diff --git a/.env.example b/.env.example
index 8e11c80..8da45c1 100644
--- a/.env.example
+++ b/.env.example
@@ -2,9 +2,10 @@
 YOULBOT_API_URL=http://localhost:8000
 
 # API 토큰 (youlbot/.env의 API_TOKEN과 동일하게 설정. 빈 값이면 개발 모드)
-YOULBOT_API_TOKEN=
+YOULBOT_API_TOKEN=youlbot-ai-token!!@@1234
 
 # 음성 설정 (로컬 실행)
 WHISPER_MODEL_SIZE=small
-TTS_VOICE=Yuna                    # macOS say 보이스 이름
-TTS_EDGE_VOICE=ko-KR-SunHiNeural  # edge-tts 보이스 (여성). 남성: ko-KR-InJoonNeural
+TTS_VOICE=Yuna
+TTS_EDGE_VOICE=ko-KR-SunHiNeural
+LOG_LEVEL=INFO
diff --git a/.gitignore b/.gitignore
index f10862a..9eab973 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,6 @@
 /.env
+.idea/
+.claude/
+__pycache__/
+*.pyc
+*.pyo
diff --git a/ROADMAP.md b/ROADMAP.md
index 7767a40..d8d05ab 100644
--- a/ROADMAP.md
+++ b/ROADMAP.md
@@ -4,16 +4,17 @@
 
 | 항목 | 현재 상태 | 심각도 |
 |------|---------|--------|
-| 아키텍처 모듈화 | UI·비즈니스 로직 혼재 (2파일) | 🔴 높음 |
-| Windows 호환성 | TTS `say` 명령어 — macOS 전용 | 🔴 즉시 |
-| Gradio Chatbot 타입 | `type="messages"` 누락 | 🔴 즉시 |
-| JSON yield 타입 불일치 | `JSONDecodeError` 시 타입 혼용 | 🟡 중간 |
-| run_id 인덱싱 버그 | `history` / `run_ids` 동기화 취약 | 🟡 중간 |
-| async/sync 혼용 | 동기 콜백에서 `run_until_complete` 사용 | 🟡 중간 |
-| 코드 중복 | `run_until_complete` 패턴 5회 반복 | 🟡 중간 |
-| 결합도 | `api_client` 직접 임포트·전역 상태 | 🔴 높음 |
-| 테스트 가능성 | ~20% (모킹 불가능) | 🔴 낮음 |
-| 로깅 | `print()` 만 사용 | 🟢 낮음 |
+| 아키텍처 모듈화 | ~~2파일 혼재~~ → config / api_client / services/ / container / app 5모듈 분리 | ✅ 완료 |
+| Windows 호환성 | ~~TTS `say` 명령어 — macOS 전용~~ → 크로스플랫폼 구현 완료 | ✅ 완료 |
+| Gradio Chatbot 타입 | ~~`type="messages"` 누락~~ → Gradio 6.x 기본 포맷 사용 | ✅ 완료 |
+| JSON yield 타입 불일치 | ~~`JSONDecodeError` 시 타입 혼용~~ → `str()` 변환 적용 | ✅ 완료 |
+| run_id 인덱싱 버그 | ~~`history` / `run_ids` 동기화 취약~~ → 방어 로직 추가 | ✅ 완료 |
+| RAG 출처 표시 | ~~thinking 박스에 혼재~~ → 답변 하단 `📄 출처` 전용 박스로 분리 | ✅ 완료 |
+| async/sync 혼용 | ~~`asyncio.run()` 5곳~~ → 모든 콜백 async 전환 완료 | ✅ 완료 |
+| 코드 중복 | ~~`asyncio.run()` 5회 반복~~ → container 위임으로 제거 | ✅ 완료 |
+| 결합도 | ~~`api_client` 직접 임포트~~ → DI container + Protocol 추상화 | ✅ 완료 |
+| 테스트 가능성 | ~~모킹 불가능~~ → pytest-asyncio 단위 테스트 10개 작성 | ✅ 완료 |
+| 로깅 | ~~`print()` 만 사용~~ → `logging` 모듈, `LOG_LEVEL` 환경변수 | ✅ 완료 |
 
 ---
 
@@ -42,8 +43,8 @@
 └──────────────┬───────────────────────────┘
                │ 생성
 ┌──────────────▼───────────────────────────┐
-│          services.py                     │
-│  ChatService / DocumentService / TTSService │
+│          services/                        │
+│  chat.py / document.py / tts.py          │
 └──────────────┬───────────────────────────┘
                │ 사용
 ┌──────────────▼───────────────────────────┐
@@ -193,13 +194,14 @@ class HTTPAPIClient:
     # 기존 함수들을 메서드로 이전
 ```
 
-### 3. 서비스 레이어 분리 → `services.py` 신규 생성
+### 3. 서비스 레이어 분리 → `services/` 패키지 신규 생성
 
 ```
-services.py
-├── ChatService(api_client)      — chat, reset, save_feedback
-├── DocumentService(api_client)  — ingest, list_documents, delete_document
-└── TTSService()                 — tts_speak (플랫폼 분기)
+services/
+├── __init__.py          — ChatService, DocumentService, TTSService 재익스포트
+├── chat.py              — ChatService: chat, reset, save_feedback
+├── document.py          — DocumentService: ingest, list_documents, delete_document
+└── tts.py               — TTSService: speak (플랫폼 분기)
 ```
 
 ### 4. 수동 DI 컨테이너 → `container.py` 신규 생성
@@ -258,10 +260,14 @@ class Container:
 ```
 youlbot-webui/
 ├── app.py              # Gradio UI 전용 — 콜백만 존재, 비즈니스 로직 없음
-├── container.py        # 수동 DI 컨테이너 (신규)
-├── services.py         # ChatService, DocumentService, TTSService (신규)
-├── api_client.py       # APIClientProtocol + HTTPAPIClient (리팩터링)
-├── config.py           # AppConfig, APIConfig dataclass (신규)
+├── container.py        # 수동 DI 컨테이너
+├── services/
+│   ├── __init__.py     # 재익스포트
+│   ├── chat.py         # ChatService
+│   ├── document.py     # DocumentService
+│   └── tts.py          # TTSService
+├── api_client.py       # APIClientProtocol + HTTPAPIClient
+├── config.py           # AppConfig, APIConfig dataclass
 ├── tests/
 │   ├── test_chat_service.py
 │   └── test_document_service.py
@@ -281,20 +287,22 @@ youlbot-webui/
 - [x] `gr.Chatbot` — Gradio 6.x 기본 dict 포맷 사용 (`type` 파라미터 불필요, 제거)
 - [x] `api_client.py` JSON yield 타입 수정
 - [x] `run_id` 인덱싱 방어 로직 추가
+- [x] RAG 출처 전용 박스 분리 — `source_box` gr.HTML + `_sources_html()` + `__sources` 토큰 처리
 
 ### P1
-- [ ] `config.py` 작성
-- [ ] `api_client.py` — `APIClientProtocol` + `HTTPAPIClient` 분리
-- [ ] `services.py` 작성 (ChatService, DocumentService, TTSService)
-- [ ] `container.py` 작성
-- [ ] `app.py` — 모든 콜백 async 전환 및 container 사용
+- [x] `config.py` 작성 (APIConfig, AppConfig)
+- [x] `api_client.py` — `APIClientProtocol` + `HTTPAPIClient` 분리
+- [x] `services/` 패키지 작성 (chat.py, document.py, tts.py + __init__.py 재익스포트)
+- [x] `container.py` 작성 (lazy singleton 프로퍼티)
+- [x] `app.py` — 모든 콜백 async 전환 및 container 사용 (`asyncio.run()` 완전 제거)
 
 ### P2
-- [ ] `logging` 모듈 도입
-- [ ] httpx `AsyncClient` 재사용
-- [ ] 입력 검증 추가
-- [ ] `tests/` 단위 테스트 작성
+- [x] `logging` 모듈 도입 — `basicConfig` + `LOG_LEVEL` 환경변수, `print()` 제거
+- [x] httpx `AsyncClient` 재사용 — `HTTPAPIClient.__init__`에서 공유 클라이언트 생성, `aclose()` 추가
+- [x] 입력 검증 추가 — `DocumentService.ingest` 파일 존재·확장자 검증, `delete_document` URL 인코딩
+- [x] `tests/` 단위 테스트 작성 — `pytest-asyncio`, `ChatService` 4개 / `DocumentService` 6개 (10/10 통과)
 
 ### P3
-- [ ] 재시도 로직
-- [ ] Pydantic Settings
+- [x] 재시도 로직 — `tenacity` / 5xx·TransportError에만 최대 3회, 지수 백오프(1→8s) / `chat` 제외 5개 메서드 적용
+- [x] Pydantic Settings — `config.py` dataclass → `BaseSettings` (flat `AppConfig`), `.env` 자동 로드
+- [x] IoC 프레임워크 전환 — 수동 DI → `dependency-injector` `DeclarativeContainer` + `providers.Singleton`
diff --git a/api_client.py b/api_client.py
index 37c61ed..e429be2 100644
--- a/api_client.py
+++ b/api_client.py
@@ -1,39 +1,68 @@
-"""율봇 API 클라이언트 — youlbot REST API(Phase 22)를 httpx로 호출."""
+"""율봇 API 클라이언트 — APIClientProtocol 인터페이스 + HTTPAPIClient 구현."""
 import json
 import os
-from typing import AsyncIterator
+import urllib.parse
+from typing import AsyncIterator, Protocol, runtime_checkable
 
 import httpx
-from dotenv import load_dotenv
+from tenacity import retry, retry_if_exception, stop_after_attempt, wait_exponential
 
-load_dotenv()
-
-_API_URL = os.getenv("YOULBOT_API_URL", "http://localhost:8000").rstrip("/")
-_API_TOKEN = os.getenv("YOULBOT_API_TOKEN", "")
+from config import AppConfig
 
 
-def _headers() -> dict:
-    if _API_TOKEN:
-        return {"Authorization": f"Bearer {_API_TOKEN}"}
-    return {}
+def _is_transient(exc: Exception) -> bool:
+    if isinstance(exc, httpx.HTTPStatusError):
+        return exc.response.status_code >= 500
+    return isinstance(exc, httpx.TransportError)
 
 
-async def chat(
-    message: str,
-    user_id: str = "default",
-    show_thinking: bool = False,
-) -> AsyncIterator[tuple[str, str | None]]:
-    """SSE 스트림을 읽어 (token, run_id) 튜플을 yield.
+_retry = retry(
+    retry=retry_if_exception(_is_transient),
+    stop=stop_after_attempt(3),
+    wait=wait_exponential(multiplier=1, min=1, max=8),
+    reraise=True,
+)
 
-    - 일반 토큰: (token_str, None)
-    - 스트림 종료: ("", run_id_or_None)  ← __done 이벤트
-    """
-    async with httpx.AsyncClient(timeout=180) as client:
-        async with client.stream(
+
+@runtime_checkable
+class APIClientProtocol(Protocol):
+    def chat(
+        self, message: str, user_id: str, show_thinking: bool
+    ) -> AsyncIterator[tuple[str, str | None]]: ...
+
+    async def reset(self, user_id: str) -> None: ...
+
+    async def ingest(self, file_path: str) -> dict: ...
+
+    async def list_documents(self) -> list[str]: ...
+
+    async def delete_document(self, source: str) -> None: ...
+
+    async def save_feedback(
+        self, user_id: str, user_msg: str, asst_msg: str, rating: int, run_id: str | None
+    ) -> None: ...
+
+
+class HTTPAPIClient:
+    def __init__(self, config: AppConfig):
+        self._url = config.youlbot_api_url.rstrip("/")
+        self._timeout = config.youlbot_api_timeout
+        self._client = httpx.AsyncClient(
+            headers={"Authorization": f"Bearer {config.youlbot_api_token}"}
+            if config.youlbot_api_token else {},
+        )
+
+    async def chat(
+        self,
+        message: str,
+        user_id: str = "default",
+        show_thinking: bool = False,
+    ) -> AsyncIterator[tuple[str, str | None]]:
+        async with self._client.stream(
             "POST",
-            f"{_API_URL}/chat",
+            f"{self._url}/chat",
             json={"message": message, "user_id": user_id, "show_thinking": show_thinking},
-            headers=_headers(),
+            timeout=self._timeout,
         ) as response:
             response.raise_for_status()
             async for line in response.aiter_lines():
@@ -50,56 +79,50 @@ async def chat(
                     return
                 yield payload, None
 
-
-async def reset(user_id: str = "default") -> None:
-    async with httpx.AsyncClient(timeout=30) as client:
-        r = await client.post(
-            f"{_API_URL}/reset",
+    @_retry
+    async def reset(self, user_id: str = "default") -> None:
+        r = await self._client.post(
+            f"{self._url}/reset",
             params={"user_id": user_id},
-            headers=_headers(),
+            timeout=30,
         )
         r.raise_for_status()
 
-
-async def ingest(file_path: str) -> dict:
-    async with httpx.AsyncClient(timeout=300) as client:
+    @_retry
+    async def ingest(self, file_path: str) -> dict:
         with open(file_path, "rb") as f:
             filename = os.path.basename(file_path)
-            r = await client.post(
-                f"{_API_URL}/ingest",
+            r = await self._client.post(
+                f"{self._url}/ingest",
                 files={"file": (filename, f, "application/octet-stream")},
-                headers=_headers(),
+                timeout=300,
             )
         r.raise_for_status()
         return r.json()
 
-
-async def list_documents() -> list[str]:
-    async with httpx.AsyncClient(timeout=30) as client:
-        r = await client.get(f"{_API_URL}/documents", headers=_headers())
+    @_retry
+    async def list_documents(self) -> list[str]:
+        r = await self._client.get(f"{self._url}/documents", timeout=30)
         r.raise_for_status()
         return r.json().get("documents", [])
 
-
-async def delete_document(source: str) -> None:
-    async with httpx.AsyncClient(timeout=30) as client:
-        r = await client.delete(
-            f"{_API_URL}/documents/{source}",
-            headers=_headers(),
-        )
+    @_retry
+    async def delete_document(self, source: str) -> None:
+        encoded = urllib.parse.quote(source, safe="")
+        r = await self._client.delete(f"{self._url}/documents/{encoded}", timeout=30)
         r.raise_for_status()
 
-
-async def save_feedback(
-    user_id: str,
-    user_msg: str,
-    asst_msg: str,
-    rating: int,
-    run_id: str | None = None,
-) -> None:
-    async with httpx.AsyncClient(timeout=30) as client:
-        r = await client.post(
-            f"{_API_URL}/feedback",
+    @_retry
+    async def save_feedback(
+        self,
+        user_id: str,
+        user_msg: str,
+        asst_msg: str,
+        rating: int,
+        run_id: str | None = None,
+    ) -> None:
+        r = await self._client.post(
+            f"{self._url}/feedback",
             json={
                 "user_id": user_id,
                 "user_msg": user_msg,
@@ -107,6 +130,9 @@ async def save_feedback(
                 "rating": rating,
                 "run_id": run_id,
             },
-            headers=_headers(),
+            timeout=30,
         )
         r.raise_for_status()
+
+    async def aclose(self) -> None:
+        await self._client.aclose()
diff --git a/app.py b/app.py
index e9e04fb..789eaee 100644
--- a/app.py
+++ b/app.py
@@ -7,35 +7,38 @@
     YOULBOT_API_URL=http://localhost:8000
     YOULBOT_API_TOKEN=           ← api.py에 API_TOKEN 설정 시 동일 값
 """
-import asyncio
 import html as _html
+import logging
 import os
-import platform
-import subprocess
-import tempfile
 
 import gradio as gr
 from dotenv import load_dotenv
 
 load_dotenv()
 
-import api_client
+logging.basicConfig(
+    level=os.getenv("LOG_LEVEL", "INFO").upper(),
+    format="%(asctime)s %(levelname)-8s %(name)s — %(message)s",
+    datefmt="%Y-%m-%d %H:%M:%S",
+)
+logger = logging.getLogger(__name__)
+
+from container import Container
+
+container = Container()
 
 USER_LABELS = ["아록", "근혜", "도율", "하율"]
 DEFAULT_USER = "아록"
 
 # ── STT (Whisper) — 로컬 실행 유지 ──────────────────────────────
 _whisper_model = None
-_WHISPER_SIZE = os.getenv("WHISPER_MODEL_SIZE", "small")
-_TTS_VOICE = os.getenv("TTS_VOICE", "Yuna")                        # macOS say 보이스
-_TTS_EDGE_VOICE = os.getenv("TTS_EDGE_VOICE", "ko-KR-SunHiNeural") # edge-tts 보이스
 
 
 def _get_whisper():
     global _whisper_model
     if _whisper_model is None:
         import whisper
-        _whisper_model = whisper.load_model(_WHISPER_SIZE)
+        _whisper_model = whisper.load_model(container.config().whisper_model_size)
     return _whisper_model
 
 
@@ -47,51 +50,6 @@ def transcribe_audio(filepath: str) -> str:
     return result["text"].strip()
 
 
-async def tts_speak(text: str) -> str | None:
-    """크로스플랫폼 TTS. macOS: say→edge-tts→pyttsx3 / Windows: edge-tts→pyttsx3"""
-    if not text:
-        return None
-
-    # macOS: say 우선 (오프라인, 내장 한국어)
-    if platform.system() == "Darwin":
-        try:
-            tmp = tempfile.NamedTemporaryFile(suffix=".aiff", delete=False)
-            tmp.close()
-            await asyncio.to_thread(
-                subprocess.run,
-                ["say", "-v", _TTS_VOICE, "-o", tmp.name, text],
-                check=True,
-                capture_output=True,
-            )
-            return tmp.name
-        except Exception:
-            pass
-
-    # Windows 1순위 / macOS say 실패 시: edge-tts (온라인)
-    try:
-        import edge_tts
-        tmp = tempfile.NamedTemporaryFile(suffix=".mp3", delete=False)
-        tmp.close()
-        await edge_tts.Communicate(text, _TTS_EDGE_VOICE).save(tmp.name)
-        return tmp.name
-    except Exception:
-        pass
-
-    # 최종 폴백: pyttsx3 (오프라인)
-    try:
-        import pyttsx3
-        tmp = tempfile.NamedTemporaryFile(suffix=".wav", delete=False)
-        tmp.close()
-        def _save():
-            engine = pyttsx3.init()
-            engine.save_to_file(text, tmp.name)
-            engine.runAndWait()
-        await asyncio.to_thread(_save)
-        return tmp.name
-    except Exception:
-        return None
-
-
 # ── 채팅 ─────────────────────────────────────────────────────────
 
 async def respond(message, history, show_thinking, user_id, use_tts, run_ids):
@@ -110,10 +68,9 @@ async def respond(message, history, show_thinking, user_id, use_tts, run_ids):
     thinking_acc = ""        # 전체 누적 (완료 후 details용)
     thinking_text = ""       # __thinking 토큰만 (줄 감지용)
     thinking_finalized = False
-    source_box_html = ""
 
     try:
-        async for token, run_id in api_client.chat(message, user_id, show_thinking):
+        async for token, run_id in container.chat_service().chat(message, user_id, show_thinking):
             if run_id is not None:
                 collected_run_id = run_id
                 break
@@ -162,13 +119,13 @@ async def respond(message, history, show_thinking, user_id, use_tts, run_ids):
     run_ids.append(collected_run_id)
 
     if use_tts:
-        audio_path = await tts_speak(tts_text)
+        audio_path = await container.tts_service().speak(tts_text)
         yield history, "", audio_path, run_ids, gr.update(), gr.update()
     else:
         yield history, "", None, run_ids, gr.update(), gr.update()
 
 
-def handle_feedback(like_data: gr.LikeData, history, run_ids, user_id):
+async def handle_feedback(like_data: gr.LikeData, history, run_ids, user_id):
     idx = like_data.index
     if isinstance(idx, (list, tuple)):
         idx = idx[0]
@@ -176,7 +133,6 @@ def handle_feedback(like_data: gr.LikeData, history, run_ids, user_id):
         return
     if history[idx].get("role") != "assistant":
         return
-    # idx 위치까지 등장한 assistant 메시지 수 = 이 메시지의 0-based 턴 번호
     asst_turn = sum(1 for m in history[:idx] if m.get("role") == "assistant")
     run_id = run_ids[asst_turn] if run_ids and asst_turn < len(run_ids) else None
 
@@ -185,33 +141,33 @@ def handle_feedback(like_data: gr.LikeData, history, run_ids, user_id):
     rating = 1 if like_data.liked else -1
 
     try:
-        asyncio.run(api_client.save_feedback(user_id, user_msg, asst_msg, rating, run_id))
+        await container.chat_service().save_feedback(user_id, user_msg, asst_msg, rating, run_id)
     except Exception as e:
-        print(f"[Feedback] 저장 실패: {e}")
+        logger.error("피드백 저장 실패: %s", e)
 
 
 def switch_user(user_id):
     return [], []
 
 
-def reset_chat(user_id):
+async def reset_chat(user_id):
     try:
-        asyncio.run(api_client.reset(user_id))
+        await container.chat_service().reset(user_id)
     except Exception as e:
-        print(f"[Reset] 실패: {e}")
+        logger.error("대화 초기화 실패: %s", e)
     return [], []
 
 
 # ── 문서 관리 ─────────────────────────────────────────────────────
 
-def ingest_files(files):
+async def ingest_files(files):
     if not files:
         return "파일을 선택해주세요."
     paths = [f if isinstance(f, str) else f.name for f in files]
     results = []
     for path in paths:
         try:
-            result = asyncio.run(api_client.ingest(path))
+            result = await container.document_service().ingest(path)
             name = os.path.basename(path)
             results.append(f"{name} → {result.get('chunks', '?')}개 청크")
         except Exception as e:
@@ -219,22 +175,22 @@ def ingest_files(files):
     return "\n".join(results)
 
 
-def list_docs():
+async def list_docs():
     try:
-        sources = asyncio.run(api_client.list_documents())
+        sources = await container.document_service().list_documents()
         return [[os.path.basename(s), s] for s in sources]
     except Exception as e:
         return [[f"오류: {e}", ""]]
 
 
-def delete_doc(source):
+async def delete_doc(source):
     if not source.strip():
-        return "삭제할 파일 경로를 입력하세요.", list_docs()
+        return "삭제할 파일 경로를 입력하세요.", await list_docs()
     try:
-        asyncio.run(api_client.delete_document(source.strip()))
-        return f"삭제 완료: {os.path.basename(source.strip())}", list_docs()
+        await container.document_service().delete_document(source.strip())
+        return f"삭제 완료: {os.path.basename(source.strip())}", await list_docs()
     except Exception as e:
-        return f"오류: {e}", list_docs()
+        return f"오류: {e}", await list_docs()
 
 
 # ── UI 구성 ──────────────────────────────────────────────────────
@@ -407,4 +363,8 @@ with gr.Blocks(title="율봇") as demo:
 
 
 if __name__ == "__main__":
-    demo.launch(server_name="0.0.0.0", server_port=7860, theme=gr.themes.Soft())
+    demo.launch(
+        server_name=container.config().server_host,
+        server_port=container.config().server_port,
+        theme=gr.themes.Soft(),
+    )
diff --git a/config.py b/config.py
new file mode 100644
index 0000000..6616007
--- /dev/null
+++ b/config.py
@@ -0,0 +1,18 @@
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+
+class AppConfig(BaseSettings):
+    # API (env: YOULBOT_API_URL, YOULBOT_API_TOKEN, YOULBOT_API_TIMEOUT)
+    youlbot_api_url: str = "http://localhost:8000"
+    youlbot_api_token: str = ""
+    youlbot_api_timeout: int = 180
+    # STT/TTS (env: WHISPER_MODEL_SIZE, TTS_VOICE, TTS_EDGE_VOICE)
+    whisper_model_size: str = "small"
+    tts_voice: str = "Yuna"
+    tts_edge_voice: str = "ko-KR-SunHiNeural"
+    # 서버 / 로깅
+    log_level: str = "INFO"
+    server_host: str = "0.0.0.0"
+    server_port: int = 7860
+
+    model_config = SettingsConfigDict(env_file=".env", extra="ignore")
diff --git a/container.py b/container.py
new file mode 100644
index 0000000..5bee74a
--- /dev/null
+++ b/container.py
@@ -0,0 +1,15 @@
+from dependency_injector import containers, providers
+
+from api_client import HTTPAPIClient
+from config import AppConfig
+from services import ChatService, DocumentService, TTSService
+
+
+class Container(containers.DeclarativeContainer):
+    config = providers.Singleton(AppConfig)
+
+    api_client = providers.Singleton(HTTPAPIClient, config=config)
+
+    chat_service = providers.Singleton(ChatService, api_client=api_client)
+    document_service = providers.Singleton(DocumentService, api_client=api_client)
+    tts_service = providers.Singleton(TTSService, config=config)
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..6eb3df5
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,2 @@
+[tool.pytest.ini_options]
+asyncio_mode = "auto"
diff --git a/requirements-dev.txt b/requirements-dev.txt
new file mode 100644
index 0000000..df39e2a
--- /dev/null
+++ b/requirements-dev.txt
@@ -0,0 +1,2 @@
+pytest>=8.0.0
+pytest-asyncio>=0.23.0
diff --git a/requirements.txt b/requirements.txt
index 5168873..74d827e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,3 +4,6 @@ python-dotenv>=1.0.0
 openai-whisper>=20231117
 edge-tts>=6.1.9
 pyttsx3>=2.90
+pydantic-settings>=2.0.0
+tenacity>=8.0.0
+dependency-injector>=4.41.0
diff --git a/services/__init__.py b/services/__init__.py
new file mode 100644
index 0000000..ec02651
--- /dev/null
+++ b/services/__init__.py
@@ -0,0 +1,5 @@
+from services.chat import ChatService
+from services.document import DocumentService
+from services.tts import TTSService
+
+__all__ = ["ChatService", "DocumentService", "TTSService"]
diff --git a/services/chat.py b/services/chat.py
new file mode 100644
index 0000000..2e58ae8
--- /dev/null
+++ b/services/chat.py
@@ -0,0 +1,26 @@
+from typing import AsyncIterator
+
+from api_client import APIClientProtocol
+
+
+class ChatService:
+    def __init__(self, api_client: APIClientProtocol):
+        self._api = api_client
+
+    def chat(
+        self, message: str, user_id: str, show_thinking: bool
+    ) -> AsyncIterator[tuple[str, str | None]]:
+        return self._api.chat(message, user_id, show_thinking)
+
+    async def reset(self, user_id: str) -> None:
+        await self._api.reset(user_id)
+
+    async def save_feedback(
+        self,
+        user_id: str,
+        user_msg: str,
+        asst_msg: str,
+        rating: int,
+        run_id: str | None,
+    ) -> None:
+        await self._api.save_feedback(user_id, user_msg, asst_msg, rating, run_id)
diff --git a/services/document.py b/services/document.py
new file mode 100644
index 0000000..b4ed2c3
--- /dev/null
+++ b/services/document.py
@@ -0,0 +1,24 @@
+from pathlib import Path
+
+from api_client import APIClientProtocol
+
+_ALLOWED_EXTENSIONS = {".pdf", ".txt"}
+
+
+class DocumentService:
+    def __init__(self, api_client: APIClientProtocol):
+        self._api = api_client
+
+    async def ingest(self, file_path: str) -> dict:
+        path = Path(file_path)
+        if not path.is_file():
+            raise ValueError(f"파일을 찾을 수 없습니다: {file_path}")
+        if path.suffix.lower() not in _ALLOWED_EXTENSIONS:
+            raise ValueError(f"지원하지 않는 파일 형식입니다: {path.suffix} (허용: pdf, txt)")
+        return await self._api.ingest(file_path)
+
+    async def list_documents(self) -> list[str]:
+        return await self._api.list_documents()
+
+    async def delete_document(self, source: str) -> None:
+        await self._api.delete_document(source)
diff --git a/services/tts.py b/services/tts.py
new file mode 100644
index 0000000..c5425d7
--- /dev/null
+++ b/services/tts.py
@@ -0,0 +1,53 @@
+import asyncio
+import platform
+import subprocess
+import tempfile
+
+from config import AppConfig
+
+
+class TTSService:
+    def __init__(self, config: AppConfig):
+        self._voice = config.tts_voice
+        self._edge_voice = config.tts_edge_voice
+
+    async def speak(self, text: str) -> str | None:
+        """크로스플랫폼 TTS. macOS: say→edge-tts→pyttsx3 / Windows: edge-tts→pyttsx3"""
+        if not text:
+            return None
+
+        if platform.system() == "Darwin":
+            try:
+                tmp = tempfile.NamedTemporaryFile(suffix=".aiff", delete=False)
+                tmp.close()
+                await asyncio.to_thread(
+                    subprocess.run,
+                    ["say", "-v", self._voice, "-o", tmp.name, text],
+                    check=True,
+                    capture_output=True,
+                )
+                return tmp.name
+            except Exception:
+                pass
+
+        try:
+            import edge_tts
+            tmp = tempfile.NamedTemporaryFile(suffix=".mp3", delete=False)
+            tmp.close()
+            await edge_tts.Communicate(text, self._edge_voice).save(tmp.name)
+            return tmp.name
+        except Exception:
+            pass
+
+        try:
+            import pyttsx3
+            tmp = tempfile.NamedTemporaryFile(suffix=".wav", delete=False)
+            tmp.close()
+            def _save():
+                engine = pyttsx3.init()
+                engine.save_to_file(text, tmp.name)
+                engine.runAndWait()
+            await asyncio.to_thread(_save)
+            return tmp.name
+        except Exception:
+            return None
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/test_chat_service.py b/tests/test_chat_service.py
new file mode 100644
index 0000000..8acf98d
--- /dev/null
+++ b/tests/test_chat_service.py
@@ -0,0 +1,40 @@
+import pytest
+from unittest.mock import AsyncMock, MagicMock
+
+from services.chat import ChatService
+
+
+@pytest.fixture
+def mock_api():
+    api = MagicMock()
+    api.reset = AsyncMock()
+    api.save_feedback = AsyncMock()
+    return api
+
+
+@pytest.fixture
+def service(mock_api):
+    return ChatService(mock_api)
+
+
+async def test_reset_delegates_to_api(service, mock_api):
+    await service.reset("user1")
+    mock_api.reset.assert_awaited_once_with("user1")
+
+
+async def test_save_feedback_delegates_to_api(service, mock_api):
+    await service.save_feedback("user1", "질문", "답변", 1, "run-123")
+    mock_api.save_feedback.assert_awaited_once_with("user1", "질문", "답변", 1, "run-123")
+
+
+async def test_save_feedback_with_no_run_id(service, mock_api):
+    await service.save_feedback("user1", "질문", "답변", -1, None)
+    mock_api.save_feedback.assert_awaited_once_with("user1", "질문", "답변", -1, None)
+
+
+def test_chat_returns_api_iterator(service, mock_api):
+    sentinel = object()
+    mock_api.chat = MagicMock(return_value=sentinel)
+    result = service.chat("안녕", "user1", False)
+    assert result is sentinel
+    mock_api.chat.assert_called_once_with("안녕", "user1", False)
diff --git a/tests/test_document_service.py b/tests/test_document_service.py
new file mode 100644
index 0000000..b911072
--- /dev/null
+++ b/tests/test_document_service.py
@@ -0,0 +1,56 @@
+import pytest
+from unittest.mock import AsyncMock, MagicMock
+
+from services.document import DocumentService
+
+
+@pytest.fixture
+def mock_api():
+    api = MagicMock()
+    api.ingest = AsyncMock(return_value={"chunks": 5})
+    api.list_documents = AsyncMock(return_value=["docs/report.pdf"])
+    api.delete_document = AsyncMock()
+    return api
+
+
+@pytest.fixture
+def service(mock_api):
+    return DocumentService(mock_api)
+
+
+async def test_ingest_valid_pdf(service, mock_api, tmp_path):
+    pdf = tmp_path / "report.pdf"
+    pdf.write_bytes(b"%PDF-1.4")
+    result = await service.ingest(str(pdf))
+    assert result == {"chunks": 5}
+    mock_api.ingest.assert_awaited_once_with(str(pdf))
+
+
+async def test_ingest_valid_txt(service, mock_api, tmp_path):
+    txt = tmp_path / "notes.txt"
+    txt.write_text("내용")
+    result = await service.ingest(str(txt))
+    assert result == {"chunks": 5}
+
+
+async def test_ingest_nonexistent_file_raises(service):
+    with pytest.raises(ValueError, match="파일을 찾을 수 없습니다"):
+        await service.ingest("/nonexistent/file.pdf")
+
+
+async def test_ingest_unsupported_extension_raises(service, tmp_path):
+    docx = tmp_path / "doc.docx"
+    docx.write_bytes(b"data")
+    with pytest.raises(ValueError, match="지원하지 않는 파일 형식"):
+        await service.ingest(str(docx))
+
+
+async def test_list_documents_delegates(service, mock_api):
+    result = await service.list_documents()
+    assert result == ["docs/report.pdf"]
+    mock_api.list_documents.assert_awaited_once()
+
+
+async def test_delete_document_delegates(service, mock_api):
+    await service.delete_document("/path/to/doc.pdf")
+    mock_api.delete_document.assert_awaited_once_with("/path/to/doc.pdf")