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+# API Coverage — Phase 20 (livekit-client, LiveKit server, Centrifugo, Web Push)
+
+> Full coverage by default. Opt-outs are explicit, reasoned decisions. The phase builds no new server-side client: LiveKit's server API is called by `sm-chatvideo-plugin` (server-sdk-go), Centrifugo by `lighthouse`, Web Push by `sm-herald-plugin`. This phase adds the browser side of the video calls (`vue-chatvideo-layer` on `livekit-client` 2.23.0, plan 04), the chat's use of Centrifugo (`vue-chat-layer`, plan 03) and herald's VAPID configuration (plan 04).
+
+## livekit-client 2.23.0 (plan 04, vue-chatvideo-layer)
+
+| capability | decision | reason |
+|---|---|---|
+| Room connect (livekit_url and the server-minted join token) | INTEGRATE | |
+| Room disconnect (stops the local tracks) | INTEGRATE | |
+| publish camera (localParticipant.setCameraEnabled) | INTEGRATE | |
+| publish microphone (localParticipant.setMicrophoneEnabled) | INTEGRATE | |
+| subscribe and attach remote tracks (TrackSubscribed, track.attach and detach) | INTEGRATE | |
+| mute and unmute | INTEGRATE | |
+| camera toggle | INTEGRATE | |
+| participant events (ParticipantConnected, ParticipantDisconnected, TrackMuted, TrackUnmuted, LocalTrackPublished) | INTEGRATE | |
+| connection state and reconnection (Reconnecting, Reconnected, Disconnected) | INTEGRATE | |
+| adaptiveStream and dynacast | INTEGRATE | |
+| audio playback unlock (AudioPlaybackStatusChanged, startAudio) | INTEGRATE | |
+| dynamic import of the package | INTEGRATE | |
+| screen share | OPT-OUT | explicitly out of scope: D-13 keeps the call page minimal and the server config has screen_share false |
+| data channel (publishData, data streams, RPC) | OPT-OUT | not needed: chat messages go through the chat plugins, not the call |
+| device selection (switchActiveDevice, getLocalDevices) | OPT-OUT | not needed for a minimal demo call: the browser's default camera and microphone are used |
+| end-to-end encryption (E2EE worker) | OPT-OUT | explicitly out of scope: a public demo call with a short-lived room; media is DTLS-SRTP encrypted in transit |
+| recording and egress | OPT-OUT | explicitly out of scope: the demo records nothing |
+| simulcast tuning (videoEncoding, layers) | OPT-OUT | not needed: the defaults with adaptiveStream and dynacast fit 1:1 calls |
+| audio-only mode | OPT-OUT | not needed: turning the camera off gives the same call without video |
+| background effects and track processors | OPT-OUT | not needed: not part of a minimal call page |
+| active speaker highlighting | OPT-OUT | not needed: calls are 1:1 DMs (D-11), so there is no speaker to pick out |
+
+## LiveKit server 1.13.1 through golem15.chatvideo (plans 02 and 05)
+
+| capability | decision | reason |
+|---|---|---|
+| room create (on video/start) | INTEGRATE | |
+| room delete (on video/end and at max_duration) | INTEGRATE | |
+| join token mint (per participant, token_ttl 900) | INTEGRATE | |
+| participant count and active rooms (reconcile) | INTEGRATE | |
+| remove participant (on video/leave) | INTEGRATE | |
+| reconcile job (chatvideo:reconcile-sessions ends idle and overdue rooms) | INTEGRATE | |
+| room max_participants (4 in livekit.yaml, next to chatvideo max_participants, D-12) | INTEGRATE | |
+| /rtc/validate (check-local call) | INTEGRATE | |
+| egress (recording, streaming) | OPT-OUT | explicitly out of scope: the demo records nothing |
+| ingress (RTMP, WHIP) | OPT-OUT | explicitly out of scope: calls start from the site only |
+| SIP | OPT-OUT | explicitly out of scope: no phone dial-in on a public demo |
+| webhooks | OPT-OUT | not needed: the reconcile job polls room state, and the call events go through Centrifugo |
+| TURN server | OPT-OUT | deferred: plan 05 decides it with the rome network setup (ICE TCP 7891 and UDP 7892 first) |
+
+## Centrifugo v6 (plans 02 to 04)
+
+| capability | decision | reason |
+|---|---|---|
+| chat namespace with presence and join/leave | INTEGRATE | |
+| user namespace (user:{id}, the chat's events and video:call:incoming) | INTEGRATE | |
+| video namespace (video:session:{id}: accepted, ended, participant joined and left) | INTEGRATE | |
+| subscribe proxy on chat, user and video | INTEGRATE | |
+| one shared client per page (vue-chat-layer realtime, onUserEvent for other layers) | INTEGRATE | |
+| server HTTP API publish (lighthouse broadcast jobs) | INTEGRATE | |
+| history and recovery | OPT-OUT | not needed: the chat refetches the open conversation over HTTP on every (re)subscribe |
+| client-side publish | OPT-OUT | explicitly out of scope: browsers never publish; Go publishes after authorizing the write |
+| client RPC | OPT-OUT | not needed: every action is an HTTP call |
+| presence on the video namespace | OPT-OUT | not needed: LiveKit's participant events show who is in the call |
+
+## Web Push through golem15.herald (plan 04)
+
+| capability | decision | reason |
+|---|---|---|
+| VAPID key pair in .env (herald:vapid-generate, D-16) | INTEGRATE | |
+| VAPID public key route (/_herald/api/v1/push/vapid-public-key, check-local herald) | INTEGRATE | |
+| subscribe UI and service worker | OPT-OUT | deferred per D-16: herald is mounted without UI in this phase |
+| push on chat events (DMs, mentions, incoming calls) | OPT-OUT | deferred per D-16: needs the subscribe UI first |
+| push to /_herald from the site (goPaths) | OPT-OUT | deferred per D-16: the site does not call herald, so /_herald is not routed by vue-demo-app |