diff --git a/ai/.env.example b/ai/.env.example
index c910b2b9..400b1c85 100644
--- a/ai/.env.example
+++ b/ai/.env.example
@@ -56,9 +56,15 @@ DEEPGRAM_BASE_URL=https://api.deepgram.com/v1
 DEEPGRAM_MODEL=whisper-large
 DEEPGRAM_LANGUAGE=ko
 DEEPGRAM_TIMEOUT_SEC=60
-# OpenAI Whisper (Mindlogic 미지원, 직접 호출).
+# OpenAI Whisper (Mindlogic 미지원, 직접 호출). OPENAI_API_KEY/OPENAI_BASE_URL 은 TTS 와 공용.
 OPENAI_API_KEY=
 OPENAI_BASE_URL=https://api.openai.com/v1
 WHISPER_MODEL=whisper-1
 WHISPER_LANGUAGE=ko
 WHISPER_TIMEOUT_SEC=60
+
+# TTS (질문 음성화). auto=OPENAI_API_KEY 보유 시 openai, 없으면 mock. (OPENAI_API_KEY 재사용)
+TTS_PROVIDER=auto
+OPENAI_TTS_MODEL=gpt-4o-mini-tts
+OPENAI_TTS_VOICE=alloy
+OPENAI_TTS_TIMEOUT_SEC=30
diff --git a/ai/CLAUDE.md b/ai/CLAUDE.md
index e900901d..8fc4a3a4 100644
--- a/ai/CLAUDE.md
+++ b/ai/CLAUDE.md
@@ -95,6 +95,7 @@ ai/
 | `ai.analyze.web` | `analyze.web` | 본 구현 (URL → trafilatura) |
 | `ai.generate.questions` | `generate.questions` | 본 구현 (Pro 모델, 질문 풀 생성, US-18) |
 | `ai.generate.followup` | `generate.followup` | 본 구현 (Flash 모델, 답변 평가+꼬리질문, US-19) |
+| `ai.generate.tts` | `generate.tts` | 본 구현 (질문 음성화, OpenAI TTS → S3 → `callback.tts`) |
 
 콜백 발행: `ai.callback.{type}` 익스체인지.
 상세 envelope/스키마/재시도: [`/docs/messaging.md`](../docs/messaging.md).
@@ -188,8 +189,8 @@ chain = prompt | llm | PydanticOutputParser(pydantic_object=...)
   - 비용: $0.006 / 분 (1시간 면접 ≈ ₩500 / USD ≈ $0.36)
   - 셀프호스팅 옵션: `whisper.cpp` 또는 `faster-whisper` (GPU 권장, 비용 ↓ but 운영 부담 ↑)
   - 브라우저 내장 SpeechRecognition API는 정확도 부족으로 채택 안 함
-- TTS 제공자 미정 → 도입 시 본 섹션 갱신
-- 추상화 계층 두기: `voice/stt/base.py` (interface), `voice/stt/whisper_api.py`, `voice/tts/{provider}.py`
+- **TTS: OpenAI TTS 채택** (`voice/tts/`) — 질문(INTERVIEWER) 메시지 음성화. `TtsProvider` 추상화 + `OpenAiTtsProvider`(`gpt-4o-mini-tts`, mp3)/`MockTtsProvider`, `build_tts_provider` factory(`TTS_PROVIDER=auto`면 OPENAI_API_KEY 보유 시 openai). `generate.tts` consumer 가 합성 → S3 PUT → `callback.tts` 발행.
+- 추상화 계층 두기: `voice/stt/base.py` (interface), `voice/stt/whisper_api.py`, `voice/tts/base.py` + `voice/tts/{provider}.py`
 - 분석:
   - WPM = words / minutes
   - 간투어: 한국어 정규식 `r"\b(음+|어+|그+)\b"` 카운트
@@ -324,6 +325,8 @@ docker run --env-file .env -p 8000:8000 stackup-ai
 - **스토리지 추상화** (`storage/`): `S3Storage`(기본) / `LocalFilesystemStorage`. `STORAGE_BACKEND` 토글.
 - **LLM 호출 로깅 본 구현** (`observability/llm_logging_callback.py`, US-30):
   LangChain `AsyncCallbackHandler` 가 토큰/latency 측정 → Core `/api/internal/ai-logs` POST.
-- 음성 모듈은 Phase 2
+- **질문 TTS consumer 본 구현** (`messaging/consumers/tts_consumer.py`, `voice/tts/`):
+  `generate.tts` 수신 → OpenAI TTS 합성(`OpenAiTtsProvider`, mock fallback) → S3 PUT(`interview/tts/{sessionId}/{messageId}.mp3`) → `callback.tts` 발행.
+- 음성 분석(STT/WPM/filler) 모듈은 Phase 2
 
 각 도입 시 본 문서 갱신.
diff --git a/ai/src/ai_server/config/settings.py b/ai/src/ai_server/config/settings.py
index 86a9ca22..cd0482b5 100644
--- a/ai/src/ai_server/config/settings.py
+++ b/ai/src/ai_server/config/settings.py
@@ -26,12 +26,14 @@ class Settings(BaseSettings):
     ai_queue_followup: str = "ai.generate.followup"
     ai_queue_feedback: str = "ai.generate.feedback"
     ai_queue_voice: str = "ai.analyze.voice"
+    ai_queue_tts: str = "ai.generate.tts"
     ai_queue_prefetch: int = 10
     ai_callback_exchange: str = "stackup.ai-to-core"
     ai_callback_routing_analysis: str = "callback.analysis"
     ai_callback_routing_questions: str = "callback.questions"
     ai_callback_routing_feedback: str = "callback.feedback"
     ai_callback_routing_voice: str = "callback.voice"
+    ai_callback_routing_tts: str = "callback.tts"
     # AI -> RealTime 직접 발행 (분석 단계 진행 상황). Core 를 거치지 않는 휘발성 알림.
     ai_realtime_exchange: str = "stackup.realtime"
     ai_realtime_routing_user: str = "realtime.user.notify"
@@ -52,6 +54,13 @@ class Settings(BaseSettings):
     deepgram_model: str = "whisper-large"   # 한국어 정확도 우선; 저비용 우선 시 nova-2.
     deepgram_language: str = "ko"
     deepgram_timeout_sec: float = 60.0
+
+    # TTS (질문 음성화). "auto" 면 openai 키 보유 시 openai, 없으면 mock.
+    tts_provider: Literal["auto", "mock", "openai"] = "auto"
+    openai_tts_model: str = "gpt-4o-mini-tts"
+    openai_tts_voice: str = "alloy"
+    openai_tts_timeout_sec: float = 30.0
+    tts_audio_key_template: str = "interview/tts/{session_id}/{message_id}.mp3"
     # 음성 분석
     voice_filler_pattern: str = r"(?:음+|어+|그+|아+)"
     ai_publisher_name: str = "ai-server"
diff --git a/ai/src/ai_server/messaging/consumers/tts_consumer.py b/ai/src/ai_server/messaging/consumers/tts_consumer.py
new file mode 100644
index 00000000..62a8341b
--- /dev/null
+++ b/ai/src/ai_server/messaging/consumers/tts_consumer.py
@@ -0,0 +1,103 @@
+from __future__ import annotations
+
+import structlog
+from aio_pika.abc import AbstractIncomingMessage
+
+from ai_server.messaging.idempotency import LruIdempotencyStore
+from ai_server.messaging.publisher import CallbackPublisher
+from ai_server.model.envelope import Envelope
+from ai_server.model.messages.tts import GenerateTtsRequest, TtsCallbackPayload
+from ai_server.storage.base import ObjectStorage
+from ai_server.voice.tts.base import TtsError, TtsProvider
+
+log = structlog.get_logger(__name__)
+
+
+class TtsConsumer:
+    """generate.tts consumer — 질문 텍스트를 TTS 합성 → S3 PUT → callback.tts 발행."""
+
+    def __init__(
+        self,
+        *,
+        tts: TtsProvider,
+        storage: ObjectStorage,
+        publisher: CallbackPublisher,
+        idempotency: LruIdempotencyStore,
+        callback_routing_key: str,
+        voice: str,
+        key_template: str,
+    ) -> None:
+        self._tts = tts
+        self._storage = storage
+        self._publisher = publisher
+        self._idempotency = idempotency
+        self._callback_routing_key = callback_routing_key
+        self._voice = voice
+        self._key_template = key_template
+
+    async def handle(self, message: AbstractIncomingMessage) -> None:
+        async with message.process(requeue=False):
+            try:
+                envelope = Envelope[GenerateTtsRequest].model_validate_json(message.body)
+            except Exception as exc:
+                log.error("tts.parse.failed", error=str(exc), delivery_tag=message.delivery_tag)
+                raise
+
+            if self._idempotency.is_seen_then_mark(envelope.message_id):
+                log.info("tts.idempotent.skip", message_id=envelope.message_id)
+                return
+
+            req = envelope.payload
+            log.info(
+                "tts.synthesize.start",
+                message_id=envelope.message_id,
+                session_id=req.session_id,
+                interview_message_id=req.message_id,
+                trace_id=envelope.trace_id,
+            )
+
+            try:
+                result = await self._tts.synthesize(req.text, voice=self._voice)
+            except TtsError as exc:
+                log.error("tts.synthesize.failed", code=exc.code, error=exc.message,
+                          session_id=req.session_id)
+                await self._publish(envelope, TtsCallbackPayload(
+                    session_id=req.session_id, message_id=req.message_id,
+                    status="FAILED", error_code=exc.code,
+                ))
+                return
+            except Exception as exc:
+                log.error("tts.synthesize.unexpected", error=str(exc), session_id=req.session_id)
+                await self._publish(envelope, TtsCallbackPayload(
+                    session_id=req.session_id, message_id=req.message_id,
+                    status="FAILED", error_code="TTS_FAILED",
+                ))
+                return
+
+            key = self._key_template.format(session_id=req.session_id, message_id=req.message_id)
+            try:
+                await self._storage.put_bytes(key, result.audio_bytes, content_type=result.content_type)
+            except Exception as exc:
+                log.error("tts.storage.failed", error=str(exc), key=key)
+                await self._publish(envelope, TtsCallbackPayload(
+                    session_id=req.session_id, message_id=req.message_id,
+                    status="FAILED", error_code="TTS_STORAGE_FAILED",
+                ))
+                return
+
+            await self._publish(envelope, TtsCallbackPayload(
+                session_id=req.session_id, message_id=req.message_id,
+                status="SUCCEEDED", audio_key=key, duration_sec=result.duration_sec,
+            ))
+            log.info("tts.synthesize.done", session_id=req.session_id,
+                     interview_message_id=req.message_id, key=key)
+
+    async def _publish(self, envelope, payload: TtsCallbackPayload) -> None:
+        await self._publisher.publish(
+            routing_key=self._callback_routing_key,
+            message_type="callback.tts",
+            payload=payload,
+            trace_id=envelope.trace_id,
+            correlation_id=envelope.message_id,
+            context=envelope.context,
+        )
diff --git a/ai/src/ai_server/messaging/runner.py b/ai/src/ai_server/messaging/runner.py
index 0e2df2f1..242279e0 100644
--- a/ai/src/ai_server/messaging/runner.py
+++ b/ai/src/ai_server/messaging/runner.py
@@ -33,8 +33,10 @@
 from ai_server.messaging.consumers.feedback_consumer import FeedbackConsumer
 from ai_server.messaging.consumers.followup_consumer import FollowupConsumer
 from ai_server.messaging.consumers.questions_consumer import QuestionsConsumer
+from ai_server.messaging.consumers.tts_consumer import TtsConsumer
 from ai_server.messaging.consumers.voice_consumer import VoiceConsumer
 from ai_server.voice.stt.factory import build_stt_provider
+from ai_server.voice.tts.factory import build_tts_provider
 from ai_server.messaging.consumers.repository_consumer import RepositoryConsumer
 from ai_server.messaging.consumers.resume_consumer import ResumeConsumer
 from ai_server.messaging.consumers.web_consumer import WebResumeConsumer
@@ -210,6 +212,18 @@ def __init__(self, settings: Settings) -> None:
             core_client=core_client,
         )
 
+        # 질문 TTS (Part A)
+        tts = build_tts_provider(settings)
+        self._tts_consumer = TtsConsumer(
+            tts=tts,
+            storage=storage,
+            publisher=self._publisher,
+            idempotency=self._idempotency,
+            callback_routing_key=settings.ai_callback_routing_tts,
+            voice=settings.openai_tts_voice,
+            key_template=settings.tts_audio_key_template,
+        )
+
         self._consumers: list[tuple[AbstractRobustQueue, str]] = []
 
     async def start(self) -> None:
@@ -254,6 +268,11 @@ async def start(self) -> None:
             queue_name=self._settings.ai_queue_voice,
             handler=self._voice_consumer.handle,
         )
+        await self._start_consumer(
+            channel,
+            queue_name=self._settings.ai_queue_tts,
+            handler=self._tts_consumer.handle,
+        )
 
     async def _start_consumer(self, channel, *, queue_name, handler) -> None:
         queue = await channel.declare_queue(
diff --git a/ai/src/ai_server/model/messages/tts.py b/ai/src/ai_server/model/messages/tts.py
new file mode 100644
index 00000000..bb12f0eb
--- /dev/null
+++ b/ai/src/ai_server/model/messages/tts.py
@@ -0,0 +1,28 @@
+from typing import Literal
+
+from pydantic import BaseModel
+
+from ai_server.model._config import camel_config
+
+
+class GenerateTtsRequest(BaseModel):
+    """Core 가 질문 메시지 commit 후 발행. AI 가 text 를 TTS 합성."""
+    model_config = camel_config()
+
+    session_id: int
+    message_id: int                      # interview_messages.id (INTERVIEWER 질문)
+    text: str
+    mode: Literal["PERSONALITY", "TECHNICAL", "INTEGRATED"]
+    job_category: Literal["FRONTEND", "BACKEND", "INFRA", "DBA"]
+
+
+class TtsCallbackPayload(BaseModel):
+    """AI → Core. 합성 결과(S3 키) 또는 실패. Core TtsCallbackPayload 와 호환."""
+    model_config = camel_config()
+
+    session_id: int
+    message_id: int
+    status: Literal["SUCCEEDED", "FAILED"]
+    audio_key: str | None = None         # camelCase 직렬화 → audioKey
+    duration_sec: float | None = None
+    error_code: str | None = None
diff --git a/ai/src/ai_server/voice/tts/__init__.py b/ai/src/ai_server/voice/tts/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/ai/src/ai_server/voice/tts/base.py b/ai/src/ai_server/voice/tts/base.py
new file mode 100644
index 00000000..c83d4969
--- /dev/null
+++ b/ai/src/ai_server/voice/tts/base.py
@@ -0,0 +1,25 @@
+from __future__ import annotations
+
+from abc import ABC, abstractmethod
+from dataclasses import dataclass
+
+
+class TtsError(Exception):
+    def __init__(self, code: str, message: str) -> None:
+        super().__init__(message)
+        self.code = code
+        self.message = message
+
+
+@dataclass(frozen=True)
+class TtsResult:
+    audio_bytes: bytes
+    duration_sec: float | None
+    content_type: str = "audio/mpeg"
+
+
+class TtsProvider(ABC):
+    model_name: str = "tts"
+
+    @abstractmethod
+    async def synthesize(self, text: str, *, voice: str) -> TtsResult: ...
diff --git a/ai/src/ai_server/voice/tts/factory.py b/ai/src/ai_server/voice/tts/factory.py
new file mode 100644
index 00000000..a06adb5f
--- /dev/null
+++ b/ai/src/ai_server/voice/tts/factory.py
@@ -0,0 +1,35 @@
+from __future__ import annotations
+
+import structlog
+
+from ai_server.config.settings import Settings
+from ai_server.voice.tts.base import TtsProvider
+from ai_server.voice.tts.mock import MockTtsProvider
+from ai_server.voice.tts.openai_tts import OpenAiTtsProvider
+
+log = structlog.get_logger(__name__)
+
+
+def build_tts_provider(settings: Settings) -> TtsProvider:
+    """TTS 공급자 선택. auto → openai 키 보유 시 openai, 없으면 mock."""
+    provider = (settings.tts_provider or "auto").lower()
+
+    if provider == "auto":
+        provider = "openai" if settings.openai_api_key else "mock"
+
+    if provider == "openai":
+        if not settings.openai_api_key:
+            log.warn("tts.fallback_to_mock", reason="OPENAI_API_KEY 누락")
+            return MockTtsProvider()
+        return OpenAiTtsProvider(
+            api_key=settings.openai_api_key,
+            base_url=settings.openai_base_url,
+            model=settings.openai_tts_model,
+            timeout_sec=settings.openai_tts_timeout_sec,
+        )
+
+    if provider == "mock":
+        return MockTtsProvider()
+
+    log.warn("tts.unknown_provider_fallback_mock", provider=provider)
+    return MockTtsProvider()
diff --git a/ai/src/ai_server/voice/tts/mock.py b/ai/src/ai_server/voice/tts/mock.py
new file mode 100644
index 00000000..638b9e35
--- /dev/null
+++ b/ai/src/ai_server/voice/tts/mock.py
@@ -0,0 +1,13 @@
+from __future__ import annotations
+
+from ai_server.voice.tts.base import TtsProvider, TtsResult
+
+
+class MockTtsProvider(TtsProvider):
+    model_name = "mock-tts"
+
+    async def synthesize(self, text: str, *, voice: str) -> TtsResult:
+        # 텍스트 길이에 비례한 가짜 오디오 바이트 + 추정 길이(분당 ~300자 가정).
+        payload = ("MOCKMP3:" + text).encode("utf-8")
+        duration = max(0.5, round(len(text) / 5.0, 2))
+        return TtsResult(audio_bytes=payload, duration_sec=duration, content_type="audio/mpeg")
diff --git a/ai/src/ai_server/voice/tts/openai_tts.py b/ai/src/ai_server/voice/tts/openai_tts.py
new file mode 100644
index 00000000..02e4b328
--- /dev/null
+++ b/ai/src/ai_server/voice/tts/openai_tts.py
@@ -0,0 +1,50 @@
+from __future__ import annotations
+
+import httpx
+import structlog
+
+from ai_server.voice.tts.base import TtsError, TtsProvider, TtsResult
+
+log = structlog.get_logger(__name__)
+
+
+class OpenAiTtsProvider(TtsProvider):
+    """OpenAI 오디오 합성 (POST /audio/speech). mp3 반환."""
+
+    def __init__(
+        self,
+        *,
+        api_key: str,
+        base_url: str,
+        model: str,
+        timeout_sec: float,
+    ) -> None:
+        self._api_key = api_key
+        self._base_url = base_url.rstrip("/")
+        self.model_name = model
+        self._timeout = timeout_sec
+
+    async def synthesize(self, text: str, *, voice: str) -> TtsResult:
+        url = f"{self._base_url}/audio/speech"
+        body = {
+            "model": self.model_name,
+            "voice": voice,
+            "input": text,
+            "response_format": "mp3",
+        }
+        headers = {"Authorization": f"Bearer {self._api_key}"}
+        try:
+            async with httpx.AsyncClient(timeout=self._timeout) as client:
+                resp = await client.post(url, json=body, headers=headers)
+        except httpx.HTTPError as exc:
+            raise TtsError("TTS_HTTP_ERROR", str(exc)) from exc
+        if resp.status_code != 200:
+            raise TtsError(
+                "TTS_API_ERROR",
+                f"openai tts status {resp.status_code}: {resp.text[:200]}",
+            )
+        audio = resp.content
+        if not audio:
+            raise TtsError("TTS_EMPTY_AUDIO", "empty audio body")
+        # OpenAI 는 duration 을 주지 않음 → None (Core completeTts 가 null 허용).
+        return TtsResult(audio_bytes=audio, duration_sec=None, content_type="audio/mpeg")
diff --git a/ai/tests/test_tts_consumer.py b/ai/tests/test_tts_consumer.py
new file mode 100644
index 00000000..2c0f5cb8
--- /dev/null
+++ b/ai/tests/test_tts_consumer.py
@@ -0,0 +1,85 @@
+import json
+from datetime import datetime, timezone
+
+import pytest
+
+from ai_server.messaging.consumers.tts_consumer import TtsConsumer
+from ai_server.voice.tts.mock import MockTtsProvider
+
+
+class _FakeStorage:
+    def __init__(self):
+        self.puts = []
+
+    async def put_bytes(self, key, data, *, content_type=None):
+        self.puts.append((key, data, content_type))
+
+
+class _FakePublisher:
+    def __init__(self):
+        self.published = []
+
+    async def publish(self, *, routing_key, message_type, payload, trace_id, correlation_id, context):
+        self.published.append((routing_key, message_type, payload))
+
+
+class _FakeIdem:
+    def is_seen_then_mark(self, mid):
+        return False
+
+
+class _FakeMsg:
+    def __init__(self, body: bytes):
+        self.body = body
+        self.delivery_tag = 1
+
+    def process(self, requeue=False):
+        class _Ctx:
+            async def __aenter__(self_): return self_
+            async def __aexit__(self_, *a): return False
+        return _Ctx()
+
+
+def _envelope_body():
+    return json.dumps({
+        "messageId": "m-1",
+        "messageType": "generate.tts",
+        "version": "v1",
+        "traceId": "t-1",
+        "publishedAt": datetime.now(timezone.utc).isoformat(),
+        "publisher": "core-server",
+        "payload": {
+            "sessionId": 7, "messageId": 42, "text": "질문 본문",
+            "mode": "TECHNICAL", "jobCategory": "BACKEND",
+        },
+        "context": {"userId": 1, "sessionId": 7},
+    }).encode("utf-8")
+
+
+@pytest.mark.asyncio
+async def test_tts_consumer_synthesizes_and_publishes():
+    storage = _FakeStorage()
+    publisher = _FakePublisher()
+    consumer = TtsConsumer(
+        tts=MockTtsProvider(),
+        storage=storage,
+        publisher=publisher,
+        idempotency=_FakeIdem(),
+        callback_routing_key="callback.tts",
+        voice="alloy",
+        key_template="interview/tts/{session_id}/{message_id}.mp3",
+    )
+
+    await consumer.handle(_FakeMsg(_envelope_body()))
+
+    assert storage.puts, "S3 PUT 발생해야 함"
+    key, data, ctype = storage.puts[0]
+    assert key == "interview/tts/7/42.mp3"
+    assert ctype == "audio/mpeg"
+    assert publisher.published, "callback.tts 발행해야 함"
+    rk, mtype, payload = publisher.published[0]
+    assert rk == "callback.tts"
+    assert mtype == "callback.tts"
+    assert payload.status == "SUCCEEDED"
+    assert payload.audio_key == "interview/tts/7/42.mp3"
+    assert payload.message_id == 42
diff --git a/ai/tests/test_tts_factory.py b/ai/tests/test_tts_factory.py
new file mode 100644
index 00000000..38591c14
--- /dev/null
+++ b/ai/tests/test_tts_factory.py
@@ -0,0 +1,31 @@
+from ai_server.config.settings import Settings
+from ai_server.voice.tts.factory import build_tts_provider
+from ai_server.voice.tts.mock import MockTtsProvider
+from ai_server.voice.tts.openai_tts import OpenAiTtsProvider
+
+
+def _settings(**over):
+    base = dict(
+        rabbitmq_url="amqp://x",
+        s3_endpoint_url="http://x",
+        s3_access_key="x",
+        s3_secret_key="x",
+        s3_bucket_name="b",
+    )
+    base.update(over)
+    return Settings(**base)
+
+
+def test_auto_falls_back_to_mock_without_key():
+    s = _settings(tts_provider="auto", openai_api_key="")
+    assert isinstance(build_tts_provider(s), MockTtsProvider)
+
+
+def test_auto_picks_openai_with_key():
+    s = _settings(tts_provider="auto", openai_api_key="sk-test")
+    assert isinstance(build_tts_provider(s), OpenAiTtsProvider)
+
+
+def test_explicit_mock():
+    s = _settings(tts_provider="mock", openai_api_key="sk-test")
+    assert isinstance(build_tts_provider(s), MockTtsProvider)
diff --git a/ai/tests/test_tts_provider.py b/ai/tests/test_tts_provider.py
new file mode 100644
index 00000000..c8792d7e
--- /dev/null
+++ b/ai/tests/test_tts_provider.py
@@ -0,0 +1,14 @@
+import pytest
+
+from ai_server.voice.tts.mock import MockTtsProvider
+
+
+@pytest.mark.asyncio
+async def test_mock_tts_returns_bytes_and_duration():
+    provider = MockTtsProvider()
+    result = await provider.synthesize("안녕하세요 질문입니다", voice="alloy")
+    assert isinstance(result.audio_bytes, bytes)
+    assert len(result.audio_bytes) > 0
+    assert result.duration_sec is not None
+    assert result.content_type == "audio/mpeg"
+    assert provider.model_name == "mock-tts"
diff --git a/backend/CLAUDE.md b/backend/CLAUDE.md
index 70c3aa9b..433dd373 100644
--- a/backend/CLAUDE.md
+++ b/backend/CLAUDE.md
@@ -359,6 +359,8 @@ docker compose up -d
 - ArchUnit 룰 적용 (의존 방향 · 순환 차단 · `@Transactional` application 한정 · entity는 domain 패키지)
 - 면접 도메인 (US-13~20) 본 구현: 세션 CRUD/start/end/interrupt, generate.questions 발행,
   callback.questions(POOL/FOLLOWUP) 수신, 자동 종료
+- 질문 TTS 발행 본 구현: 질문 영속 후 `QuestionPersistedEvent`(AFTER_COMMIT) → `SessionTtsRequester` 가 `generate.tts` 발행,
+  `callback.tts` 수신해 메시지에 오디오 경로 반영(`TtsCallbackService`)
 - AI 호출 로깅 (US-30) 본 구현: `/api/internal/ai-logs` + `ai_request_logs` INSERT
 - **Spring AI 미사용** — LLM·임베딩 호출은 모두 AI 서버 위임. Core는 RabbitMQ 발행만 담당.
 - **Redis 미사용** — 휘발성 데이터는 DB short-lived 레코드 또는 인메모리로.
diff --git a/backend/src/main/java/com/stackup/stackup/common/config/properties/RabbitMqProperties.java b/backend/src/main/java/com/stackup/stackup/common/config/properties/RabbitMqProperties.java
index 3076aab2..8bc4f4e3 100644
--- a/backend/src/main/java/com/stackup/stackup/common/config/properties/RabbitMqProperties.java
+++ b/backend/src/main/java/com/stackup/stackup/common/config/properties/RabbitMqProperties.java
@@ -69,6 +69,7 @@ public record Names(
 			@NotBlank String aiGenerateFollowup,
 			@NotBlank String aiGenerateFeedback,
 			@NotBlank String aiAnalyzeVoice,
+			@NotBlank String aiGenerateTts,
 			@NotBlank String coreCallbackAnalysis,
 			@NotBlank String coreCallbackQuestions,
 			@NotBlank String coreCallbackFeedback,
@@ -85,6 +86,7 @@ public record RoutingKeyProperties(
 		@NotBlank String generateFollowup,
 		@NotBlank String generateFeedback,
 		@NotBlank String analyzeVoice,
+		@NotBlank String generateTts,
 		@NotBlank String callbackAnalysis,
 		@NotBlank String callbackQuestions,
 		@NotBlank String callbackFeedback,
diff --git a/backend/src/main/java/com/stackup/stackup/common/messaging/RabbitMqConfig.java b/backend/src/main/java/com/stackup/stackup/common/messaging/RabbitMqConfig.java
index a6040d89..de24ba78 100644
--- a/backend/src/main/java/com/stackup/stackup/common/messaging/RabbitMqConfig.java
+++ b/backend/src/main/java/com/stackup/stackup/common/messaging/RabbitMqConfig.java
@@ -97,6 +97,11 @@ public Queue aiAnalyzeVoiceQueue() {
         return workQueue(properties.queues().names().aiAnalyzeVoice());
     }
 
+    @Bean
+    public Queue aiGenerateTtsQueue() {
+        return workQueue(properties.queues().names().aiGenerateTts());
+    }
+
     @Bean
     public Queue coreCallbackAnalysisQueue() {
         return workQueue(properties.queues().names().coreCallbackAnalysis());
@@ -134,6 +139,7 @@ public Declarables rabbitDeclarables(
         Queue aiGenerateFollowupQueue,
         Queue aiGenerateFeedbackQueue,
         Queue aiAnalyzeVoiceQueue,
+        Queue aiGenerateTtsQueue,
         Queue coreCallbackAnalysisQueue,
         Queue coreCallbackQuestionsQueue,
         Queue coreCallbackFeedbackQueue,
@@ -146,6 +152,7 @@ public Declarables rabbitDeclarables(
         Queue dlqAiGenerateFollowup = dlq(properties.queues().names().aiGenerateFollowup());
         Queue dlqAiGenerateFeedback = dlq(properties.queues().names().aiGenerateFeedback());
         Queue dlqAiAnalyzeVoice = dlq(properties.queues().names().aiAnalyzeVoice());
+        Queue dlqAiGenerateTts = dlq(properties.queues().names().aiGenerateTts());
         Queue dlqCoreCallbackAnalysis = dlq(properties.queues().names().coreCallbackAnalysis());
         Queue dlqCoreCallbackQuestions = dlq(properties.queues().names().coreCallbackQuestions());
         Queue dlqCoreCallbackFeedback = dlq(properties.queues().names().coreCallbackFeedback());
@@ -163,6 +170,7 @@ public Declarables rabbitDeclarables(
             aiGenerateFollowupQueue,
             aiGenerateFeedbackQueue,
             aiAnalyzeVoiceQueue,
+            aiGenerateTtsQueue,
             coreCallbackAnalysisQueue,
             coreCallbackQuestionsQueue,
             coreCallbackFeedbackQueue,
@@ -174,6 +182,7 @@ public Declarables rabbitDeclarables(
             dlqAiGenerateFollowup,
             dlqAiGenerateFeedback,
             dlqAiAnalyzeVoice,
+            dlqAiGenerateTts,
             dlqCoreCallbackAnalysis,
             dlqCoreCallbackQuestions,
             dlqCoreCallbackFeedback,
@@ -185,6 +194,7 @@ public Declarables rabbitDeclarables(
             BindingBuilder.bind(aiGenerateFollowupQueue).to(coreToAiExchange).with(properties.routingKeys().generateFollowup()),
             BindingBuilder.bind(aiGenerateFeedbackQueue).to(coreToAiExchange).with(properties.routingKeys().generateFeedback()),
             BindingBuilder.bind(aiAnalyzeVoiceQueue).to(coreToAiExchange).with(properties.routingKeys().analyzeVoice()),
+            BindingBuilder.bind(aiGenerateTtsQueue).to(coreToAiExchange).with(properties.routingKeys().generateTts()),
             BindingBuilder.bind(coreCallbackAnalysisQueue).to(aiToCoreExchange).with(properties.routingKeys().callbackAnalysis()),
             BindingBuilder.bind(coreCallbackQuestionsQueue).to(aiToCoreExchange).with(properties.routingKeys().callbackQuestions()),
             BindingBuilder.bind(coreCallbackFeedbackQueue).to(aiToCoreExchange).with(properties.routingKeys().callbackFeedback()),
@@ -196,6 +206,7 @@ public Declarables rabbitDeclarables(
             BindingBuilder.bind(dlqAiGenerateFollowup).to(deadLetterExchange).with(dlqAiGenerateFollowup.getName()),
             BindingBuilder.bind(dlqAiGenerateFeedback).to(deadLetterExchange).with(dlqAiGenerateFeedback.getName()),
             BindingBuilder.bind(dlqAiAnalyzeVoice).to(deadLetterExchange).with(dlqAiAnalyzeVoice.getName()),
+            BindingBuilder.bind(dlqAiGenerateTts).to(deadLetterExchange).with(dlqAiGenerateTts.getName()),
             BindingBuilder.bind(dlqCoreCallbackAnalysis).to(deadLetterExchange).with(dlqCoreCallbackAnalysis.getName()),
             BindingBuilder.bind(dlqCoreCallbackQuestions).to(deadLetterExchange).with(dlqCoreCallbackQuestions.getName()),
             BindingBuilder.bind(dlqCoreCallbackFeedback).to(deadLetterExchange).with(dlqCoreCallbackFeedback.getName()),
diff --git a/backend/src/main/java/com/stackup/stackup/session/application/QuestionsCallbackService.java b/backend/src/main/java/com/stackup/stackup/session/application/QuestionsCallbackService.java
index 9115d239..d13d784a 100644
--- a/backend/src/main/java/com/stackup/stackup/session/application/QuestionsCallbackService.java
+++ b/backend/src/main/java/com/stackup/stackup/session/application/QuestionsCallbackService.java
@@ -7,6 +7,7 @@
 import com.stackup.stackup.session.application.dto.QuestionsCallbackEnvelope;
 import com.stackup.stackup.session.application.dto.QuestionsCallbackPayload;
 import com.stackup.stackup.session.application.dto.QuestionsCallbackPayload.GeneratedQuestion;
+import com.stackup.stackup.session.application.event.QuestionPersistedEvent;
 import com.stackup.stackup.session.application.event.SessionEndedEvent;
 import org.springframework.context.ApplicationEventPublisher;
 import com.stackup.stackup.session.domain.InterviewMessage;
@@ -88,6 +89,8 @@ private void applyInitialQuestion(InterviewSession session, QuestionsCallbackPay
             InterviewMessage.interviewer(session, 1, first.question())
         );
         session.incrementQuestionCount();
+        events.publishEvent(new QuestionPersistedEvent(
+            session.getUser().getId(), session.getId(), message.getId()));
         events.publishEvent(RealtimeNotifyEvent.session(session.getId(), SseEventType.SESSION_MESSAGE, message.getId()));
         // 사용자 user 채널에도 알림 — frontend 가 documentId/sessionId 사전 인지 없이도 받을 수 있게
         events.publishEvent(RealtimeNotifyEvent.user(
@@ -116,6 +119,9 @@ private void applyFollowup(InterviewSession session, QuestionsCallbackPayload pa
         );
         session.incrementQuestionCount();
 
+        events.publishEvent(new QuestionPersistedEvent(
+            session.getUser().getId(), session.getId(), message.getId()));
+
         events.publishEvent(RealtimeNotifyEvent.session(session.getId(), SseEventType.SESSION_MESSAGE, message.getId()));
         events.publishEvent(RealtimeNotifyEvent.user(
             session.getUser().getId(),
diff --git a/backend/src/main/java/com/stackup/stackup/session/application/SessionTtsRequester.java b/backend/src/main/java/com/stackup/stackup/session/application/SessionTtsRequester.java
new file mode 100644
index 00000000..ac5dd3cc
--- /dev/null
+++ b/backend/src/main/java/com/stackup/stackup/session/application/SessionTtsRequester.java
@@ -0,0 +1,54 @@
+package com.stackup.stackup.session.application;
+
+import com.stackup.stackup.common.config.properties.RabbitMqProperties;
+import com.stackup.stackup.common.messaging.MessageContext;
+import com.stackup.stackup.common.messaging.RabbitMessagePublisher;
+import com.stackup.stackup.session.application.dto.GenerateTtsPayload;
+import com.stackup.stackup.session.application.event.QuestionPersistedEvent;
+import com.stackup.stackup.session.domain.InterviewMessage;
+import com.stackup.stackup.session.domain.InterviewMessageRepository;
+import com.stackup.stackup.session.domain.InterviewSession;
+import lombok.RequiredArgsConstructor;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.annotation.Propagation;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.transaction.event.TransactionPhase;
+import org.springframework.transaction.event.TransactionalEventListener;
+
+// 질문(INTERVIEWER) 메시지 commit 후 발화 → generate.tts envelope 발행 (Part A).
+@Component
+@RequiredArgsConstructor
+public class SessionTtsRequester {
+
+    private static final Logger log = LoggerFactory.getLogger(SessionTtsRequester.class);
+
+    private final RabbitMessagePublisher publisher;
+    private final RabbitMqProperties properties;
+    private final InterviewMessageRepository messageRepository;
+
+    @Transactional(readOnly = true, propagation = Propagation.REQUIRES_NEW)
+    @TransactionalEventListener(phase = TransactionPhase.AFTER_COMMIT)
+    public void onQuestionPersisted(QuestionPersistedEvent event) {
+        InterviewMessage message = messageRepository.findById(event.messageId()).orElse(null);
+        if (message == null) {
+            log.warn("generate.tts skipped — message not found. messageId={}", event.messageId());
+            return;
+        }
+        InterviewSession session = message.getSession();
+        GenerateTtsPayload payload = new GenerateTtsPayload(
+            session.getId(),
+            message.getId(),
+            message.getContent(),
+            session.getMode(),
+            session.getJobCategory()
+        );
+        publisher.publishToAi(
+            properties.routingKeys().generateTts(),
+            payload,
+            new MessageContext(event.userId(), session.getId(), null, null)
+        );
+        log.info("generate.tts published. sessionId={}, messageId={}", session.getId(), message.getId());
+    }
+}
diff --git a/backend/src/main/java/com/stackup/stackup/session/application/dto/GenerateTtsPayload.java b/backend/src/main/java/com/stackup/stackup/session/application/dto/GenerateTtsPayload.java
new file mode 100644
index 00000000..abc2491a
--- /dev/null
+++ b/backend/src/main/java/com/stackup/stackup/session/application/dto/GenerateTtsPayload.java
@@ -0,0 +1,14 @@
+package com.stackup.stackup.session.application.dto;
+
+import com.stackup.stackup.session.domain.JobCategory;
+import com.stackup.stackup.session.domain.SessionMode;
+
+// generate.tts envelope payload (Core → AI). AI 가 text 를 TTS 합성 → S3 PUT → callback.tts 발행.
+public record GenerateTtsPayload(
+    Long sessionId,
+    Long messageId,
+    String text,
+    SessionMode mode,
+    JobCategory jobCategory
+) {
+}
diff --git a/backend/src/main/java/com/stackup/stackup/session/application/event/QuestionPersistedEvent.java b/backend/src/main/java/com/stackup/stackup/session/application/event/QuestionPersistedEvent.java
new file mode 100644
index 00000000..209501d7
--- /dev/null
+++ b/backend/src/main/java/com/stackup/stackup/session/application/event/QuestionPersistedEvent.java
@@ -0,0 +1,9 @@
+package com.stackup.stackup.session.application.event;
+
+// INTERVIEWER 질문 메시지 영속 후 발행. SessionTtsRequester 가 AFTER_COMMIT 에 받아 generate.tts 발행.
+public record QuestionPersistedEvent(
+    Long userId,
+    Long sessionId,
+    Long messageId
+) {
+}
diff --git a/backend/src/main/resources/application.yml b/backend/src/main/resources/application.yml
index df8031e3..cb48ce3c 100644
--- a/backend/src/main/resources/application.yml
+++ b/backend/src/main/resources/application.yml
@@ -96,6 +96,7 @@ app:
           ai-generate-followup: ai.generate.followup
           ai-generate-feedback: ai.generate.feedback
           ai-analyze-voice: ai.analyze.voice
+          ai-generate-tts: ai.generate.tts
           core-callback-analysis: core.callback.analysis
           core-callback-questions: core.callback.questions
           core-callback-feedback: core.callback.feedback
@@ -108,6 +109,7 @@ app:
         generate-followup: generate.followup
         generate-feedback: generate.feedback
         analyze-voice: analyze.voice
+        generate-tts: generate.tts
         callback-analysis: callback.analysis
         callback-questions: callback.questions
         callback-feedback: callback.feedback
diff --git a/backend/src/test/java/com/stackup/stackup/common/messaging/RabbitMessagePublisherTest.java b/backend/src/test/java/com/stackup/stackup/common/messaging/RabbitMessagePublisherTest.java
index 9085e434..7c79b5c1 100644
--- a/backend/src/test/java/com/stackup/stackup/common/messaging/RabbitMessagePublisherTest.java
+++ b/backend/src/test/java/com/stackup/stackup/common/messaging/RabbitMessagePublisherTest.java
@@ -94,6 +94,7 @@ private RabbitMqProperties rabbitMqProperties() {
                     "ai.generate.followup",
                     "ai.generate.feedback",
                     "ai.analyze.voice",
+                    "ai.generate.tts",
                     "core.callback.analysis",
                     "core.callback.questions",
                     "core.callback.feedback",
@@ -108,6 +109,7 @@ private RabbitMqProperties rabbitMqProperties() {
                 "generate.followup",
                 "generate.feedback",
                 "analyze.voice",
+                "generate.tts",
                 "callback.analysis",
                 "callback.questions",
                 "callback.feedback",
diff --git a/backend/src/test/java/com/stackup/stackup/common/messaging/RabbitMqConfigTest.java b/backend/src/test/java/com/stackup/stackup/common/messaging/RabbitMqConfigTest.java
index 6f56fa37..c9ddc9cf 100644
--- a/backend/src/test/java/com/stackup/stackup/common/messaging/RabbitMqConfigTest.java
+++ b/backend/src/test/java/com/stackup/stackup/common/messaging/RabbitMqConfigTest.java
@@ -63,6 +63,7 @@ private RabbitMqProperties rabbitMqProperties() {
                     "ai.generate.followup",
                     "ai.generate.feedback",
                     "ai.analyze.voice",
+                    "ai.generate.tts",
                     "core.callback.analysis",
                     "core.callback.questions",
                     "core.callback.feedback",
@@ -77,6 +78,7 @@ private RabbitMqProperties rabbitMqProperties() {
                 "generate.followup",
                 "generate.feedback",
                 "analyze.voice",
+                "generate.tts",
                 "callback.analysis",
                 "callback.questions",
                 "callback.feedback",
diff --git a/backend/src/test/java/com/stackup/stackup/session/application/SessionFeedbackRequesterTest.java b/backend/src/test/java/com/stackup/stackup/session/application/SessionFeedbackRequesterTest.java
index a5247e91..bcd484c1 100644
--- a/backend/src/test/java/com/stackup/stackup/session/application/SessionFeedbackRequesterTest.java
+++ b/backend/src/test/java/com/stackup/stackup/session/application/SessionFeedbackRequesterTest.java
@@ -136,6 +136,7 @@ private RabbitMqProperties.RoutingKeyProperties mockRoutingKeys() {
         return new RabbitMqProperties.RoutingKeyProperties(
             "analyze.resume", "analyze.repository",
             "generate.questions", "generate.followup", "generate.feedback", "analyze.voice",
+            "generate.tts",
             "callback.analysis", "callback.questions", "callback.feedback", "callback.voice",
             "callback.tts",
             "realtime.session.notify", "realtime.user.notify", "realtime.document.notify");
diff --git a/backend/src/test/java/com/stackup/stackup/session/application/SessionQuestionsRequesterTest.java b/backend/src/test/java/com/stackup/stackup/session/application/SessionQuestionsRequesterTest.java
index 07d924e3..f1cbd760 100644
--- a/backend/src/test/java/com/stackup/stackup/session/application/SessionQuestionsRequesterTest.java
+++ b/backend/src/test/java/com/stackup/stackup/session/application/SessionQuestionsRequesterTest.java
@@ -62,6 +62,7 @@ private RabbitMqProperties.RoutingKeyProperties mockRoutingKeys() {
         return new RabbitMqProperties.RoutingKeyProperties(
             "analyze.resume", "analyze.repository",
             "generate.questions", "generate.followup", "generate.feedback", "analyze.voice",
+            "generate.tts",
             "callback.analysis", "callback.questions", "callback.feedback", "callback.voice",
             "callback.tts",
             "realtime.session.notify", "realtime.user.notify", "realtime.document.notify");
diff --git a/backend/src/test/java/com/stackup/stackup/session/application/SessionTtsRequesterTest.java b/backend/src/test/java/com/stackup/stackup/session/application/SessionTtsRequesterTest.java
new file mode 100644
index 00000000..c93d7a02
--- /dev/null
+++ b/backend/src/test/java/com/stackup/stackup/session/application/SessionTtsRequesterTest.java
@@ -0,0 +1,62 @@
+package com.stackup.stackup.session.application;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import com.stackup.stackup.common.config.properties.RabbitMqProperties;
+import com.stackup.stackup.common.messaging.MessageContext;
+import com.stackup.stackup.common.messaging.RabbitMessagePublisher;
+import com.stackup.stackup.session.application.dto.GenerateTtsPayload;
+import com.stackup.stackup.session.application.event.QuestionPersistedEvent;
+import com.stackup.stackup.session.domain.InterviewMessage;
+import com.stackup.stackup.session.domain.InterviewMessageRepository;
+import com.stackup.stackup.session.domain.InterviewSession;
+import java.util.Optional;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+@ExtendWith(MockitoExtension.class)
+class SessionTtsRequesterTest {
+
+    @Mock RabbitMessagePublisher publisher;
+    @Mock RabbitMqProperties properties;
+    @Mock RabbitMqProperties.RoutingKeyProperties routingKeys;
+    @Mock InterviewMessageRepository messageRepository;
+    @InjectMocks SessionTtsRequester requester;
+
+    @Test
+    void publishesGenerateTts_whenQuestionPersisted() {
+        InterviewSession session = org.mockito.Mockito.mock(InterviewSession.class);
+        when(session.getId()).thenReturn(7L);
+        InterviewMessage message = org.mockito.Mockito.mock(InterviewMessage.class);
+        when(message.getId()).thenReturn(42L);
+        when(message.getContent()).thenReturn("당신의 프로젝트에서...");
+        when(message.getSession()).thenReturn(session);
+        when(messageRepository.findById(42L)).thenReturn(Optional.of(message));
+        when(properties.routingKeys()).thenReturn(routingKeys);
+        when(routingKeys.generateTts()).thenReturn("generate.tts");
+
+        requester.onQuestionPersisted(new QuestionPersistedEvent(1L, 7L, 42L));
+
+        ArgumentCaptor<GenerateTtsPayload> captor = ArgumentCaptor.forClass(GenerateTtsPayload.class);
+        verify(publisher).publishToAi(eq("generate.tts"), captor.capture(), any(MessageContext.class));
+        org.assertj.core.api.Assertions.assertThat(captor.getValue().messageId()).isEqualTo(42L);
+        org.assertj.core.api.Assertions.assertThat(captor.getValue().text()).isEqualTo("당신의 프로젝트에서...");
+    }
+
+    @Test
+    void skips_whenMessageNotFound() {
+        when(messageRepository.findById(99L)).thenReturn(Optional.empty());
+
+        requester.onQuestionPersisted(new QuestionPersistedEvent(1L, 7L, 99L));
+
+        verify(publisher, never()).publishToAi(any(), any(), any());
+    }
+}
diff --git a/backend/src/test/java/com/stackup/stackup/session/application/VoiceAnswerUploadServiceTest.java b/backend/src/test/java/com/stackup/stackup/session/application/VoiceAnswerUploadServiceTest.java
index 4a7c4d81..bb45b0ac 100644
--- a/backend/src/test/java/com/stackup/stackup/session/application/VoiceAnswerUploadServiceTest.java
+++ b/backend/src/test/java/com/stackup/stackup/session/application/VoiceAnswerUploadServiceTest.java
@@ -213,6 +213,7 @@ private RabbitMqProperties rabbitMqProperties() {
                     "ai.generate.followup",
                     "ai.generate.feedback",
                     "ai.analyze.voice",
+                    "ai.generate.tts",
                     "core.callback.analysis",
                     "core.callback.questions",
                     "core.callback.feedback",
@@ -226,6 +227,7 @@ private RabbitMqProperties rabbitMqProperties() {
                 "generate.followup",
                 "generate.feedback",
                 "analyze.voice",
+                "generate.tts",
                 "callback.analysis",
                 "callback.questions",
                 "callback.feedback",
diff --git a/docs/environment.md b/docs/environment.md
index 11064f0e..c4f990d7 100644
--- a/docs/environment.md
+++ b/docs/environment.md
@@ -146,7 +146,10 @@ ANALYZED_WEB_RESUME_MD_KEY_TEMPLATE=analyzed/web-resume/{resume_id}/summary.md
 # ===== STT/TTS (Phase 2) =====
 STT_PROVIDER=whisper-api          # whisper-api | whisper-self-hosted
 WHISPER_MODEL=whisper-1           # OpenAI Whisper API 모델
-TTS_PROVIDER=                     # 결정 시 추가
+TTS_PROVIDER=auto                 # auto | mock | openai (auto=OPENAI_API_KEY 보유 시 openai)
+OPENAI_TTS_MODEL=gpt-4o-mini-tts  # OpenAI TTS 모델 (질문 음성화)
+OPENAI_TTS_VOICE=alloy            # TTS 보이스
+OPENAI_TTS_TIMEOUT_SEC=30         # TTS HTTP 타임아웃(초)
 ```
 
 ---
diff --git a/docs/messaging.md b/docs/messaging.md
index c20b68d9..29cd6f83 100644
--- a/docs/messaging.md
+++ b/docs/messaging.md
@@ -24,6 +24,7 @@
 | `ai.analyze.web` | `stackup.core-to-ai` | `analyze.web` | AI Server |
 | `ai.generate.questions` | `stackup.core-to-ai` | `generate.questions` | AI Server |
 | `ai.generate.followup` | `stackup.core-to-ai` | `generate.followup` | AI Server |
+| `ai.generate.tts` | `stackup.core-to-ai` | `generate.tts` | AI Server |
 | `core.callback.analysis` | `stackup.ai-to-core` | `callback.analysis` | Core Server |
 | `core.callback.questions` | `stackup.ai-to-core` | `callback.questions` | Core Server |
 | `q.realtime.session.notify` | `stackup.realtime` | `realtime.session.*` · `realtime.user.*` · `realtime.document.*` | RealTime Server |
@@ -40,6 +41,7 @@
 | `dlq.ai.analyze.web` | `stackup.dlx` | `dlq.ai.analyze.web` | `ai.analyze.web` 처리 실패 |
 | `dlq.ai.generate.questions` | `stackup.dlx` | `dlq.ai.generate.questions` | `ai.generate.questions` 처리 실패 |
 | `dlq.ai.generate.followup` | `stackup.dlx` | `dlq.ai.generate.followup` | `ai.generate.followup` 처리 실패 |
+| `dlq.ai.generate.tts` | `stackup.dlx` | `dlq.ai.generate.tts` | `ai.generate.tts` 처리 실패 |
 | `dlq.core.callback.analysis` | `stackup.dlx` | `dlq.core.callback.analysis` | `core.callback.analysis` 처리 실패 |
 | `dlq.core.callback.questions` | `stackup.dlx` | `dlq.core.callback.questions` | `core.callback.questions` 처리 실패 |
 | `dlq.q.realtime.session.notify` | `stackup.dlx` | `dlq.q.realtime.session.notify` | `q.realtime.session.notify` 처리 실패 |
@@ -60,7 +62,7 @@
 ```
 
 `action` ∈ `analyze | generate | callback | realtime`
-`aggregate` ∈ `resume | repository | web | questions | followup | analysis | feedback | session`
+`aggregate` ∈ `resume | repository | web | questions | followup | tts | analysis | feedback | session`
 
 새 routing key 추가 시 본 패턴 유지.
 
@@ -121,6 +123,7 @@
 | 레포 분석 (US-10) | `analyze.repository` | `callback.analysis` | `core.callback.analysis` |
 | 질문 풀 생성 (US-18) | `generate.questions` | `callback.questions` | `core.callback.questions` |
 | 꼬리질문 생성 (US-19) | `generate.followup` | `callback.questions` | `core.callback.questions` |
+| 질문 TTS 합성 | `generate.tts` | `callback.tts` | `core.callback.tts` |
 | 피드백 생성 (US-24) | `generate.feedback` *(예정)* | `callback.feedback` *(예정)* | `core.callback.feedback` *(예정)* |
 | 세션 알림 (RT2 SSE) | `realtime.session.notify` | (없음 — 단방향 push) | `q.realtime.session.notify` |
 
@@ -283,6 +286,40 @@
 
 > `callback.questions` 큐는 두 종류(`POOL`, `FOLLOWUP`)를 받으므로 consumer는 `payload.kind`로 분기.
 
+### 5.9a `generate.tts`
+```json
+{
+  "messageType": "generate.tts",
+  "payload": {
+    "sessionId": 99,
+    "messageId": 502,
+    "text": "당신의 프로젝트에서 가장 어려웠던 점은 무엇인가요?",
+    "mode": "TECHNICAL",
+    "jobCategory": "BACKEND"
+  },
+  "context": { "userId": 123, "sessionId": 99 }
+}
+```
+
+> 질문(INTERVIEWER) 메시지 영속 후 Core 가 발행. `messageId` 는 `interview_messages.id`. AI 가 `text` 를 TTS 합성 → S3 PUT → `callback.tts` 회신.
+
+### 5.9b `callback.tts`
+```json
+{
+  "messageType": "callback.tts",
+  "payload": {
+    "sessionId": 99,
+    "messageId": 502,
+    "status": "SUCCEEDED",
+    "audioKey": "interview/tts/99/502.mp3",
+    "durationSec": 4.2,
+    "errorCode": null
+  }
+}
+```
+
+> 실패 시 `status: "FAILED"` + `errorCode`(`TTS_API_ERROR`/`TTS_STORAGE_FAILED` 등), `audioKey`/`durationSec` 는 null. OpenAI TTS 는 duration 을 주지 않으므로 `durationSec` 는 null 일 수 있다.
+
 ### 5.10 `generate.feedback` *(예정)*
 ```json
 {
diff --git a/infra/CLAUDE.md b/infra/CLAUDE.md
index 318f609b..25601bd4 100644
--- a/infra/CLAUDE.md
+++ b/infra/CLAUDE.md
@@ -113,6 +113,7 @@ docker exec -i stackup-postgres psql -U stackup stackup < backup.sql
 | `ai.analyze.web` | `stackup.core-to-ai` | `analyze.web` | `dlq.ai.analyze.web` | AI Server |
 | `ai.generate.questions` | `stackup.core-to-ai` | `generate.questions` | `dlq.ai.generate.questions` | AI Server |
 | `ai.generate.followup` | `stackup.core-to-ai` | `generate.followup` | `dlq.ai.generate.followup` | AI Server |
+| `ai.generate.tts` | `stackup.core-to-ai` | `generate.tts` | `dlq.ai.generate.tts` | AI Server |
 | `core.callback.analysis` | `stackup.ai-to-core` | `callback.analysis` | `dlq.core.callback.analysis` | Core Server |
 | `core.callback.questions` | `stackup.ai-to-core` | `callback.questions` | `dlq.core.callback.questions` | Core Server |
 | `q.realtime.session.notify` | `stackup.realtime` | `realtime.session.*` | `dlq.q.realtime.session.notify` | RealTime Server |
diff --git a/infra/rabbitmq/definitions.json b/infra/rabbitmq/definitions.json
index 8ddcd475..6b027b73 100644
--- a/infra/rabbitmq/definitions.json
+++ b/infra/rabbitmq/definitions.json
@@ -120,6 +120,16 @@
         "x-dead-letter-routing-key": "dlq.ai.analyze.voice"
       }
     },
+    {
+      "name": "ai.generate.tts",
+      "vhost": "/",
+      "durable": true,
+      "auto_delete": false,
+      "arguments": {
+        "x-dead-letter-exchange": "stackup.dlx",
+        "x-dead-letter-routing-key": "dlq.ai.generate.tts"
+      }
+    },
     {
       "name": "core.callback.analysis",
       "vhost": "/",
@@ -229,6 +239,13 @@
       "auto_delete": false,
       "arguments": {}
     },
+    {
+      "name": "dlq.ai.generate.tts",
+      "vhost": "/",
+      "durable": true,
+      "auto_delete": false,
+      "arguments": {}
+    },
     {
       "name": "dlq.core.callback.analysis",
       "vhost": "/",
@@ -322,6 +339,13 @@
       "destination_type": "queue",
       "routing_key": "analyze.voice"
     },
+    {
+      "source": "stackup.core-to-ai",
+      "vhost": "/",
+      "destination": "ai.generate.tts",
+      "destination_type": "queue",
+      "routing_key": "generate.tts"
+    },
     {
       "source": "stackup.ai-to-core",
       "vhost": "/",
@@ -427,6 +451,13 @@
       "destination_type": "queue",
       "routing_key": "dlq.ai.analyze.voice"
     },
+    {
+      "source": "stackup.dlx",
+      "vhost": "/",
+      "destination": "dlq.ai.generate.tts",
+      "destination_type": "queue",
+      "routing_key": "dlq.ai.generate.tts"
+    },
     {
       "source": "stackup.dlx",
       "vhost": "/",