                           | 16 +++----
 sdk/index.ts                                  |  8 ++--
 sdk/src/{session => }/MatrixRTCClient.ts      | 39 ++++++++-------
 sdk/src/api.ts                                |  4 +-
 .../HomeserverConnected.test.ts               |  0
 .../HomeserverConnected.ts                    |  0
 .../JsRtcSessionBehaviors.test.ts}            |  4 +-
 .../JsRtcSessionBehaviors.ts}                 |  0
 .../LocalMember.test.ts                       |  5 +-
 sdk/src/{session => matrixrtc}/LocalMember.ts |  2 +-
 .../{session => matrixrtc}/LocalTransport.ts  |  4 +-
 .../MatrixMemberMetadata.test.ts              |  0
 .../MatrixMemberMetadata.ts                   |  0
 sdk/src/{session => matrixrtc}/Members.ts     |  2 +-
 .../TransportAutoDiscovery.test.ts}           | 18 +++----
 .../TransportAutoDiscovery.ts}                |  8 ++--
 .../{session => matrixrtc}/Transports.test.ts |  5 +-
 sdk/src/{session => matrixrtc}/Transports.ts  |  2 +-
 .../joinJsSdkSession.ts                       |  0
 sdk/src/{session => matrixrtc}/status.test.ts |  2 +-
 sdk/src/{session => matrixrtc}/status.ts      |  0
 sdk/src/{backend => media-backend}/api.ts     |  0
 .../livekit/Connection.test.ts                |  0
 .../livekit/Connection.ts                     |  0
 .../livekit/ConnectionFactory.ts              |  0
 .../livekit/ConnectionManager.test.ts         |  0
 .../livekit/ConnectionManager.ts              |  0
 .../livekit/DataChannel.test.ts               |  0
 .../livekit/DataChannel.ts                    |  0
 .../livekit/KeyProvider.ts                    |  0
 .../livekit/LivekitBackend.test.ts            |  0
 .../livekit/LivekitBackend.ts                 |  0
 .../livekit/LivekitMediaTrack.test.ts         |  0
 .../livekit/LivekitMediaTrack.ts              |  0
 .../livekit/LivekitMemberMedia.test.ts        |  0
 .../livekit/LivekitMemberMedia.ts             |  0
 .../livekit/LocalMedia.ts                     |  0
 .../livekit/MatrixKeyProvider.test.ts         |  0
 .../livekit/MatrixKeyProvider.ts              |  0
 .../livekit/Publisher.ts                      |  0
 .../livekit/connectionState.ts                |  0
 .../livekit/livekitOptions.test.ts            |  0
 .../livekit/livekitOptions.ts                 |  0
 .../livekit/openIDSFU.test.ts                 |  0
 .../livekit/openIDSFU.ts                      |  0
 .../livekit/publishOptions.ts                 |  0
 .../livekit/test.ts                           |  0
 sdk/src/utils/displayname.test.ts             |  2 +-
 51 files changed, 96 insertions(+), 85 deletions(-)
 rename sdk/src/{session => }/MatrixRTCClient.ts (90%)
 rename sdk/src/{session => matrixrtc}/HomeserverConnected.test.ts (100%)
 rename sdk/src/{session => matrixrtc}/HomeserverConnected.ts (100%)
 rename sdk/src/{session/SessionBehaviors.test.ts => matrixrtc/JsRtcSessionBehaviors.test.ts} (91%)
 rename sdk/src/{session/SessionBehaviors.ts => matrixrtc/JsRtcSessionBehaviors.ts} (100%)
 rename sdk/src/{session => matrixrtc}/LocalMember.test.ts (98%)
 rename sdk/src/{session => matrixrtc}/LocalMember.ts (99%)
 rename sdk/src/{session => matrixrtc}/LocalTransport.ts (93%)
 rename sdk/src/{session => matrixrtc}/MatrixMemberMetadata.test.ts (100%)
 rename sdk/src/{session => matrixrtc}/MatrixMemberMetadata.ts (100%)
 rename sdk/src/{session => matrixrtc}/Members.ts (97%)
 rename sdk/src/{session/RtcTransportAutoDiscovery.test.ts => matrixrtc/TransportAutoDiscovery.test.ts} (90%)
 rename sdk/src/{session/RtcTransportAutoDiscovery.ts => matrixrtc/TransportAutoDiscovery.ts} (93%)
 rename sdk/src/{session => matrixrtc}/Transports.test.ts (96%)
 rename sdk/src/{session => matrixrtc}/Transports.ts (96%)
 rename sdk/src/{session => matrixrtc}/joinJsSdkSession.ts (100%)
 rename sdk/src/{session => matrixrtc}/status.test.ts (97%)
 rename sdk/src/{session => matrixrtc}/status.ts (100%)
 rename sdk/src/{backend => media-backend}/api.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/Connection.test.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/Connection.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/ConnectionFactory.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/ConnectionManager.test.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/ConnectionManager.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/DataChannel.test.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/DataChannel.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/KeyProvider.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/LivekitBackend.test.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/LivekitBackend.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/LivekitMediaTrack.test.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/LivekitMediaTrack.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/LivekitMemberMedia.test.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/LivekitMemberMedia.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/LocalMedia.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/MatrixKeyProvider.test.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/MatrixKeyProvider.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/Publisher.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/connectionState.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/livekitOptions.test.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/livekitOptions.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/openIDSFU.test.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/openIDSFU.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/publishOptions.ts (100%)
 rename sdk/src/{backend => media-backend}/livekit/test.ts (100%)

diff --git a/eslint/SdkImportBoundary.js b/eslint/SdkImportBoundary.js
index a86ab6196..5586f0ddd 100644
--- a/eslint/SdkImportBoundary.js
+++ b/eslint/SdkImportBoundary.js
@@ -22,8 +22,8 @@ const BANNED_PACKAGES = [
 
 /**
  * Packages only a media backend may import. The session speaks MatrixRTC and
- * sees media through `sdk/src/backend/api.ts`; a backend under
- * `sdk/src/backend/<name>/` is the one place its protocol's library appears.
+ * sees media through `sdk/src/media-backend/api.ts`; a backend under
+ * `sdk/src/media-backend/<name>/` is the one place its protocol's library appears.
  */
 const BACKEND_PACKAGES = ["livekit-client", "@livekit/"];
 
@@ -32,7 +32,7 @@ const BACKEND_PACKAGES = ["livekit-client", "@livekit/"];
  * outside `sdk/` by relative path (that is `src/`, `component/`,
  * `playwright/`) or one of the packages above. The development harness under
  * `sdk/dev/` is a host, not part of the library, and is exempt. Keeps the
- * session free of any one media backend, too: outside `sdk/src/backend/`,
+ * session free of any one media backend, too: outside `sdk/src/media-backend/`,
  * a backend's packages may only be imported for their types, and only in
  * the public API, the errors and the test helpers that have to name them.
  */
@@ -52,7 +52,7 @@ const rule = ESLintUtils.RuleCreator(
       bannedPackage:
         "The SDK must not import '{{specifier}}': a host supplies that, the SDK has no UI.",
       backendPackage:
-        "Only a media backend under sdk/src/backend/ may import '{{specifier}}'; the session sees media through backend/api.ts.",
+        "Only a media backend under sdk/src/media-backend/ may import '{{specifier}}'; the session sees media through media-backend/api.ts.",
     },
     schema: [],
   },
@@ -63,7 +63,7 @@ const rule = ESLintUtils.RuleCreator(
     if (!filename.startsWith(sdkRoot)) return {};
     if (filename.startsWith(resolve(sdkRoot, "dev") + sep)) return {};
     const inBackend = filename.startsWith(
-      resolve(sdkRoot, "src", "backend") + sep,
+      resolve(sdkRoot, "src", "media-backend") + sep,
     );
 
     const matchesPackage = (specifier, pkg) =>
diff --git a/sdk/README.md b/sdk/README.md
index dffdb7fe4..4c59ed632 100644
--- a/sdk/README.md
+++ b/sdk/README.md
@@ -6,7 +6,7 @@ the media of every member, as observables. It has no UI. Element Call's own
 `CallViewModel` is meant to become one consumer of it. The design is in
 [`SdkArchitecture.md`](./SdkArchitecture.md), the migration from the view model
 in [`SdkMigration.md`](./SdkMigration.md). Media goes through one media backend
-behind `MediaBackend`; LiveKit, under `src/backend/livekit/`, is the only one
+behind `MediaBackend`; LiveKit, under `src/media-backend/livekit/`, is the only one
 today and the only place that imports `livekit-client`.
 
 **Status:** first implementation. `createMatrixRTCClient` joins the session, connects to
diff --git a/sdk/SdkArchitecture.md b/sdk/SdkArchitecture.md
index b2ff14db1..4419a3aba 100644
--- a/sdk/SdkArchitecture.md
+++ b/sdk/SdkArchitecture.md
@@ -64,10 +64,10 @@ therefore `Element Call → sdk`, never the reverse. The migration from today's
 The left box is MatrixRTC: who is in the session, with which transport, the
 keys, the delayed leave, and the join state machine. The right box is a media
 backend: whatever carries the media, behind the `MediaBackend` interface in
-`sdk/src/backend/api.ts`. The client is the join of the two: a member exists
+`sdk/src/media-backend/api.ts`. The client is the join of the two: a member exists
 once its membership does, and gets its media once the backend has something
 for that membership on its transport. LiveKit is the one backend today; a
-cascading SFU or full mesh is another folder under `sdk/src/backend/`, handed
+cascading SFU or full mesh is another folder under `sdk/src/media-backend/`, handed
 in through `options.backend`, and nothing in the left box changes.
 
 ### How Element Call uses it
@@ -127,20 +127,20 @@ it, and `leave()` also sends the leave.
 
 ## Vocabulary
 
-| Word              | Meaning here                                                                                                                                                                                      | Elsewhere                                                         |
-| ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------- |
-| client            | a `MatrixRTCClient`: one room, one slot, one local member                                                                                                                                         | `MatrixClient` is always written out                              |
-| membership        | one device's MatrixRTC state event, seen by hosts as `RTCMembership`, the js-sdk `CallMembership` behind it                                                                                       |                                                                   |
-| member            | an `RTCMember`: a membership plus what the SDK derives from it (display name, transport, media)                                                                                                   | Element Call's "matrixLivekitMember"                              |
-| media             | a `MemberMedia`: what a member sends, once it has arrived on its transport. `null` while waiting for media                                                                                        | Element Call's `MediaViewModel` is a view of it                   |
-| track             | a `MediaTrack`: one publication of a member, audio or video, with `source`, `kind`, `id` and the behaviors on it. `LocalAudioMediaTrack` and `LocalVideoMediaTrack` add the controls over our own | LiveKit `TrackPublication` and `Track`, which never leave the SDK |
-| source            | a `MediaSource`: what a track is captured from, `microphone`, `camera`, `screenShare`, `screenShareAudio` or `unknown`. Picked out of `tracks$` with `trackBySource$`                             | LiveKit `Track.Source`                                            |
-| publish request   | a `PublishRequest`: a source, where to capture it from and how to encode it. Given at the join in `LocalMediaInputs.publish`, or later to `publish` on the local member                           |                                                                   |
-| active            | `isActive$` on an audio track: the track carries sound, as the backend measures it. "Speaking" is a call's reading of it on the microphone track                                                  | LiveKit "speaking", `isSpeaking`                                  |
-| attach, detach    | handing a `<video>` or `<audio>` element to a track and taking it back. The SDK owns the stream and the observers on the element                                                                  | LiveKit `Track.attach`                                            |
-| transport         | where media is exchanged: a LiveKit service url today, described by `TransportMetadata`                                                                                                           | MSC4143 "focus"                                                   |
-| media backend     | a `MediaBackend`: what carries the media, behind `sdk/src/backend/api.ts`. One per client, chosen with `options.backend`; LiveKit under `sdk/src/backend/livekit/` is the one that exists         | "SFU", a LiveKit room, a peer connection                          |
-| application, slot | what the session is for (`m.call`) and which one of them in the room (`ROOM`)                                                                                                                     | MSC4143                                                           |
+| Word              | Meaning here                                                                                                                                                                                          | Elsewhere                                                         |
+| ----------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------- |
+| client            | a `MatrixRTCClient`: one room, one slot, one local member                                                                                                                                             | `MatrixClient` is always written out                              |
+| membership        | one device's MatrixRTC state event, seen by hosts as `RTCMembership`, the js-sdk `CallMembership` behind it                                                                                           |                                                                   |
+| member            | an `RTCMember`: a membership plus what the SDK derives from it (display name, transport, media)                                                                                                       | Element Call's "matrixLivekitMember"                              |
+| media             | a `MemberMedia`: what a member sends, once it has arrived on its transport. `null` while waiting for media                                                                                            | Element Call's `MediaViewModel` is a view of it                   |
+| track             | a `MediaTrack`: one publication of a member, audio or video, with `source`, `kind`, `id` and the behaviors on it. `LocalAudioMediaTrack` and `LocalVideoMediaTrack` add the controls over our own     | LiveKit `TrackPublication` and `Track`, which never leave the SDK |
+| source            | a `MediaSource`: what a track is captured from, `microphone`, `camera`, `screenShare`, `screenShareAudio` or `unknown`. Picked out of `tracks$` with `trackBySource$`                                 | LiveKit `Track.Source`                                            |
+| publish request   | a `PublishRequest`: a source, where to capture it from and how to encode it. Given at the join in `LocalMediaInputs.publish`, or later to `publish` on the local member                               |                                                                   |
+| active            | `isActive$` on an audio track: the track carries sound, as the backend measures it. "Speaking" is a call's reading of it on the microphone track                                                      | LiveKit "speaking", `isSpeaking`                                  |
+| attach, detach    | handing a `<video>` or `<audio>` element to a track and taking it back. The SDK owns the stream and the observers on the element                                                                      | LiveKit `Track.attach`                                            |
+| transport         | where media is exchanged: a LiveKit service url today, described by `TransportMetadata`                                                                                                               | MSC4143 "focus"                                                   |
+| media backend     | a `MediaBackend`: what carries the media, behind `sdk/src/media-backend/api.ts`. One per client, chosen with `options.backend`; LiveKit under `sdk/src/media-backend/livekit/` is the one that exists | "SFU", a LiveKit room, a peer connection                          |
+| application, slot | what the session is for (`m.call`) and which one of them in the room (`ROOM`)                                                                                                                         | MSC4143                                                           |
 
 Names use `RTC` in capitals, as the js-sdk does: `MatrixRTCClient`, `RTCMember`,
 `matrixRTCMode`.
@@ -489,10 +489,10 @@ call-specific.
 
 The client speaks MatrixRTC: memberships, the transports named in them, the
 delayed leave, the keys. What carries the media is a backend behind one
-interface, `MediaBackend` in `sdk/src/backend/api.ts`, created once per client.
-LiveKit under `sdk/src/backend/livekit/` is the only backend today, and the only
+interface, `MediaBackend` in `sdk/src/media-backend/api.ts`, created once per client.
+LiveKit under `sdk/src/media-backend/livekit/` is the only backend today, and the only
 place in the SDK that imports `livekit-client`; the import boundary lint rule
-enforces that outside `sdk/src/backend/` the LiveKit packages appear in type
+enforces that outside `sdk/src/media-backend/` the LiveKit packages appear in type
 imports only.
 
 The seam sits above the connection manager on purpose. One connection per
@@ -547,7 +547,7 @@ Every member has media. Today, in Element Call, that media _is_ a `livekit-clien
 participant, handed straight through to the view models. In the SDK the participant
 is wrapped in a `MemberMedia`, so that nothing outside the SDK imports
 `Participant`, `TrackPublication`, `Track` or `TrackReference`. The adapter in
-`sdk/src/media/` is the only place that reads a participant.
+`sdk/src/media-backend/livekit/` is the only place that reads a participant.
 
 ```ts
 export type MediaSource =
@@ -709,10 +709,12 @@ sdk/
   src/errors.ts       MatrixRTCError and its codes
   src/config.ts       MatrixRTCMode, session timings, media quality
   src/encryption.ts   E2eeType, EncryptionSystem
+  src/MatrixRTCClient.ts  createMatrixRTCClient: wires the two folders below
   src/reactive/       Behavior, ObservableScope, the observable operators
-  src/session/        MatrixRTCClient, the local member, publisher, connections,
-                      memberships, transports, discovery, JWT, join
-  src/media/          the LiveKit adapter: MemberMedia and MediaTrack
+  src/matrixrtc/      the MatrixRTC side: the local member, memberships, member
+                      metadata, transports, discovery, status, the js-sdk join
+  src/media-backend/  the MediaBackend interface in api.ts; livekit/ is the one
+                      backend: connections, publisher, JWT, keys, MemberMedia, MediaTrack
   src/utils/          LazyBehavior, mapScoped, network retry, display names, test helpers
   dev/                the harness (below)
   SdkArchitecture.md  this document
diff --git a/sdk/SdkMigration.md b/sdk/SdkMigration.md
index f8537f39a..acebc8eff 100644
--- a/sdk/SdkMigration.md
+++ b/sdk/SdkMigration.md
@@ -8,14 +8,14 @@ symbols, so it ages with the code; the architecture document should not.
 
 ## Status
 
-| Slice                                                                                                                                                                                        | State                |
-| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------- |
-| 1. Scaffold: `sdk/` packaging, the interface, the harness, the smoke test                                                                                                                    | done, October 2026   |
-| 2. First implementation of `createMatrixRTCClient` under `sdk/src`, the media adapter, the e2e suite                                                                                         | done, 1 October 2026 |
-| 3. Copy the shared modules into `sdk/src/` with their tests, drop every `src/` import, turn on the import boundary                                                                           | done, 2 October 2026 |
-| 4. `createCallViewModel$` consumes the client; media view models take `media$`; Element Call imports the primitives and enums from the SDK and deletes its own copies                        | done, 2 October 2026 |
-| 5. `sendData`/`data$` on the client; the legacy bundle `sdk-target-based-on-call-view-model/` is rebuilt on the SDK with its interface unchanged, since it is in production use              | done, 2 October 2026 |
-| 12. The media backend seam: everything LiveKit behind `MediaBackend` in `sdk/src/backend/livekit/`, the `backend` option, the lint guard; see [`MediaBackendPlan.md`](./MediaBackendPlan.md) | done, 4 October 2026 |
+| Slice                                                                                                                                                                                              | State                |
+| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------- |
+| 1. Scaffold: `sdk/` packaging, the interface, the harness, the smoke test                                                                                                                          | done, October 2026   |
+| 2. First implementation of `createMatrixRTCClient` under `sdk/src`, the media adapter, the e2e suite                                                                                               | done, 1 October 2026 |
+| 3. Copy the shared modules into `sdk/src/` with their tests, drop every `src/` import, turn on the import boundary                                                                                 | done, 2 October 2026 |
+| 4. `createCallViewModel$` consumes the client; media view models take `media$`; Element Call imports the primitives and enums from the SDK and deletes its own copies                              | done, 2 October 2026 |
+| 5. `sendData`/`data$` on the client; the legacy bundle `sdk-target-based-on-call-view-model/` is rebuilt on the SDK with its interface unchanged, since it is in production use                    | done, 2 October 2026 |
+| 12. The media backend seam: everything LiveKit behind `MediaBackend` in `sdk/src/media-backend/livekit/`, the `backend` option, the lint guard; see [`MediaBackendPlan.md`](./MediaBackendPlan.md) | done, 4 October 2026 |
 
 Element Call now consumes the SDK. `InCallView` creates the client from the
 configuration, settings and URL parameters, and hands it to `createCallViewModel$`,
diff --git a/sdk/index.ts b/sdk/index.ts
index f42be364d..787f0e2c7 100644
--- a/sdk/index.ts
+++ b/sdk/index.ts
@@ -53,15 +53,15 @@ export {
 } from "./src/errors";
 
 export * from "./src/api";
-export * from "./src/backend/api";
+export * from "./src/media-backend/api";
 export { trackBySource$, type TrackOfSource } from "./src/utils/tracks";
-export { createMatrixRTCClient } from "./src/session/MatrixRTCClient";
+export { createMatrixRTCClient } from "./src/MatrixRTCClient";
 export {
   createLivekitBackend,
   type LivekitBackendOptions,
-} from "./src/backend/livekit/LivekitBackend";
+} from "./src/media-backend/livekit/LivekitBackend";
 // For a developer panel to check a transport url before using it
 export {
   getSFUConfigWithOpenID as authenticateWithTransport,
   type TokenEndpoint,
-} from "./src/backend/livekit/openIDSFU";
+} from "./src/media-backend/livekit/openIDSFU";
diff --git a/sdk/src/session/MatrixRTCClient.ts b/sdk/src/MatrixRTCClient.ts
similarity index 90%
rename from sdk/src/session/MatrixRTCClient.ts
rename to sdk/src/MatrixRTCClient.ts
index 2384b05ef..05c8d468e 100644
--- a/sdk/src/session/MatrixRTCClient.ts
+++ b/sdk/src/MatrixRTCClient.ts
@@ -18,11 +18,11 @@ import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/En
 import { v4 as uuidv4 } from "uuid";
 import { combineLatest, filter, from, fromEvent, map, Observable } from "rxjs";
 
-import { defaultSessionTimings, MatrixRTCMode } from "../config";
-import { E2eeType } from "../encryption";
-import { type ObservableScope } from "../reactive/ObservableScope";
-import { filterBehavior, generateItems } from "../reactive/observable";
-import { mapScoped } from "../utils/mapScoped";
+import { defaultSessionTimings, MatrixRTCMode } from "./config";
+import { E2eeType } from "./encryption";
+import { type ObservableScope } from "./reactive/ObservableScope";
+import { filterBehavior, generateItems } from "./reactive/observable";
+import { mapScoped } from "./utils/mapScoped";
 import {
   type DataMessage,
   type LocalMediaInputs,
@@ -30,33 +30,36 @@ import {
   type MatrixRTCClient,
   type MatrixRTCClientOptions,
   type RemoteRTCMember,
-} from "../api";
+} from "./api";
 import {
   type MediaBackend,
   type MediaBackendContext,
   type MediaKey,
-} from "../backend/api";
-import { createLivekitBackend } from "../backend/livekit/LivekitBackend";
-import { MatrixRTCError } from "../errors";
-import { createHomeserverConnected$ } from "./HomeserverConnected";
-import { joinJsSdkSession } from "./joinJsSdkSession";
-import { createLocalMembership$, type PreparedTransport } from "./LocalMember";
-import { discoverLocalTransport } from "./LocalTransport";
+} from "./media-backend/api";
+import { createLivekitBackend } from "./media-backend/livekit/LivekitBackend";
+import { MatrixRTCError } from "./errors";
+import { createHomeserverConnected$ } from "./matrixrtc/HomeserverConnected";
+import { joinJsSdkSession } from "./matrixrtc/joinJsSdkSession";
+import {
+  createLocalMembership$,
+  type PreparedTransport,
+} from "./matrixrtc/LocalMember";
+import { discoverLocalTransport } from "./matrixrtc/LocalTransport";
 import {
   createMatrixMemberMetadata$,
   createRoomMembers$,
-} from "./MatrixMemberMetadata";
+} from "./matrixrtc/MatrixMemberMetadata";
 import {
   createLocalRTCMember,
   createRemoteRTCMember,
   membershipKeys,
-} from "./Members";
+} from "./matrixrtc/Members";
 import {
   createKeyRotationSuppressed$,
   createMemberships$,
-} from "./SessionBehaviors";
-import { fatalError, sessionStatus } from "./status";
-import { createTransportRegistry } from "./Transports";
+} from "./matrixrtc/JsRtcSessionBehaviors";
+import { fatalError, sessionStatus } from "./matrixrtc/status";
+import { createTransportRegistry } from "./matrixrtc/Transports";
 
 /**
  * Takes the whole `MatrixClient` rather than a slice of it, and finds the
diff --git a/sdk/src/api.ts b/sdk/src/api.ts
index 96bb5f4f2..ac75dcc0e 100644
--- a/sdk/src/api.ts
+++ b/sdk/src/api.ts
@@ -6,7 +6,7 @@ Please see LICENSE in the repository root for full details.
 */
 
 /**
- * The public types of the SDK. `createMatrixRTCClient` in `session/MatrixRTCClient.ts`
+ * The public types of the SDK. `createMatrixRTCClient` in `MatrixRTCClient.ts`
  * is the only way to obtain an implementation of them.
  */
 
@@ -23,7 +23,7 @@ import {
 import { type Observable } from "rxjs";
 
 import { type Behavior } from "./reactive/Behavior";
-import { type MediaBackendFactory } from "./backend/api";
+import { type MediaBackendFactory } from "./media-backend/api";
 import { type EncryptionSystem } from "./encryption";
 import {
   type MatrixRTCMode,
diff --git a/sdk/src/session/HomeserverConnected.test.ts b/sdk/src/matrixrtc/HomeserverConnected.test.ts
similarity index 100%
rename from sdk/src/session/HomeserverConnected.test.ts
rename to sdk/src/matrixrtc/HomeserverConnected.test.ts
diff --git a/sdk/src/session/HomeserverConnected.ts b/sdk/src/matrixrtc/HomeserverConnected.ts
similarity index 100%
rename from sdk/src/session/HomeserverConnected.ts
rename to sdk/src/matrixrtc/HomeserverConnected.ts
diff --git a/sdk/src/session/SessionBehaviors.test.ts b/sdk/src/matrixrtc/JsRtcSessionBehaviors.test.ts
similarity index 91%
rename from sdk/src/session/SessionBehaviors.test.ts
rename to sdk/src/matrixrtc/JsRtcSessionBehaviors.test.ts
index fca24767c..9070ff2a6 100644
--- a/sdk/src/session/SessionBehaviors.test.ts
+++ b/sdk/src/matrixrtc/JsRtcSessionBehaviors.test.ts
@@ -9,10 +9,10 @@ import { describe, expect, it, vi } from "vitest";
 import { MatrixRTCSessionEvent } from "matrix-js-sdk/lib/matrixrtc";
 import { EventEmitter } from "events";
 
-import { createKeyRotationSuppressed$ } from "./SessionBehaviors";
+import { createKeyRotationSuppressed$ } from "./JsRtcSessionBehaviors";
 import { testScope } from "../utils/test";
 
-describe("SessionBehaviors", () => {
+describe("JsRtcSessionBehaviors", () => {
   describe("createKeyRotationSuppressed$", () => {
     it("emits initial value from isKeyRotationSuppressed and updates when KeyRotationSuppressedChanged event is emitted", () => {
       const scope = testScope();
diff --git a/sdk/src/session/SessionBehaviors.ts b/sdk/src/matrixrtc/JsRtcSessionBehaviors.ts
similarity index 100%
rename from sdk/src/session/SessionBehaviors.ts
rename to sdk/src/matrixrtc/JsRtcSessionBehaviors.ts
diff --git a/sdk/src/session/LocalMember.test.ts b/sdk/src/matrixrtc/LocalMember.test.ts
similarity index 98%
rename from sdk/src/session/LocalMember.test.ts
rename to sdk/src/matrixrtc/LocalMember.test.ts
index 826ec9dd3..5a26f87f9 100644
--- a/sdk/src/session/LocalMember.test.ts
+++ b/sdk/src/matrixrtc/LocalMember.test.ts
@@ -12,7 +12,10 @@ import { describe, expect, it, vi } from "vitest";
 
 import { defaultSessionTimings } from "../config";
 import { MatrixRTCError } from "../errors";
-import { type LocalMediaBackend, MediaConnectionState } from "../backend/api";
+import {
+  type LocalMediaBackend,
+  MediaConnectionState,
+} from "../media-backend/api";
 import { type HomeserverConnected } from "./HomeserverConnected";
 import {
   createLocalMembership$,
diff --git a/sdk/src/session/LocalMember.ts b/sdk/src/matrixrtc/LocalMember.ts
similarity index 99%
rename from sdk/src/session/LocalMember.ts
rename to sdk/src/matrixrtc/LocalMember.ts
index 9630376f6..79972acb6 100644
--- a/sdk/src/session/LocalMember.ts
+++ b/sdk/src/matrixrtc/LocalMember.ts
@@ -42,7 +42,7 @@ import {
   type MediaBackend,
   MediaConnectionState,
   type TransportCapabilities,
-} from "../backend/api";
+} from "../media-backend/api";
 import { type HomeserverConnected } from "./HomeserverConnected";
 
 export enum TransportState {
diff --git a/sdk/src/session/LocalTransport.ts b/sdk/src/matrixrtc/LocalTransport.ts
similarity index 93%
rename from sdk/src/session/LocalTransport.ts
rename to sdk/src/matrixrtc/LocalTransport.ts
index 39c041e67..e08f6f023 100644
--- a/sdk/src/session/LocalTransport.ts
+++ b/sdk/src/matrixrtc/LocalTransport.ts
@@ -11,7 +11,7 @@ import { type Transport } from "matrix-js-sdk/lib/matrixrtc";
 
 import { type MatrixRTCClientOptions } from "../api";
 import { MatrixRTCTransportMissingError } from "../errors";
-import { RtcTransportAutoDiscovery } from "./RtcTransportAutoDiscovery";
+import { TransportAutoDiscovery } from "./TransportAutoDiscovery";
 
 /**
  * The transport the local member advertises: the one the host names, else the
@@ -32,7 +32,7 @@ export async function discoverLocalTransport(
 ): Promise<Transport> {
   const transport = transportUrl
     ? { type: "livekit", livekit_service_url: transportUrl }
-    : await new RtcTransportAutoDiscovery({
+    : await new TransportAutoDiscovery({
         client,
         transportType,
         fallbackTransportUrl,
diff --git a/sdk/src/session/MatrixMemberMetadata.test.ts b/sdk/src/matrixrtc/MatrixMemberMetadata.test.ts
similarity index 100%
rename from sdk/src/session/MatrixMemberMetadata.test.ts
rename to sdk/src/matrixrtc/MatrixMemberMetadata.test.ts
diff --git a/sdk/src/session/MatrixMemberMetadata.ts b/sdk/src/matrixrtc/MatrixMemberMetadata.ts
similarity index 100%
rename from sdk/src/session/MatrixMemberMetadata.ts
rename to sdk/src/matrixrtc/MatrixMemberMetadata.ts
diff --git a/sdk/src/session/Members.ts b/sdk/src/matrixrtc/Members.ts
similarity index 97%
rename from sdk/src/session/Members.ts
rename to sdk/src/matrixrtc/Members.ts
index 40716e2aa..f12eb2302 100644
--- a/sdk/src/session/Members.ts
+++ b/sdk/src/matrixrtc/Members.ts
@@ -17,7 +17,7 @@ import {
   type RemoteRTCMember,
   type RTCMember,
 } from "../api";
-import { type LocalMediaBackend } from "../backend/api";
+import { type LocalMediaBackend } from "../media-backend/api";
 import { type TransportRegistry } from "./Transports";
 
 /** What every member is built from, besides its own membership and media. */
diff --git a/sdk/src/session/RtcTransportAutoDiscovery.test.ts b/sdk/src/matrixrtc/TransportAutoDiscovery.test.ts
similarity index 90%
rename from sdk/src/session/RtcTransportAutoDiscovery.test.ts
rename to sdk/src/matrixrtc/TransportAutoDiscovery.test.ts
index f07f00da7..c774a5706 100644
--- a/sdk/src/session/RtcTransportAutoDiscovery.test.ts
+++ b/sdk/src/matrixrtc/TransportAutoDiscovery.test.ts
@@ -21,11 +21,11 @@ import {
 } from "matrix-js-sdk/lib/matrixrtc";
 
 import {
-  RtcTransportAutoDiscovery,
-  type RtcTransportAutoDiscoveryProps,
-} from "./RtcTransportAutoDiscovery.ts";
+  TransportAutoDiscovery,
+  type TransportAutoDiscoveryProps,
+} from "./TransportAutoDiscovery.ts";
 
-type DiscoveryClient = RtcTransportAutoDiscoveryProps["client"];
+type DiscoveryClient = TransportAutoDiscoveryProps["client"];
 
 const backendTransport: LivekitTransport = {
   type: "livekit",
@@ -47,7 +47,7 @@ function makeClient(): MockedObject<DiscoveryClient> {
   } as unknown as MockedObject<DiscoveryClient>;
 }
 
-describe("RtcTransportAutoDiscovery", () => {
+describe("TransportAutoDiscovery", () => {
   beforeEach(() => {
     vi.clearAllMocks();
   });
@@ -62,7 +62,7 @@ describe("RtcTransportAutoDiscovery", () => {
       const client = makeClient();
       client._unstable_getRTCTransports.mockResolvedValue(transports);
 
-      const discovery = new RtcTransportAutoDiscovery({
+      const discovery = new TransportAutoDiscovery({
         client,
         transportType: "livekit",
         fallbackTransportUrl: configTransport.livekit_service_url,
@@ -93,7 +93,7 @@ describe("RtcTransportAutoDiscovery", () => {
       )
       .mockResolvedValue([backendTransport]);
 
-    const discovery = new RtcTransportAutoDiscovery({
+    const discovery = new TransportAutoDiscovery({
       client,
       transportType: "livekit",
       fallbackTransportUrl: "https://config.example.org",
@@ -117,7 +117,7 @@ describe("RtcTransportAutoDiscovery", () => {
       const client = makeClient();
       client._unstable_getRTCTransports.mockResolvedValue(transports);
 
-      const discovery = new RtcTransportAutoDiscovery({
+      const discovery = new TransportAutoDiscovery({
         client,
         transportType: "livekit",
         fallbackTransportUrl: configTransport.livekit_service_url,
@@ -134,7 +134,7 @@ describe("RtcTransportAutoDiscovery", () => {
     const client = makeClient();
     client._unstable_getRTCTransports.mockResolvedValue([]);
 
-    const discovery = new RtcTransportAutoDiscovery({
+    const discovery = new TransportAutoDiscovery({
       client,
       transportType: "livekit",
       fallbackTransportUrl: undefined,
diff --git a/sdk/src/session/RtcTransportAutoDiscovery.ts b/sdk/src/matrixrtc/TransportAutoDiscovery.ts
similarity index 93%
rename from sdk/src/session/RtcTransportAutoDiscovery.ts
rename to sdk/src/matrixrtc/TransportAutoDiscovery.ts
index 00e9c2e70..b278fcfd7 100644
--- a/sdk/src/session/RtcTransportAutoDiscovery.ts
+++ b/sdk/src/matrixrtc/TransportAutoDiscovery.ts
@@ -15,7 +15,7 @@ type TransportDiscoveryClient = Pick<
   "getDomain" | "_unstable_getRTCTransports"
 >;
 
-export interface RtcTransportAutoDiscoveryProps {
+export interface TransportAutoDiscoveryProps {
   client: TransportDiscoveryClient;
   /** The transport type the media backend serves. */
   transportType: string;
@@ -24,7 +24,7 @@ export interface RtcTransportAutoDiscoveryProps {
   logger: Logger;
 }
 
-export class RtcTransportAutoDiscovery {
+export class TransportAutoDiscovery {
   private readonly client: TransportDiscoveryClient;
   private readonly transportType: string;
   private readonly fallbackTransportUrl: string | undefined;
@@ -35,11 +35,11 @@ export class RtcTransportAutoDiscovery {
     transportType,
     fallbackTransportUrl,
     logger,
-  }: RtcTransportAutoDiscoveryProps) {
+  }: TransportAutoDiscoveryProps) {
     this.client = client;
     this.transportType = transportType;
     this.fallbackTransportUrl = fallbackTransportUrl;
-    this.logger = logger.getChild("[RtcTransportAutoDiscovery]");
+    this.logger = logger.getChild("[TransportAutoDiscovery]");
   }
 
   public async discoverPreferredTransport(): Promise<Transport | null> {
diff --git a/sdk/src/session/Transports.test.ts b/sdk/src/matrixrtc/Transports.test.ts
similarity index 96%
rename from sdk/src/session/Transports.test.ts
rename to sdk/src/matrixrtc/Transports.test.ts
index 407b90d7b..dbd17b606 100644
--- a/sdk/src/session/Transports.test.ts
+++ b/sdk/src/matrixrtc/Transports.test.ts
@@ -10,7 +10,10 @@ import { BehaviorSubject } from "rxjs";
 import { describe, expect, it } from "vitest";
 
 import { type ResolvedTransport } from "../api";
-import { type BackendConnection, MediaConnectionState } from "../backend/api";
+import {
+  type BackendConnection,
+  MediaConnectionState,
+} from "../media-backend/api";
 import { testScope } from "../utils/test";
 import { createTransportRegistry, transportId } from "./Transports";
 
diff --git a/sdk/src/session/Transports.ts b/sdk/src/matrixrtc/Transports.ts
similarity index 96%
rename from sdk/src/session/Transports.ts
rename to sdk/src/matrixrtc/Transports.ts
index b81b65716..fbeb839d9 100644
--- a/sdk/src/session/Transports.ts
+++ b/sdk/src/matrixrtc/Transports.ts
@@ -11,7 +11,7 @@ import { distinctUntilChanged, map } from "rxjs";
 import { type Behavior } from "../reactive/Behavior";
 import { type ObservableScope } from "../reactive/ObservableScope";
 import { type TransportMetadata } from "../api";
-import { type MediaBackend, MediaConnectionState } from "../backend/api";
+import { type MediaBackend, MediaConnectionState } from "../media-backend/api";
 
 export interface TransportRegistry {
   /** The one `TransportMetadata` for a transport, however many memberships name it. */
diff --git a/sdk/src/session/joinJsSdkSession.ts b/sdk/src/matrixrtc/joinJsSdkSession.ts
similarity index 100%
rename from sdk/src/session/joinJsSdkSession.ts
rename to sdk/src/matrixrtc/joinJsSdkSession.ts
diff --git a/sdk/src/session/status.test.ts b/sdk/src/matrixrtc/status.test.ts
similarity index 97%
rename from sdk/src/session/status.test.ts
rename to sdk/src/matrixrtc/status.test.ts
index 7edc5bc1d..d6a97ddaf 100644
--- a/sdk/src/session/status.test.ts
+++ b/sdk/src/matrixrtc/status.test.ts
@@ -8,7 +8,7 @@ Please see LICENSE in the repository root for full details.
 import { describe, expect, it } from "vitest";
 import { Status } from "matrix-js-sdk/lib/matrixrtc";
 
-import { MediaConnectionState } from "../backend/api";
+import { MediaConnectionState } from "../media-backend/api";
 import { MatrixRTCError } from "../api";
 import {
   type LocalMemberState,
diff --git a/sdk/src/session/status.ts b/sdk/src/matrixrtc/status.ts
similarity index 100%
rename from sdk/src/session/status.ts
rename to sdk/src/matrixrtc/status.ts
diff --git a/sdk/src/backend/api.ts b/sdk/src/media-backend/api.ts
similarity index 100%
rename from sdk/src/backend/api.ts
rename to sdk/src/media-backend/api.ts
diff --git a/sdk/src/backend/livekit/Connection.test.ts b/sdk/src/media-backend/livekit/Connection.test.ts
similarity index 100%
rename from sdk/src/backend/livekit/Connection.test.ts
rename to sdk/src/media-backend/livekit/Connection.test.ts
diff --git a/sdk/src/backend/livekit/Connection.ts b/sdk/src/media-backend/livekit/Connection.ts
similarity index 100%
rename from sdk/src/backend/livekit/Connection.ts
rename to sdk/src/media-backend/livekit/Connection.ts
diff --git a/sdk/src/backend/livekit/ConnectionFactory.ts b/sdk/src/media-backend/livekit/ConnectionFactory.ts
similarity index 100%
rename from sdk/src/backend/livekit/ConnectionFactory.ts
rename to sdk/src/media-backend/livekit/ConnectionFactory.ts
diff --git a/sdk/src/backend/livekit/ConnectionManager.test.ts b/sdk/src/media-backend/livekit/ConnectionManager.test.ts
similarity index 100%
rename from sdk/src/backend/livekit/ConnectionManager.test.ts
rename to sdk/src/media-backend/livekit/ConnectionManager.test.ts
diff --git a/sdk/src/backend/livekit/ConnectionManager.ts b/sdk/src/media-backend/livekit/ConnectionManager.ts
similarity index 100%
rename from sdk/src/backend/livekit/ConnectionManager.ts
rename to sdk/src/media-backend/livekit/ConnectionManager.ts
diff --git a/sdk/src/backend/livekit/DataChannel.test.ts b/sdk/src/media-backend/livekit/DataChannel.test.ts
similarity index 100%
rename from sdk/src/backend/livekit/DataChannel.test.ts
rename to sdk/src/media-backend/livekit/DataChannel.test.ts
diff --git a/sdk/src/backend/livekit/DataChannel.ts b/sdk/src/media-backend/livekit/DataChannel.ts
similarity index 100%
rename from sdk/src/backend/livekit/DataChannel.ts
rename to sdk/src/media-backend/livekit/DataChannel.ts
diff --git a/sdk/src/backend/livekit/KeyProvider.ts b/sdk/src/media-backend/livekit/KeyProvider.ts
similarity index 100%
rename from sdk/src/backend/livekit/KeyProvider.ts
rename to sdk/src/media-backend/livekit/KeyProvider.ts
diff --git a/sdk/src/backend/livekit/LivekitBackend.test.ts b/sdk/src/media-backend/livekit/LivekitBackend.test.ts
similarity index 100%
rename from sdk/src/backend/livekit/LivekitBackend.test.ts
rename to sdk/src/media-backend/livekit/LivekitBackend.test.ts
diff --git a/sdk/src/backend/livekit/LivekitBackend.ts b/sdk/src/media-backend/livekit/LivekitBackend.ts
similarity index 100%
rename from sdk/src/backend/livekit/LivekitBackend.ts
rename to sdk/src/media-backend/livekit/LivekitBackend.ts
diff --git a/sdk/src/backend/livekit/LivekitMediaTrack.test.ts b/sdk/src/media-backend/livekit/LivekitMediaTrack.test.ts
similarity index 100%
rename from sdk/src/backend/livekit/LivekitMediaTrack.test.ts
rename to sdk/src/media-backend/livekit/LivekitMediaTrack.test.ts
diff --git a/sdk/src/backend/livekit/LivekitMediaTrack.ts b/sdk/src/media-backend/livekit/LivekitMediaTrack.ts
similarity index 100%
rename from sdk/src/backend/livekit/LivekitMediaTrack.ts
rename to sdk/src/media-backend/livekit/LivekitMediaTrack.ts
diff --git a/sdk/src/backend/livekit/LivekitMemberMedia.test.ts b/sdk/src/media-backend/livekit/LivekitMemberMedia.test.ts
similarity index 100%
rename from sdk/src/backend/livekit/LivekitMemberMedia.test.ts
rename to sdk/src/media-backend/livekit/LivekitMemberMedia.test.ts
diff --git a/sdk/src/backend/livekit/LivekitMemberMedia.ts b/sdk/src/media-backend/livekit/LivekitMemberMedia.ts
similarity index 100%
rename from sdk/src/backend/livekit/LivekitMemberMedia.ts
rename to sdk/src/media-backend/livekit/LivekitMemberMedia.ts
diff --git a/sdk/src/backend/livekit/LocalMedia.ts b/sdk/src/media-backend/livekit/LocalMedia.ts
similarity index 100%
rename from sdk/src/backend/livekit/LocalMedia.ts
rename to sdk/src/media-backend/livekit/LocalMedia.ts
diff --git a/sdk/src/backend/livekit/MatrixKeyProvider.test.ts b/sdk/src/media-backend/livekit/MatrixKeyProvider.test.ts
similarity index 100%
rename from sdk/src/backend/livekit/MatrixKeyProvider.test.ts
rename to sdk/src/media-backend/livekit/MatrixKeyProvider.test.ts
diff --git a/sdk/src/backend/livekit/MatrixKeyProvider.ts b/sdk/src/media-backend/livekit/MatrixKeyProvider.ts
similarity index 100%
rename from sdk/src/backend/livekit/MatrixKeyProvider.ts
rename to sdk/src/media-backend/livekit/MatrixKeyProvider.ts
diff --git a/sdk/src/backend/livekit/Publisher.ts b/sdk/src/media-backend/livekit/Publisher.ts
similarity index 100%
rename from sdk/src/backend/livekit/Publisher.ts
rename to sdk/src/media-backend/livekit/Publisher.ts
diff --git a/sdk/src/backend/livekit/connectionState.ts b/sdk/src/media-backend/livekit/connectionState.ts
similarity index 100%
rename from sdk/src/backend/livekit/connectionState.ts
rename to sdk/src/media-backend/livekit/connectionState.ts
diff --git a/sdk/src/backend/livekit/livekitOptions.test.ts b/sdk/src/media-backend/livekit/livekitOptions.test.ts
similarity index 100%
rename from sdk/src/backend/livekit/livekitOptions.test.ts
rename to sdk/src/media-backend/livekit/livekitOptions.test.ts
diff --git a/sdk/src/backend/livekit/livekitOptions.ts b/sdk/src/media-backend/livekit/livekitOptions.ts
similarity index 100%
rename from sdk/src/backend/livekit/livekitOptions.ts
rename to sdk/src/media-backend/livekit/livekitOptions.ts
diff --git a/sdk/src/backend/livekit/openIDSFU.test.ts b/sdk/src/media-backend/livekit/openIDSFU.test.ts
similarity index 100%
rename from sdk/src/backend/livekit/openIDSFU.test.ts
rename to sdk/src/media-backend/livekit/openIDSFU.test.ts
diff --git a/sdk/src/backend/livekit/openIDSFU.ts b/sdk/src/media-backend/livekit/openIDSFU.ts
similarity index 100%
rename from sdk/src/backend/livekit/openIDSFU.ts
rename to sdk/src/media-backend/livekit/openIDSFU.ts
diff --git a/sdk/src/backend/livekit/publishOptions.ts b/sdk/src/media-backend/livekit/publishOptions.ts
similarity index 100%
rename from sdk/src/backend/livekit/publishOptions.ts
rename to sdk/src/media-backend/livekit/publishOptions.ts
diff --git a/sdk/src/backend/livekit/test.ts b/sdk/src/media-backend/livekit/test.ts
similarity index 100%
rename from sdk/src/backend/livekit/test.ts
rename to sdk/src/media-backend/livekit/test.ts
diff --git a/sdk/src/utils/displayname.test.ts b/sdk/src/utils/displayname.test.ts
index 4d6653d8f..daaeb5f69 100644
--- a/sdk/src/utils/displayname.test.ts
+++ b/sdk/src/utils/displayname.test.ts
@@ -20,7 +20,7 @@ import {
   daveRTL,
 } from "./test-fixtures";
 import { mockMatrixRoom } from "./test";
-import { roomToMembersMap } from "../session/MatrixMemberMetadata";
+import { roomToMembersMap } from "../matrixrtc/MatrixMemberMetadata";
 
 describe("shouldDisambiguate", () => {
   test("should not disambiguate a solo member", () => {