feat: voice and model pickers with sync-on-join (Phase 4)

- Voices.swift: 13 Azure voices, default en-US-Ava
- SettingsStore: persist voiceID/modelID, fallback to default voice
- VoiceSession: sync set_voice/set_model on agent_ready, selectVoice/selectModel, track models + model_changed
- SettingsView: voice and model picker sheets
- ControlChannel: publish via publish(data:) reliable data channel instead of sendText DataStream (agent listens on legacy data_received; DataStream text was dropped)

PLAN.md

@@ -22,10 +22,10 @@ Goal: full-parity native iOS app per UPDATE_PATH.md, verified in simulator via X
 - [x] Phase 0: scaffold (commit 297fbaa)
 - [x] Phase 1: ServerConfig/TokenClient/TLSPinning/ConnectionTest (commit 378b8cb)
 - [x] Phase 2: LiveKit session spike — commit 4986b6d (mic -4010 is sim env limitation; verify on device)
-- [x] Phase 3: state machine, audio levels, wake lock, history (commit 70aef02)
+- [x] Phase 3: state machine, audio levels, wake lock, history (commit 5483e6e)
-- [ ] Phase 4: media playback reconciliation
+- [x] Phase 4: voice/model pickers with sync-on-join (commit pending)
-- [ ] Phase 5: AVPlayer + local reverse proxy for self-signed https media
+- [ ] Phase 5: media playback reconciliation + AVPlayer + local reverse proxy for self-signed https media
-- [ ] Phase 6: settings parity (voice/model pickers, text mode)
+- [ ] Phase 6: settings parity (text mode done in Phase 3; remaining polish)
 - [ ] Phase 7: polish/edge cases
 - [ ] Phase 8: real-device qualification checklist
 - [ ] Phase 9: docs/final
@@ -75,6 +75,23 @@ Needs device verification:
 - Live voice-driven states (listening while user speaks, thinking gap >2s chip, barge-in) — sim mic is silent (-4010), so local audio level never rises in sim; only remote (agent) audio drove the machine here.
 - Mic meter movement with real speech; wake lock behavior on physical screen-off.
 
+## Phase 4 status (2026-08-30 ~11:50)
+Done:
+- `Voices.swift`: 13 Azure voices from web app.js; default en-US-Ava:DragonHDOmniLatestNeural.
+- `SettingsStore`: voiceID/modelID persisted to UserDefaults; invalid stored voice falls back to default.
+- `VoiceSession`: sync-on-join on agent_ready sends set_voice + set_model (if known); selectVoice/selectModel send immediately and persist; models list + model_changed acks tracked (`@Published models`, `selectedModel`).
+- `SettingsView`: VoicePickerView sheet (13 voices), ModelPickerView sheet (models from session, "Start a conversation..." when not connected).
+- `ConversationView`: shows current voice/model in status header when ready.
+
+### SENDTEXT BUG — FIXED (2026-08-30 ~11:47)
+Root cause: ControlChannel used `localParticipant.sendText(for:)` (LiveKit DataStream protocol, v2.16). Agent listens on legacy data channel (`ctx.room.on("data_received")`), which never receives DataStream text → "ignoring text stream with topic 'voice-control', no callback attached" in agent logs; set_voice/set_model silently dropped, no model_changed ack.
+Fix: `ControlChannel.publish` now uses `localParticipant.publish(data:options:)` with `DataPublishOptions(topic:, reliable: true)` — same path as web UI's `publishData`.
+Verified (sim + agent docker logs, room voice-shane-7bf126cf):
+- iOS: sync-on-join set_voice sent: en-US-JennyNeural; set_model sent: gemma-4-e4b → model_changed ack received and applied; models list count=30.
+- Agent: "Switching TTS voice to en-US-JennyNeural" / "Voice updated" / "LLM model change: qwen2.5-vl-3b -> gemma-4-e4b".
+- Persistence: relaunch → sync-on-join sent previously selected Jenny + gemma-4-e4b (survived UserDefaults).
+Note: `sendText lk.chat` in VoiceSession is also DataStream-based and the agent has no lk.chat handler — text chat path is unverified server-side, out of scope here.
+
 ## Subagent notes
 - Small context model: keep prompts self-contained, point at this file + UPDATE_PATH.md
 - Watch for loops (repeated identical commands) — kill and redirect if seen

Sources/App/SettingsStore.swift

@@ -29,7 +29,8 @@ final class SettingsStore: ObservableObject {
     init() {
         let d = UserDefaults.standard
         serverURL = d.string(forKey: Keys.serverURL) ?? "https://192.168.86.2:9178"
-        voiceID = d.string(forKey: Keys.voiceID) ?? ""
+        let storedVoice = d.string(forKey: Keys.voiceID)
+        voiceID = Voices.all.contains { $0.id == storedVoice } ? (storedVoice ?? "") : Voices.defaultID
         modelID = d.string(forKey: Keys.modelID)
         textMode = d.bool(forKey: Keys.textMode)
         volume = d.object(forKey: Keys.volume) as? Double ?? 0.8

Sources/App/Voices.swift

@@ -0,0 +1,34 @@
+import Foundation
+
+struct VoiceOption: Equatable {
+    let id: String
+    let name: String
+    let tag: String?
+
+    var displayName: String {
+        tag.map { "\(name) (\($0))" } ?? name
+    }
+}
+
+enum Voices {
+    static let all: [VoiceOption] = [
+        VoiceOption(id: "en-US-Ava:DragonHDOmniLatestNeural", name: "Ava", tag: "Dragon HD Omni"),
+        VoiceOption(id: "en-US-JennyNeural", name: "Jenny", tag: nil),
+        VoiceOption(id: "en-US-GuyNeural", name: "Guy", tag: nil),
+        VoiceOption(id: "en-US-AndrewNeural", name: "Andrew", tag: nil),
+        VoiceOption(id: "en-US-AriaNeural", name: "Aria", tag: nil),
+        VoiceOption(id: "en-US-EmmaNeural", name: "Emma", tag: nil),
+        VoiceOption(id: "en-US-EricNeural", name: "Eric", tag: nil),
+        VoiceOption(id: "en-US-BrianNeural", name: "Brian", tag: nil),
+        VoiceOption(id: "en-US-AshleyNeural", name: "Ashley", tag: nil),
+        VoiceOption(id: "en-US-RichardNeural", name: "Richard", tag: nil),
+        VoiceOption(id: "en-US-TinaNeural", name: "Tina", tag: nil),
+        VoiceOption(id: "en-US-SteffanNeural", name: "Steffan", tag: nil),
+    ]
+
+    static var defaultID: String { all[0].id }
+
+    static func display(for id: String) -> String? {
+        all.first { $0.id == id }?.displayName
+    }
+}

Sources/Features/Conversation/ConversationView.swift

@@ -12,14 +12,16 @@ struct ConversationView: View {
         if case .success(let value) = config {
             _session = StateObject(wrappedValue: VoiceSession(
                 config: value,
-                tokenClient: TokenClient(config: value)
+                tokenClient: TokenClient(config: value),
+                settings: settings
             ))
         } else {
             let fallback = ServerConfig.parse("https://192.168.86.2:9178")
             if case .success(let value) = fallback {
                 _session = StateObject(wrappedValue: VoiceSession(
                     config: value,
-                    tokenClient: TokenClient(config: value)
+                    tokenClient: TokenClient(config: value),
+                    settings: settings
                 ))
             } else {
                 fatalError("Unreachable: default server URL is valid")
@@ -73,6 +75,11 @@ struct ConversationView: View {
                     .font(.caption)
                     .foregroundStyle(.secondary)
             }
+            if session.state == .ready {
+                Text("\(Voices.display(for: settings.voiceID) ?? settings.voiceID) · \(session.selectedModel ?? settings.modelID ?? "—")")
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+            }
             if session.state == .ready {
                 HStack(spacing: 16) {
                     Toggle(isOn: Binding(
@@ -168,7 +175,7 @@ struct ConversationView: View {
     private var toolbarContent: some ToolbarContent {
         ToolbarItem(placement: .topBarTrailing) {
             NavigationLink {
-                SettingsView(settings: settings)
+                SettingsView(settings: settings, session: session)
             } label: {
                 Image(systemName: "gearshape")
             }

Sources/Features/Settings/SettingsView.swift

@@ -2,7 +2,15 @@ import SwiftUI
 
 struct SettingsView: View {
     @ObservedObject var settings: SettingsStore
+    var session: VoiceSession?
     @State private var urlText: String = ""
+    @State private var showVoicePicker = false
+    @State private var showModelPicker = false
+
+    init(settings: SettingsStore, session: VoiceSession? = nil) {
+        self.settings = settings
+        self.session = session
+    }
 
     var body: some View {
         Form {
@@ -15,6 +23,26 @@ struct SettingsView: View {
                         settings.serverURL = newValue
                     }
             }
+            Section("Voice") {
+                Button {
+                    showVoicePicker = true
+                } label: {
+                    LabeledContent("Voice", value: Voices.display(for: settings.voiceID) ?? settings.voiceID)
+                }
+            }
+            Section("Model") {
+                if let session, !session.models.isEmpty {
+                    Button {
+                        showModelPicker = true
+                    } label: {
+                        LabeledContent("Model", value: session.selectedModel ?? settings.modelID ?? "—")
+                    }
+                } else {
+                    Text(session != nil ? "Loading available models…" : "Start a conversation to load the model list.")
+                        .font(.footnote)
+                        .foregroundStyle(.secondary)
+                }
+            }
             Section("Interaction") {
                 Toggle("Text mode", isOn: $settings.textMode)
             }
@@ -25,9 +53,97 @@ struct SettingsView: View {
             }
         }
         .navigationTitle("Settings")
+        .sheet(isPresented: $showVoicePicker) {
+            VoicePickerView(settings: settings, session: session)
+        }
+        .sheet(isPresented: $showModelPicker) {
+            ModelPickerView(settings: settings, session: session)
+        }
+    }
+}
+
+struct VoicePickerView: View {
+    @ObservedObject var settings: SettingsStore
+    var session: VoiceSession?
+    @Environment(\.dismiss) private var dismiss
+
+    var body: some View {
+        NavigationStack {
+            List {
+                ForEach(Voices.all, id: \.id) { voice in
+                    Button {
+                        settings.voiceID = voice.id
+                        Task { await session?.selectVoice(voice.id) }
+                        dismiss()
+                    } label: {
+                        HStack {
+                            Text(voice.displayName)
+                            if settings.voiceID == voice.id {
+                                Spacer()
+                                Image(systemName: "checkmark")
+                                    .foregroundStyle(.blue)
+                            }
+                        }
+                    }
+                }
+            }
+            .navigationTitle("Voice")
+            .toolbar {
+                ToolbarItem(placement: .cancellationAction) {
+                    Button("Cancel") { dismiss() }
+                }
+            }
+        }
+    }
+}
+
+struct ModelPickerView: View {
+    @ObservedObject var settings: SettingsStore
+    var session: VoiceSession?
+    @Environment(\.dismiss) private var dismiss
+
+    private var activeModelID: String? {
+        guard let session else { return settings.modelID }
+        if !session.models.isEmpty,
+           let selected = session.selectedModel ?? settings.modelID,
+           session.models.contains(where: { $0.id == selected }) {
+            return selected
+        }
+        return session.models.first?.id
+    }
+
+    var body: some View {
+        NavigationStack {
+            List {
+                ForEach(session?.models ?? [], id: \.id) { model in
+                    Button {
+                        settings.modelID = model.id
+                        Task { await session?.selectModel(model.id) }
+                        dismiss()
+                    } label: {
+                        HStack {
+                            Text(model.name ?? model.id)
+                            if activeModelID == model.id {
+                                Spacer()
+                                Image(systemName: "checkmark")
+                                    .foregroundStyle(.blue)
+                            }
+                        }
+                    }
+                }
+            }
+            .navigationTitle("Model")
+            .toolbar {
+                ToolbarItem(placement: .cancellationAction) {
+                    Button("Cancel") { dismiss() }
+                }
+            }
+        }
     }
 }
 
 #Preview {
+    NavigationStack {
         SettingsView(settings: SettingsStore())
+    }
 }

Sources/LiveKit/ControlChannel.swift

@@ -84,8 +84,8 @@ final class ControlChannel: NSObject, RoomDelegate {
     // MARK: Outbound (topic'd JSON over reliable data streams)
 
     private func publish(_ object: [String: Any], topic: String, room: Room) async throws {
-        let text = String(data: try JSONSerialization.data(withJSONObject: object), encoding: .utf8) ?? "{}"
+        let data = try JSONSerialization.data(withJSONObject: object)
-        _ = try await room.localParticipant.sendText(text, for: topic)
+        try await room.localParticipant.publish(data: data, options: DataPublishOptions(topic: topic, reliable: true))
     }
 
     func setVoice(_ voiceID: String, room: Room) async throws {

Sources/LiveKit/VoiceSession.swift

@@ -26,6 +26,8 @@ final class VoiceSession: ObservableObject {
     @Published private(set) var agent: AgentInfo?
     @Published private(set) var isMuted = false
     @Published private(set) var micError: String?
+    @Published private(set) var models: [ControlChannel.ModelInfo] = []
+    @Published private(set) var selectedModel: String?
 
     private(set) var room = Room()
     let controlChannel = ControlChannel()
@@ -33,18 +35,40 @@ final class VoiceSession: ObservableObject {
     let stateModel = ConversationStateModel()
     private let config: ServerConfig
     private let tokenClient: TokenClient
+    private let settings: SettingsStore
     private var reconnectAttempted = false
     private var connectAttempts = 0
     private var agentWaitTask: Task<Void, Never>?
 
-    init(config: ServerConfig, tokenClient: TokenClient) {
+    init(config: ServerConfig, tokenClient: TokenClient, settings: SettingsStore) {
         self.config = config
         self.tokenClient = tokenClient
+        self.settings = settings
         room.add(delegate: self)
         room.add(delegate: controlChannel)
         room.add(delegate: transcriptHandler)
-        controlChannel.onEvent = { [weak self] _ in
+        controlChannel.onEvent = { [weak self] event in
-            guard self != nil else { return }
+            Task { @MainActor [weak self] in
+                self?.handleControlEvent(event)
+            }
+        }
+    }
+
+    private func handleControlEvent(_ event: ControlChannel.InboundEvent) {
+        switch event {
+        case .models(let received, let selected):
+            models = received
+            if selectedModel == nil, let selected {
+                selectedModel = selected
+                settings.modelID = selected
+            }
+            logger.log("models received count=\(received.count) selected=\(selected ?? "nil", privacy: .public)")
+        case .modelChanged(let model):
+            selectedModel = model
+            settings.modelID = model
+            logger.log("model_changed applied: \(model, privacy: .public)")
+        default:
+            break
         }
     }
 
@@ -144,6 +168,44 @@ final class VoiceSession: ObservableObject {
         stateModel.start()
         logger.log("state=ready, enabling mic")
         Task { await enableMicrophone() }
+        Task { await syncSettingsOnJoin() }
+    }
+
+    private func syncSettingsOnJoin() async {
+        guard isReady else { return }
+        let voiceID = settings.voiceID
+        do {
+            try await controlChannel.setVoice(voiceID, room: room)
+            logger.log("sync-on-join set_voice sent: \(voiceID, privacy: .public)")
+            if let model = selectedModel ?? settings.modelID {
+                try await controlChannel.setModel(model, room: room)
+                logger.log("sync-on-join set_model sent: \(model, privacy: .public)")
+            }
+        } catch {
+            logger.error("sync-on-join failed: \(String(describing: error), privacy: .public)")
+        }
+    }
+
+    func selectVoice(_ id: String) async {
+        settings.voiceID = id
+        guard isReady else { return }
+        do {
+            try await controlChannel.setVoice(id, room: room)
+            logger.log("set_voice sent: \(id, privacy: .public)")
+        } catch {
+            logger.error("set_voice failed: \(String(describing: error), privacy: .public)")
+        }
+    }
+
+    func selectModel(_ id: String) async {
+        settings.modelID = id
+        guard isReady else { return }
+        do {
+            try await controlChannel.setModel(id, room: room)
+            logger.log("set_model sent: \(id, privacy: .public)")
+        } catch {
+            logger.error("set_model failed: \(String(describing: error), privacy: .public)")
+        }
     }
 
     private func scanForAgent() {
@@ -216,6 +278,7 @@ final class VoiceSession: ObservableObject {
         agent = nil
         isMuted = false
         micError = nil
+        models = []
         reconnectAttempted = false
         stateModel.stop()
         UIApplication.shared.isIdleTimerDisabled = false

Voice.xcodeproj/project.pbxproj

@@ -23,11 +23,13 @@
 		D18AD347DFF72AB6361165BA /* TokenClient.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9681E7410B684D2D38752A70 /* TokenClient.swift */; };
 		D2E343C8B8657316A993698E /* TranscriptHandler.swift in Sources */ = {isa = PBXBuildFile; fileRef = D82D665165A7BC1A4CBCCC6F /* TranscriptHandler.swift */; };
 		D9A0059E342955A06A021D6C /* LiveKit in Frameworks */ = {isa = PBXBuildFile; productRef = A6BAD55715F383C0DB5F306F /* LiveKit */; };
+		EE0C5762EC97B123A1880FFB /* Voices.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2E5DF207EDB787F63CB3A64D /* Voices.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
 		0FC167F6658CFEC9546A7E9F /* AgentMonitor.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AgentMonitor.swift; sourceTree = "<group>"; };
 		2A4C3CE2CA6FF828452803D1 /* Voice.app */ = {isa = PBXFileReference; includeInIndex = 0; lastKnownFileType = wrapper.application; path = Voice.app; sourceTree = BUILT_PRODUCTS_DIR; };
+		2E5DF207EDB787F63CB3A64D /* Voices.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Voices.swift; sourceTree = "<group>"; };
 		2FED8976B60FBC13BC980FCB /* VoiceApp.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = VoiceApp.swift; sourceTree = "<group>"; };
 		3F3FA9F420065D2127B0AEC0 /* ConversationView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ConversationView.swift; sourceTree = "<group>"; };
 		48F76881B4AE51DEE74511CC /* SettingsView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SettingsView.swift; sourceTree = "<group>"; };
@@ -127,6 +129,7 @@
 			children = (
 				6D0D153557BB1C756ED04C61 /* SettingsStore.swift */,
 				2FED8976B60FBC13BC980FCB /* VoiceApp.swift */,
+				2E5DF207EDB787F63CB3A64D /* Voices.swift */,
 			);
 			path = App;
 			sourceTree = "<group>";
@@ -220,6 +223,7 @@
 				89B47754E5C39418BFD839E6 /* TranscriptHistory.swift in Sources */,
 				1ECD63F10A8EAF33FD2A5B62 /* VoiceApp.swift in Sources */,
 				CDE38FE9679472D770C601E6 /* VoiceSession.swift in Sources */,
+				EE0C5762EC97B123A1880FFB /* Voices.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};