diff --git a/src/plugin-sdk/realtime-voice.ts b/src/plugin-sdk/realtime-voice.ts
index d88b6d34b7b..a13a04b5ec9 100644
--- a/src/plugin-sdk/realtime-voice.ts
+++ b/src/plugin-sdk/realtime-voice.ts
@@ -8,6 +8,7 @@ export type {
   RealtimeVoiceBrowserSession,
   RealtimeVoiceBrowserSessionCreateRequest,
   RealtimeVoiceBridgeCreateRequest,
+  RealtimeVoiceProviderCapabilities,
   RealtimeVoiceCloseReason,
   RealtimeVoiceProviderConfig,
   RealtimeVoiceProviderConfiguredContext,
@@ -22,6 +23,29 @@ export {
   REALTIME_VOICE_AUDIO_FORMAT_G711_ULAW_8KHZ,
   REALTIME_VOICE_AUDIO_FORMAT_PCM16_24KHZ,
 } from "../realtime-voice/provider-types.js";
+export {
+  createTalkEventSequencer,
+  TALK_EVENT_TYPES,
+  type TalkBrain,
+  type TalkEvent,
+  type TalkEventContext,
+  type TalkEventInput,
+  type TalkEventSequencer,
+  type TalkEventType,
+  type TalkMode,
+  type TalkTransport,
+} from "../realtime-voice/talk-events.js";
+export {
+  createTalkSessionController,
+  normalizeTalkTransport,
+  type TalkEnsureTurnResult,
+  type TalkSessionController,
+  type TalkSessionControllerParams,
+  type TalkTurnFailure,
+  type TalkTurnFailureReason,
+  type TalkTurnResult,
+  type TalkTurnSuccess,
+} from "../realtime-voice/talk-session-controller.js";
 export {
   buildRealtimeVoiceAgentConsultChatMessage,
   buildRealtimeVoiceAgentConsultPrompt,
@@ -44,6 +68,18 @@ export {
   type RealtimeVoiceAgentConsultResult,
   type RealtimeVoiceAgentConsultRuntime,
 } from "../realtime-voice/agent-consult-runtime.js";
+export {
+  createRealtimeVoiceAgentTalkbackQueue,
+  type RealtimeVoiceAgentTalkbackQueue,
+  type RealtimeVoiceAgentTalkbackQueueParams,
+  type RealtimeVoiceAgentTalkbackResult,
+} from "../realtime-voice/agent-talkback-runtime.js";
+export {
+  resolveRealtimeVoiceFastContextConsult,
+  type RealtimeVoiceFastContextConfig,
+  type RealtimeVoiceFastContextConsultResult,
+  type RealtimeVoiceFastContextLabels,
+} from "../realtime-voice/fast-context-runtime.js";
 export {
   canonicalizeRealtimeVoiceProviderId,
   getRealtimeVoiceProvider,
@@ -62,6 +98,18 @@ export {
   type RealtimeVoiceBridgeSessionParams,
   type RealtimeVoiceMarkStrategy,
 } from "../realtime-voice/session-runtime.js";
+export {
+  extendRealtimeVoiceOutputEchoSuppression,
+  getRealtimeVoiceBridgeEventHealth,
+  getRealtimeVoiceTranscriptHealth,
+  isLikelyRealtimeVoiceAssistantEchoTranscript,
+  recordRealtimeVoiceBridgeEvent,
+  recordRealtimeVoiceTranscript,
+  type RealtimeVoiceBridgeEventHealth,
+  type RealtimeVoiceBridgeEventLogEntry,
+  type RealtimeVoiceTranscriptEntry,
+  type RealtimeVoiceTranscriptHealth,
+} from "../realtime-voice/session-log-runtime.js";
 export {
   convertPcmToMulaw8k,
   mulawToPcm,
diff --git a/src/plugins/types.ts b/src/plugins/types.ts
index 3718330c388..612a442bb1d 100644
--- a/src/plugins/types.ts
+++ b/src/plugins/types.ts
@@ -47,6 +47,7 @@ import type {
   RealtimeVoiceBrowserSession,
   RealtimeVoiceBrowserSessionCreateRequest,
   RealtimeVoiceBridgeCreateRequest,
+  RealtimeVoiceProviderCapabilities,
   RealtimeVoiceProviderConfig,
   RealtimeVoiceProviderConfiguredContext,
   RealtimeVoiceProviderId,
@@ -1839,6 +1840,7 @@ export type RealtimeVoiceProviderPlugin = {
   aliases?: string[];
   defaultModel?: string;
   autoSelectOrder?: number;
+  capabilities?: RealtimeVoiceProviderCapabilities;
   resolveConfig?: (ctx: RealtimeVoiceProviderResolveConfigContext) => RealtimeVoiceProviderConfig;
   isConfigured: (ctx: RealtimeVoiceProviderConfiguredContext) => boolean;
   createBridge: (req: RealtimeVoiceBridgeCreateRequest) => RealtimeVoiceBridge;
diff --git a/src/realtime-voice/agent-talkback-runtime.test.ts b/src/realtime-voice/agent-talkback-runtime.test.ts
new file mode 100644
index 00000000000..cea54ed7e66
--- /dev/null
+++ b/src/realtime-voice/agent-talkback-runtime.test.ts
@@ -0,0 +1,173 @@
+import { describe, expect, it, vi } from "vitest";
+import { createRealtimeVoiceAgentTalkbackQueue } from "./agent-talkback-runtime.js";
+
+function makeLogger() {
+  return {
+    info: vi.fn(),
+    warn: vi.fn(),
+  };
+}
+
+describe("realtime voice agent talkback queue", () => {
+  it("debounces transcript fragments into one consult", async () => {
+    vi.useFakeTimers();
+    const logger = makeLogger();
+    const consult = vi.fn(async ({ question }) => ({ text: `answer:${question}` }));
+    const deliver = vi.fn();
+    const queue = createRealtimeVoiceAgentTalkbackQueue({
+      debounceMs: 100,
+      isStopped: () => false,
+      logger,
+      logPrefix: "[test]",
+      responseStyle: "brief",
+      fallbackText: "fallback",
+      consult,
+      deliver,
+    });
+
+    queue.enqueue("first");
+    queue.enqueue("second");
+    await vi.advanceTimersByTimeAsync(100);
+
+    expect(consult).toHaveBeenCalledWith({
+      question: "first\nsecond",
+      responseStyle: "brief",
+      signal: expect.any(AbortSignal),
+    });
+    expect(deliver).toHaveBeenCalledWith("answer:first\nsecond");
+    vi.useRealTimers();
+  });
+
+  it("accumulates pending questions while a consult is active", async () => {
+    vi.useFakeTimers();
+    const logger = makeLogger();
+    let finishFirst: ((value: { text: string }) => void) | undefined;
+    const consult = vi
+      .fn()
+      .mockImplementationOnce(
+        () =>
+          new Promise<{ text: string }>((resolve) => {
+            finishFirst = resolve;
+          }),
+      )
+      .mockResolvedValueOnce({ text: "second-answer" });
+    const deliver = vi.fn();
+    const queue = createRealtimeVoiceAgentTalkbackQueue({
+      debounceMs: 10,
+      isStopped: () => false,
+      logger,
+      logPrefix: "[test]",
+      responseStyle: "brief",
+      fallbackText: "fallback",
+      consult,
+      deliver,
+    });
+
+    queue.enqueue("first");
+    await vi.advanceTimersByTimeAsync(10);
+    queue.enqueue("ignored");
+    queue.enqueue("second");
+    await vi.advanceTimersByTimeAsync(10);
+    finishFirst?.({ text: "first-answer" });
+    await vi.runAllTimersAsync();
+
+    expect(consult).toHaveBeenNthCalledWith(1, {
+      question: "first",
+      responseStyle: "brief",
+      signal: expect.any(AbortSignal),
+    });
+    expect(consult).toHaveBeenNthCalledWith(2, {
+      question: "ignored\nsecond",
+      responseStyle: "brief",
+      signal: expect.any(AbortSignal),
+    });
+    expect(deliver).toHaveBeenCalledWith("first-answer");
+    expect(deliver).toHaveBeenCalledWith("second-answer");
+    vi.useRealTimers();
+  });
+
+  it("delivers fallback text when consult fails", async () => {
+    vi.useFakeTimers();
+    const logger = makeLogger();
+    const deliver = vi.fn();
+    const queue = createRealtimeVoiceAgentTalkbackQueue({
+      debounceMs: 1,
+      isStopped: () => false,
+      logger,
+      logPrefix: "[test]",
+      responseStyle: "brief",
+      fallbackText: "fallback",
+      consult: vi.fn(async () => {
+        throw new Error("boom");
+      }),
+      deliver,
+    });
+
+    queue.enqueue("question");
+    await vi.advanceTimersByTimeAsync(1);
+
+    expect(logger.warn).toHaveBeenCalledWith("[test] consult failed: boom");
+    expect(deliver).toHaveBeenCalledWith("fallback");
+    vi.useRealTimers();
+  });
+
+  it("cancels pending debounced work on close", async () => {
+    vi.useFakeTimers();
+    const consult = vi.fn(async () => ({ text: "answer" }));
+    const queue = createRealtimeVoiceAgentTalkbackQueue({
+      debounceMs: 100,
+      isStopped: () => false,
+      logger: makeLogger(),
+      logPrefix: "[test]",
+      responseStyle: "brief",
+      fallbackText: "fallback",
+      consult,
+      deliver: vi.fn(),
+    });
+
+    queue.enqueue("question");
+    queue.close();
+    await vi.advanceTimersByTimeAsync(100);
+
+    expect(consult).not.toHaveBeenCalled();
+    vi.useRealTimers();
+  });
+
+  it("aborts the active consult on close without delivering fallback", async () => {
+    vi.useFakeTimers();
+    const logger = makeLogger();
+    let signal: AbortSignal | undefined;
+    const consult = vi.fn(
+      ({ signal: nextSignal }) =>
+        new Promise<{ text: string }>((_resolve, reject) => {
+          signal = nextSignal;
+          nextSignal.addEventListener("abort", () => {
+            const error = new Error("aborted");
+            error.name = "AbortError";
+            reject(error);
+          });
+        }),
+    );
+    const deliver = vi.fn();
+    const queue = createRealtimeVoiceAgentTalkbackQueue({
+      debounceMs: 1,
+      isStopped: () => false,
+      logger,
+      logPrefix: "[test]",
+      responseStyle: "brief",
+      fallbackText: "fallback",
+      consult,
+      deliver,
+    });
+
+    queue.enqueue("question");
+    await vi.advanceTimersByTimeAsync(1);
+    queue.close();
+    await vi.runAllTimersAsync();
+
+    expect(signal?.aborted).toBe(true);
+    expect(deliver).not.toHaveBeenCalled();
+    expect(logger.warn).not.toHaveBeenCalled();
+    vi.useRealTimers();
+  });
+});
diff --git a/src/realtime-voice/agent-talkback-runtime.ts b/src/realtime-voice/agent-talkback-runtime.ts
new file mode 100644
index 00000000000..638c5fbb3ae
--- /dev/null
+++ b/src/realtime-voice/agent-talkback-runtime.ts
@@ -0,0 +1,131 @@
+import type { RuntimeLogger } from "../plugins/runtime/types-core.js";
+
+export type RealtimeVoiceAgentTalkbackResult = {
+  text: string;
+};
+
+export type RealtimeVoiceAgentTalkbackQueue = {
+  close(): void;
+  enqueue(question: string): void;
+};
+
+export type RealtimeVoiceAgentTalkbackQueueParams = {
+  debounceMs: number;
+  isStopped: () => boolean;
+  logger: Pick<RuntimeLogger, "info" | "warn">;
+  logPrefix: string;
+  responseStyle: string;
+  fallbackText: string;
+  consult: (args: {
+    question: string;
+    responseStyle: string;
+    signal: AbortSignal;
+  }) => Promise<RealtimeVoiceAgentTalkbackResult>;
+  deliver: (text: string) => void;
+};
+
+export function createRealtimeVoiceAgentTalkbackQueue(
+  params: RealtimeVoiceAgentTalkbackQueueParams,
+): RealtimeVoiceAgentTalkbackQueue {
+  let active = false;
+  let pendingQuestion: string | undefined;
+  let debounceTimer: ReturnType<typeof setTimeout> | undefined;
+  let activeAbortController: AbortController | undefined;
+
+  const clearDebounceTimer = () => {
+    if (!debounceTimer) {
+      return;
+    }
+    clearTimeout(debounceTimer);
+    debounceTimer = undefined;
+  };
+
+  const run = async (question: string): Promise<void> => {
+    const trimmed = question.trim();
+    if (!trimmed || params.isStopped()) {
+      return;
+    }
+    if (active) {
+      pendingQuestion = appendPendingQuestion(pendingQuestion, trimmed);
+      return;
+    }
+
+    active = true;
+    let nextQuestion: string | undefined = trimmed;
+    try {
+      while (nextQuestion) {
+        if (params.isStopped()) {
+          return;
+        }
+        const currentQuestion = nextQuestion;
+        pendingQuestion = undefined;
+        params.logger.info(`${params.logPrefix} consult: ${currentQuestion}`);
+        activeAbortController = new AbortController();
+        const result = await params.consult({
+          question: currentQuestion,
+          responseStyle: params.responseStyle,
+          signal: activeAbortController.signal,
+        });
+        activeAbortController = undefined;
+        const text = result.text.trim();
+        if (!params.isStopped() && text) {
+          params.deliver(text);
+        }
+        nextQuestion = pendingQuestion;
+      }
+    } catch (error) {
+      activeAbortController = undefined;
+      if (params.isStopped() || isAbortError(error)) {
+        return;
+      }
+      const message = error instanceof Error ? error.message : String(error);
+      params.logger.warn(`${params.logPrefix} consult failed: ${message}`);
+      params.deliver(params.fallbackText);
+    } finally {
+      active = false;
+      const queuedQuestion = pendingQuestion;
+      pendingQuestion = undefined;
+      if (queuedQuestion && !params.isStopped()) {
+        void run(queuedQuestion);
+      }
+    }
+  };
+
+  return {
+    close: () => {
+      clearDebounceTimer();
+      pendingQuestion = undefined;
+      activeAbortController?.abort();
+    },
+    enqueue: (question) => {
+      const trimmed = question.trim();
+      if (!trimmed || params.isStopped()) {
+        return;
+      }
+      if (active) {
+        pendingQuestion = appendPendingQuestion(pendingQuestion, trimmed);
+        clearDebounceTimer();
+        return;
+      }
+      pendingQuestion = appendPendingQuestion(pendingQuestion, trimmed);
+      clearDebounceTimer();
+      debounceTimer = setTimeout(() => {
+        debounceTimer = undefined;
+        const queuedQuestion = pendingQuestion;
+        pendingQuestion = undefined;
+        if (queuedQuestion && !params.isStopped()) {
+          void run(queuedQuestion);
+        }
+      }, params.debounceMs);
+      debounceTimer.unref?.();
+    },
+  };
+}
+
+function appendPendingQuestion(current: string | undefined, next: string): string {
+  return current ? `${current}\n${next}` : next;
+}
+
+function isAbortError(error: unknown): boolean {
+  return error instanceof Error && error.name === "AbortError";
+}
diff --git a/src/realtime-voice/fast-context-runtime.ts b/src/realtime-voice/fast-context-runtime.ts
new file mode 100644
index 00000000000..ca34b861103
--- /dev/null
+++ b/src/realtime-voice/fast-context-runtime.ts
@@ -0,0 +1,189 @@
+import type { OpenClawConfig } from "../config/types.openclaw.js";
+import { formatErrorMessage } from "../infra/errors.js";
+import { getActiveMemorySearchManager } from "../plugins/memory-runtime.js";
+import type { RealtimeVoiceAgentConsultResult } from "./agent-consult-runtime.js";
+import { parseRealtimeVoiceAgentConsultArgs } from "./agent-consult-tool.js";
+
+type Logger = {
+  debug?: (message: string) => void;
+};
+
+type MemorySearchHit = {
+  path: string;
+  startLine: number;
+  endLine: number;
+  snippet: string;
+  source: "memory" | "sessions";
+  score: number;
+};
+
+export type RealtimeVoiceFastContextConfig = {
+  enabled: boolean;
+  maxResults: number;
+  sources: Array<"memory" | "sessions">;
+  timeoutMs: number;
+  fallbackToConsult: boolean;
+};
+
+export type RealtimeVoiceFastContextLabels = {
+  audienceLabel: string;
+  contextName: string;
+};
+
+type FastContextLookupResult =
+  | { status: "unavailable"; error?: string }
+  | { status: "hits"; hits: MemorySearchHit[] };
+
+export type RealtimeVoiceFastContextConsultResult =
+  | { handled: false }
+  | { handled: true; result: RealtimeVoiceAgentConsultResult };
+
+const MAX_SNIPPET_CHARS = 700;
+
+class RealtimeFastContextTimeoutError extends Error {
+  constructor(timeoutMs: number) {
+    super(`fast context lookup timed out after ${timeoutMs}ms`);
+    this.name = "RealtimeFastContextTimeoutError";
+  }
+}
+
+function normalizeSnippet(text: string): string {
+  const normalized = text.replace(/\s+/g, " ").trim();
+  if (normalized.length <= MAX_SNIPPET_CHARS) {
+    return normalized;
+  }
+  return `${normalized.slice(0, MAX_SNIPPET_CHARS - 1).trimEnd()}...`;
+}
+
+function buildSearchQuery(args: unknown): string {
+  const parsed = parseRealtimeVoiceAgentConsultArgs(args);
+  return [parsed.question, parsed.context].filter(Boolean).join("\n\n");
+}
+
+function resolveLabels(
+  labels?: Partial<RealtimeVoiceFastContextLabels>,
+): RealtimeVoiceFastContextLabels {
+  return {
+    audienceLabel: labels?.audienceLabel?.trim() || "person",
+    contextName: labels?.contextName?.trim() || "OpenClaw memory context",
+  };
+}
+
+function buildContextText(params: {
+  query: string;
+  hits: MemorySearchHit[];
+  labels: RealtimeVoiceFastContextLabels;
+}): string {
+  const hits = params.hits
+    .map((hit, index) => {
+      const location = `${hit.path}:${hit.startLine}-${hit.endLine}`;
+      return `${index + 1}. [${hit.source}] ${location}\n${normalizeSnippet(hit.snippet)}`;
+    })
+    .join("\n\n");
+  return [
+    `Fast ${params.labels.contextName} found for the live ${params.labels.audienceLabel}.`,
+    `Use this context only if it answers the ${params.labels.audienceLabel}'s question. If it is not relevant, say briefly that you do not have that context handy.`,
+    `Question:\n${params.query}`,
+    `Context:\n${hits}`,
+  ].join("\n\n");
+}
+
+function buildMissText(query: string, labels: RealtimeVoiceFastContextLabels): string {
+  return [
+    `No relevant ${labels.contextName} was found quickly for the live ${labels.audienceLabel}.`,
+    `Answer briefly that you do not have that context handy. Do not keep checking unless the ${labels.audienceLabel} asks you to.`,
+    `Question:\n${query}`,
+  ].join("\n\n");
+}
+
+async function withTimeout<T>(promise: Promise<T>, timeoutMs: number): Promise<T> {
+  let timer: ReturnType<typeof setTimeout> | undefined;
+  try {
+    return await Promise.race([
+      promise,
+      new Promise<T>((_resolve, reject) => {
+        timer = setTimeout(() => reject(new RealtimeFastContextTimeoutError(timeoutMs)), timeoutMs);
+      }),
+    ]);
+  } finally {
+    if (timer) {
+      clearTimeout(timer);
+    }
+  }
+}
+
+async function lookupFastContext(params: {
+  cfg: OpenClawConfig;
+  agentId: string;
+  sessionKey: string;
+  config: RealtimeVoiceFastContextConfig;
+  query: string;
+}): Promise<FastContextLookupResult> {
+  const memory = await getActiveMemorySearchManager({
+    cfg: params.cfg,
+    agentId: params.agentId,
+  });
+  if (!memory.manager) {
+    return {
+      status: "unavailable",
+      error: memory.error ?? "no active memory manager",
+    };
+  }
+  const hits = await memory.manager.search(params.query, {
+    maxResults: params.config.maxResults,
+    sessionKey: params.sessionKey,
+    sources: params.config.sources,
+  });
+  return { status: "hits", hits };
+}
+
+export async function resolveRealtimeVoiceFastContextConsult(params: {
+  cfg: OpenClawConfig;
+  agentId: string;
+  sessionKey: string;
+  config: RealtimeVoiceFastContextConfig;
+  args: unknown;
+  logger: Logger;
+  labels?: Partial<RealtimeVoiceFastContextLabels>;
+}): Promise<RealtimeVoiceFastContextConsultResult> {
+  if (!params.config.enabled) {
+    return { handled: false };
+  }
+
+  const labels = resolveLabels(params.labels);
+  const query = buildSearchQuery(params.args);
+  try {
+    const lookup = await withTimeout(
+      lookupFastContext({
+        cfg: params.cfg,
+        agentId: params.agentId,
+        sessionKey: params.sessionKey,
+        config: params.config,
+        query,
+      }),
+      params.config.timeoutMs,
+    );
+    if (lookup.status === "unavailable") {
+      params.logger.debug?.(`[realtime-voice] fast context unavailable: ${lookup.error}`);
+      return params.config.fallbackToConsult
+        ? { handled: false }
+        : { handled: true, result: { text: buildMissText(query, labels) } };
+    }
+    const { hits } = lookup;
+    if (hits.length === 0) {
+      return params.config.fallbackToConsult
+        ? { handled: false }
+        : { handled: true, result: { text: buildMissText(query, labels) } };
+    }
+    return {
+      handled: true,
+      result: { text: buildContextText({ query, hits, labels }) },
+    };
+  } catch (error) {
+    const message = formatErrorMessage(error);
+    params.logger.debug?.(`[realtime-voice] fast context lookup failed: ${message}`);
+    return params.config.fallbackToConsult
+      ? { handled: false }
+      : { handled: true, result: { text: buildMissText(query, labels) } };
+  }
+}
diff --git a/src/realtime-voice/provider-types.ts b/src/realtime-voice/provider-types.ts
index d40d420e026..cc784fb175e 100644
--- a/src/realtime-voice/provider-types.ts
+++ b/src/realtime-voice/provider-types.ts
@@ -1,4 +1,5 @@
 import type { OpenClawConfig } from "../config/types.openclaw.js";
+import type { TalkTransport } from "./talk-events.js";
 
 export type RealtimeVoiceProviderId = string;
 
@@ -72,6 +73,17 @@ export type RealtimeVoiceBridgeCallbacks = {
 
 export type RealtimeVoiceProviderConfig = Record<string, unknown>;
 
+export type RealtimeVoiceProviderCapabilities = {
+  transports: TalkTransport[];
+  inputAudioFormats: RealtimeVoiceAudioFormat[];
+  outputAudioFormats: RealtimeVoiceAudioFormat[];
+  supportsBrowserSession?: boolean;
+  supportsBargeIn?: boolean;
+  supportsToolCalls?: boolean;
+  supportsVideoFrames?: boolean;
+  supportsSessionResumption?: boolean;
+};
+
 export type RealtimeVoiceProviderResolveConfigContext = {
   cfg: OpenClawConfig;
   rawConfig: RealtimeVoiceProviderConfig;
@@ -107,7 +119,7 @@ export type RealtimeVoiceBrowserAudioContract = {
 
 export type RealtimeVoiceBrowserWebRtcSdpSession = {
   provider: RealtimeVoiceProviderId;
-  transport?: "webrtc-sdp";
+  transport: "webrtc";
   clientSecret: string;
   offerUrl?: string;
   offerHeaders?: Record<string, string>;
@@ -118,7 +130,7 @@ export type RealtimeVoiceBrowserWebRtcSdpSession = {
 
 export type RealtimeVoiceBrowserJsonPcmWebSocketSession = {
   provider: RealtimeVoiceProviderId;
-  transport: "json-pcm-websocket";
+  transport: "provider-websocket";
   protocol: string;
   clientSecret: string;
   websocketUrl: string;
diff --git a/src/realtime-voice/session-log-runtime.test.ts b/src/realtime-voice/session-log-runtime.test.ts
new file mode 100644
index 00000000000..e97f6f68d79
--- /dev/null
+++ b/src/realtime-voice/session-log-runtime.test.ts
@@ -0,0 +1,80 @@
+import { describe, expect, it } from "vitest";
+import {
+  extendRealtimeVoiceOutputEchoSuppression,
+  getRealtimeVoiceBridgeEventHealth,
+  getRealtimeVoiceTranscriptHealth,
+  isLikelyRealtimeVoiceAssistantEchoTranscript,
+  recordRealtimeVoiceBridgeEvent,
+  recordRealtimeVoiceTranscript,
+  type RealtimeVoiceBridgeEventLogEntry,
+  type RealtimeVoiceTranscriptEntry,
+} from "./session-log-runtime.js";
+
+describe("realtime voice session log runtime", () => {
+  it("records bounded transcript health", () => {
+    const transcript: RealtimeVoiceTranscriptEntry[] = [];
+    recordRealtimeVoiceTranscript(transcript, "user", "hello", 1);
+    recordRealtimeVoiceTranscript(transcript, "assistant", "hi", 1);
+
+    expect(getRealtimeVoiceTranscriptHealth(transcript)).toMatchObject({
+      realtimeTranscriptLines: 1,
+      lastRealtimeTranscriptRole: "assistant",
+      lastRealtimeTranscriptText: "hi",
+    });
+  });
+
+  it("skips noisy audio append events and records bridge health", () => {
+    const events: RealtimeVoiceBridgeEventLogEntry[] = [];
+    recordRealtimeVoiceBridgeEvent(events, {
+      direction: "client",
+      type: "input_audio_buffer.append",
+    });
+    recordRealtimeVoiceBridgeEvent(events, {
+      direction: "server",
+      type: "response.done",
+      detail: "ok",
+    });
+
+    expect(getRealtimeVoiceBridgeEventHealth(events)).toMatchObject({
+      lastRealtimeEventType: "server:response.done",
+      lastRealtimeEventDetail: "ok",
+    });
+  });
+
+  it("detects likely assistant echo transcripts", () => {
+    const nowMs = Date.now();
+    const transcript: RealtimeVoiceTranscriptEntry[] = [
+      {
+        at: new Date(nowMs - 1000).toISOString(),
+        role: "assistant",
+        text: "The deployment finished cleanly and all checks passed",
+      },
+    ];
+
+    expect(
+      isLikelyRealtimeVoiceAssistantEchoTranscript({
+        transcript,
+        text: "deployment finished cleanly and all checks passed",
+        lookbackMs: 45_000,
+        nowMs,
+      }),
+    ).toBe(true);
+  });
+
+  it("extends output echo suppression from audio duration", () => {
+    expect(
+      extendRealtimeVoiceOutputEchoSuppression({
+        audio: Buffer.alloc(96),
+        bytesPerMs: 48,
+        tailMs: 3000,
+        nowMs: 100,
+        lastOutputPlayableUntilMs: 0,
+        suppressInputUntilMs: 0,
+      }),
+    ).toEqual({
+      durationMs: 2,
+      lastOutputPlayableUntilMs: 102,
+      suppressInputUntilMs: 3102,
+    });
+  });
+});
diff --git a/src/realtime-voice/session-log-runtime.ts b/src/realtime-voice/session-log-runtime.ts
new file mode 100644
index 00000000000..361eea3929f
--- /dev/null
+++ b/src/realtime-voice/session-log-runtime.ts
@@ -0,0 +1,155 @@
+import type { RealtimeVoiceBridgeEvent, RealtimeVoiceRole } from "./provider-types.js";
+
+export type RealtimeVoiceTranscriptEntry = {
+  at: string;
+  role: RealtimeVoiceRole;
+  text: string;
+};
+
+export type RealtimeVoiceTranscriptHealth = {
+  realtimeTranscriptLines: number;
+  lastRealtimeTranscriptAt?: string;
+  lastRealtimeTranscriptRole?: RealtimeVoiceRole;
+  lastRealtimeTranscriptText?: string;
+  recentRealtimeTranscript: RealtimeVoiceTranscriptEntry[];
+};
+
+export type RealtimeVoiceBridgeEventLogEntry = RealtimeVoiceBridgeEvent & {
+  at: string;
+};
+
+export type RealtimeVoiceBridgeEventHealth = {
+  lastRealtimeEventAt?: string;
+  lastRealtimeEventType?: string;
+  lastRealtimeEventDetail?: string;
+  recentRealtimeEvents: RealtimeVoiceBridgeEventLogEntry[];
+};
+
+export function recordRealtimeVoiceTranscript(
+  transcript: RealtimeVoiceTranscriptEntry[],
+  role: RealtimeVoiceRole,
+  text: string,
+  maxEntries = 40,
+): RealtimeVoiceTranscriptEntry {
+  const entry = { at: new Date().toISOString(), role, text };
+  transcript.push(entry);
+  if (transcript.length > maxEntries) {
+    transcript.splice(0, transcript.length - maxEntries);
+  }
+  return entry;
+}
+
+export function getRealtimeVoiceTranscriptHealth(
+  transcript: RealtimeVoiceTranscriptEntry[],
+): RealtimeVoiceTranscriptHealth {
+  const last = transcript.at(-1);
+  return {
+    realtimeTranscriptLines: transcript.length,
+    lastRealtimeTranscriptAt: last?.at,
+    lastRealtimeTranscriptRole: last?.role,
+    lastRealtimeTranscriptText: last?.text,
+    recentRealtimeTranscript: transcript.slice(-5),
+  };
+}
+
+export function recordRealtimeVoiceBridgeEvent(
+  events: RealtimeVoiceBridgeEventLogEntry[],
+  event: RealtimeVoiceBridgeEvent,
+  maxEntries = 40,
+): void {
+  if (event.direction === "client" && event.type === "input_audio_buffer.append") {
+    return;
+  }
+  events.push({ at: new Date().toISOString(), ...event });
+  if (events.length > maxEntries) {
+    events.splice(0, events.length - maxEntries);
+  }
+}
+
+export function getRealtimeVoiceBridgeEventHealth(
+  events: RealtimeVoiceBridgeEventLogEntry[],
+): RealtimeVoiceBridgeEventHealth {
+  const last = events.at(-1);
+  return {
+    lastRealtimeEventAt: last?.at,
+    lastRealtimeEventType: last ? `${last.direction}:${last.type}` : undefined,
+    lastRealtimeEventDetail: last?.detail,
+    recentRealtimeEvents: events.slice(-10),
+  };
+}
+
+function normalizeTranscriptForEchoMatch(text: string): string[] {
+  return text
+    .toLowerCase()
+    .replace(/['’]/g, "")
+    .replace(/[^a-z0-9]+/g, " ")
+    .trim()
+    .split(/\s+/)
+    .filter((token) => token.length > 1);
+}
+
+function hasMeaningfulEchoOverlap(userTokens: string[], assistantTokens: string[]): boolean {
+  if (userTokens.length < 4 || assistantTokens.length < 4) {
+    return false;
+  }
+  const uniqueUserTokens = [...new Set(userTokens)];
+  if (uniqueUserTokens.length < 4) {
+    return false;
+  }
+  const assistantTokenSet = new Set(assistantTokens);
+  const overlap = uniqueUserTokens.filter((token) => assistantTokenSet.has(token)).length;
+  return overlap / uniqueUserTokens.length >= 0.58;
+}
+
+export function isLikelyRealtimeVoiceAssistantEchoTranscript(params: {
+  transcript: RealtimeVoiceTranscriptEntry[];
+  text: string;
+  lookbackMs: number;
+  nowMs?: number;
+}): boolean {
+  const userTokens = normalizeTranscriptForEchoMatch(params.text);
+  if (userTokens.length < 4) {
+    return false;
+  }
+  const nowMs = params.nowMs ?? Date.now();
+  const recentAssistantText = params.transcript
+    .filter((entry) => {
+      if (entry.role !== "assistant") {
+        return false;
+      }
+      const at = Date.parse(entry.at);
+      return Number.isFinite(at) && nowMs - at <= params.lookbackMs;
+    })
+    .slice(-6)
+    .map((entry) => entry.text)
+    .join(" ");
+  if (!recentAssistantText.trim()) {
+    return false;
+  }
+  const userNormalized = userTokens.join(" ");
+  const assistantTokens = normalizeTranscriptForEchoMatch(recentAssistantText);
+  const assistantNormalized = assistantTokens.join(" ");
+  return (
+    (userNormalized.length >= 18 && assistantNormalized.includes(userNormalized)) ||
+    (assistantNormalized.length >= 18 && userNormalized.includes(assistantNormalized)) ||
+    hasMeaningfulEchoOverlap(userTokens, assistantTokens)
+  );
+}
+
+export function extendRealtimeVoiceOutputEchoSuppression(params: {
+  audio: Buffer;
+  bytesPerMs: number;
+  tailMs: number;
+  nowMs: number;
+  lastOutputPlayableUntilMs: number;
+  suppressInputUntilMs: number;
+}): { lastOutputPlayableUntilMs: number; suppressInputUntilMs: number; durationMs: number } {
+  const durationMs = Math.ceil(params.audio.byteLength / params.bytesPerMs);
+  const playbackStartMs = Math.max(params.nowMs, params.lastOutputPlayableUntilMs);
+  const playbackEndMs = playbackStartMs + durationMs;
+  return {
+    durationMs,
+    lastOutputPlayableUntilMs: playbackEndMs,
+    suppressInputUntilMs: Math.max(params.suppressInputUntilMs, playbackEndMs + params.tailMs),
+  };
+}
diff --git a/src/realtime-voice/talk-events.test.ts b/src/realtime-voice/talk-events.test.ts
new file mode 100644
index 00000000000..6da2411daf1
--- /dev/null
+++ b/src/realtime-voice/talk-events.test.ts
@@ -0,0 +1,90 @@
+import { describe, expect, it } from "vitest";
+import { createTalkEventSequencer } from "./talk-events.js";
+
+describe("talk event envelope", () => {
+  it("adds stable session context and monotonically increasing sequence numbers", () => {
+    const events = createTalkEventSequencer(
+      {
+        sessionId: "session-1",
+        mode: "realtime",
+        transport: "gateway-relay",
+        brain: "agent-consult",
+        provider: "openai",
+      },
+      { now: () => "2026-05-05T12:00:00.000Z" },
+    );
+
+    expect(events.next({ type: "session.started", payload: { ok: true } })).toEqual({
+      id: "session-1:1",
+      sessionId: "session-1",
+      seq: 1,
+      timestamp: "2026-05-05T12:00:00.000Z",
+      mode: "realtime",
+      transport: "gateway-relay",
+      brain: "agent-consult",
+      provider: "openai",
+      type: "session.started",
+      payload: { ok: true },
+      turnId: undefined,
+      captureId: undefined,
+      final: undefined,
+      callId: undefined,
+      itemId: undefined,
+      parentId: undefined,
+    });
+    expect(events.next({ type: "session.ready", payload: null }).seq).toBe(2);
+  });
+
+  it("preserves turn, capture, and provider correlation fields", () => {
+    const events = createTalkEventSequencer({
+      sessionId: "session-voice",
+      mode: "stt-tts",
+      transport: "managed-room",
+      brain: "agent-consult",
+    });
+
+    expect(
+      events.next({
+        type: "tool.call",
+        turnId: "turn-1",
+        captureId: "capture-1",
+        callId: "call-1",
+        itemId: "item-1",
+        parentId: "parent-1",
+        final: false,
+        timestamp: "2026-05-05T12:00:01.000Z",
+        payload: { name: "openclaw_agent_consult" },
+      }),
+    ).toMatchObject({
+      id: "session-voice:1",
+      sessionId: "session-voice",
+      mode: "stt-tts",
+      transport: "managed-room",
+      brain: "agent-consult",
+      type: "tool.call",
+      turnId: "turn-1",
+      captureId: "capture-1",
+      callId: "call-1",
+      itemId: "item-1",
+      parentId: "parent-1",
+      final: false,
+      payload: { name: "openclaw_agent_consult" },
+    });
+  });
+
+  it("rejects turn and capture scoped events without correlation ids", () => {
+    const events = createTalkEventSequencer({
+      sessionId: "session-voice",
+      mode: "stt-tts",
+      transport: "managed-room",
+      brain: "agent-consult",
+    });
+
+    expect(() => events.next({ type: "turn.started", payload: {} })).toThrow(
+      "Talk event turn.started requires turnId",
+    );
+    expect(() => events.next({ type: "capture.started", payload: {} })).toThrow(
+      "Talk event capture.started requires captureId",
+    );
+  });
+});
diff --git a/src/realtime-voice/talk-events.ts b/src/realtime-voice/talk-events.ts
new file mode 100644
index 00000000000..5887c70632d
--- /dev/null
+++ b/src/realtime-voice/talk-events.ts
@@ -0,0 +1,145 @@
+export const TALK_EVENT_TYPES = [
+  "session.started",
+  "session.ready",
+  "session.closed",
+  "session.error",
+  "session.replaced",
+  "turn.started",
+  "turn.ended",
+  "turn.cancelled",
+  "capture.started",
+  "capture.stopped",
+  "capture.cancelled",
+  "capture.once",
+  "input.audio.delta",
+  "input.audio.committed",
+  "transcript.delta",
+  "transcript.done",
+  "output.text.delta",
+  "output.text.done",
+  "output.audio.started",
+  "output.audio.delta",
+  "output.audio.done",
+  "tool.call",
+  "tool.progress",
+  "tool.result",
+  "tool.error",
+  "usage.metrics",
+  "latency.metrics",
+  "health.changed",
+] as const;
+
+export type TalkEventType = (typeof TALK_EVENT_TYPES)[number];
+
+export type TalkMode = "realtime" | "stt-tts" | "transcription";
+
+export type TalkTransport = "webrtc" | "provider-websocket" | "gateway-relay" | "managed-room";
+
+export type TalkBrain = "agent-consult" | "direct-tools" | "none";
+
+export type TalkEventContext = {
+  sessionId: string;
+  mode: TalkMode;
+  transport: TalkTransport;
+  brain: TalkBrain;
+  provider?: string;
+};
+
+export type TalkEvent<TPayload = unknown> = TalkEventContext & {
+  id: string;
+  type: TalkEventType;
+  turnId?: string;
+  captureId?: string;
+  seq: number;
+  timestamp: string;
+  final?: boolean;
+  callId?: string;
+  itemId?: string;
+  parentId?: string;
+  payload: TPayload;
+};
+
+export type TalkEventInput<TPayload = unknown> = {
+  type: TalkEventType;
+  payload: TPayload;
+  turnId?: string;
+  captureId?: string;
+  timestamp?: string;
+  final?: boolean;
+  callId?: string;
+  itemId?: string;
+  parentId?: string;
+};
+
+export type TalkEventSequencer = {
+  next<TPayload>(input: TalkEventInput<TPayload>): TalkEvent<TPayload>;
+};
+
+const TURN_SCOPED_TALK_EVENT_TYPES = new Set<TalkEventType>([
+  "turn.started",
+  "turn.ended",
+  "turn.cancelled",
+  "input.audio.delta",
+  "input.audio.committed",
+  "transcript.delta",
+  "transcript.done",
+  "output.text.delta",
+  "output.text.done",
+  "output.audio.started",
+  "output.audio.delta",
+  "output.audio.done",
+  "tool.call",
+  "tool.progress",
+  "tool.result",
+  "tool.error",
+]);
+
+const CAPTURE_SCOPED_TALK_EVENT_TYPES = new Set<TalkEventType>([
+  "capture.started",
+  "capture.stopped",
+  "capture.cancelled",
+  "capture.once",
+]);
+
+function assertTalkEventCorrelation(input: TalkEventInput): void {
+  if (TURN_SCOPED_TALK_EVENT_TYPES.has(input.type) && !input.turnId?.trim()) {
+    throw new Error(`Talk event ${input.type} requires turnId`);
+  }
+  if (CAPTURE_SCOPED_TALK_EVENT_TYPES.has(input.type) && !input.captureId?.trim()) {
+    throw new Error(`Talk event ${input.type} requires captureId`);
+  }
+}
+
+export function createTalkEventSequencer(
+  context: TalkEventContext,
+  options: { now?: () => Date | string } = {},
+): TalkEventSequencer {
+  let seq = 0;
+  const now = options.now ?? (() => new Date());
+  return {
+    next<TPayload>(input: TalkEventInput<TPayload>): TalkEvent<TPayload> {
+      assertTalkEventCorrelation(input);
+      seq += 1;
+      const timestamp =
+        input.timestamp ??
+        (() => {
+          const value = now();
+          return typeof value === "string" ? value : value.toISOString();
+        })();
+      return {
+        ...context,
+        id: `${context.sessionId}:${seq}`,
+        type: input.type,
+        turnId: input.turnId,
+        captureId: input.captureId,
+        seq,
+        timestamp,
+        final: input.final,
+        callId: input.callId,
+        itemId: input.itemId,
+        parentId: input.parentId,
+        payload: input.payload,
+      };
+    },
+  };
+}
diff --git a/src/realtime-voice/talk-session-controller.test.ts b/src/realtime-voice/talk-session-controller.test.ts
new file mode 100644
index 00000000000..34e1693f440
--- /dev/null
+++ b/src/realtime-voice/talk-session-controller.test.ts
@@ -0,0 +1,124 @@
+import { describe, expect, it } from "vitest";
+import { createTalkSessionController, normalizeTalkTransport } from "./talk-session-controller.js";
+
+function createController() {
+  return createTalkSessionController(
+    {
+      sessionId: "talk-session",
+      mode: "realtime",
+      transport: "gateway-relay",
+      brain: "agent-consult",
+      provider: "test",
+      maxRecentEvents: 3,
+    },
+    { now: () => "2026-05-05T00:00:00.000Z" },
+  );
+}
+
+describe("createTalkSessionController", () => {
+  it("emits common envelopes and keeps bounded recent event history", () => {
+    const talk = createController();
+
+    talk.emit({ type: "session.started", payload: {} });
+    const firstTurn = talk.ensureTurn();
+    talk.emit({
+      type: "input.audio.delta",
+      turnId: firstTurn.turnId,
+      payload: { byteLength: 5 },
+    });
+    talk.emit({
+      type: "transcript.done",
+      turnId: firstTurn.turnId,
+      payload: { text: "hello" },
+      final: true,
+    });
+
+    expect(firstTurn.event).toMatchObject({
+      id: "talk-session:2",
+      type: "turn.started",
+      sessionId: "talk-session",
+      turnId: "turn-1",
+      mode: "realtime",
+      transport: "gateway-relay",
+      brain: "agent-consult",
+      provider: "test",
+      seq: 2,
+      timestamp: "2026-05-05T00:00:00.000Z",
+    });
+    expect(talk.recentEvents.map((event) => event.type)).toEqual([
+      "turn.started",
+      "input.audio.delta",
+      "transcript.done",
+    ]);
+  });
+
+  it("rejects stale turn completion before clearing the active turn", () => {
+    const talk = createController();
+    talk.ensureTurn({ turnId: "turn-old" });
+    expect(talk.endTurn({ turnId: "turn-other" })).toEqual({
+      ok: false,
+      reason: "stale_turn",
+    });
+    expect(talk.activeTurnId).toBe("turn-old");
+
+    const ended = talk.endTurn({ turnId: "turn-old", payload: { reason: "done" } });
+
+    expect(ended).toMatchObject({
+      ok: true,
+      turnId: "turn-old",
+      event: {
+        type: "turn.ended",
+        turnId: "turn-old",
+        payload: { reason: "done" },
+        final: true,
+      },
+    });
+    expect(talk.activeTurnId).toBeUndefined();
+  });
+
+  it("tracks output audio lifecycle without duplicate started events", () => {
+    const talk = createController();
+
+    const first = talk.startOutputAudio({ payload: { callId: "call-1" } });
+    const second = talk.startOutputAudio({ payload: { callId: "call-1" } });
+    const done = talk.finishOutputAudio({ payload: { reason: "mark" } });
+
+    expect(first.event).toMatchObject({
+      type: "output.audio.started",
+      turnId: "turn-1",
+    });
+    expect(second).toEqual({ turnId: "turn-1" });
+    expect(done).toMatchObject({
+      type: "output.audio.done",
+      turnId: "turn-1",
+      payload: { reason: "mark" },
+      final: true,
+    });
+    expect(talk.outputAudioActive).toBe(false);
+  });
+
+  it("clears stale output audio state when a replacement turn starts", () => {
+    const talk = createController();
+
+    talk.startOutputAudio({ turnId: "turn-old" });
+    expect(talk.outputAudioActive).toBe(true);
+
+    const current = talk.startTurn({ turnId: "turn-current" });
+
+    expect(current).toMatchObject({
+      turnId: "turn-current",
+      event: expect.objectContaining({ type: "turn.started", turnId: "turn-current" }),
+    });
+    expect(talk.activeTurnId).toBe("turn-current");
+    expect(talk.outputAudioActive).toBe(false);
+  });
+});
+
+describe("normalizeTalkTransport", () => {
+  it("maps legacy public transport names to canonical names", () => {
+    expect(normalizeTalkTransport(undefined)).toBeUndefined();
+    expect(normalizeTalkTransport("webrtc-sdp")).toBe("webrtc");
+    expect(normalizeTalkTransport("json-pcm-websocket")).toBe("provider-websocket");
+    expect(normalizeTalkTransport("gateway-relay")).toBe("gateway-relay");
+  });
+});
diff --git a/src/realtime-voice/talk-session-controller.ts b/src/realtime-voice/talk-session-controller.ts
new file mode 100644
index 00000000000..3643853704c
--- /dev/null
+++ b/src/realtime-voice/talk-session-controller.ts
@@ -0,0 +1,206 @@
+import {
+  createTalkEventSequencer,
+  type TalkBrain,
+  type TalkEvent,
+  type TalkEventContext,
+  type TalkEventInput,
+  type TalkEventSequencer,
+  type TalkMode,
+  type TalkTransport,
+} from "./talk-events.js";
+
+export type TalkTurnFailureReason = "no_active_turn" | "stale_turn";
+
+export type TalkTurnSuccess = {
+  event: TalkEvent;
+  ok: true;
+  turnId: string;
+};
+
+export type TalkTurnFailure = {
+  ok: false;
+  reason: TalkTurnFailureReason;
+};
+
+export type TalkTurnResult = TalkTurnSuccess | TalkTurnFailure;
+
+export type TalkEnsureTurnResult = {
+  event?: TalkEvent;
+  turnId: string;
+};
+
+export type TalkSessionController = {
+  readonly activeTurnId: string | undefined;
+  readonly context: TalkEventContext;
+  readonly outputAudioActive: boolean;
+  readonly recentEvents: readonly TalkEvent[];
+  clearActiveTurn(): void;
+  emit<TPayload>(input: TalkEventInput<TPayload>): TalkEvent<TPayload>;
+  ensureTurn(params?: { payload?: unknown; turnId?: string }): TalkEnsureTurnResult;
+  startTurn(params?: { payload?: unknown; turnId?: string }): TalkEnsureTurnResult;
+  endTurn(params?: { payload?: unknown; turnId?: string }): TalkTurnResult;
+  cancelTurn(params?: { payload?: unknown; turnId?: string }): TalkTurnResult;
+  finishOutputAudio(params?: { payload?: unknown; turnId?: string }): TalkEvent | undefined;
+  startOutputAudio(params?: { payload?: unknown; turnId?: string }): TalkEnsureTurnResult;
+};
+
+export type TalkSessionControllerParams = TalkEventContext & {
+  maxRecentEvents?: number;
+  turnIdPrefix?: string;
+};
+
+export function createTalkSessionController(
+  params: TalkSessionControllerParams,
+  options: { now?: () => Date | string; sequencer?: TalkEventSequencer } = {},
+): TalkSessionController {
+  const { maxRecentEvents = 20, turnIdPrefix = "turn", ...context } = params;
+  const sequencer = options.sequencer ?? createTalkEventSequencer(context, { now: options.now });
+  const recentEvents: TalkEvent[] = [];
+  let activeTurnId: string | undefined;
+  let outputAudioActive = false;
+  let turnSeq = 0;
+
+  const remember = <TPayload>(event: TalkEvent<TPayload>): TalkEvent<TPayload> => {
+    recentEvents.push(event as TalkEvent);
+    if (recentEvents.length > maxRecentEvents) {
+      recentEvents.splice(0, recentEvents.length - maxRecentEvents);
+    }
+    return event;
+  };
+
+  const emit = <TPayload>(input: TalkEventInput<TPayload>): TalkEvent<TPayload> => {
+    return remember(sequencer.next(input));
+  };
+
+  const resolveActiveTurn = (requestedTurnId: string | undefined): string | TalkTurnFailure => {
+    if (!activeTurnId) {
+      return { ok: false, reason: "no_active_turn" };
+    }
+    const normalizedRequested = normalizeOptionalString(requestedTurnId);
+    if (normalizedRequested && normalizedRequested !== activeTurnId) {
+      return { ok: false, reason: "stale_turn" };
+    }
+    return activeTurnId;
+  };
+
+  const ensureTurn = (ensureParams: { payload?: unknown; turnId?: string } = {}) => {
+    if (activeTurnId) {
+      return { turnId: activeTurnId };
+    }
+    return startTurn(ensureParams);
+  };
+
+  const startTurn = (startParams: { payload?: unknown; turnId?: string } = {}) => {
+    const turnId = normalizeOptionalString(startParams.turnId) ?? `${turnIdPrefix}-${++turnSeq}`;
+    outputAudioActive = false;
+    activeTurnId = turnId;
+    return {
+      turnId,
+      event: emit({
+        type: "turn.started",
+        turnId,
+        payload: startParams.payload ?? {},
+      }),
+    };
+  };
+
+  const finishTurn = (
+    type: "turn.ended" | "turn.cancelled",
+    paramsForTurn: { payload?: unknown; turnId?: string } = {},
+  ): TalkTurnResult => {
+    const turnId = resolveActiveTurn(paramsForTurn.turnId);
+    if (typeof turnId !== "string") {
+      return turnId;
+    }
+    outputAudioActive = false;
+    activeTurnId = undefined;
+    return {
+      ok: true,
+      turnId,
+      event: emit({
+        type,
+        turnId,
+        payload: paramsForTurn.payload ?? {},
+        final: true,
+      }),
+    };
+  };
+
+  return {
+    get activeTurnId() {
+      return activeTurnId;
+    },
+    context,
+    get outputAudioActive() {
+      return outputAudioActive;
+    },
+    get recentEvents() {
+      return recentEvents;
+    },
+    clearActiveTurn() {
+      activeTurnId = undefined;
+      outputAudioActive = false;
+    },
+    emit,
+    ensureTurn,
+    startTurn,
+    endTurn(paramsForTurn) {
+      return finishTurn("turn.ended", paramsForTurn);
+    },
+    cancelTurn(paramsForTurn) {
+      return finishTurn("turn.cancelled", paramsForTurn);
+    },
+    finishOutputAudio(paramsForOutput = {}) {
+      if (!outputAudioActive) {
+        return undefined;
+      }
+      const turnId = resolveActiveTurn(paramsForOutput.turnId);
+      if (typeof turnId !== "string") {
+        return undefined;
+      }
+      outputAudioActive = false;
+      return emit({
+        type: "output.audio.done",
+        turnId,
+        payload: paramsForOutput.payload ?? {},
+        final: true,
+      });
+    },
+    startOutputAudio(paramsForOutput = {}) {
+      const turn = ensureTurn({ turnId: paramsForOutput.turnId, payload: {} });
+      if (outputAudioActive) {
+        return { turnId: turn.turnId };
+      }
+      outputAudioActive = true;
+      return {
+        turnId: turn.turnId,
+        event: emit({
+          type: "output.audio.started",
+          turnId: turn.turnId,
+          payload: paramsForOutput.payload ?? {},
+        }),
+      };
+    },
+  };
+}
+
+export function normalizeTalkTransport(value: string | undefined): string | undefined {
+  const normalized = normalizeOptionalString(value);
+  if (!normalized) {
+    return undefined;
+  }
+  if (normalized === "webrtc-sdp") {
+    return "webrtc";
+  }
+  if (normalized === "json-pcm-websocket") {
+    return "provider-websocket";
+  }
+  return normalized;
+}
+
+export type { TalkBrain, TalkEvent, TalkEventContext, TalkEventInput, TalkMode, TalkTransport };
+
+function normalizeOptionalString(value: string | undefined): string | undefined {
+  const trimmed = value?.trim();
+  return trimmed ? trimmed : undefined;
+}