Add the FEATURES_SPEC process for turning explorations into specs and PRs

FEATURES_SPEC/AGENTS.md describes how an exploration is distilled into a feature spec and how a spec is turned into PRs against a current main; the product spec template is the sidecar a brainstorming session fills in. The folder is excluded from oxfmt: a product spec is immutable once a spec leaves draft, and the process documents are prose in their own style. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Add AGENTS.md documenting the repo's conventions
2026-10-19 23:52:26 +00:00 · 2026-09-10 15:28:39 +02:00 · 2026-09-10 15:28:39 +02:00
51 changed files with 1298 additions and 856 deletions
@@ -2,5 +2,5 @@
  "$schema": "./node_modules/oxfmt/configuration_schema.json",
  "printWidth": 80,
  "sortPackageJson": false,
-  "ignorePatterns": ["pnpm-lock.yaml", "node_modules", "dist"]
+  "ignorePatterns": ["pnpm-lock.yaml", "node_modules", "dist", "FEATURES_SPEC"]
 }
@@ -16,8 +16,8 @@ host's page. It is the MatrixRTC reference implementation.
  `@media`, global `i18next` or the `widget` global — take it from a provider.
 - The change works standalone, as a widget and as a component. Say what you checked.
 - Every gate below is green before you push.
- Hand off after the first implementation, before the quality pass. Then commit on
-  the user's word where the setup allows it, or hand them the message.
+- Hand off after the first implementation, before the quality pass. Commit when the
+  user confirms direction, not before.

 ## Read before you

@@ -48,7 +48,5 @@ pnpm i18n:check
 - View model + marble tests, thin view, a story per state, an e2e spec.
 - Any new shared component called out explicitly, with why nothing existing fit.
 - Template filled for real: what, why, before/after screenshots, repro steps.
- Anything that redraws continuously — an animation frame, a stream — says what it
-  costs, or better, counts the redraws in a test.
 - Branch `<handle>/<topic>`. Plain imperative commit subjects, no prefixes.
 - Once review starts, fix forward. Never force-push a regeneration over a review.
@@ -0,0 +1,415 @@
+# FEATURE_SPEC — Agent Instructions
+
+This folder holds **feature specs distilled from experiments**. A spec is the durable
+artifact of an exploration; the exploration branch is not. Each spec must contain
+enough information for an agent to produce mergeable PRs against a *current* `main`
+without access to the original branch.
+
+## What this folder is not
+
+- Not a design-doc archive. Specs that are not intended to be implemented do not
+  belong here.
+- Not a place for narrative. Prose that does not constrain the implementation or its
+  verification should be cut.
+- Not a substitute for the PR description. The spec explains *why* and *what must be
+  true*; the PR explains *this diff*.
+
+## File naming
+
+`YYYY-MM_Snake_Case_Title.md` — e.g. `2026-09_Raise_Hand_Improvements.md`
+
+The filename is immutable once committed. Renames break links from PRs, issues and
+the drift log. If scope changes fundamentally, write a new spec and set
+`supersedes:` / `superseded_by:`.
+
+A sidecar `YYYY-MM_Snake_Case_Title.product.md` holds the product spec — user stories,
+functional requirements, success criteria. Copy `_TEMPLATE.product.md`. Product owns
+it; see "Brainstorming: the product spec".
+
+An optional sidecar `YYYY-MM_Snake_Case_Title.notes.md` holds lessons learned,
+narrative, dead-end logs and anything else that is worth keeping but does not
+constrain the implementation. Rules:
+
+- The sidecar is **never load-bearing**. Agents do not read it to derive
+  implementation, and nothing in it may contradict or extend the spec. If a note
+  constrains the work, it belongs in `## Decisions`, `## Rejected alternatives` or
+  `## Measurements` instead.
+- Agents may append to it (an observation from a drift check, a wrong turn during
+  implementation) and must never rewrite or delete existing content.
+- An agent that is `blocked` may read the sidecar to draft an open question, but
+  quotes what it found rather than acting on it.
+- No sidecar is required. An empty one is worse than none.
+
+## Style: facts only
+
+Applies to the spec file only. The product spec is prose by design and the notes
+sidecar is unconstrained. The spec is re-read on every regeneration, where prose costs context
+and dilutes the contract, so:
+
+- Bullets, not paragraphs. Declarative present tense. No motivation, no background,
+  no summary of what the code currently does beyond locating the change.
+- Name things instead of describing them — a path, a symbol, an event type, a command,
+  an event id. A reference is shorter and more precise than a sentence about it. Which
+  kind of reference is allowed depends on the section; see "Reference durability".
+- One line per decision plus at most one sentence of rationale. If the rationale needs
+  more, the extra goes in the sidecar.
+- No judgement adjectives (clean, elegant, proper, obviously) and no hedging (should
+  probably, might be nice). Either it is a constraint or it is not in the spec.
+- `## Problem` is at most five bullets.
+- Target under 200 lines for the whole spec; over 300 lines, split the feature or move
+  material to the sidecar.
+
+The test for any line: does it constrain the implementation, constrain its
+verification, or record a measured fact? If not, delete it or move it to the sidecar.
+
+## Reference durability
+
+The spec must stay implementable against a `main` nobody has seen yet, so which
+references are allowed depends on how fast they rot. Most to least durable:
+
+1. Protocol identifiers — `m.reaction`, `m.call.member`, `m.relates_to`, a reaction
+   key. MSC-bound; effectively permanent.
+2. Observable behaviour. Permanent.
+3. Concept names — membership, participation, session.
+4. Test names. Survive file moves and renames, because the test moves with the code.
+5. Exported symbols. Survive refactors sometimes.
+6. File paths. Rot fast.
+7. Line numbers. Never.
+
+Per section:
+
+- `## Problem`, `## Measurements`, `## Slicing plan`, `## Drift log` — any reference,
+  paths and internal symbols included. These describe the codebase **as of `base`**. A
+  reference going stale here is a finding for the drift check, not a defect, and
+  removing the concrete references would leave the drift check with nothing to verify.
+- `## Decisions`, `## Acceptance criteria` — levels 1 to 4 only. No file paths, no
+  internal symbols. This is the part that has to hold against a future `main`.
+- An acceptance criterion that is not user-observable is tagged `[internal]` and
+  anchored by **its test name**, not by the symbol under test. The test name moves with
+  a refactor; the symbol does not.
+
+`[internal]` ACs are legitimate and expected: an invariant that no current consumer can
+observe is exactly what protects the consumer that does not exist yet. Tagging them
+keeps visible which ACs defend a product requirement and which defend a code
+invariant.
+
+## Required frontmatter
+
+```yaml
+---
+status: draft            # see state machine below
+blocked_from: null       # state to return to when leaving `blocked`
+title: Raise hand improvements
+owner: <human handle>    # a human, always
+signoff:                 # join condition for leaving exploration.signoff
+  eng: pending
+  design: pending
+  product: pending
+experiment_ref: <branch name or commit sha of the spike, if any>
+base: <sha of main the spec was validated against>
+repos: [matrix-js-sdk, element-call]    # in dependency order
+specs: [MSC4143]         # protocol documents touched, if any
+supersedes: []
+superseded_by: null
+---
+```
+
+`base` is mandatory and is what makes drift detectable. `owner` is a human even when
+every section was drafted by an agent.
+
+## Brainstorming: the product spec
+
+The usual entry point is a human handing an agent a one-line feature idea. The output
+of that session is `<stem>.product.md`, not code and not a feature spec. Copy
+`_TEMPLATE.product.md` and fill it.
+
+Ownership: an agent may create and fill this file during `brainstorm`. From `draft`
+onwards **product owns it and agents do not edit it** — not to fix wording, not to
+resolve a marker, not to reconcile it with the code. Agents raise mismatches in the
+feature spec's `## Open questions`.
+
+If product's source of truth lives outside the repo (a tracker, a design doc), put its
+URL in the header `**Source**:` line and keep the requirement text and ids in the repo
+anyway. The ids are what the feature spec references; a link alone cannot be traced.
+
+Agent behaviour during the session:
+
+- **Ask, do not assume.** An unanswered question is recorded as
+  `[NEEDS CLARIFICATION: <the question>]`, inline where the answer would go. Filling a
+  gap with a plausible guess is the main failure mode of this state — the marker is a
+  deliverable, not a defect.
+- Ask in one round of at most five questions, ordered by how much the answer changes
+  the shape of the feature. Do not interview.
+- **No implementation in the product spec.** No file paths, symbols, libraries, event
+  types, API shapes or framework names. If a requirement cannot be stated without them,
+  it is not a product requirement.
+- Every user story must be independently deployable and demonstrable on its own. A
+  story that only makes sense once another story ships is not a story; merge it.
+- More than four priority levels means more than one feature. Split before `draft`.
+- Never invent an SC number. Ask for the target, or mark it
+  `[NEEDS CLARIFICATION]`.
+
+For protocol and infrastructure work, success criteria may be expressed as observable
+client behaviour or a wire-level invariant ("a client joining mid-session converges
+within one sync"), but still never as a code path or an internal API.
+
+`FR-###` and `SC-###` ids are immutable once assigned. Product may revise the document
+at any time, including after `in_production`, but a changed requirement gets a **new
+id** and the old one is marked superseded — never edited in place. Renumbering silently
+breaks every AC that references it, and there is no way to detect that afterwards.
+
+A new or changed FR after `implement` does not amend the current spec's scope. It is
+either a new feature spec or the next iteration; the mapping table simply shows an
+unmapped FR, which is the intended signal.
+
+## Traceability
+
+The product spec states intent; the feature spec states what must be true and how it is
+checked. They are kept in sync by ids, not by duplication.
+
+- Every `FR-###` maps to at least one acceptance criterion. Tag the AC with its
+  origin: `AC2 [FR-003] — <observable behaviour>`.
+- Every `SC-###` maps to an entry in `## Measurements` with a method. An SC with no
+  measurement blocks `exploration.signoff`.
+- Every user story maps to at least one slice. **Slice order follows story priority**
+  (P1 first) unless a technical dependency overrides it, and the override is recorded
+  in the slicing plan with its reason.
+- An AC with no `FR` origin is allowed and expected — implementation-level invariants
+  have no counterpart in the product spec. The converse is not: an unmapped FR is an
+  incomplete spec.
+- Agents do not resolve a mismatch between the two. The product spec wins on intent,
+  the feature spec wins on verification; a genuine contradiction is `blocked`.
+
+## Status state machine
+
+Transitions are explicit; an agent may perform only the ones marked (agent).
+
+```
+brainstorm ─► draft ─► exploration ─► implement ─► qa ─► in_production
+                           │              │        │
+                           └──────────────┴────────┴──► blocked ──► (blocked_from)
+                                                           │
+                                                           └──► abandoned
+```
+
+Exploration has sub-states, written dotted in `status`:
+
+```
+exploration.scoping ─► exploration.iterating ─► exploration.signoff
+        ▲                       │                      │
+        └───────────────────────┴──────────────────────┘
+```
+
+- `brainstorm` → `draft`: human. Requires `<stem>.product.md` to exist with at least one
+  P1 story carrying acceptance scenarios, every FR and SC id assigned, and every
+  remaining `[NEEDS CLARIFICATION]` copied into the feature spec's `## Open questions`.
+- `draft` → `exploration.scoping`: human. Requires `## Problem` and `## Out of scope`.
+  Scoping before the branch exists is what keeps exploration from becoming the
+  long-lived branch this folder replaces.
+- `exploration.scoping` → `.iterating`: human. `experiment_ref` must name the branch.
+- `.iterating` → `.signoff`: human. Requires `## Decisions`, `## Acceptance criteria`,
+  `## Rejected alternatives` and `## Measurements` to be complete, no
+  `[NEEDS CLARIFICATION]` left in the product spec, and full traceability (below).
+- `.signoff` → `implement`: **only when all three sign-offs in `signoff:` are `ok`.**
+  This is a join, not a sequence — a single reviewer cannot advance it. On entering
+  `implement`, the exploration branch stops being a base: it is reference material,
+  and implementation branches off current `main` (see "Turning a spec into PRs").
+- `.signoff` → `.iterating`: human, on any sign-off returning changes. Reset the
+  rejecting role to `pending`; leave the others as they are.
+- `implement` → `qa`: (agent) when every acceptance criterion is covered, as recorded
+  in `## PRs`, and the feature flag is enabled in the QA environment.
+- `qa` → `in_production`: human. The flag is on by default in production.
+- `qa` → `implement`: (agent) when a QA finding needs code. See "QA feedback".
+- any active state → `blocked`: (agent) when drift or an unresolved question prevents
+  progress. Requires a drift-log entry and `blocked_from: <state>`. Do not guess and
+  continue. Leaving `blocked` returns to `blocked_from`, never to a fixed state.
+- any state → `abandoned`: human only.
+
+`in_production` is terminal. A production regression does not reopen the spec: it
+either is an ordinary bug fix with no spec, or it is a new spec. The acceptance
+criteria remain as the regression contract (see "QA feedback").
+
+## QA feedback
+
+The point of the `qa` state is not to record that testing happened. It is to make the
+spec a better regeneration source than it was before implementation. So:
+
+- Every reproduced QA finding becomes **either** a new acceptance criterion **or** a
+  new entry in `## Rejected alternatives`. Never a prose note, never only a bug
+  tracker link.
+- (agent) may **append** ACs during `qa`, with provenance:
+  `AC7 [qa: <issue ref>] — <observable behaviour>` plus its check. Appending is
+  allowed; rewriting or reordering existing ACs is not.
+- A finding that invalidates a decision does not become an AC. It sets `blocked` — a
+  decision is human-owned in every state.
+- A finding that is out of scope goes to `## Out of scope` with its issue ref, so the
+  next regeneration does not treat it as a gap.
+
+This also applies after `in_production`: a production bug that reveals a missing AC is
+appended with `[prod: <ref>]` provenance without any state change.
+
+## Required sections
+
+Order matters — agents read top-down and the first three sections are the contract.
+
+1. **`## Problem`** — up to five bullets. What breaks today, for whom, observably,
+   with the file or symbol where it breaks.
+2. **`## Decisions`** — the choices the exploration settled, each with a one-line
+   rationale. **Human-owned. An agent must never add, remove or reword a decision.**
+   If a decision is missing, set `blocked` and ask.
+3. **`## Acceptance criteria`** — the load-bearing section. Each item must be
+   mechanically checkable and name its check:
+   - `AC1 [FR-002] — <observable behaviour>` / `check: yarn vitest run src/reactions/ReactionsReader.test.tsx -t "backfill"`
+   - `AC2 [FR-002] — <observable behaviour>` / `check: manual, <exact steps>`
+   - `AC3 [internal] — <invariant>` / `check: yarn vitest run <file> -t "<test name>"`
+   An acceptance criterion without a check is a wish; reject the spec (`blocked`).
+4. **`## Rejected alternatives`** — what the experiment tried and why it failed,
+   including measurements. This exists so regeneration does not re-walk dead ends. If
+   this section is empty for a spec with an `experiment_ref`, the spec is incomplete.
+5. **`## Measurements`** — numbers from the experiment with the method used to obtain
+   them (command, hardware, load profile). Numbers without a method are not usable as
+   regression baselines and must be marked `unverified`. A baseline states its direction: a
+   count that unrelated work grows — tests passing, test files — is a floor (`≥ n`); a
+   cost — latency, CPU, bundle size — is a ceiling (`≤ n`). An exact count is stale as
+   soon as `main` moves and is not a drift finding.
+6. **`## Out of scope`** — explicit non-goals, so agents stop expanding the diff.
+7. **`## Slicing plan`** — ordered, independently mergeable PRs (see below).
+8. **`## Drift log`** — append-only, agent-written.
+9. **`## PRs`** — append-only list of `#<n> — <state> — <ACs covered>`.
+
+Optional: `## Open questions` (blocks `exploration.signoff`), `## Migration / compat` (mandatory
+whenever wire format, event schema, or a published API changes).
+
+## Turning a spec into PRs
+
+Run these steps in order. Do not skip step 2.
+
+1. **Fetch and pin.** `git fetch origin` and record `origin/main`'s sha as `head`.
+   Never start from the exploration branch, and never rebase it — the branch is
+   reference material, not a base.
+2. **Drift check** against `base..head`:
+   - Do all files, symbols and modules named in the spec still exist?
+   - Have the invariants in `## Decisions` been contradicted by changes in main?
+   - Do the commands in `## Acceptance criteria` still run?
+   Write the result as a drift-log entry. On a contradicted decision: set `blocked`,
+   do not implement.
+3. **Re-derive the slicing plan** if drift changed it. Each slice must:
+   - build and pass CI on its own,
+   - be reviewable in one sitting (target < 400 changed lines, hard stop at 800 —
+     split further rather than exceeding it),
+   - map to at least one acceptance criterion, and
+   - land behind a flag or be inert if it is not the last slice of a user-visible
+     change.
+4. **Implement one slice at a time**, branch `spec/<spec-slug>/<n>-<short>` off the
+   pinned `head`. Tests for the slice's ACs go in the same PR as the code. A PR merges
+   only when every check of every AC it lists passes on that PR: automated checks in
+   CI, manual checks performed by a human reviewer with the result recorded in the PR
+   description. An AC is *covered* once such a PR has merged.
+5. **Open the PR** linking the spec path and listing the ACs it covers. Update
+   `## PRs` and `status`.
+6. **Do not touch merged or reviewed slices.** See the regeneration rule.
+
+## The regeneration rule
+
+Regeneration from spec is only allowed **before a human has reviewed the PR**.
+
+Once review has started, the PR is a shared artifact: rebase, fix forward, push
+incremental commits. Regenerating discards the reviewer's context and silently
+invalidates their approvals. If regeneration is unavoidable after review, close the
+old PR with an explanation and open a new one — never force-push a fresh generation
+over a reviewed branch.
+
+## Cross-repo and protocol work
+
+When `repos` has more than one entry, PRs are opened in `repos` order and each PR
+body states which upstream PR it depends on. Merging out of order is a spec
+violation, not an optimisation.
+
+When `specs` is non-empty:
+- the implementation PR references the section of the MSC it implements,
+- unmerged MSCs require the implementation to be feature-flagged and documented as
+  unstable (unstable prefixes, not stable identifiers), and
+- any deviation from the MSC text is recorded in `## Drift log`, not silently
+  resolved in favour of the code.
+
+## Drift-log format
+
+Append-only, newest last:
+
+```
+### 2026-09-14 — drift check (base 4f2a1c9 → head 9b17e02)
+- `ReactionsReader.getLastReactionEvent` now takes a `CallMembership` instead of an
+  event id → AC2 and AC3 check commands still valid, slice 3 needs rework
+- BLOCKING: decision D2 assumes a membership event change may keep a hand raised; main
+  now clears all reaction relations on membership replacement. Needs owner decision.
+```
+
+Drift entries are never rewritten or deleted, including entries that were later
+resolved. The log is the record of why the implementation diverged from the
+exploration.
+
+## Hard rules
+
+- Never fill a `[NEEDS CLARIFICATION]` marker with a guess, in any state.
+- Never put file paths, symbols or library names in the product spec.
+- Never reference a file path or an internal symbol in `## Decisions` or
+  `## Acceptance criteria`. Behaviour, protocol identifiers, concepts and test names
+  only.
+- Never edit `<stem>.product.md` after `draft`, and never renumber an FR or SC id.
+- Never add a line that does not constrain the implementation, constrain its
+  verification, or record a measured fact. It goes in the sidecar or nowhere.
+- Never modify `## Decisions`, `## Problem`, or `## Acceptance criteria`. These are
+  the human contract. Propose changes in `## Open questions` and set `blocked`.
+- Never invent measurements or acceptance checks. Absent is better than plausible.
+- Never widen scope past `## Out of scope`, even when the fix looks trivial.
+- Never open a PR while `status` is `draft`, any `exploration.*`, or `blocked`.
+- Never delete a spec file. Terminal states are `in_production` or `abandoned`.
+- If the spec and current `main` disagree about how the system works, **main wins as
+  description, the spec wins as intent** — record the difference and stop.
+
+## Spec template
+
+```markdown
+---
+status: draft
+blocked_from: null
+title:
+owner:
+signoff:
+  eng: pending
+  design: pending
+  product: pending
+experiment_ref:
+base:
+repos: []
+specs: []
+supersedes: []
+superseded_by: null
+---
+
+## Problem
+
+## Decisions
+- D1 — <decision> — <why>
+
+## Acceptance criteria
+- AC1 [FR-###] — <observable behaviour>
+  - check: <command or exact manual steps>
+- AC2 [internal] — <invariant>
+  - check: <command, anchored by test name>
+
+## Rejected alternatives
+- <approach> — <why it failed> — <evidence>
+
+## Measurements
+- <metric>: <value> (method: <command / setup>)
+
+## Out of scope
+
+## Slicing plan
+1. <slice> — covers AC1 — depends on: none
+
+## Drift log
+
+## PRs
+```
@@ -0,0 +1,117 @@
+# Feature Specification: [FEATURE NAME]
+
+**Feature Branch**: `[###-feature-name]`
+**Created**: [DATE]
+**Feature Spec**: `[YYYY-MM_Title.md]`  <!-- status lives in the feature spec's frontmatter, not here -->
+**Owner**: [product handle]
+**Source**: [URL of the tracker/doc this mirrors, or "this file"]
+**Input**: User description: "$ARGUMENTS"
+
+## User Scenarios & Testing *(mandatory)*
+
+<!--
+  IMPORTANT: User stories should be PRIORITIZED as user journeys ordered by importance.
+  Each user story/journey must be INDEPENDENTLY TESTABLE - meaning if you implement just ONE of them,
+  you should still have a viable MVP (Minimum Viable Product) that delivers value.
+
+  Assign priorities (P1, P2, P3, etc.) to each story, where P1 is the most critical.
+  Think of each story as a standalone slice of functionality that can be:
+  - Developed independently
+  - Tested independently
+  - Deployed independently
+  - Demonstrated to users independently
+-->
+
+### User Story 1 - [Brief Title] (Priority: P1)
+
+[Describe this user journey in plain language]
+
+**Why this priority**: [Explain the value and why it has this priority level]
+
+**Independent Test**: [Describe how this can be tested independently - e.g., "Can be fully tested by [specific action] and delivers [specific value]"]
+
+**Acceptance Scenarios**:
+
+1. **Given** [initial state], **When** [action], **Then** [expected outcome]
+2. **Given** [initial state], **When** [action], **Then** [expected outcome]
+
+---
+
+### User Story 2 - [Brief Title] (Priority: P2)
+
+[Describe this user journey in plain language]
+
+**Why this priority**: [Explain the value and why it has this priority level]
+
+**Independent Test**: [Describe how this can be tested independently]
+
+**Acceptance Scenarios**:
+
+1. **Given** [initial state], **When** [action], **Then** [expected outcome]
+
+---
+
+### User Story 3 - [Brief Title] (Priority: P3)
+
+[Describe this user journey in plain language]
+
+**Why this priority**: [Explain the value and why it has this priority level]
+
+**Independent Test**: [Describe how this can be tested independently]
+
+**Acceptance Scenarios**:
+
+1. **Given** [initial state], **When** [action], **Then** [expected outcome]
+
+---
+
+[Add more user stories as needed, each with an assigned priority]
+
+### Edge Cases
+
+<!--
+  ACTION REQUIRED: The content in this section represents placeholders.
+  Fill them out with the right edge cases.
+-->
+
+- What happens when [boundary condition]?
+- How does system handle [error scenario]?
+
+## Requirements *(mandatory)*
+
+<!--
+  ACTION REQUIRED: The content in this section represents placeholders.
+  Fill them out with the right functional requirements.
+-->
+
+### Functional Requirements
+
+- **FR-001**: System MUST [specific capability, e.g., "allow users to create accounts"]
+- **FR-002**: System MUST [specific capability, e.g., "validate email addresses"]
+- **FR-003**: Users MUST be able to [key interaction, e.g., "reset their password"]
+- **FR-004**: System MUST [data requirement, e.g., "persist user preferences"]
+- **FR-005**: System MUST [behavior, e.g., "log all security events"]
+
+*Example of marking unclear requirements:*
+
+- **FR-006**: System MUST authenticate users via [NEEDS CLARIFICATION: auth method not specified - email/password, SSO, OAuth?]
+- **FR-007**: System MUST retain user data for [NEEDS CLARIFICATION: retention period not specified]
+
+### Key Entities *(include if feature involves data)*
+
+- **[Entity 1]**: [What it represents, key attributes without implementation]
+- **[Entity 2]**: [What it represents, relationships to other entities]
+
+## Success Criteria *(mandatory)*
+
+<!--
+  ACTION REQUIRED: Define measurable success criteria.
+  These must be technology-agnostic and measurable.
+-->
+
+### Measurable Outcomes
+
+- **SC-001**: [Measurable metric, e.g., "Users can complete account creation in under 2 minutes"]
+- **SC-002**: [Measurable metric, e.g., "System handles 1000 concurrent users without degradation"]
+- **SC-003**: [User satisfaction metric, e.g., "90% of users successfully complete primary task on first attempt"]
+- **SC-004**: [Business metric, e.g., "Reduce support tickets related to [X] by 50%"]
@@ -1,17 +0,0 @@
-id: "lk-jwt-service-othersite"
-as_token: "ec_dev_as_token_othersite_0123456789ab"
-hs_token: "ec_dev_hs_token_othersite_0123456789ab"
-sender_localpart: "_lk_jwt_service"
-namespaces:
-  users:
-    - exclusive: false
-      regex: "@.*:homeserver-1" # Cover all local users
-# Required for Synapse to call POST /_matrix/app/v1/ping on this service.
-url: "http://auth-server-1:16080"
-# Enable membership look-ups via /is_joined.
-io.element.msc4502.scopes:
-  ["urn:matrix:client:io.element.msc4502:rooms:is_joined"]
-# Route /_matrix/client/(v*|unstable/*)/rtc/livekit/* C-S and S-S requests to this
-# service.
-io.element.msc4512.proxy_prefix: "rtc/livekit"
-io.element.msc4512.proxy_url: "http://auth-server-1:16080"
@@ -1,17 +0,0 @@
-id: "lk-jwt-service"
-as_token: "ec_dev_as_token_main_0123456789ab"
-hs_token: "ec_dev_hs_token_main_0123456789ab"
-sender_localpart: "_lk_jwt_service"
-namespaces:
-  users:
-    - exclusive: false
-      regex: "@.*:homeserver" # Cover all local users
-# Required for Synapse to call POST /_matrix/app/v1/ping on this service.
-url: "http://auth-server:6080"
-# Enable membership look-ups via /is_joined.
-io.element.msc4502.scopes:
-  ["urn:matrix:client:io.element.msc4502:rooms:is_joined"]
-# Route /_matrix/client/(v*|unstable/*)/rtc/livekit/* C-S and S-S requests to this
-# service.
-io.element.msc4512.proxy_prefix: "rtc/livekit"
-io.element.msc4512.proxy_url: "http://auth-server:6080"
@@ -42,13 +42,6 @@ experimental_features:
  msc4354_enabled: true
  # MatrixRTC
  msc4143_enabled: true
-  # Enable membership look-up via /is_joined.
-  msc4502_enabled: true
-  # Enable C-S & S-S request proxying for application services.
-  msc4512_enabled: true
-
-app_service_config_files:
-  - /data/cfg/app-service.yaml

 # The maximum allowed duration by which sent events can be delayed, as
 # per MSC4140. Must be a positive value if set.  Defaults to no
@@ -42,13 +42,6 @@ experimental_features:
  msc4354_enabled: true
  # MatrixRTC
  msc4143_enabled: true
-  # Enable membership look-up via /is_joined.
-  msc4502_enabled: true
-  # Enable C-S & S-S request proxying for application services.
-  msc4512_enabled: true
-
-app_service_config_files:
-  - /data/cfg/app-service.yaml

 # The maximum allowed duration by which sent events can be delayed, as
 # per MSC4140. Must be a positive value if set.  Defaults to no
@@ -42,13 +42,6 @@ experimental_features:
  msc4354_enabled: true
  # MatrixRTC
  msc4143_enabled: true
-  # Enable membership look-up via /is_joined.
-  msc4502_enabled: true
-  # Enable C-S & S-S request proxying for application services.
-  msc4512_enabled: true
-
-app_service_config_files:
-  - /data/cfg/app-service.yaml

 # The maximum allowed duration by which sent events can be delayed, as
 # per MSC4140. Must be a positive value if set.  Defaults to no
@@ -42,13 +42,6 @@ experimental_features:
  msc4354_enabled: true
  # MatrixRTC
  msc4143_enabled: true
-  # Enable membership look-up via /is_joined.
-  msc4502_enabled: true
-  # Enable C-S & S-S request proxying for application services.
-  msc4512_enabled: true
-
-app_service_config_files:
-  - /data/cfg/app-service.yaml

 # The maximum allowed duration by which sent events can be delayed, as
 # per MSC4140. Must be a positive value if set.  Defaults to no
@@ -3,7 +3,7 @@ networks:

 services:
  auth-service:
-    image: ghcr.io/element-hq/lk-jwt-service:0.7.0
+    image: ghcr.io/element-hq/lk-jwt-service:0.4.4
    pull_policy: always
    hostname: auth-server
    environment:
@@ -15,14 +15,6 @@ services:
      # a self-signed certificate
      - LIVEKIT_INSECURE_SKIP_VERIFY_TLS=YES_I_KNOW_WHAT_I_AM_DOING
      - LIVEKIT_FULL_ACCESS_HOMESERVERS=*
-      # Registers this instance as an application service on the main homeserver
-      - LIVEKIT_AS_REGISTRATION_FILE=/etc/lk-jwt-service/app-service.yaml
-      - LIVEKIT_HS_SERVER_NAME=synapse.m.localhost
-      # Neither homeserver serves /.well-known/matrix/client, so the C-S API
-      # location has to be given explicitly.
-      - LIVEKIT_CS_API_URL_OVERRIDES=synapse.m.localhost=http://homeserver:8008,synapse.othersite.m.localhost=http://homeserver-1:18008
-    volumes:
-      - ./backend/app-service.yaml:/etc/lk-jwt-service/app-service.yaml:Z
    deploy:
      restart_policy:
        condition: on-failure
@@ -33,7 +25,7 @@ services:
      - ecbackend

  auth-service-1:
-    image: ghcr.io/element-hq/lk-jwt-service:0.7.0
+    image: ghcr.io/element-hq/lk-jwt-service:0.4.4
    pull_policy: always
    hostname: auth-server-1
    environment:
@@ -45,14 +37,6 @@ services:
      # a self-signed certificate
      - LIVEKIT_INSECURE_SKIP_VERIFY_TLS=YES_I_KNOW_WHAT_I_AM_DOING
      - LIVEKIT_FULL_ACCESS_HOMESERVERS=*
-      # Registers this instance as an application service on the other homeserver.
-      - LIVEKIT_AS_REGISTRATION_FILE=/etc/lk-jwt-service/app-service.yaml
-      - LIVEKIT_HS_SERVER_NAME=synapse.othersite.m.localhost
-      # Neither homeserver serves /.well-known/matrix/client, so the C-S API
-      # location has to be given explicitly.
-      - LIVEKIT_CS_API_URL_OVERRIDES=synapse.m.localhost=http://homeserver:8008,synapse.othersite.m.localhost=http://homeserver-1:18008
-    volumes:
-      - ./backend/app-service-othersite.yaml:/etc/lk-jwt-service/app-service.yaml:Z
    deploy:
      restart_policy:
        condition: on-failure
@@ -110,10 +94,7 @@ services:

  synapse:
    hostname: homeserver
-    # develop (not latest) is required for application service C-S/S-S proxying
-    # (MSC4512) and membership look-ups (MSC4502), which are not in a stable
-    # release yet.
-    image: ghcr.io/element-hq/synapse:develop
+    image: ghcr.io/element-hq/synapse:latest
    pull_policy: always
    environment:
      - SYNAPSE_CONFIG_PATH=/data/cfg/homeserver.yaml
@@ -126,16 +107,12 @@ services:
    volumes:
      - ./backend/synapse_tmp:/data:Z
      - ./backend/dev_homeserver.yaml:/data/cfg/homeserver.yaml:Z
-      - ./backend/app-service.yaml:/data/cfg/app-service.yaml:Z
    networks:
      - ecbackend

  synapse-1:
    hostname: homeserver-1
-    # develop (not latest) is required for application service C-S/S-S proxying
-    # (MSC4512) and membership look-ups (MSC4502), which are not in a stable
-    # release yet.
-    image: ghcr.io/element-hq/synapse:develop
+    image: ghcr.io/element-hq/synapse:latest
    pull_policy: always
    environment:
      - SYNAPSE_CONFIG_PATH=/data/cfg/homeserver.yaml
@@ -148,7 +125,6 @@ services:
    volumes:
      - ./backend/synapse_tmp_othersite:/data:Z
      - ./backend/dev_homeserver-othersite.yaml:/data/cfg/homeserver.yaml:Z
-      - ./backend/app-service-othersite.yaml:/data/cfg/app-service.yaml:Z
    networks:
      - ecbackend

@@ -3,23 +3,17 @@
 services:
  synapse:
    # Pin to a SHA so that upstream cannot break our tests. Renovate handles regular updates.
-    # develop (not latest) is required for application service C-S/S-S proxying
-    # (MSC4512) and membership look-ups (MSC4502), which are not in a stable
-    # release yet.
-    image: ghcr.io/element-hq/synapse:develop@sha256:337921fd22be310d453344b2265f6c9942315446595df3cf81866f71ca2055a7
+    image: ghcr.io/element-hq/synapse:latest@sha256:da325af40104051923899e5f5a2f1d537e6e3ccf2f0f38285689ae9bbfdb190a
    volumes:
      - ./backend/playwright_homeserver.yaml:/data/cfg/homeserver.yaml:Z
  synapse-1:
    # Pin to a SHA so that upstream cannot break our tests. Renovate handles regular updates.
-    # develop (not latest) is required for application service C-S/S-S proxying
-    # (MSC4512) and membership look-ups (MSC4502), which are not in a stable
-    # release yet.
-    image: ghcr.io/element-hq/synapse:develop@sha256:337921fd22be310d453344b2265f6c9942315446595df3cf81866f71ca2055a7
+    image: ghcr.io/element-hq/synapse:latest@sha256:da325af40104051923899e5f5a2f1d537e6e3ccf2f0f38285689ae9bbfdb190a
    volumes:
      - ./backend/playwright_homeserver-othersite.yaml:/data/cfg/homeserver.yaml:Z
  element-web:
    # Pin to a SHA so that upstream cannot break our tests. Renovate handles regular updates.
-    image: ghcr.io/element-hq/element-web:develop@sha256:3993d53bc2c784c0376b86e00230aef0ee2c9a705b2166e9229555117e8db167
+    image: ghcr.io/element-hq/element-web:develop@sha256:6ed62b2963ae098a1f79521eb516834dcf29452168e281cc359d9cfb4380adf6
  element-web-1:
    # Pin to a SHA so that upstream cannot break our tests. Renovate handles regular updates.
-    image: ghcr.io/element-hq/element-web:develop@sha256:3993d53bc2c784c0376b86e00230aef0ee2c9a705b2166e9229555117e8db167
+    image: ghcr.io/element-hq/element-web:develop@sha256:6ed62b2963ae098a1f79521eb516834dcf29452168e281cc359d9cfb4380adf6
@@ -12,8 +12,6 @@ lines a PR touches.
 - Reuse the factories in `src/utils/test.ts` — `mockRemoteParticipant`,
  `mockMatrixRoom`, `mockLivekitRoom`, `MockRTCSession`. Hand-rolled mocks drift.
 - Snapshots live in `__snapshots__/`; update with `pnpm test <Name> -u`.
- How often something redraws is testable: drive the frames and count commits, not
-  render calls. An effect with no dependency array runs once per commit.
 - `component/**/*.test.ts` runs in the same jsdom project as `src`.

 ## Storybook
@@ -39,12 +39,10 @@ Git-ignored. One kebab-case subfolder per task, matching the branch topic:

 ## Commit and PR readiness

- Commit once the user confirms direction, or asks for one. Not before. Where the
-  setup has no git identity, a sandbox included, write the message to
-  `commit-msg.txt` and hand it over instead.
- Ready means every gate in [AGENTS.md](../../AGENTS.md#gates) is green and the
-  change is covered at the layers [testing.md](./testing.md) asks for. Read the diff
-  against [code-style.md](./code-style.md) first.
- Re-run the whole checklist after any fix. Only on green, either way.
+- Commit once the user confirms direction, or asks for one. Not before.
+- Before committing, every gate in [AGENTS.md](../../AGENTS.md#gates) is green and
+  the change is covered at the layers [testing.md](./testing.md) asks for. Read the
+  diff against [code-style.md](./code-style.md).
+- Re-run the whole checklist after any fix. Commit only on green.
 - Once a human has started reviewing, fix forward — never force-push a
  regeneration over a review in progress.
@@ -83,7 +83,7 @@
    "@types/sdp-transform": "^2.4.5",
    "@typescript-eslint/utils": "^8.61.0",
    "@use-gesture/react": "^10.2.11",
-    "@vector-im/compound-design-tokens": "^11.0.0",
+    "@vector-im/compound-design-tokens": "^10.0.0",
    "@vector-im/compound-web": "^10.0.0",
    "@vitejs/plugin-react": "^6.0.2",
    "@vitest/browser-playwright": "^4.1.5",
@@ -109,15 +109,10 @@ export const widgetTest = test.extend<MyFixtures>({
      await TestHelpers.dismissInviteUnknownUserModal(ewPage1);

      // Accept the invite
-      await TestHelpers.closeReleaseAnnouncement(
-        ewPage2,
-        "Introducing Sections",
-      );
-      await TestHelpers.expandAllSections(ewPage2);
      await expect(
-        TestHelpers.roomListItem(ewPage2, "Welcome Room"),
+        ewPage2.getByRole("option", { name: "Welcome Room" }),
      ).toBeVisible();
-      await TestHelpers.roomListItem(ewPage2, "Welcome Room").click();
+      await ewPage2.getByRole("option", { name: "Welcome Room" }).click();
      await ewPage2.getByRole("button", { name: "Accept" }).click();
      await expect(
        ewPage2
@@ -157,12 +152,8 @@ export const widgetTest = test.extend<MyFixtures>({
      ).toBeVisible();

      // Accept the DM invite from brooks
-      await TestHelpers.closeReleaseAnnouncement(
-        ewPage2,
-        "Introducing Sections",
-      );
-      await TestHelpers.expandAllSections(ewPage2);
-      await TestHelpers.roomListItem(ewPage2, brooksDisplayName).click();
+      // This how playwright record selects the DM invite in the room list
+      await ewPage2.getByRole("button", { name: "Open room" }).click();
      await ewPage2.getByRole("button", { name: "Start chatting" }).click();
    }

@@ -7,8 +7,6 @@ Please see LICENSE in the repository root for full details.

 import { expect, test } from "@playwright/test";

-import { SpaHelpers } from "./spa-helpers";
-
 // Skip test for Firefox, due to page.keyboard.press("Tab") not reliable on headless mode
 test.skip(
  ({ browserName }) => browserName === "firefox",
@@ -19,12 +17,6 @@ test("can only interact with header and footer while reconnecting", async ({
  page,
 }) => {
  await page.goto("/");
-
-  // The reconnecting state is entered via the probablyLeft timer, which
-  // mirrors the delayed leave event's timeout. With delegation that timeout
-  // is one hour, putting it out of reach of the clock fast-forward below.
-  // Keep the leave client-managed so its short timeout applies.
-  await SpaHelpers.disableLeaveDelegation(page);
  await page.getByTestId("home_callName").click();
  await page.getByTestId("home_callName").fill("Test call");
  await page.getByTestId("home_displayName").click();
@@ -19,7 +19,6 @@ async function setupTwoUserSpaCall(
  browser: Browser,
  page: Page,
  browserName: string,
-  opts: { disableGuestLeaveDelegation?: boolean } = {},
 ): Promise<{ guestPage: Page }> {
  test.skip(
    browserName === "firefox",
@@ -53,9 +52,6 @@ async function setupTwoUserSpaCall(

  await guestPage.goto("/");

-  if (opts.disableGuestLeaveDelegation)
-    await SpaHelpers.disableLeaveDelegation(guestPage);
-
  let pevaraHasSentStickyEvent = false;

  const pevaraResolver = Promise.withResolvers<void>();
@@ -106,13 +102,7 @@ test("One to One rejoin after improper leave does not crash EC", async ({
  page,
  browserName,
 }) => {
-  // With delegation, the backend sends the guest's delayed leave event within
-  // moments of the improper leave, so the stale membership this test needs
-  // would be cleaned up before the rejoin. Keep the guest's leave
-  // client-managed so the stale membership lingers.
-  const { guestPage } = await setupTwoUserSpaCall(browser, page, browserName, {
-    disableGuestLeaveDelegation: true,
-  });
+  const { guestPage } = await setupTwoUserSpaCall(browser, page, browserName);

  await SpaHelpers.expectVideoTilesCount(page, 2);
  await SpaHelpers.expectVideoTilesCount(guestPage, 2);
@@ -111,24 +111,6 @@ async function setRtcModeFromSettings(
  await page.getByTestId("modal_close").click();
 }

-/**
- * Makes the delayed-leave delegation support probes fail so that the client
- * manages its delayed leave event itself instead of delegating it to the
- * backend.
- *
- * Must be installed before the page joins a call.
- */
-async function disableLeaveDelegation(page: Page): Promise<void> {
-  // Covers both the transport probe (<livekit_service_url>/delegate_delayed_leave)
-  // and the homeserver probe (MSC4195, .../rtc/livekit/delegate_delayed_leave).
-  await page.route("**/delegate_delayed_leave", async (route) =>
-    route.fulfill({
-      status: 404,
-      headers: { "Access-Control-Allow-Origin": "*" },
-    }),
-  );
-}
-
 /**
 * Expect a certain number of video tiles to be present and visible.
 */
@@ -151,6 +133,5 @@ export const SpaHelpers = {
  createCall,
  getCallInviteLink,
  joinCallFromInviteLink,
-  disableLeaveDelegation,
  expectVideoTilesCount,
 };
@@ -11,7 +11,6 @@ import {
  type JSHandle,
  type Page,
  type FrameLocator,
-  type Locator,
 } from "@playwright/test";
 import { type MatrixClient } from "matrix-js-sdk";

@@ -204,16 +203,6 @@ export class TestHelpers {
    }
  }

-  public static async expandAllSections(page: Page): Promise<void> {
-    try {
-      await page
-        .getByRole("button", { name: "Expand all sections" })
-        .click({ timeout: 2000 });
-    } catch {
-      // Already expanded or button not present
-    }
-  }
-
  public static async createRoom(
    name: string,
    page: Page,
@@ -264,9 +253,9 @@ export class TestHelpers {
    roomName: string,
    page: Page,
  ): Promise<void> {
-    await TestHelpers.closeReleaseAnnouncement(page, "Introducing Sections");
-    await TestHelpers.expandAllSections(page);
-    await TestHelpers.roomListItem(page, roomName).click({ timeout: 10000 });
+    await page.getByRole("option", { name: roomName }).click({
+      timeout: 10000,
+    });
    await page.getByRole("button", { name: "Accept" }).click({
      timeout: 5000,
    });
@@ -361,17 +350,6 @@ export class TestHelpers {
      .click();
  }

-  /**
-   * Locates a room in the room list by its name.
-   *
-   * Matches on the aria-label prefix because the item's role differs between
-   * the flat room list (`option`) and the sectioned room list (`button`), and
-   * the label may carry a suffix such as " invitation.".
-   */
-  public static roomListItem(page: Page, roomName: string): Locator {
-    return page.locator(`[aria-label^="Open room ${roomName}"]`);
-  }
-
  /**
   * Switches to a room in the room list by its name.
   * @param page - The EW page
@@ -381,8 +359,7 @@ export class TestHelpers {
    page: Page,
    roomName: string,
  ): Promise<void> {
-    await TestHelpers.expandAllSections(page);
-    await TestHelpers.roomListItem(page, roomName).click();
+    await page.getByRole("option", { name: `Open room ${roomName}` }).click();
  }

  public static async dismissInviteUnknownUserModal(page: Page): Promise<void> {
@@ -39,13 +39,13 @@ importers:
        version: 11.7.12
      '@livekit/components-core':
        specifier: ^0.12.0
-        version: 0.12.15(livekit-client@2.22.3(@types/dom-mediacapture-record@1.0.22))(tslib@2.8.1)
+        version: 0.12.15(livekit-client@2.22.2(@types/dom-mediacapture-record@1.0.22))(tslib@2.8.1)
      '@livekit/components-react':
        specifier: ^2.0.0
-        version: 2.9.24(livekit-client@2.22.3(@types/dom-mediacapture-record@1.0.22))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)(tslib@2.8.1)
+        version: 2.9.24(livekit-client@2.22.2(@types/dom-mediacapture-record@1.0.22))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)(tslib@2.8.1)
      '@livekit/track-processors':
        specifier: ^0.7.1
-        version: 0.7.2(@types/dom-mediacapture-transform@0.1.11)(livekit-client@2.22.3(@types/dom-mediacapture-record@1.0.22))
+        version: 0.7.2(@types/dom-mediacapture-transform@0.1.11)(livekit-client@2.22.2(@types/dom-mediacapture-record@1.0.22))
      '@mediapipe/tasks-vision':
        specifier: ^0.10.18
        version: 0.10.35
@@ -131,11 +131,11 @@ importers:
        specifier: ^10.2.11
        version: 10.3.1(react@19.2.8)
      '@vector-im/compound-design-tokens':
-        specifier: ^11.0.0
-        version: 11.0.0(@types/react@19.2.18)(react@19.2.8)
+        specifier: ^10.0.0
+        version: 10.2.4(@types/react@19.2.18)(react@19.2.8)
      '@vector-im/compound-web':
        specifier: ^10.0.0
-        version: 10.0.1(@fontsource/inconsolata@5.3.0)(@fontsource/inter@5.3.0)(@types/react-dom@19.2.5(@types/react@19.2.18))(@types/react@19.2.18)(@vector-im/compound-design-tokens@11.0.0(@types/react@19.2.18)(react@19.2.8))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
+        version: 10.0.1(@fontsource/inconsolata@5.3.0)(@fontsource/inter@5.3.0)(@types/react-dom@19.2.5(@types/react@19.2.18))(@types/react@19.2.18)(@vector-im/compound-design-tokens@10.2.4(@types/react@19.2.18)(react@19.2.8))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
      '@vitejs/plugin-react':
        specifier: ^6.0.2
        version: 6.1.1(@rolldown/plugin-babel@0.2.3(@babel/core@7.29.7(supports-color@7.2.0))(@babel/runtime@8.0.0)(rolldown@1.2.7)(vite@8.2.2(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0)))(babel-plugin-react-compiler@1.0.0)(vite@8.2.2(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0))
@@ -183,7 +183,7 @@ importers:
        version: 5.88.1(@emnapi/core@1.11.2)(@emnapi/runtime@1.11.2)(@types/node@24.13.3)(typescript@5.9.3)
      livekit-client:
        specifier: ^2.18.1
-        version: 2.22.3(@types/dom-mediacapture-record@1.0.22)
+        version: 2.22.2(@types/dom-mediacapture-record@1.0.22)
      lodash-es:
        specifier: ^4.17.21
        version: 4.18.1
@@ -3229,8 +3229,8 @@ packages:
    peerDependencies:
      react: '>= 16.8.0'

-  '@vector-im/compound-design-tokens@11.0.0':
-    resolution: {integrity: sha512-pWz0Q67Xbo8gwzaTeFbTTcM6i29ju6PR7SqyuExr2nIV3j9K785cOInft8FA2CM7PEapkr6TRtJKR/4xtWh2RA==}
+  '@vector-im/compound-design-tokens@10.2.4':
+    resolution: {integrity: sha512-2aCjhSvJxktPWnvh5s9Xdc0Rd76AfHqbDbN4QjOxo2VIac6zYdLyQbxMUQ5ZeoR9G3vAxILd0H1UvApRfMilpQ==}
    peerDependencies:
      '@adobe/leonardo-contrast-colors': ^1.0.0
      '@types/react': '*'
@@ -4605,8 +4605,8 @@ packages:
  lines-and-columns@1.2.4:
    resolution: {integrity: sha512-7ylylesZQ/PV29jhEDl3Ufjo6ZX7gCqJr5F7PKrqc93v7fzSymt1BpwEU8nAUXs8qzzvqhbjhK5QZg6Mt/HkBg==}

-  livekit-client@2.22.3:
-    resolution: {integrity: sha512-jw9zBKXY5Gtr5MZ7vEON3QhMNccuDvYHck1PFSyG1aaateQPqgKZFBMgZkFZaXHIf9RV4MDW5xpTK2b/+qbwOg==}
+  livekit-client@2.22.2:
+    resolution: {integrity: sha512-o3yLYoH2eHVR/DmIZzgC96FMvtR4+g/DjeqNwS5zp12EjqrqiRULxm6Oq/YsTE97WnA6fhy23+a2hGkbce5SPA==}
    peerDependencies:
      '@types/dom-mediacapture-record': ^1

@@ -7079,21 +7079,21 @@ snapshots:
      '@jridgewell/resolve-uri': 3.1.2
      '@jridgewell/sourcemap-codec': 1.6.0

-  '@livekit/components-core@0.12.15(livekit-client@2.22.3(@types/dom-mediacapture-record@1.0.22))(tslib@2.8.1)':
+  '@livekit/components-core@0.12.15(livekit-client@2.22.2(@types/dom-mediacapture-record@1.0.22))(tslib@2.8.1)':
    dependencies:
      '@floating-ui/dom': 1.7.6
-      livekit-client: 2.22.3(@types/dom-mediacapture-record@1.0.22)
+      livekit-client: 2.22.2(@types/dom-mediacapture-record@1.0.22)
      loglevel: 1.9.1
      rxjs: 7.8.2
      tslib: 2.8.1

-  '@livekit/components-react@2.9.24(livekit-client@2.22.3(@types/dom-mediacapture-record@1.0.22))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)(tslib@2.8.1)':
+  '@livekit/components-react@2.9.24(livekit-client@2.22.2(@types/dom-mediacapture-record@1.0.22))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)(tslib@2.8.1)':
    dependencies:
-      '@livekit/components-core': 0.12.15(livekit-client@2.22.3(@types/dom-mediacapture-record@1.0.22))(tslib@2.8.1)
+      '@livekit/components-core': 0.12.15(livekit-client@2.22.2(@types/dom-mediacapture-record@1.0.22))(tslib@2.8.1)
      clsx: 2.1.1
      events: 3.3.0
      jose: 6.2.9
-      livekit-client: 2.22.3(@types/dom-mediacapture-record@1.0.22)
+      livekit-client: 2.22.2(@types/dom-mediacapture-record@1.0.22)
      react: 19.2.8
      react-dom: 19.2.8(react@19.2.8)
      tslib: 2.8.1
@@ -7105,11 +7105,11 @@ snapshots:
    dependencies:
      '@bufbuild/protobuf': 1.10.1

-  '@livekit/track-processors@0.7.2(@types/dom-mediacapture-transform@0.1.11)(livekit-client@2.22.3(@types/dom-mediacapture-record@1.0.22))':
+  '@livekit/track-processors@0.7.2(@types/dom-mediacapture-transform@0.1.11)(livekit-client@2.22.2(@types/dom-mediacapture-record@1.0.22))':
    dependencies:
      '@mediapipe/tasks-vision': 0.10.35
      '@types/dom-mediacapture-transform': 0.1.11
-      livekit-client: 2.22.3(@types/dom-mediacapture-record@1.0.22)
+      livekit-client: 2.22.2(@types/dom-mediacapture-record@1.0.22)

  '@matrix-org/matrix-sdk-crypto-wasm@18.5.0': {}

@@ -8695,12 +8695,12 @@ snapshots:
      '@use-gesture/core': 10.3.1
      react: 19.2.8

-  '@vector-im/compound-design-tokens@11.0.0(@types/react@19.2.18)(react@19.2.8)':
+  '@vector-im/compound-design-tokens@10.2.4(@types/react@19.2.18)(react@19.2.8)':
    optionalDependencies:
      '@types/react': 19.2.18
      react: 19.2.8

-  '@vector-im/compound-web@10.0.1(@fontsource/inconsolata@5.3.0)(@fontsource/inter@5.3.0)(@types/react-dom@19.2.5(@types/react@19.2.18))(@types/react@19.2.18)(@vector-im/compound-design-tokens@11.0.0(@types/react@19.2.18)(react@19.2.8))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)':
+  '@vector-im/compound-web@10.0.1(@fontsource/inconsolata@5.3.0)(@fontsource/inter@5.3.0)(@types/react-dom@19.2.5(@types/react@19.2.18))(@types/react@19.2.18)(@vector-im/compound-design-tokens@10.2.4(@types/react@19.2.18)(react@19.2.8))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)':
    dependencies:
      '@floating-ui/react': 0.27.20(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
      '@floating-ui/react-dom': 2.1.9(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
@@ -8712,7 +8712,7 @@ snapshots:
      '@radix-ui/react-progress': 1.1.16(@types/react-dom@19.2.5(@types/react@19.2.18))(@types/react@19.2.18)(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
      '@radix-ui/react-separator': 1.1.15(@types/react-dom@19.2.5(@types/react@19.2.18))(@types/react@19.2.18)(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
      '@radix-ui/react-slot': 1.3.3(@types/react@19.2.18)(react@19.2.8)
-      '@vector-im/compound-design-tokens': 11.0.0(@types/react@19.2.18)(react@19.2.8)
+      '@vector-im/compound-design-tokens': 10.2.4(@types/react@19.2.18)(react@19.2.8)
      classnames: 2.5.1
      react: 19.2.8
      vaul: 1.1.2(@types/react-dom@19.2.5(@types/react@19.2.18))(@types/react@19.2.18)(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
@@ -10180,7 +10180,7 @@ snapshots:

  lines-and-columns@1.2.4: {}

-  livekit-client@2.22.3(@types/dom-mediacapture-record@1.0.22):
+  livekit-client@2.22.2(@types/dom-mediacapture-record@1.0.22):
    dependencies:
      '@livekit/mutex': 1.1.1
      '@livekit/protocol': 1.50.4
@@ -9,7 +9,7 @@ exports[`Can close reaction dialog 1`] = `
    aria-disabled="false"
    aria-expanded="true"
    aria-haspopup="true"
-    aria-labelledby="_r_bh_"
+    aria-labelledby="_r_bb_"
    class="_button_1nw83_8 _has-icon_1nw83_60 _icon-only_1nw83_53"
    data-kind="primary"
    data-size="lg"
@@ -25,7 +25,6 @@ import {
 import {
  setLogExtension as setLKLogExtension,
  setLogLevel as setLKLogLevel,
-  LoggerNames as LKLoggerNames,
 } from "livekit-client";

 import { getUrlParams } from "./UrlParams";
@@ -227,9 +226,6 @@ export class Initializer {

    enableExtendedLivekitLogs.value$.subscribe((enabled) => {
      setLKLogLevel(enabled ? "trace" : "info");
-      // ICE candidate types and connection states are what you need to diagnose
-      // "could not establish pc connection", so always keep those in the rageshake
-      setLKLogLevel("debug", LKLoggerNames.ICE);
    });

    window.setLKLogLevel = setLKLogLevel;
@@ -24,12 +24,10 @@ import { testAudioContext } from "../useAudioContext.test";
 import * as MediaDevicesContext from "../MediaDevicesContext";
 import { LivekitRoomAudioRenderer } from "./MatrixAudioRenderer";
 import {
-  mockLocalParticipant,
  mockMediaDevices,
  mockRemoteParticipant,
  mockTrack,
 } from "../utils/test";
-import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
 import { initializeWidget } from "../widget";
 initializeWidget();
 export const TestAudioContextConstructor = vi.fn(
@@ -133,57 +131,6 @@ it("should render for member", () => {
  expect(queryAllByTestId("audio")).toHaveLength(1);
 });

-function spyOnWarn(): ReturnType<typeof vi.fn> {
-  const warn = vi.fn();
-  vi.spyOn(rootLogger, "getChild").mockReturnValue({
-    warn,
-  } as unknown as typeof rootLogger);
-  return warn;
-}
-
-it("should not render or warn for the local participant", () => {
-  const warn = spyOnWarn();
-  const local = mockLocalParticipant({ identity: "@alice:DEV0" });
-  vi.mocked(useTracks).mockReturnValue([mockTrack(local)]);
-  const { queryAllByTestId } = render(
-    <MediaDevicesProvider value={mockMediaDevices({})}>
-      <LivekitRoomAudioRenderer
-        validIdentities={[]}
-        livekitRoom={{ remoteParticipants: new Map() } as unknown as Room}
-        url={""}
-      />
-    </MediaDevicesProvider>,
-  );
-  expect(queryAllByTestId("audio")).toHaveLength(0);
-  expect(warn).not.toHaveBeenCalled();
-});
-
-it("should warn only once per unexpected participant", () => {
-  const warn = spyOnWarn();
-  const { rerender } = renderTestComponent(
-    [{ userId: "@bob", deviceId: "DEV0" }],
-    ["@alice:DEV0"],
-    [
-      {
-        participantId: "@alice:DEV0",
-        kind: Track.Kind.Audio,
-        source: Track.Source.Microphone,
-      },
-    ],
-  );
-  expect(warn).toHaveBeenCalledTimes(1);
-  rerender(
-    <MediaDevicesProvider value={mockMediaDevices({})}>
-      <LivekitRoomAudioRenderer
-        validIdentities={[]}
-        livekitRoom={{ remoteParticipants: new Map() } as unknown as Room}
-        url={""}
-      />
-    </MediaDevicesProvider>,
-  );
-  expect(warn).toHaveBeenCalledTimes(1);
-});
-
 it("should not render without member", () => {
  const { container, queryAllByTestId } = renderTestComponent(
    [{ userId: "@bob", deviceId: "DEV0" }],
@@ -8,7 +8,7 @@ Please see LICENSE in the repository root for full details.
 import { getTrackReferenceId } from "@livekit/components-core";
 import { type Room as LivekitRoom } from "livekit-client";
 import { type RemoteAudioTrack, Track } from "livekit-client";
-import { useEffect, useMemo, useRef, useState, type ReactNode } from "react";
+import { useEffect, useMemo, useState, type ReactNode } from "react";
 import {
  useTracks,
  AudioTrack,
@@ -60,9 +60,6 @@ export function LivekitRoomAudioRenderer({
  muted,
 }: MatrixAudioRendererProps): ReactNode {
  const logger = rootLogger.getChild("[MatrixAudioRenderer]");
-  // Identities we have already warned about, so that re-renders (which happen
-  // on every active speaker update) don't repeat the warning.
-  const warnedIdentities = useRef(new Set<string>());
  const tracks = useTracks(
    [
      Track.Source.Microphone,
@@ -75,27 +72,22 @@ export function LivekitRoomAudioRenderer({
      room: livekitRoom,
    },
  )
-    // Only keep remote audio tracks (we never render our own audio)
-    .filter(
-      (ref) =>
-        ref.publication.kind === Track.Kind.Audio && !ref.participant.isLocal,
-    )
+    // Only keep audio tracks
+    .filter((ref) => ref.publication.kind === Track.Kind.Audio)
    // Only keep tracks from participants that are in the validIdentities list
    .filter((ref) => {
-      const { identity } = ref.participant;
-      const isValid = validIdentities.includes(identity);
-      if (!isValid && !warnedIdentities.current.has(identity)) {
-        warnedIdentities.current.add(identity);
+      const isValid = validIdentities.includes(ref.participant.identity);
+      if (!isValid) {
+        // TODO make sure to also skip the warn logging for the local identity
        // Log that there is an invalid identity, that means that someone is publishing audio that is not expected to be in the call.
        logger.warn(
-          `Audio track ${identity} from ${url} has no matching matrix call member`,
+          `Audio track ${ref.participant.identity} from ${url} has no matching matrix call member`,
          `current members: ${validIdentities.join()}`,
          `track will not get rendered`,
        );
-      } else if (isValid) {
-        warnedIdentities.current.delete(identity);
+        return false;
      }
-      return isValid;
+      return true;
    });

  // This component is also (in addition to the "only play audio for connected members" logic above)
@@ -1,87 +0,0 @@
-/*
-Copyright 2026 Element Creations Ltd.
-
-SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
-Please see LICENSE in the repository root for full details.
-*/
-
-import { describe, expect, it, vi } from "vitest";
-import { type LocalVideoTrack } from "livekit-client";
-import {
-  type BackgroundOptions,
-  type ProcessorWrapper,
-} from "@livekit/track-processors";
-
-import { applyProcessor, trackProcessorSync } from "./TrackProcessorContext";
-import { constant } from "../state/Behavior";
-import { flushPromises, testScope } from "../utils/test";
-
-const processor = {} as ProcessorWrapper<BackgroundOptions>;
-
-function mockTrack(
-  readyState: MediaStreamTrackState,
-  current?: ProcessorWrapper<BackgroundOptions>,
-): LocalVideoTrack {
-  return {
-    mediaStreamTrack: { readyState },
-    getProcessor: vi.fn().mockReturnValue(current),
-    setProcessor: vi.fn().mockResolvedValue(undefined),
-    stopProcessor: vi.fn().mockResolvedValue(undefined),
-  } as unknown as LocalVideoTrack;
-}
-
-describe("applyProcessor", () => {
-  it("attaches the processor to a live track", () => {
-    const track = mockTrack("live");
-    applyProcessor(track, processor);
-    expect(track.setProcessor).toHaveBeenCalledWith(processor);
-  });
-
-  it("does not attach the processor to an ended track", () => {
-    const track = mockTrack("ended");
-    applyProcessor(track, processor);
-    expect(track.setProcessor).not.toHaveBeenCalled();
-  });
-
-  it("does not surface a rejected setProcessor", async () => {
-    const track = mockTrack("live");
-    vi.mocked(track.setProcessor).mockRejectedValue(
-      new TypeError("Input track cannot be ended"),
-    );
-    const unhandled = vi.fn();
-    process.on("unhandledRejection", unhandled);
-    applyProcessor(track, processor);
-    await flushPromises();
-    process.off("unhandledRejection", unhandled);
-    expect(unhandled).not.toHaveBeenCalled();
-  });
-
-  it("stops the processor when none is wanted", () => {
-    const track = mockTrack("live", processor);
-    applyProcessor(track, undefined);
-    expect(track.stopProcessor).toHaveBeenCalled();
-  });
-
-  it("does not surface a rejected stopProcessor", async () => {
-    const track = mockTrack("live", processor);
-    vi.mocked(track.stopProcessor).mockRejectedValue(new Error("nope"));
-    const unhandled = vi.fn();
-    process.on("unhandledRejection", unhandled);
-    applyProcessor(track, undefined);
-    await flushPromises();
-    process.off("unhandledRejection", unhandled);
-    expect(unhandled).not.toHaveBeenCalled();
-  });
-});
-
-describe("trackProcessorSync", () => {
-  it("applies the processor to the current track", () => {
-    const track = mockTrack("live");
-    trackProcessorSync(
-      testScope(),
-      constant(track),
-      constant({ supported: true, processor }),
-    );
-    expect(track.setProcessor).toHaveBeenCalledWith(processor);
-  });
-});
@@ -19,7 +19,6 @@ import {
  useMemo,
 } from "react";
 import { type LocalVideoTrack } from "livekit-client";
-import { logger } from "matrix-js-sdk/lib/logger";
 import { combineLatest, map, type Observable } from "rxjs";
 import { useObservable } from "observable-hooks";

@@ -66,34 +65,6 @@ export function useTrackProcessorObservable$(): Observable<ProcessorState> {
  return state$;
 }

-/**
- * Attaches or detaches the processor so that the track matches the desired
- * state, without throwing.
- */
-export function applyProcessor(
-  videoTrack: LocalVideoTrack,
-  processor: ProcessorWrapper<BackgroundOptions> | undefined,
-): void {
-  if (processor && !videoTrack.getProcessor()) {
-    // A MediaStreamTrackProcessor cannot be constructed on an ended track
-    // (e.g. the camera was stopped while the processor was being applied),
-    // and setProcessor rejects with a TypeError. The track is going away
-    // anyway, so there is nothing to attach to.
-    if (videoTrack.mediaStreamTrack.readyState === "ended") {
-      logger.debug("Not attaching video processor to an ended track");
-      return;
-    }
-    videoTrack.setProcessor(processor).catch((e) => {
-      logger.warn("Failed to attach video processor", e);
-    });
-  }
-  if (!processor && videoTrack.getProcessor()) {
-    videoTrack.stopProcessor().catch((e) => {
-      logger.warn("Failed to stop video processor", e);
-    });
-  }
-}
-
 /**
 * Updates your video tracks to always use the given processor.
 */
@@ -107,7 +78,13 @@ export const trackProcessorSync = (
    .subscribe(([videoTrack, processorState]) => {
      if (!processorState) return;
      if (!videoTrack) return;
-      applyProcessor(videoTrack, processorState.processor);
+      const { processor } = processorState;
+      if (processor && !videoTrack.getProcessor()) {
+        void videoTrack.setProcessor(processor);
+      }
+      if (!processor && videoTrack.getProcessor()) {
+        void videoTrack.stopProcessor();
+      }
    });
 };

@@ -117,7 +94,12 @@ export const useTrackProcessorSync = (
  const { processor } = useTrackProcessor();
  useEffect(() => {
    if (!videoTrack) return;
-    applyProcessor(videoTrack, processor);
+    if (processor && !videoTrack.getProcessor()) {
+      void videoTrack.setProcessor(processor);
+    }
+    if (!processor && videoTrack.getProcessor()) {
+      void videoTrack.stopProcessor();
+    }
  }, [processor, videoTrack]);
 };

@@ -29,8 +29,6 @@ import waveSoundOgg from "../sound/reactions/wave.ogg?url";
 import waveSoundMp3 from "../sound/reactions/wave.mp3?url";
 import baduntssSoundOgg from "../sound/reactions/baduntss.ogg?url";
 import baduntssSoundMp3 from "../sound/reactions/baduntss.mp3?url";
-import bellSoundOgg from "../sound/reactions/bell.ogg?url";
-import bellSoundMp3 from "../sound/reactions/bell.mp3?url";

 export const ElementCallReactionEventType = "io.element.call.reaction";

@@ -204,15 +202,6 @@ export const ReactionSet: ReactionOption[] = [
      mp3: baduntssSoundMp3,
    },
  },
-  {
-    emoji: "🛎️",
-    name: "bell",
-    alias: ["ding"],
-    sound: {
-      ogg: bellSoundOgg,
-      mp3: bellSoundMp3,
-    },
-  },
 ];

 export interface RaisedHandInfo {
@@ -10,7 +10,6 @@ The following sound effects have been licensed from Pixabay, under https://pixab
 - `reactions/generic`
 - `reactions/lightbulb`
 - `reactions/party`
- `reactions/bell`

 ### Other

@@ -10,7 +10,6 @@ import * as ComponentsCore from "@livekit/components-core";

 import { ObservableScope } from "./ObservableScope";
 import { AudioOutput } from "./MediaDevices";
-import { audioOutput as audioOutputSetting } from "../settings/settings";
 import { withTestScheduler } from "../utils/test";

 const BT_SPEAKER = {
@@ -94,8 +93,6 @@ describe("AudioOutput Tests", () => {

  beforeEach(() => {
    testScope = new ObservableScope();
-    // Device preferences persist in localStorage across tests
-    audioOutputSetting.setValue(undefined);
  });

  afterEach(() => {
@@ -153,9 +150,7 @@ describe("AudioOutput Tests", () => {

      expectObservable(audioOutput.selected$).toBe("abcde", {
        a: undefined,
-        // No "default" pseudo-device (Firefox): the virtual browser default is
-        // selected until the user picks something.
-        b: { id: "", virtualEarpiece: false },
+        b: { id: LAPTOP_SPEAKER.deviceId, virtualEarpiece: false },
        c: { id: MONITOR_SPEAKER.deviceId, virtualEarpiece: false },
        d: { id: LAPTOP_SPEAKER.deviceId, virtualEarpiece: false },
        e: { id: MONITOR_SPEAKER.deviceId, virtualEarpiece: false },
@@ -163,61 +158,6 @@ describe("AudioOutput Tests", () => {
    });
  });

-  it("falls back to the browser default when the selected device disappears", () => {
-    withTestScheduler(({ behavior, cold, schedule, expectObservable }) => {
-      vi.mocked(ComponentsCore.createMediaDeviceObserver).mockReturnValue(
-        cold("a---b", {
-          a: DEVICE_LIST_B,
-          // The monitor is unplugged (or a Bluetooth sink changes profile)
-          b: [LAPTOP_SPEAKER],
-        }),
-      );
-
-      const audioOutput = new AudioOutput(
-        behavior("a", { a: true }),
-        testScope,
-      );
-
-      schedule("--a", {
-        a: () => audioOutput.select(MONITOR_SPEAKER.deviceId),
-      });
-
-      expectObservable(audioOutput.selected$).toBe("a-b-c", {
-        a: { id: "", virtualEarpiece: false },
-        b: { id: MONITOR_SPEAKER.deviceId, virtualEarpiece: false },
-        // Rather than pinning some other physical device, let the browser route
-        c: { id: "", virtualEarpiece: false },
-      });
-    });
-  });
-
-  it("lists the virtual browser default first when there is no default pseudo-device", () => {
-    withTestScheduler(({ behavior, cold, expectObservable }) => {
-      vi.mocked(ComponentsCore.createMediaDeviceObserver).mockReturnValue(
-        cold("a", { a: DEVICE_LIST_B }),
-      );
-
-      const audioOutput = new AudioOutput(
-        behavior("a", { a: true }),
-        testScope,
-      );
-
-      expectObservable(audioOutput.available$).toBe("a", {
-        a: new Map([
-          ["", { type: "default", name: null }],
-          [
-            LAPTOP_SPEAKER.deviceId,
-            { type: "name", name: LAPTOP_SPEAKER.label },
-          ],
-          [
-            MONITOR_SPEAKER.deviceId,
-            { type: "name", name: MONITOR_SPEAKER.label },
-          ],
-        ]),
-      });
-    });
-  });
-
  it("Test mappings", () => {
    // In a real life setup there would be first a blanked list
    // then the real one.
@@ -16,6 +16,7 @@ import {
 import { type Room as MatrixRoom } from "matrix-js-sdk";
 import {
  BehaviorSubject,
+  catchError,
  combineLatest,
  distinctUntilChanged,
  filter,
@@ -38,7 +39,6 @@ import {
  throttleTime,
  timer,
  takeUntil,
-  from,
 } from "rxjs";
 import { type Logger, logger as rootLogger } from "matrix-js-sdk/lib/logger";
 import {
@@ -112,7 +112,7 @@ import {
  TransportState,
 } from "./localMember/LocalMember.ts";
 import {
-  getLocalTransport,
+  createLocalTransport$,
  type LocalTransport,
 } from "./localMember/LocalTransport.ts";
 import {
@@ -563,26 +563,20 @@ export function createCallViewModel$(
  const ownMembershipIdentity: CallMembershipIdentityParts = {
    userId,
    deviceId,
-    // Consumed by the sticky membership manager as `member.id`, *and* stamped
-    // into every to-device key event by the key transport. A pre-sticky
-    // membership advertises `${userId}:${deviceId}` as its `membershipID`
-    // instead, so a uuid there names a member no peer can resolve.
-    memberId:
-      matrixRTCMode === MatrixRTCMode.Matrix_2_0
-        ? uuidv4()
-        : `${userId}:${deviceId}`,
+    // This will only be consumed by the sticky membership manager. So it has no impact on legacy calls.
+    memberId: uuidv4(),
  };

-  const localTransport$ = options.localTransport
-    ? constant(options.localTransport)
-    : from(
-        getLocalTransport({
-          ownMembershipIdentity,
-          client,
-          roomId: matrixRoom.roomId,
-          matrixRTCMode,
-        }),
-      );
+  const localTransport =
+    options.localTransport ??
+    createLocalTransport$({
+      scope: scope,
+      memberships$: memberships$,
+      ownMembershipIdentity,
+      client,
+      roomId: matrixRoom.roomId,
+      matrixRTCMode,
+    });

  const connectionFactory =
    options.connectionFactory ??
@@ -599,7 +593,17 @@ export function createCallViewModel$(
  const connectionManager = createConnectionManager$({
    scope: scope,
    connectionFactory: connectionFactory,
-    localTransport$,
+    localTransport$: scope.behavior(
+      localTransport.active$.pipe(
+        catchError((e: unknown) => {
+          logger.info(
+            "could not pass local transport to createConnectionManager$. localTransport$ threw an error",
+            e,
+          );
+          return of(null);
+        }),
+      ),
+    ),
    remoteTransports$: membershipsAndTransports.transports$,
    logger: logger,
    ownMembershipIdentity,
@@ -655,7 +659,7 @@ export function createCallViewModel$(
    connectionManager,
    client,
    matrixRTCSession,
-    localTransport$,
+    localTransport,
    roomId: matrixRoom.roomId,
    hideScreensharing,
    hostBridge,
@@ -210,8 +210,11 @@ export function withCallViewModel(mode: MatrixRTCMode) {
        connectionState$,
        windowSize$,
        localTransport: {
-          transport: exampleTransport,
-          sfuConfig: exampleSfuConfig,
+          active$: constant({
+            transport: exampleTransport,
+            sfuConfig: exampleSfuConfig,
+          }),
+          advertised$: constant(exampleTransport),
        },
        connectionFactory: {
          createConnection(
@@ -21,7 +21,7 @@ import {
  beforeEach,
  afterEach,
 } from "vitest";
-import { BehaviorSubject, map, of, Subject } from "rxjs";
+import { BehaviorSubject, map, of } from "rxjs";
 import { logger } from "matrix-js-sdk/lib/logger";
 import { type LocalParticipant, type LocalTrack } from "livekit-client";
 import fetchMock from "fetch-mock";
@@ -50,7 +50,10 @@ import {
  TrackState,
  watchScreenShareToggle,
 } from "./LocalMember";
-import { MatrixRTCTransportMissingError } from "../../../utils/errors";
+import {
+  FailToGetOpenIdToken,
+  MatrixRTCTransportMissingError,
+} from "../../../utils/errors";
 import { Epoch, ObservableScope } from "../../ObservableScope";
 import { constant } from "../../Behavior";
 import { ConnectionManagerData } from "../remoteMembers/ConnectionManager";
@@ -58,7 +61,10 @@ import { ConnectionState, type Connection } from "../remoteMembers/Connection";
 import { type Publisher } from "./Publisher";
 import { initializeWidget } from "../../../widget";
 import { nullHostBridge } from "../../../HostBridge";
-import { type LocalTransport } from "./LocalTransport";
+import {
+  type LocalTransport,
+  type LocalTransportWithSFUConfig,
+} from "./LocalTransport";
 import * as openIDSFU from "../../../livekit/openIDSFU";

 initializeWidget();
@@ -255,7 +261,7 @@ describe("LocalMembership", () => {
  });

  it("throws error on missing RTC config error", () => {
-    withTestScheduler(({ scope, hot, expectObservable }) => {
+    withTestScheduler(({ scope, hot, behavior, expectObservable }) => {
      const localTransport$ = scope.behavior<null | LivekitTransportConfig>(
        hot("1ms #", {}, new MatrixRTCTransportMissingError("domain.com")),
        null,
@@ -271,15 +277,16 @@ describe("LocalMembership", () => {
        ),
      };

+      const aLocalTransport: LocalTransport = {
+        advertised$: localTransport$,
+        active$: behavior("a", { a: null }),
+      };
+
      const localMembership = createLocalMembership$({
        scope,
        ...defaultCreateLocalMemberValues,
        connectionManager: mockConnectionManager,
-        localTransport$: hot(
-          "1ms #",
-          {},
-          new MatrixRTCTransportMissingError("domain.com"),
-        ),
+        localTransport: aLocalTransport,
      });

      expectObservable(localMembership.localMemberState$).toBe("ne", {
@@ -289,9 +296,61 @@ describe("LocalMembership", () => {
    });
  });

+  it("Should not publish to active transport if advertised has errors", () => {
+    withTestScheduler(({ scope, hot, behavior, expectObservable }) => {
+      const advertised$ = scope.behavior<null | LivekitTransportConfig>(
+        hot("--#", {}, new FailToGetOpenIdToken(new Error("foo"))),
+        null,
+      );
+
+      // Populate a connection for active
+      const connectionManagerData = new ConnectionManagerData();
+      connectionManagerData.add(connectionTransportBConnected, []);
+      const mockConnectionManager = {
+        transports$: constant(new Epoch([bTransport])),
+        connectionManagerData$: constant(new Epoch(connectionManagerData)),
+      };
+
+      const aLocalTransport: LocalTransport = {
+        advertised$,
+        active$: behavior("a", { n: null, a: bTransportWithSFUConfig }),
+      };
+
+      defaultCreateLocalMemberValues.createPublisherFactory.mockImplementation(
+        () => {
+          return {} as unknown as Publisher;
+        },
+      );
+      const publisherFactory =
+        defaultCreateLocalMemberValues.createPublisherFactory as ReturnType<
+          typeof vi.fn
+        >;
+
+      const localMembership = createLocalMembership$({
+        scope,
+        ...defaultCreateLocalMemberValues,
+        connectionManager: mockConnectionManager,
+        localTransport: aLocalTransport,
+      });
+
+      expectObservable(localMembership.localMemberState$).toBe("n-e", {
+        n: TransportState.Waiting,
+        e: expect.toSatisfy((e) => e instanceof FailToGetOpenIdToken),
+      });
+
+      // Should not have created any publisher
+      expect(publisherFactory).toHaveBeenCalledTimes(0);
+    });
+  });
+
  it("logs if callIntent cannot be updated", async () => {
    const scope = new ObservableScope();

+    const aLocalTransport: LocalTransport = {
+      advertised$: constant(aTransport),
+      active$: constant(aTransportWithSFUConfig),
+    };
+
    const mockConnectionManager = {
      transports$: constant(new Epoch([])),
      connectionManagerData$: constant(new Epoch(new ConnectionManagerData())),
@@ -307,7 +366,7 @@ describe("LocalMembership", () => {
        leaveRoomSession: vi.fn(),
      },
      connectionManager: mockConnectionManager,
-      localTransport$: constant(mockTransport),
+      localTransport: aLocalTransport,
    });
    const expextedLog =
      "'not connected yet' while updating the call intent (this is expected on startup)";
@@ -319,19 +378,33 @@ describe("LocalMembership", () => {
    scope.end();
  });

-  const mockTransportConfig = {
+  const aTransport = {
    livekit_service_url: "a",
  } as LivekitTransportConfig;

-  const mockTransport = {
-    transport: mockTransportConfig,
+  const aTransportWithSFUConfig = {
+    transport: aTransport,
    sfuConfig: {
      jwt: "foo",
      livekitAlias: "bar",
      livekitIdentity: "baz",
      url: "bro",
    },
-  } as LocalTransport;
+  } as LocalTransportWithSFUConfig;
+
+  const bTransport = {
+    livekit_service_url: "b",
+  } as LivekitTransportConfig;
+
+  const bTransportWithSFUConfig = {
+    transport: bTransport,
+    sfuConfig: {
+      jwt: "foo2",
+      livekitAlias: "bar2",
+      livekitIdentity: "baz2",
+      url: "bro2",
+    },
+  } as LocalTransportWithSFUConfig;

  const connectionTransportAConnected = {
    livekitRoom: mockLivekitRoom({
@@ -341,13 +414,18 @@ describe("LocalMembership", () => {
      } as unknown as LocalParticipant,
    }),
    state$: constant(ConnectionState.LivekitConnected),
-    transport: mockTransportConfig,
-  } as Connection;
+    transport: aTransport,
+  } as unknown as Connection;
  const connectionTransportAConnecting = {
    ...connectionTransportAConnected,
    state$: constant(ConnectionState.LivekitConnecting),
    livekitRoom: mockLivekitRoom({}),
  } as unknown as Connection;
+  const connectionTransportBConnected = {
+    state$: constant(ConnectionState.LivekitConnected),
+    transport: bTransport,
+    livekitRoom: mockLivekitRoom({}),
+  } as unknown as Connection;

  const authCallSpy = vi
    .spyOn(openIDSFU, "getSFUConfigWithOpenID")
@@ -381,7 +459,10 @@ describe("LocalMembership", () => {
          ),
        },
        joinMatrixRTC,
-        localTransport$: constant(mockTransport),
+        localTransport: {
+          advertised$: constant(aTransport),
+          active$: constant(aTransportWithSFUConfig),
+        },
        delayId$,
      });

@@ -390,7 +471,7 @@ describe("LocalMembership", () => {
      await flushPromises();
      // Joins with timings appropriate for the level of delegation support
      expect(joinMatrixRTC).toHaveBeenCalledWith(
-        mockTransportConfig,
+        aTransport,
        delayedLeaveTimings,
      );

@@ -424,7 +505,75 @@ describe("LocalMembership", () => {
    },
  );

-  it("only starts tracks if requested", async () => {
+  it("recreates publisher if new connection is used, always unpublish and end tracks", async () => {
+    const scope = new ObservableScope();
+
+    const activeTransport$ = new BehaviorSubject(aTransportWithSFUConfig);
+    const aLocalTransport: LocalTransport = {
+      advertised$: constant(aTransport),
+      active$: activeTransport$,
+    };
+
+    const publishers: Publisher[] = [];
+    let seed = 0;
+    defaultCreateLocalMemberValues.createPublisherFactory.mockImplementation(
+      () => {
+        const a = seed;
+        seed += 1;
+        logger.info(`creating [${a}]`);
+        const p = {
+          // It is enought to check if destroy is called. Destroy itself is tested in the publisher to make sure it does
+          // all the cleanup we need.
+          destroy: vi.fn(),
+          stopPublishing: vi.fn().mockImplementation(() => {
+            logger.info(`stopPublishing [${a}]`);
+          }),
+          stopTracks: vi.fn(),
+        };
+        publishers.push(p as unknown as Publisher);
+        return p;
+      },
+    );
+    const publisherFactory =
+      defaultCreateLocalMemberValues.createPublisherFactory as ReturnType<
+        typeof vi.fn
+      >;
+
+    const connectionManagerData = new ConnectionManagerData();
+    connectionManagerData.add(connectionTransportAConnected, []);
+    connectionManagerData.add(connectionTransportBConnected, []);
+    createLocalMembership$({
+      scope,
+      ...defaultCreateLocalMemberValues,
+      connectionManager: {
+        connectionManagerData$: constant(new Epoch(connectionManagerData)),
+      },
+      localTransport: aLocalTransport,
+    });
+    await flushPromises();
+    activeTransport$.next({
+      ...aTransportWithSFUConfig,
+      transport: bTransport,
+    });
+    await flushPromises();
+
+    expect(publisherFactory).toHaveBeenCalledTimes(2);
+    expect(publishers.length).toBe(2);
+    // stop the first Publisher and let the second one life.
+    expect(publishers[0].destroy).toHaveBeenCalled();
+    expect(publishers[1].destroy).not.toHaveBeenCalled();
+    expect(publisherFactory.mock.calls[0][0].transport).toBe(aTransport);
+    expect(publisherFactory.mock.calls[1][0].transport).toBe(bTransport);
+    scope.end();
+    await flushPromises();
+    // stop all tracks after ending scopes
+    expect(publishers[1].destroy).toHaveBeenCalled();
+    // expect(publishers[1].stopTracks).toHaveBeenCalled();
+
+    defaultCreateLocalMemberValues.createPublisherFactory.mockReset();
+  });
+
+  it("only start tracks if requested", async () => {
    const scope = new ObservableScope();

    const publishers: Publisher[] = [];
@@ -453,6 +602,11 @@ describe("LocalMembership", () => {
        typeof vi.fn
      >;

+    const aLocalTransport: LocalTransport = {
+      advertised$: constant(aTransport),
+      active$: constant(aTransportWithSFUConfig),
+    };
+
    const connectionManagerData = new ConnectionManagerData();
    connectionManagerData.add(connectionTransportAConnected, []);
    // connectionManagerData.add(connectionTransportB, []);
@@ -462,7 +616,7 @@ describe("LocalMembership", () => {
      connectionManager: {
        connectionManagerData$: constant(new Epoch(connectionManagerData)),
      },
-      localTransport$: constant(mockTransport),
+      localTransport: aLocalTransport,
    });
    await flushPromises();
    expect(publisherFactory).toHaveBeenCalledOnce();
@@ -483,8 +637,16 @@ describe("LocalMembership", () => {
  //
  it("tracks livekit state correctly", async () => {
    const scope = new ObservableScope();
+
    const connectionManagerData = new ConnectionManagerData();
-    const localTransport$ = new Subject<LocalTransport>();
+
+    const activeTransport$ =
+      new BehaviorSubject<null | LocalTransportWithSFUConfig>(null);
+
+    const aLocalTransport: LocalTransport = {
+      advertised$: constant(aTransport),
+      active$: activeTransport$,
+    };

    const connectionManagerData$ = new BehaviorSubject(
      new Epoch(connectionManagerData),
@@ -525,14 +687,14 @@ describe("LocalMembership", () => {
      connectionManager: {
        connectionManagerData$,
      },
-      localTransport$,
+      localTransport: aLocalTransport,
    });

    await flushPromises();
    expect(localMembership.localMemberState$.value).toStrictEqual(
      TransportState.Waiting,
    );
-    localTransport$.next(mockTransport);
+    activeTransport$.next(aTransportWithSFUConfig);
    await flushPromises();
    expect(localMembership.localMemberState$.value).toStrictEqual({
      matrix: RTCMemberStatus.Connected,
@@ -557,7 +719,7 @@ describe("LocalMembership", () => {
    });

    (
-      connectionManagerData2.getConnectionForTransport(mockTransportConfig)!
+      connectionManagerData2.getConnectionForTransport(aTransport)!
        .state$ as BehaviorSubject<ConnectionState>
    ).next(ConnectionState.LivekitConnected);
    expect(localMembership.localMemberState$.value).toStrictEqual({
@@ -660,7 +822,10 @@ describe("LocalMembership", () => {
        connectionManager: {
          connectionManagerData$: constant(new Epoch(connectionManagerData)),
        },
-        localTransport$: constant(mockTransport),
+        localTransport: {
+          advertised$: constant(aTransport),
+          active$: constant(aTransportWithSFUConfig),
+        },
      });

      await flushPromises();
@@ -697,7 +862,10 @@ describe("LocalMembership", () => {
        connectionManager: {
          connectionManagerData$: constant(new Epoch(connectionManagerData)),
        },
-        localTransport$: constant(mockTransport),
+        localTransport: {
+          advertised$: constant(aTransport),
+          active$: constant(aTransportWithSFUConfig),
+        },
      });

      await flushPromises();
@@ -745,7 +913,10 @@ describe("LocalMembership", () => {
        connectionManager: {
          connectionManagerData$: constant(new Epoch(connectionManagerData)),
        },
-        localTransport$: constant(mockTransport),
+        localTransport: {
+          advertised$: constant(aTransport),
+          active$: constant(aTransportWithSFUConfig),
+        },
      });

      await flushPromises();
@@ -786,7 +957,10 @@ describe("LocalMembership", () => {
        connectionManager: {
          connectionManagerData$: constant(new Epoch(connectionManagerData)),
        },
-        localTransport$: constant(mockTransport),
+        localTransport: {
+          advertised$: constant(aTransport),
+          active$: constant(aTransportWithSFUConfig),
+        },
      });

      await flushPromises();
@@ -852,7 +1026,10 @@ describe("LocalMembership", () => {
        connectionManager: {
          connectionManagerData$: constant(new Epoch(connectionManagerData)),
        },
-        localTransport$: constant(mockTransport),
+        localTransport: {
+          advertised$: constant(aTransport),
+          active$: constant(aTransportWithSFUConfig),
+        },
      });
      return { scope, localMembership };
    };
@@ -862,7 +1039,7 @@ describe("LocalMembership", () => {
      const setScreenShareEnabled = vi.fn().mockRejectedValue(error);
      const connection = {
        state$: constant(ConnectionState.LivekitConnected),
-        transport: mockTransportConfig,
+        transport: aTransport,
        livekitRoom: mockLivekitRoom({
          localParticipant: mockLocalParticipant({
            isScreenShareEnabled: false,
@@ -38,10 +38,6 @@ import {
  startWith,
  switchMap,
  tap,
-  NEVER,
-  concat,
-  race,
-  Subject,
 } from "rxjs";
 import { type Logger } from "matrix-js-sdk/lib/logger";
 import { deepCompare } from "matrix-js-sdk/lib/utils";
@@ -81,6 +77,8 @@ import {
 } from "../remoteMembers/Connection.ts";
 import { type HomeserverConnected } from "./HomeserverConnected.ts";
 import { type LocalTransport } from "./LocalTransport.ts";
+import { areLivekitTransportsEqual } from "../remoteMembers/MatrixLivekitMembers.ts";
+import { or$ } from "../../../utils/observable.ts";
 import { getSFUConfigWithOpenID } from "../../../livekit/openIDSFU.ts";

 export enum TransportState {
@@ -150,7 +148,7 @@ interface Props {
  homeserverConnected: HomeserverConnected;
  roomId: string;
  ownMembershipIdentity: CallMembershipIdentityParts;
-  localTransport$: Observable<LocalTransport>;
+  localTransport: LocalTransport;
  client: Pick<MatrixClient, "getDeviceId" | "getOpenIdToken">;
  matrixRTCSession: Pick<
    MatrixRTCSession,
@@ -196,7 +194,7 @@ interface Props {
 export const createLocalMembership$ = ({
  scope,
  connectionManager,
-  localTransport$: localTransportWithErrors$,
+  localTransport,
  homeserverConnected,
  createPublisherFactory,
  joinMatrixRTC,
@@ -254,24 +252,20 @@ export const createLocalMembership$ = ({
  const logger = parentLogger.getChild("[LocalMembership]");
  logger.debug(`Creating local membership..`);

-  // Unwrap the local transport and set the state of the LocalMembership to error in case the transport is an error.
-  const fatalTransportError$ = new Subject<ElementCallError>();
-  const localTransport$ = localTransportWithErrors$.pipe(
-    catchError((e: unknown) => {
-      let error: ElementCallError;
-      if (e instanceof ElementCallError) {
-        error = e;
-      } else {
-        error = new UnknownCallError(
-          e instanceof Error
-            ? e
-            : new Error("Unknown error from localTransport"),
-        );
-      }
-      fatalTransportError$.next(error);
-      return NEVER; // Make this Observable swallow the error
-    }),
-  );
+  // We consider error on the transport as fatal.
+  // Whether it is the active transport or the preferred transport.
+  const handleTransportError = (e: unknown): Observable<null> => {
+    let error: ElementCallError;
+    if (e instanceof ElementCallError) {
+      error = e;
+    } else {
+      error = new UnknownCallError(
+        e instanceof Error ? e : new Error("Unknown error from localTransport"),
+      );
+    }
+    setTransportError(error);
+    return of(null);
+  };

  async function checkDelegationSupport(
    endpointUrl: string,
@@ -309,40 +303,58 @@ export const createLocalMembership$ = ({

  // The transport that we will advertise in our membership, paired with info as
  // to whether delayed event delegation is supported
-  const joinParams$ = scope.behavior(
-    localTransport$.pipe(
-      switchMap(async ({ transport }) => {
-        const transportSupportsDelegation = checkDelegationSupport(
-          transport.livekit_service_url + "/delegate_delayed_leave",
-          `transport ${transport.livekit_service_url}`,
-        );
-        return {
-          transport,
-          delegationSupported:
-            (await homeserverSupportsDelegation) ||
-            (await transportSupportsDelegation),
-        };
+  const joinParams$ = localTransport.advertised$.pipe(
+    catchError(handleTransportError),
+    distinctUntilChanged(areLivekitTransportsEqual),
+    switchMap((transport) => {
+      if (transport === null) return of(null);
+      const transportSupportsDelegation = checkDelegationSupport(
+        transport.livekit_service_url + "/delegate_delayed_leave",
+        `transport ${transport.livekit_service_url}`,
+      );
+      return or$(
+        from(homeserverSupportsDelegation),
+        from(transportSupportsDelegation),
+      ).pipe(
+        map((delegationSupported) => ({ transport, delegationSupported })),
+        startWith(null),
+      );
+    }),
+  );
+
+  // Unwrap the local transport and set the state of the LocalMembership to error in case the transport is an error.
+  const activeTransport$ = scope.behavior(
+    combineLatest([localTransport.active$, localTransport.advertised$]).pipe(
+      map(([active, advertised]) => {
+        // Our policy is to not publish to another transport if our prefered transport is miss-configured
+        if (advertised == null) return null;
+
+        return active?.transport ?? null;
      }),
+      catchError(handleTransportError),
+      distinctUntilChanged(areLivekitTransportsEqual),
    ),
-    null,
  );

  // Drop Epoch data here since we will not combine this anymore
  const localConnection$ = scope.behavior(
    combineLatest([
      connectionManager.connectionManagerData$,
-      localTransport$,
+      activeTransport$,
    ]).pipe(
-      map(([{ value: connectionData }, { transport }]) =>
-        connectionData.getConnectionForTransport(transport),
-      ),
+      map(([{ value: connectionData }, localTransport]) => {
+        if (localTransport === null) {
+          return null;
+        }
+
+        return connectionData.getConnectionForTransport(localTransport);
+      }),
      tap((connection) => {
        logger.info(
          `Local connection updated: ${connection?.transport?.livekit_service_url}`,
        );
      }),
    ),
-    null,
  );

  // Tracks error that happen when creating the local tracks.
@@ -478,6 +490,18 @@ export const createLocalMembership$ = ({
    }
  };

+  const fatalTransportError$ = new BehaviorSubject<ElementCallError | null>(
+    null,
+  );
+
+  const setTransportError = (e: ElementCallError): void => {
+    if (fatalTransportError$.value !== null) {
+      logger.error("Multiple Transport Errors:", e);
+    } else {
+      fatalTransportError$.next(e);
+    }
+  };
+
  const localConnectionState$ = localConnection$.pipe(
    switchMap((connection) => (connection ? connection.state$ : of(null))),
  );
@@ -485,29 +509,38 @@ export const createLocalMembership$ = ({
  const mediaState$: Behavior<LocalMemberMediaState> = scope.behavior(
    combineLatest([
      localConnectionState$,
+      activeTransport$,
      joinAndPublishRequested$,
      from(trackStartRequested.promise).pipe(
        map(() => true),
        startWith(false),
      ),
    ]).pipe(
-      map(([localConnectionState, shouldPublish, shouldStartTracks]) => {
-        const trackState: TrackState = shouldStartTracks
-          ? TrackState.Ready
-          : TrackState.WaitingForUser;
+      map(
+        ([
+          localConnectionState,
+          localTransport,
+          shouldPublish,
+          shouldStartTracks,
+        ]) => {
+          if (!localTransport) return null;
+          const trackState: TrackState = shouldStartTracks
+            ? TrackState.Ready
+            : TrackState.WaitingForUser;

-        if (
-          localConnectionState !== ConnectionState.LivekitConnected ||
-          trackState !== TrackState.Ready
-        )
-          return {
-            connection: localConnectionState,
-            tracks: trackState,
-          };
-        if (!shouldPublish) return PublishState.WaitingForUser;
-        // if (!publishing) return PublishState.Starting;
-        return PublishState.Publishing;
-      }),
+          if (
+            localConnectionState !== ConnectionState.LivekitConnected ||
+            trackState !== TrackState.Ready
+          )
+            return {
+              connection: localConnectionState,
+              tracks: trackState,
+            };
+          if (!shouldPublish) return PublishState.WaitingForUser;
+          // if (!publishing) return PublishState.Starting;
+          return PublishState.Publishing;
+        },
+      ),
      distinctUntilChanged(deepCompare),
    ),
  );
@@ -521,36 +554,30 @@ export const createLocalMembership$ = ({
  };

  const localMemberState$ = scope.behavior<LocalMemberState>(
-    concat(
-      // Waiting until…
-      of(TransportState.Waiting),
-      race(
-        // either there is a fatal transport error
-        fatalTransportError$,
-        // or the transport is available.
-        localTransport$.pipe(
-          switchMap(() =>
-            // Once available, track session/media state.
-            combineLatest([
-              mediaState$,
-              homeserverConnected.rtsSession$,
-              fatalMatrixError$,
-              publishError$,
-            ]).pipe(
-              map(
-                ([
-                  mediaState,
-                  rtcSessionStatus,
-                  fatalMatrixError,
-                  publishError,
-                ]) => ({
-                  matrix: fatalMatrixError ?? rtcSessionStatus,
-                  media: publishError ?? mediaState,
-                }),
-              ),
-            ),
-          ),
-        ),
+    combineLatest([
+      mediaState$,
+      homeserverConnected.rtsSession$,
+      fatalMatrixError$,
+      fatalTransportError$,
+      publishError$,
+    ]).pipe(
+      map(
+        ([
+          mediaState,
+          rtcSessionStatus,
+          fatalMatrixError,
+          fatalTransportError,
+          publishError,
+        ]) => {
+          if (fatalTransportError !== null) return fatalTransportError;
+          // `mediaState` will be 'null' until the transport/connection appears.
+          if (mediaState && rtcSessionStatus)
+            return {
+              matrix: fatalMatrixError ?? rtcSessionStatus,
+              media: publishError ?? mediaState,
+            };
+          return TransportState.Waiting;
+        },
      ),
    ),
  );
@@ -658,7 +685,7 @@ export const createLocalMembership$ = ({
      });
  });

-  // Join and leave the session as needed
+  // Keep matrix rtc session in sync with advertisedTransport$, connectRequested$
  scope.reconcile(
    scope.behavior(combineLatest([joinParams$, joinAndPublishRequested$])),
    async ([joinParams, shouldConnect]) => {
@@ -14,10 +14,19 @@ import {
  type MockedObject,
  vi,
 } from "vitest";
+import { type CallMembership } from "matrix-js-sdk/lib/matrixrtc";
+import { lastValueFrom } from "rxjs";
 import fetchMock from "fetch-mock";

-import { mockConfig, ownMemberMock } from "../../../utils/test";
-import { getLocalTransport } from "./LocalTransport";
+import {
+  mockConfig,
+  flushPromises,
+  ownMemberMock,
+  testScope,
+} from "../../../utils/test";
+import { createLocalTransport$ } from "./LocalTransport";
+import { constant } from "../../Behavior";
+import { Epoch, ObservableScope } from "../../ObservableScope";
 import {
  MatrixRTCTransportMissingError,
  FailToGetOpenIdToken,
@@ -38,79 +47,118 @@ describe("LocalTransport", () => {
  beforeEach(() => vi.clearAllMocks());

  it("throws if config is missing", async () => {
-    await expect(
-      getLocalTransport({
-        roomId: "!room:example.org",
-        client: {
-          // eslint-disable-next-line @typescript-eslint/naming-convention
-          _unstable_getRTCTransports: async () => Promise.resolve([]),
-          getDomain: () => "example.org",
-          // These won't be called in this error path but satisfy the type
-          getOpenIdToken: vi.fn(),
-          getDeviceId: vi.fn(),
-        },
-        ownMembershipIdentity: ownMemberMock,
-        matrixRTCMode: MatrixRTCMode.Compatibility,
-      }),
-    ).rejects.toThrow(new MatrixRTCTransportMissingError("example.org"));
+    const { advertised$, active$ } = createLocalTransport$({
+      scope: testScope(),
+      roomId: "!room:example.org",
+      memberships$: constant(new Epoch<CallMembership[]>([])),
+      client: {
+        // eslint-disable-next-line @typescript-eslint/naming-convention
+        _unstable_getRTCTransports: async () => Promise.resolve([]),
+        getDomain: () => "example.org",
+        // These won't be called in this error path but satisfy the type
+        getOpenIdToken: vi.fn(),
+        getDeviceId: vi.fn(),
+      },
+      ownMembershipIdentity: ownMemberMock,
+      matrixRTCMode: MatrixRTCMode.Compatibility,
+    });
+    await flushPromises();
+
+    expect(() => advertised$.value).toThrow(
+      new MatrixRTCTransportMissingError("example.org"),
+    );
+    expect(() => active$.value).toThrow(
+      new MatrixRTCTransportMissingError("example.org"),
+    );
  });

  it("throws FailToGetOpenIdToken when OpenID fetch fails", async () => {
    // Provide a valid config so makeTransportInternal resolves a transport
+    const scope = new ObservableScope();
    mockConfig({
      livekit: { livekit_service_url: "https://lk.example.org" },
    });
-    vi.spyOn(openIDSFU, "getSFUConfigWithOpenID").mockRejectedValue(
-      new FailToGetOpenIdToken(new Error("no openid")),
+    const resolver = Promise.withResolvers<void>();
+    vi.spyOn(openIDSFU, "getSFUConfigWithOpenID").mockImplementation(
+      async () => {
+        await resolver.promise;
+        throw new FailToGetOpenIdToken(new Error("no openid"));
+      },
    );
+    const observations: unknown[] = [];
+    const errors: Error[] = [];
+    const { advertised$, active$ } = createLocalTransport$({
+      scope,
+      roomId: "!example_room_id",
+      memberships$: constant(new Epoch<CallMembership[]>([])),
+      client: {
+        getDomain: () => "example.org",
+        // eslint-disable-next-line @typescript-eslint/naming-convention
+        _unstable_getRTCTransports: async () => Promise.resolve([]),
+        getOpenIdToken: vi.fn(),
+        getDeviceId: vi.fn(),
+      },
+      ownMembershipIdentity: ownMemberMock,
+      matrixRTCMode: MatrixRTCMode.Compatibility,
+    });
+    active$.subscribe(
+      (o) => observations.push(o),
+      (e) => errors.push(e),
+    );
+    resolver.resolve();
+    await flushPromises();

-    await expect(
-      getLocalTransport({
-        roomId: "!example_room_id",
-        client: {
-          getDomain: () => "example.org",
-          // eslint-disable-next-line @typescript-eslint/naming-convention
-          _unstable_getRTCTransports: async () => Promise.resolve([]),
-          getOpenIdToken: vi.fn(),
-          getDeviceId: vi.fn(),
-        },
-        ownMembershipIdentity: ownMemberMock,
-        matrixRTCMode: MatrixRTCMode.Compatibility,
-      }),
-    ).rejects.toThrow(new FailToGetOpenIdToken(new Error("no openid")));
+    const expectedError = new FailToGetOpenIdToken(new Error("no openid"));
+    expect(observations).toStrictEqual([null]);
+    expect(errors).toStrictEqual([expectedError]);
+    expect(() => advertised$.value).toThrow(expectedError);
+    expect(() => active$.value).toThrow(expectedError);
  });

-  it("returns preferred transport", async () => {
+  it("emits preferred transport after OpenID resolves", async () => {
    // Use config so transport discovery succeeds, but delay OpenID JWT fetch
    mockConfig({
      livekit: { livekit_service_url: "https://lk.example.org" },
    });

-    vi.spyOn(openIDSFU, "getSFUConfigWithOpenID").mockResolvedValue({
+    const openIdResolver = Promise.withResolvers<openIDSFU.SFUConfig>();
+
+    vi.spyOn(openIDSFU, "getSFUConfigWithOpenID").mockReturnValue(
+      openIdResolver.promise,
+    );
+
+    const { advertised$, active$ } = createLocalTransport$({
+      scope: testScope(),
+      roomId: "!room:example.org",
+      memberships$: constant(new Epoch<CallMembership[]>([])),
+      client: {
+        // eslint-disable-next-line @typescript-eslint/naming-convention
+        _unstable_getRTCTransports: async () => Promise.resolve([]),
+        getDomain: () => "example.org",
+        getOpenIdToken: vi.fn(),
+        getDeviceId: vi.fn(),
+      },
+      ownMembershipIdentity: ownMemberMock,
+      matrixRTCMode: MatrixRTCMode.Compatibility,
+    });
+
+    openIdResolver.resolve?.({
      url: "https://lk.example.org",
      jwt: "jwt",
      livekitAlias: "Akph4alDMhen",
      livekitIdentity: ownMemberMock.userId + ":" + ownMemberMock.deviceId,
    });
-
-    expect(
-      await getLocalTransport({
-        roomId: "!room:example.org",
-        client: {
-          // eslint-disable-next-line @typescript-eslint/naming-convention
-          _unstable_getRTCTransports: async () => Promise.resolve([]),
-          getDomain: () => "example.org",
-          getOpenIdToken: vi.fn(),
-          getDeviceId: vi.fn(),
-        },
-        ownMembershipIdentity: ownMemberMock,
-        matrixRTCMode: MatrixRTCMode.Compatibility,
-      }),
-    ).toStrictEqual({
-      transport: {
-        livekit_service_url: "https://lk.example.org",
-        type: "livekit",
-      },
+    expect(advertised$.value).toBe(null);
+    expect(active$.value).toBe(null);
+    await flushPromises();
+    // final
+    const expectedTransport = {
+      livekit_service_url: "https://lk.example.org",
+      type: "livekit",
+    };
+    expect(advertised$.value).toStrictEqual(expectedTransport);
+    expect(active$.value).toStrictEqual({
+      transport: expectedTransport,
      sfuConfig: {
        jwt: "jwt",
        livekitAlias: "Akph4alDMhen",
@@ -120,19 +168,22 @@ describe("LocalTransport", () => {
    });
  });

-  type LocalTransportProps = Parameters<typeof getLocalTransport>[0];
+  type LocalTransportProps = Parameters<typeof createLocalTransport$>[0];

  describe("transport configuration mechanisms", () => {
    let localTransportOpts: LocalTransportProps & {
      client: MockedObject<LocalTransportProps["client"]>;
    };
+    let openIdResolver: PromiseWithResolvers<openIDSFU.SFUConfig>;
    beforeEach(() => {
      mockConfig({});
      customLivekitUrl.setValue(customLivekitUrl.defaultValue);
      localTransportOpts = {
        ownMembershipIdentity: ownMemberMock,
+        scope: testScope(),
        roomId: "!example_room_id",
        matrixRTCMode: MatrixRTCMode.Compatibility,
+        memberships$: constant(new Epoch<CallMembership[]>([])),
        client: {
          getDomain: vi.fn().mockReturnValue("example.org"),
          // eslint-disable-next-line @typescript-eslint/naming-convention
@@ -141,6 +192,10 @@ describe("LocalTransport", () => {
          getDeviceId: vi.fn(),
        },
      };
+      openIdResolver = Promise.withResolvers<openIDSFU.SFUConfig>();
+      vi.spyOn(openIDSFU, "getSFUConfigWithOpenID").mockReturnValue(
+        openIdResolver.promise,
+      );
    });

    afterEach(() => {
@@ -151,15 +206,19 @@ describe("LocalTransport", () => {
      mockConfig({
        livekit: { livekit_service_url: "https://lk.example.org" },
      });
-      vi.spyOn(openIDSFU, "getSFUConfigWithOpenID").mockResolvedValue(
-        openIdResponse,
-      );
-
-      expect(await getLocalTransport(localTransportOpts)).toStrictEqual({
-        transport: {
-          livekit_service_url: "https://lk.example.org",
-          type: "livekit",
-        },
+      const { advertised$, active$ } =
+        createLocalTransport$(localTransportOpts);
+      openIdResolver.resolve?.(openIdResponse);
+      expect(advertised$.value).toBe(null);
+      expect(active$.value).toBe(null);
+      await flushPromises();
+      const expectedTransport = {
+        livekit_service_url: "https://lk.example.org",
+        type: "livekit",
+      };
+      expect(advertised$.value).toStrictEqual(expectedTransport);
+      expect(active$.value).toStrictEqual({
+        transport: expectedTransport,
        sfuConfig: {
          jwt: "e30=.eyJzdWIiOiJAbWU6ZXhhbXBsZS5vcmc6QUJDREVGIiwidmlkZW8iOnsicm9vbSI6IiFleGFtcGxlX3Jvb21faWQifX0=.e30=",
          livekitAlias: "Akph4alDMhen",
@@ -171,11 +230,12 @@ describe("LocalTransport", () => {

    it("supports getting transport via user settings", async () => {
      customLivekitUrl.setValue("https://lk.example.org");
-      vi.spyOn(openIDSFU, "getSFUConfigWithOpenID").mockResolvedValue(
-        openIdResponse,
-      );
-
-      expect(await getLocalTransport(localTransportOpts)).toStrictEqual({
+      const { advertised$, active$ } =
+        createLocalTransport$(localTransportOpts);
+      openIdResolver.resolve?.(openIdResponse);
+      expect(advertised$.value).toBe(null);
+      await flushPromises();
+      expect(active$.value).toStrictEqual({
        transport: {
          livekit_service_url: "https://lk.example.org",
          type: "livekit",
@@ -193,15 +253,19 @@ describe("LocalTransport", () => {
      localTransportOpts.client._unstable_getRTCTransports.mockResolvedValue([
        { type: "livekit", livekit_service_url: "https://lk.example.org" },
      ]);
-      vi.spyOn(openIDSFU, "getSFUConfigWithOpenID").mockResolvedValue(
-        openIdResponse,
-      );
-
-      expect(await getLocalTransport(localTransportOpts)).toStrictEqual({
-        transport: {
-          livekit_service_url: "https://lk.example.org",
-          type: "livekit",
-        },
+      const { advertised$, active$ } =
+        createLocalTransport$(localTransportOpts);
+      openIdResolver.resolve?.(openIdResponse);
+      expect(advertised$.value).toBe(null);
+      expect(active$.value).toBe(null);
+      await flushPromises();
+      const expectedTransport = {
+        livekit_service_url: "https://lk.example.org",
+        type: "livekit",
+      };
+      expect(advertised$.value).toStrictEqual(expectedTransport);
+      expect(active$.value).toStrictEqual({
+        transport: expectedTransport,
        sfuConfig: {
          jwt: "e30=.eyJzdWIiOiJAbWU6ZXhhbXBsZS5vcmc6QUJDREVGIiwidmlkZW8iOnsicm9vbSI6IiFleGFtcGxlX3Jvb21faWQifX0=.e30=",
          livekitAlias: "Akph4alDMhen",
@@ -215,31 +279,38 @@ describe("LocalTransport", () => {
      localTransportOpts.client._unstable_getRTCTransports.mockResolvedValue([
        { type: "livekit", livekit_service_url: "https://lk.example.org" },
      ]);
-      vi.spyOn(openIDSFU, "getSFUConfigWithOpenID").mockRejectedValue(
+      openIdResolver.reject(
        new FailToGetOpenIdToken(new Error("Test driven error")),
      );
-
-      await expect(getLocalTransport(localTransportOpts)).rejects.toThrow(
-        expect.any(FailToGetOpenIdToken),
-      );
+      await expect(async () =>
+        lastValueFrom(createLocalTransport$(localTransportOpts).active$),
+      ).rejects.toThrow(expect.any(FailToGetOpenIdToken));
    });

    it("throws if no options are available", async () => {
-      await expect(
-        getLocalTransport({
-          ownMembershipIdentity: ownMemberMock,
-          roomId: "!example_room_id",
-          matrixRTCMode: MatrixRTCMode.Compatibility,
-          client: {
-            getDomain: () => "example.org",
-            // eslint-disable-next-line @typescript-eslint/naming-convention
-            _unstable_getRTCTransports: async () => Promise.resolve([]),
-            // These won't be called in this error path but satisfy the type
-            getOpenIdToken: vi.fn(),
-            getDeviceId: vi.fn(),
-          },
-        }),
-      ).rejects.toThrow(new MatrixRTCTransportMissingError("example.org"));
+      const { advertised$, active$ } = createLocalTransport$({
+        scope: testScope(),
+        ownMembershipIdentity: ownMemberMock,
+        roomId: "!example_room_id",
+        matrixRTCMode: MatrixRTCMode.Compatibility,
+        memberships$: constant(new Epoch<CallMembership[]>([])),
+        client: {
+          getDomain: () => "example.org",
+          // eslint-disable-next-line @typescript-eslint/naming-convention
+          _unstable_getRTCTransports: async () => Promise.resolve([]),
+          // These won't be called in this error path but satisfy the type
+          getOpenIdToken: vi.fn(),
+          getDeviceId: vi.fn(),
+        },
+      });
+      await flushPromises();
+
+      expect(() => advertised$.value).toThrow(
+        new MatrixRTCTransportMissingError("example.org"),
+      );
+      expect(() => active$.value).toThrow(
+        new MatrixRTCTransportMissingError("example.org"),
+      );
    });
  });
 });
@@ -5,11 +5,17 @@ SPDX-License-IdFentifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */

-import { type LivekitTransportConfig } from "matrix-js-sdk/lib/matrixrtc";
+import {
+  type CallMembership,
+  type LivekitTransportConfig,
+} from "matrix-js-sdk/lib/matrixrtc";
 import { type MatrixClient } from "matrix-js-sdk";
+import { distinctUntilChanged, from, map, of, switchMap } from "rxjs";
 import { logger as rootLogger, type Logger } from "matrix-js-sdk/lib/logger";
 import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";

+import { type Behavior } from "../../Behavior.ts";
+import { type Epoch, type ObservableScope } from "../../ObservableScope.ts";
 import { Config } from "../../../config/Config.ts";
 import {
  FailToGetOpenIdToken,
@@ -21,12 +27,19 @@ import {
  type SFUConfig,
  type OpenIDClientParts,
 } from "../../../livekit/openIDSFU.ts";
+import { areLivekitTransportsEqual } from "../remoteMembers/MatrixLivekitMembers.ts";
 import { customLivekitUrl } from "../../../settings/settings.ts";
 import { RtcTransportAutoDiscovery } from "./RtcTransportAutoDiscovery.ts";
 import { type MatrixRTCMode } from "../../../config/ConfigOptions.ts";

+/*
+ * It figures out “which LiveKit focus URL/alias the local user should use,”
+ * and ensures the SFU path is primed before advertising that choice.
+ */
 interface Props {
+  scope: ObservableScope;
  ownMembershipIdentity: CallMembershipIdentityParts;
+  memberships$: Behavior<Epoch<CallMembership[]>>;
  client: Pick<MatrixClient, "getDomain" | "_unstable_getRTCTransports"> &
    OpenIDClientParts;
  // Used by the jwt service to create the livekit room and compute the livekit alias.
@@ -55,65 +68,114 @@ interface Props {
 //
 // 2.
 // We need to make sure we do not sent livekit_alias in sticky events and that we drop all code for sending state events!
-export interface LocalTransport {
+export interface LocalTransportWithSFUConfig {
  transport: LivekitTransportConfig;
  sfuConfig: SFUConfig;
 }

-export function isLocalTransport(
-  obj: LivekitTransportConfig | LocalTransport,
-): obj is LocalTransport {
+export function isLocalTransportWithSFUConfig(
+  obj: LivekitTransportConfig | LocalTransportWithSFUConfig,
+): obj is LocalTransportWithSFUConfig {
  return "transport" in obj && "sfuConfig" in obj;
 }

+export interface LocalTransport {
+  /**
+   * The transport to be advertised in our MatrixRTC membership. `null` when not
+   * yet fetched/validated.
+   */
+  advertised$: Behavior<LivekitTransportConfig | null>;
+  /**
+   * The transport to connect to and publish media on. `null` when not yet known
+   * or available.
+   */
+  active$: Behavior<LocalTransportWithSFUConfig | null>;
+}
+
 /**
- * Connects to the JWT service and determines the transport that the local member should use.
+ * Connects to the JWT service and determines the transports that the local member should use.
 *
 * @prop useOldJwtEndpoint Whether to set forceOldJwtEndpoint on the returned transport and to use the old JWT endpoint.
 * This is used when the connection manager needs to know if it has to use the legacy endpoint which implies a string concatenated rtcBackendIdentity.
 * (which is expected for non sticky event based rtc member events)
- * @returns The transport to advertise in our MatrixRTC membership and publish media on.
+ * @returns The transport to advertise in the local MatrixRTC membership, along with the transport to actively publish media to.
 * @throws MatrixRTCTransportMissingError | FailToGetOpenIdToken
 */
-export async function getLocalTransport({
+export const createLocalTransport$ = ({
+  scope,
+  memberships$,
  ownMembershipIdentity,
  client,
  roomId,
  matrixRTCMode,
-}: Props): Promise<LocalTransport> {
+}: Props): LocalTransport => {
  const logger = rootLogger.getChild("[LocalTransport]");
-  const discovery = new RtcTransportAutoDiscovery({
+
+  const transportDiscovery = new RtcTransportAutoDiscovery({
    client: client,
    resolvedConfig: Config.get(),
    logger: logger,
  });
-  const customUrl = customLivekitUrl.value$.value;

-  // Respect the user's custom URL, if set
-  const transport: LivekitTransportConfig | null = customUrl
-    ? { type: "livekit", livekit_service_url: customUrl }
-    : await discovery.discoverPreferredTransport();
+  // Get the preferred transport from the current deployment.
+  const discoveredTransport$ = from(
+    transportDiscovery.discoverPreferredTransport(),
+  );

-  if (transport === null)
-    throw new MatrixRTCTransportMissingError(client.getDomain() ?? "");
+  const preferredConfig$ = customLivekitUrl.value$.pipe(
+    switchMap((customUrl) => {
+      if (customUrl) {
+        return of({
+          type: "livekit",
+          livekit_service_url: customUrl,
+        } as LivekitTransportConfig);
+      } else {
+        return discoveredTransport$;
+      }
+    }),
+    map((config) => {
+      if (!config) {
+        // Bubbled up from the preferredConfig$ observable.
+        throw new MatrixRTCTransportMissingError(client.getDomain() ?? "");
+      }
+      return config;
+    }),
+    distinctUntilChanged(areLivekitTransportsEqual),
+  );

-  try {
-    return await doOpenIdAndJWTFromUrl(
-      transport,
-      matrixRTCMode,
-      ownMembershipIdentity,
-      roomId,
-      client,
-      logger,
-    );
-  } catch (e) {
-    logger.error(
-      `Failed to authenticate to transport ${transport.livekit_service_url}`,
-      e,
-    );
-    throw mapAuthErrorToUserFriendlyError(e);
-  }
-}
+  const preferredTransport$ = preferredConfig$.pipe(
+    switchMap(async (transport) => {
+      try {
+        return await doOpenIdAndJWTFromUrl(
+          transport,
+          matrixRTCMode,
+          ownMembershipIdentity,
+          roomId,
+          client,
+          logger,
+        );
+      } catch (e) {
+        logger.error(
+          `Failed to authenticate to transport ${transport.livekit_service_url}`,
+          e,
+        );
+        throw mapAuthErrorToUserFriendlyError(e);
+      }
+    }),
+  );
+
+  // Always publish on and advertise the preferred transport.
+  return {
+    advertised$: scope.behavior(
+      preferredTransport$.pipe(
+        map((t) => t.transport),
+        distinctUntilChanged(areLivekitTransportsEqual),
+      ),
+      null,
+    ),
+    active$: scope.behavior(preferredTransport$, null),
+  };
+};

 /**
 *  Utility to ensure the user can authenticate with the SFU.
@@ -137,7 +199,7 @@ async function doOpenIdAndJWTFromUrl(
  roomId: string,
  client: Pick<MatrixClient, "_unstable_getRTCTransports"> & OpenIDClientParts,
  logger?: Logger,
-): Promise<LocalTransport> {
+): Promise<LocalTransportWithSFUConfig> {
  const sfuConfig = await getSFUConfigWithOpenID(
    client,
    membership,
@@ -394,34 +394,6 @@ describe("Start connection states", () => {
    expect(connectedState).toEqual(ConnectionState.LivekitConnected);
  });

-  it("stopping while connecting does not report an error", async () => {
-    setupTest();
-    const connection = setupRemoteConnection();
-
-    const capturedStates: (ConnectionState | Error)[] = [];
-    const s = connection.state$.subscribe((value) => {
-      capturedStates.push(value);
-    });
-    onTestFinished(() => s.unsubscribe());
-
-    // livekit-client rejects a pending connect() when disconnect() is called.
-    const pendingConnect = Promise.withResolvers<void>();
-    fakeLivekitRoom.connect.mockReturnValue(pendingConnect.promise);
-    fakeLivekitRoom.disconnect.mockResolvedValue(undefined);
-
-    const started = connection.start();
-    await vi.waitFor(() => expect(fakeLivekitRoom.connect).toHaveBeenCalled());
-    const stopping = connection.stop();
-    pendingConnect.reject(new Error("Client initiated disconnect"));
-    await stopping;
-
-    // start() resolves rather than rejecting (it is not awaited by the
-    // ConnectionManager, so a rejection would be unhandled).
-    await expect(started).resolves.toBeUndefined();
-    expect(capturedStates.at(-1)).toEqual(ConnectionState.Stopped);
-    expect(capturedStates.some((st) => st instanceof Error)).toBe(false);
-  });
-
  it("shutting down the scope should stop the connection", async () => {
    setupTest();
    vi.useFakeTimers();
@@ -373,15 +373,6 @@ export class Connection {
      // If we were stopped while connecting, don't proceed to update state.
      if (this.stopped) return;
    } catch (error) {
-      if (this.stopped) {
-        // stop() was called while we were connecting, which makes the pending
-        // connect reject. That is the abort we asked for, not a failure, so
-        // don't record an error state on a stopped connection or rethrow it
-        // (start() is not awaited by the ConnectionManager, so a throw here
-        // becomes an unhandled promise rejection).
-        this.logger.debug(`Connect aborted because the connection was stopped`);
-        return;
-      }
      this.logger.debug(`Failed to connect to LiveKit room: ${error}`);
      this._state$.next(
        error instanceof ElementCallError
@@ -420,11 +411,9 @@ export class Connection {
      `stop: disconnecing from lk room ${this.transport.livekit_service_url}`,
    );
    if (this.stopped) return;
-    // Mark as stopped before disconnecting so that a connect() aborted by the
-    // disconnect sees the flag and does not report the abort as an error.
-    this.stopped = true;
    await this.livekitRoom.disconnect();
    this._state$.next(ConnectionState.Stopped);
+    this.stopped = true;
    this.logger.debug(
      `stop: DONE disconnecing from lk room ${this.transport.livekit_service_url}`,
    );
@@ -6,7 +6,7 @@ Please see LICENSE in the repository root for full details.
 */

 import { afterEach, beforeEach, describe, expect, test, vi } from "vitest";
-import { BehaviorSubject, NEVER } from "rxjs";
+import { BehaviorSubject } from "rxjs";
 import { type LivekitTransportConfig } from "matrix-js-sdk/lib/matrixrtc";
 import { type RemoteParticipant } from "livekit-client";
 import { logger } from "matrix-js-sdk/lib/logger";
@@ -20,7 +20,7 @@ import { type ConnectionFactory } from "./ConnectionFactory.ts";
 import { type Connection } from "./Connection.ts";
 import { ownMemberMock, withTestScheduler } from "../../../utils/test.ts";
 import { areLivekitTransportsEqual } from "./MatrixLivekitMembers.ts";
-import { type Behavior } from "../../Behavior.ts";
+import { constant, type Behavior } from "../../Behavior.ts";

 // Some test constants

@@ -74,7 +74,7 @@ describe("connections$ stream", () => {
      const { connectionManagerData$ } = createConnectionManager$({
        scope: testScope,
        connectionFactory: fakeConnectionFactory,
-        localTransport$: NEVER,
+        localTransport$: constant(null),
        remoteTransports$: behavior("a", {
          a: new Epoch([TRANSPORT_1, TRANSPORT_2], 0),
        }),
@@ -115,7 +115,7 @@ describe("connections$ stream", () => {
      const { connectionManagerData$ } = createConnectionManager$({
        scope: testScope,
        connectionFactory: fakeConnectionFactory,
-        localTransport$: NEVER,
+        localTransport$: constant(null),
        remoteTransports$: behavior("abcdef", {
          a: new Epoch([TRANSPORT_1], 0),
          b: new Epoch([TRANSPORT_1], 1),
@@ -162,7 +162,7 @@ describe("connections$ stream", () => {
      const { connectionManagerData$ } = createConnectionManager$({
        scope: testScope,
        connectionFactory: fakeConnectionFactory,
-        localTransport$: NEVER,
+        localTransport$: constant(null),
        remoteTransports$: behavior("abc", {
          a: new Epoch([TRANSPORT_1], 0),
          b: new Epoch([TRANSPORT_1, TRANSPORT_2], 1),
@@ -297,7 +297,7 @@ describe("connectionManagerData$ stream", () => {
      const { connectionManagerData$ } = createConnectionManager$({
        scope: testScope,
        connectionFactory: fakeConnectionFactory,
-        localTransport$: NEVER,
+        localTransport$: constant(null),
        remoteTransports$: behavior("a", {
          a: new Epoch([TRANSPORT_1, TRANSPORT_2], 0),
        }),
@@ -7,16 +7,7 @@ Please see LICENSE in the repository root for full details.
 */

 import { type LivekitTransportConfig } from "matrix-js-sdk/lib/matrixrtc";
-import {
-  combineLatest,
-  map,
-  type Observable,
-  of,
-  switchMap,
-  startWith,
-  catchError,
-  NEVER,
-} from "rxjs";
+import { combineLatest, map, of, switchMap } from "rxjs";
 import { type Logger } from "matrix-js-sdk/lib/logger";
 import { type RemoteParticipant } from "livekit-client";
 import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
@@ -28,8 +19,8 @@ import { generateItemsWithEpoch } from "../../../utils/observable.ts";
 import { areLivekitTransportsEqual } from "./MatrixLivekitMembers.ts";
 import { type ConnectionFactory } from "./ConnectionFactory.ts";
 import {
-  isLocalTransport,
-  type LocalTransport,
+  isLocalTransportWithSFUConfig,
+  type LocalTransportWithSFUConfig,
 } from "../localMember/LocalTransport.ts";
 import { type SFUConfig } from "../../../livekit/openIDSFU.ts";

@@ -87,7 +78,7 @@ export class ConnectionManagerData {
 interface Props {
  scope: ObservableScope;
  connectionFactory: ConnectionFactory;
-  localTransport$: Observable<LocalTransport>;
+  localTransport$: Behavior<LocalTransportWithSFUConfig | null>;
  remoteTransports$: Behavior<Epoch<LivekitTransportConfig[]>>;

  logger: Logger;
@@ -130,14 +121,6 @@ export function createConnectionManager$({
  const logger = parentLogger.getChild("[ConnectionManager]");
  // TODO logger: only construct one logger from the client and make it compatible via a EC specific sing

-  const localTransportAsArray$ = localTransport$.pipe(
-    // LocalMember already surfaces local transport errors properly in the UI,
-    // here we can just swallow them
-    catchError(() => NEVER),
-    map((transport) => [transport]),
-    startWith([]),
-  );
-
  /**
   * All transports currently managed by the ConnectionManager.
   *
@@ -147,12 +130,16 @@ export function createConnectionManager$({
   * externally this is modified via `registerTransports()`.
   */
  const localAndRemoteTransports$: Behavior<
-    Epoch<(LivekitTransportConfig | LocalTransport)[]>
+    Epoch<(LivekitTransportConfig | LocalTransportWithSFUConfig)[]>
  > = scope.behavior(
-    combineLatest([localTransportAsArray$, remoteTransports$]).pipe(
+    combineLatest([remoteTransports$, localTransport$]).pipe(
      // Combine local and remote transports into one transport array
      // and set the forceOldJwtEndpoint property on the local transport
-      map(([localTransportAsArray, remoteTransports]) => {
+      map(([remoteTransports, localTransport]) => {
+        let localTransportAsArray: LocalTransportWithSFUConfig[] = [];
+        if (localTransport) {
+          localTransportAsArray = [localTransport];
+        }
        const dedupedRemote = removeDuplicateTransports(remoteTransports.value);
        const remoteWithoutLocal = dedupedRemote.filter(
          (transport) =>
@@ -183,9 +170,8 @@ export function createConnectionManager$({
        "ConnectionManager connections$",
        function* (transports) {
          for (const transport of transports) {
-            if (isLocalTransport(transport)) {
-              // This is the local transport; only the `LocalTransport`
-              // interface has a `sfuConfig` field.
+            if (isLocalTransportWithSFUConfig(transport)) {
+              // This is the local transport; only the `LocalTransportWithSFUConfig` has a `sfuConfig` field.
              yield {
                keys: [
                  transport.transport.livekit_service_url,
@@ -6,7 +6,7 @@ Please see LICENSE in the repository root for full details.
 */

 import { test, vi, expect, beforeEach, afterEach } from "vitest";
-import { BehaviorSubject, NEVER } from "rxjs";
+import { BehaviorSubject } from "rxjs";
 import { type Room as LivekitRoom } from "livekit-client";
 import EventEmitter from "events";
 import fetchMock from "fetch-mock";
@@ -34,6 +34,7 @@ import {
 } from "./MatrixLivekitMembers.ts";
 import { createConnectionManager$ } from "./ConnectionManager.ts";
 import { membershipsAndTransports$ } from "../../SessionBehaviors.ts";
+import { constant } from "../../Behavior.ts";
 import { localRtcMember, testJWTToken } from "../../../utils/test-fixtures.ts";

 // Test the integration of ConnectionManager and MatrixLivekitMerger
@@ -123,7 +124,7 @@ test("bob, carl, then bob joining no tracks yet", () => {
    const connectionManager = createConnectionManager$({
      scope: testScope,
      connectionFactory: ecConnectionFactory,
-      localTransport$: NEVER,
+      localTransport$: constant(null),
      remoteTransports$: membershipsAndTransports.transports$,
      logger: logger,
      ownMembershipIdentity: ownMemberMock,
@@ -257,21 +257,14 @@ export class AudioOutput implements MediaDevice<
      map((availableRaw) => {
        let available: Map<string, AudioOutputDeviceLabel> =
          buildDeviceMap(availableRaw);
-        // Create a virtual default audio output for browsers that don't have one
-        // (Firefox, Safari). Its device ID must be the empty string because
-        // that's what setSinkId recognizes. It goes first so that it is the
-        // fallback when no output has been explicitly chosen (or the chosen
-        // one disappears), rather than pinning the first physical device
-        // with setSinkId: pinned sinks are not re-routed by the browser, and
-        // Firefox leaves the audio elements silent when a pinned sink goes
-        // away (e.g. a Bluetooth headset switching profile when its
-        // microphone is opened). We can't know which physical device the
-        // browser default resolves to, so the entry carries no name.
+        // Create a virtual default audio output for browsers that don't have one.
+        // Its device ID must be the empty string because that's what setSinkId
+        // recognizes.
        if (available.size && !available.has("") && !available.has("default"))
-          available = new Map<string, AudioOutputDeviceLabel>([
-            ["", { type: "default", name: null }],
-            ...available,
-          ]);
+          available.set("", {
+            type: "default",
+            name: availableRaw[0]?.label || null,
+          });
        // eslint-disable-next-line @typescript-eslint/no-explicit-any
        const isSafari = !!(window as any).GestureEvent; // non standard api only found on Safari. https://developer.mozilla.org/en-US/docs/Web/API/GestureEvent#browser_compatibility
        if (isSafari) {
@@ -22,10 +22,6 @@ import {
 } from "./ObservableScope";
 import { type Behavior } from "./Behavior";

-/**
- * Tracks the transports used by ourselves, plus all other MatrixRTC session
- * members.
- */
 export const membershipsAndTransports$ = (
  scope: ObservableScope,
  memberships$: Behavior<Epoch<CallMembership[]>>,
@@ -35,6 +31,14 @@ export const membershipsAndTransports$ = (
  >;
  transports$: Behavior<Epoch<LivekitTransportConfig[]>>;
 } => {
+  /**
+   * Lists the transports used by ourselves, plus all other MatrixRTC session
+   * members.
+   * For completeness this also lists the preferred transport and
+   * whether we are in multi-SFU mode or sticky events mode.
+   * `advertisedTransport$` reads these values together, so bundling them avoids inconsistent state or
+   * excessive updates when using RxJS.
+   */
  const membershipsWithTransport$: Behavior<
    Epoch<
      {
@@ -9,9 +9,30 @@ import { expect, test } from "vitest";
 import { type Observable, of, Subject, switchMap } from "rxjs";

 import { withTestScheduler } from "./test";
-import { filterBehavior, generateItems, pauseWhen } from "./observable";
+import { or$, filterBehavior, generateItems, pauseWhen } from "./observable";
 import { type Behavior } from "../state/Behavior";

+const yesNo = {
+  y: true,
+  n: false,
+};
+
+test("or$", () => {
+  withTestScheduler(({ behavior, expectObservable }) => {
+    const input1Marbles = "ny--n--";
+    const input2Marbles = "n-y--n-";
+    const input3Marbles = "n--y--n";
+    const outputMarbles = "nyyyyyn";
+    expectObservable(
+      or$(
+        behavior(input1Marbles, yesNo),
+        behavior(input2Marbles, yesNo),
+        behavior(input3Marbles, yesNo),
+      ),
+    ).toBe(outputMarbles, yesNo);
+  });
+});
+
 test("pauseWhen", () => {
  withTestScheduler(({ behavior, expectObservable }) => {
    const inputMarbles = " abcdefgh-i-jk-";
@@ -8,6 +8,7 @@ Please see LICENSE in the repository root for full details.
 import {
  type Observable,
  audit,
+  combineLatest,
  concat,
  defer,
  filter,
@@ -112,6 +113,14 @@ export function getValue<T>(state$: Observable<T>): T {
  return value;
 }

+/**
+ * Creates an Observable that has a value of true whenever some of its inputs
+ * are true.
+ */
+export function or$(...inputs: Observable<boolean>[]): Observable<boolean> {
+  return combineLatest(inputs, (...flags) => flags.some((flag) => flag));
+}
+
 /**
 * RxJS operator that pauses all changes in the input value whenever a Behavior
 * is true. When the Behavior returns to being false, the most recently
@@ -9,7 +9,7 @@ import { defineConfig, searchForWorkspaceRoot } from "vite";
 import { realpathSync } from "node:fs";
 import * as fs from "node:fs";

-import { vitePluginsConfig } from "./vite.config.ts";
+import { vitePluginsConfig } from "./vite.config";
 import { scopeStylesToRoot } from "./component/build/scopeStylesToRoot";

 // Serves the harness under `component/dev`, which embeds Element Call as a
@@ -7,7 +7,7 @@ Please see LICENSE in the repository root for full details.

 import { defineConfig } from "vite";

-import { vitePluginsConfig } from "./vite.config.ts";
+import { vitePluginsConfig } from "./vite.config";
 import { scopeStylesToRoot } from "./component/build/scopeStylesToRoot";

 // Config for Element Call as a React component, to be imported by an
@@ -8,7 +8,7 @@ Please see LICENSE in the repository root for full details.
 import { defineConfig, mergeConfig } from "vite";
 import generateFile from "vite-plugin-generate-file";

-import fullConfig from "./vite.config.ts";
+import fullConfig from "./vite.config";

 const base = "./";

@@ -1,6 +1,6 @@
 import { defineConfig, mergeConfig } from "vitest/config";
 import { playwright } from "@vitest/browser-playwright";
-import { vitePluginsConfig } from "./vite.config.ts";
+import { vitePluginsConfig } from "./vite.config";
 import { storybookTest } from "@storybook/addon-vitest/vitest-plugin";
 import path from "node:path";
 import { fileURLToPath } from "node:url";