Check if livekit is configured on the relay during room creation/edit

src/app/components/RoomForm.svelte

@@ -15,6 +15,7 @@
   import ModalBody from "@lib/components/ModalBody.svelte"
   import {pushToast} from "@app/util/toast"
   import {uploadFile} from "@app/core/commands"
+  import {checkRelayHasLivekit} from "@app/voice"
 
   type RoomMode = "text" | "voice" | "both"
 
@@ -46,10 +47,29 @@
 
   const values = $state(initialValues)
   let roomMode = $state<RoomMode>(getRoomModeFromEvent(initialValues.event))
+  let relayHasLivekit = $state<boolean | undefined>(undefined)
+
+  $effect(() => {
+    const u = url
+    let cancelled = false
+    checkRelayHasLivekit(u).then(has => {
+      if (!cancelled) relayHasLivekit = has
+    })
+    return () => {
+      cancelled = true
+    }
+  })
 
   const submit = async () => {
     const room = $state.snapshot(values)
 
+    if ((roomMode === "voice" || roomMode === "both") && !relayHasLivekit) {
+      return pushToast({
+        theme: "error",
+        message: "This relay does not support voice rooms.",
+      })
+    }
+
     if (imageFile) {
       const {error, result} = await uploadFile(imageFile, {
         maxWidth: 256,
@@ -211,8 +231,12 @@
       {#snippet input()}
         <select class="select select-bordered w-full" bind:value={roomMode} aria-label="Room type">
           <option value="text">Text only</option>
-          <option value="both">Text and voice</option>
-          <option value="voice">Voice only</option>
+          <option value="both" disabled={relayHasLivekit === false}>
+            Text and voice{relayHasLivekit === false ? " (not setup)" : ""}
+          </option>
+          <option value="voice" disabled={relayHasLivekit === false}>
+            Voice only{relayHasLivekit === false ? " (not setup)" : ""}
+          </option>
         </select>
       {/snippet}
     </FieldInline>

src/app/voice.ts

@@ -1,3 +1,7 @@
+/**
+ * Voice rooms via LiveKit. Note: Voice does not work on localhost in Firefox
+ * (ICE candidate gathering fails). Use Chrome or test from deployed HTTPS.
+ */
 import {DisconnectReason, Room, RoomEvent, Track} from "livekit-client"
 import {getToken} from "nostr-tools/nip98"
 import {derived, get, writable} from "svelte/store"
@@ -9,6 +13,27 @@ import {pushToast} from "@app/util/toast"
 
 export const ROOM_PRESENCE = 10312
 
+const livekitEndpoint = (url: string, groupId: string) => {
+  const httpUrl = url
+    .replace(/^wss:\/\//, "https://")
+    .replace(/^ws:\/\//, "http://")
+    .replace(/\/$/, "")
+  return `${httpUrl}/.well-known/nip29/livekit/${groupId}`
+}
+
+export const checkRelayHasLivekit = async (url: string): Promise<boolean> => {
+  const endpoint = livekitEndpoint(url, "nop")
+
+  try {
+    // Currently we are hitting the API with no auth because zooid returns a 401 livekit
+    // is configured and 404 if it is not. But we need a standardized solution in the NIP.
+    const response = await fetch(endpoint)
+    return response.status === 401
+  } catch {
+    return false
+  }
+}
+
 const PRESENCE_INTERVAL_MS = 60_000
 const PRESENCE_EXPIRY_S = 300
 
@@ -26,11 +51,7 @@ const fetchLivekitToken = async (
   groupId: string,
   signal?: AbortSignal,
 ): Promise<{server_url: string; participant_token: string}> => {
-  const httpUrl = url
-    .replace(/^wss:\/\//, "https://")
-    .replace(/^ws:\/\//, "http://")
-    .replace(/\/$/, "")
-  const endpoint = `${httpUrl}/.well-known/nip29/livekit/${groupId}`
+  const endpoint = livekitEndpoint(url, groupId)
 
   const $signer = signer.get()
   if (!$signer) throw new Error("No signer available")