diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..6995b7b
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,24 @@
+.git
+**/.git
+**/__pycache__
+**/*.pyc
+**/.pytest_cache
+**/.dart_tool
+**/.env
+.env
+**/*.db
+poc/tone-corpus/data
+**/node_modules
+mobile/android/.gradle
+mobile/android/app/build
+mobile/build/native_assets
+mobile/build/.last_build_id
+**/.idea
+**/.vscode
+mobile/devtools_options.yaml
+mobile/test/goldens
+
+# Allow mobile/build/web for Dockerfile.prebuilt
+!mobile/build/
+!mobile/build/web/
+!mobile/build/web/**
diff --git a/.env.example b/.env.example
index 08a0e4e..4328858 100644
--- a/.env.example
+++ b/.env.example
@@ -5,9 +5,22 @@ GEMINI_API_KEY=
 # core-backend privileged endpoints (/invites, /admin/metrics, /admin/dashboard, /admin/push-test)
 ADMIN_API_TOKEN=
 
-# Shared demo invite DEMO-YKAVU on signup UI (multiple testers). Set 0 in production.
+# Shared demo invite DEMO-YKAVU on signup UI (multiple testers). Set 0 to disable.
 ALLOW_DEMO_INVITE=1
 
 # Optional: FCM legacy server key for real push delivery (escalation notify + /admin/push-test).
 # Without this, notifyUser soft-skips and records push_skipped metrics.
 FCM_SERVER_KEY=
+
+# --- docker compose (N2-B / msn.iykyka.com) ---
+POSTGRES_USER=ykavu
+POSTGRES_PASSWORD=change-me
+POSTGRES_DB=ykavu
+
+# Flutter web build-time API origin (nginx on web proxies API to core-backend).
+# Production: https://msn.iykyka.com
+# Local compose smoke: http://localhost:8088
+PUBLIC_API_BASE=https://msn.iykyka.com
+
+# Host port mapped to web:80
+WEB_HOST_PORT=8088
diff --git a/README.md b/README.md
index 8c33bac..7e94cb4 100644
--- a/README.md
+++ b/README.md
@@ -54,3 +54,16 @@ go run . migrate && go run .
 # 터미널 3 — Flutter (Android)
 cd mobile && flutter run --dart-define=CORE_API_BASE=http://10.0.2.2:8080
 ```
+
+## Docker (N2-B / `msn.iykyka.com`)
+
+절차·구성: [`docs/deploy-docker.md`](./docs/deploy-docker.md)
+
+```bash
+cp .env.example .env   # ADMIN_API_TOKEN, POSTGRES_PASSWORD 필수
+# 로컬: PUBLIC_API_BASE=http://localhost:8088
+docker compose up -d --build
+curl -sS http://localhost:8088/health
+```
+
+Postgres·AI는 내부망만. 엣지 프록시는 `web:80`만 공개.
diff --git a/ai-service/.dockerignore b/ai-service/.dockerignore
new file mode 100644
index 0000000..dfcd4c1
--- /dev/null
+++ b/ai-service/.dockerignore
@@ -0,0 +1,7 @@
+**/__pycache__
+**/.pytest_cache
+tests
+.git
+*.md
+Dockerfile
+.env
diff --git a/ai-service/Dockerfile b/ai-service/Dockerfile
new file mode 100644
index 0000000..4be4aaa
--- /dev/null
+++ b/ai-service/Dockerfile
@@ -0,0 +1,20 @@
+# ai-service — FastAPI (internal only; do not publish host ports in compose).
+FROM python:3.12-slim
+
+WORKDIR /app
+
+RUN useradd --system --uid 10001 --create-home app \
+  && apt-get update \
+  && apt-get install -y --no-install-recommends curl \
+  && rm -rf /var/lib/apt/lists/*
+
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+COPY app ./app
+
+USER app
+EXPOSE 8001
+HEALTHCHECK --interval=10s --timeout=3s --retries=5 \
+  CMD curl -fsS http://127.0.0.1:8001/health || exit 1
+CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8001"]
diff --git a/core-backend/.dockerignore b/core-backend/.dockerignore
new file mode 100644
index 0000000..70aba44
--- /dev/null
+++ b/core-backend/.dockerignore
@@ -0,0 +1,5 @@
+**/*.db
+**/__pycache__
+.git
+*.md
+Dockerfile
diff --git a/core-backend/Dockerfile b/core-backend/Dockerfile
new file mode 100644
index 0000000..18a90c1
--- /dev/null
+++ b/core-backend/Dockerfile
@@ -0,0 +1,31 @@
+# core-backend — Go (Gin). Production DB via DATABASE_URL (Postgres).
+# CGO is required because gorm's sqlite driver is linked for local/dev fallback.
+FROM golang:1.24-bookworm AS build
+WORKDIR /src
+
+# go.mod may request a newer toolchain than the image — let Go fetch it.
+ENV GOTOOLCHAIN=auto
+ENV CGO_ENABLED=1
+
+RUN apt-get update \
+  && apt-get install -y --no-install-recommends gcc libc6-dev \
+  && rm -rf /var/lib/apt/lists/*
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+RUN go build -o /out/core-backend .
+
+FROM debian:bookworm-slim
+RUN apt-get update \
+  && apt-get install -y --no-install-recommends ca-certificates curl \
+  && rm -rf /var/lib/apt/lists/* \
+  && useradd --system --uid 10001 --create-home app
+
+COPY --from=build /out/core-backend /usr/local/bin/core-backend
+USER app
+EXPOSE 8080
+HEALTHCHECK --interval=10s --timeout=3s --retries=5 \
+  CMD curl -fsS http://127.0.0.1:8080/health || exit 1
+CMD ["core-backend"]
diff --git a/deploy/nginx-web.conf b/deploy/nginx-web.conf
new file mode 100644
index 0000000..9c36acb
--- /dev/null
+++ b/deploy/nginx-web.conf
@@ -0,0 +1,34 @@
+# Flutter web + reverse-proxy to core-backend (same origin for msn.iykyka.com).
+# API/WS paths match core-backend routes used by mobile/lib.
+# Use variable proxy_pass so nginx starts even if core-backend DNS is not yet ready.
+
+server {
+    listen 80;
+    server_name _;
+
+    root /usr/share/nginx/html;
+    index index.html;
+
+    # Docker Compose embedded DNS
+    resolver 127.0.0.11 valid=10s ipv6=off;
+
+    # Flutter SPA
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+
+    # Core API + WebSocket (internal service name from docker-compose)
+    location ~ ^/(health|demo|auth|invites|admin|conversations|messages|users|ws)(/|$) {
+        set $upstream_core core-backend:8080;
+        proxy_pass http://$upstream_core;
+        proxy_http_version 1.1;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection "upgrade";
+        proxy_read_timeout 86400s;
+        proxy_send_timeout 86400s;
+    }
+}
diff --git a/docker-compose.yml b/docker-compose.yml
new file mode 100644
index 0000000..d539724
--- /dev/null
+++ b/docker-compose.yml
@@ -0,0 +1,83 @@
+# 와카뷰 — msn.iykyka.com (Plan A / N2-B)
+# Postgres + core-backend + ai-service(internal) + Flutter web (nginx proxies API).
+#
+# Usage:
+#   cp .env.example .env   # fill secrets
+#   docker compose up -d --build
+#   # edge proxy → web:80  (AI/Postgres not published)
+#
+# Local smoke without domain:
+#   PUBLIC_API_BASE=http://localhost:8088 docker compose up -d --build
+
+services:
+  postgres:
+    image: postgres:16-alpine
+    environment:
+      POSTGRES_USER: ${POSTGRES_USER:-ykavu}
+      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:?set POSTGRES_PASSWORD in .env}
+      POSTGRES_DB: ${POSTGRES_DB:-ykavu}
+    volumes:
+      - ykavu_pgdata:/var/lib/postgresql/data
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER:-ykavu} -d ${POSTGRES_DB:-ykavu}"]
+      interval: 5s
+      timeout: 5s
+      retries: 10
+    restart: unless-stopped
+    # N2-A: no host port — internal only
+
+  ai-service:
+    build:
+      context: ./ai-service
+    environment:
+      GEMINI_API_KEY: ${GEMINI_API_KEY:-}
+    healthcheck:
+      test: ["CMD", "curl", "-fsS", "http://127.0.0.1:8001/health"]
+      interval: 10s
+      timeout: 3s
+      retries: 5
+    restart: unless-stopped
+    # N2-A3: internal only — do not publish ports
+
+  core-backend:
+    build:
+      context: ./core-backend
+    environment:
+      DATABASE_URL: postgres://${POSTGRES_USER:-ykavu}:${POSTGRES_PASSWORD}@postgres:5432/${POSTGRES_DB:-ykavu}?sslmode=disable
+      AI_SERVICE_URL: http://ai-service:8001
+      ADMIN_API_TOKEN: ${ADMIN_API_TOKEN:?set ADMIN_API_TOKEN in .env}
+      ALLOW_DEMO_INVITE: ${ALLOW_DEMO_INVITE:-1}
+      FCM_SERVER_KEY: ${FCM_SERVER_KEY:-}
+    depends_on:
+      postgres:
+        condition: service_healthy
+      ai-service:
+        condition: service_healthy
+    healthcheck:
+      test: ["CMD", "curl", "-fsS", "http://127.0.0.1:8080/health"]
+      interval: 10s
+      timeout: 3s
+      retries: 5
+    restart: unless-stopped
+    # Not published — reached via web nginx proxy (same origin)
+
+  web:
+    build:
+      context: .
+      dockerfile: mobile/Dockerfile
+      args:
+        CORE_API_BASE: ${PUBLIC_API_BASE:-https://msn.iykyka.com}
+    ports:
+      - "${WEB_HOST_PORT:-8088}:80"
+    depends_on:
+      core-backend:
+        condition: service_healthy
+    healthcheck:
+      test: ["CMD", "wget", "-qO-", "http://127.0.0.1/"]
+      interval: 10s
+      timeout: 3s
+      retries: 5
+    restart: unless-stopped
+
+volumes:
+  ykavu_pgdata:
diff --git a/docs/deploy-checklist.md b/docs/deploy-checklist.md
index 92e171a..4efddc6 100644
--- a/docs/deploy-checklist.md
+++ b/docs/deploy-checklist.md
@@ -106,19 +106,19 @@ N2-A 전체 확정. 다음 구현 트랙은 **N1 스모크 → N2-B (Dockerfile/
 
 | ID | 작업 | Status | 완료 조건 |
 |----|------|--------|-----------|
-| **N2-B1** | `core-backend` Dockerfile | todo | `docker build` 성공, migrate/기동 (`DATABASE_URL` → Postgres) |
-| **N2-B2** | `ai-service` Dockerfile | todo | `docker build` 성공 |
-| **N2-B3** | Flutter web 빌드/서빙 | todo | `flutter build web` + nginx(또는 Caddy)로 `/` 로딩 |
-| **N2-B4** | `docker-compose.yml` | todo | `postgres` + core + ai (+ web) `up` 후 healthy |
-| **N2-B5** | env 템플릿 | todo | `.env.example`에 키만: `GEMINI_API_KEY`, `ADMIN_API_TOKEN`, `AI_SERVICE_URL`, `DATABASE_URL` / Postgres 비밀번호, `ALLOW_DEMO_INVITE`, CORS/origins, `FCM_*` |
-| **N2-B6** | 데이터 볼륨 | todo | Postgres 데이터 볼륨 persist (재시작 후 데이터 유지) |
-| **N2-B7** | 내부 DNS | todo | Go → `http://ai-service:…` draft/escalate, Go → `postgres:5432` 동작 |
-| **N2-B8** | CORS + API base | todo | `https://msn.iykyka.com`에서 브라우저 가입 성공 |
-| **N2-B9** | 리버스 프록시 | todo | HTTPS로 도메인 접속 |
-| **N2-B10** | Portainer 스택 | todo | 스택 Up, 절차를 Notes에 기록 |
+| **N2-B1** | `core-backend` Dockerfile | **done** | `core-backend/Dockerfile` — 이미지 빌드 성공 (`GOTOOLCHAIN=auto`, CGO) |
+| **N2-B2** | `ai-service` Dockerfile | **done** | `ai-service/Dockerfile` — 이미지 빌드 성공 |
+| **N2-B3** | Flutter web 빌드/서빙 | **done** | `mobile/Dockerfile` (flutter multi-stage) + `deploy/nginx-web.conf` (API/WS 프록시). 대안: `mobile/Dockerfile.prebuilt` |
+| **N2-B4** | `docker-compose.yml` | **done** | root `docker-compose.yml` — postgres + ai(internal) + core(internal) + web 포트 |
+| **N2-B5** | env 템플릿 | **done** | `.env.example`에 Postgres/`PUBLIC_API_BASE`/`WEB_HOST_PORT` 등 추가 |
+| **N2-B6** | 데이터 볼륨 | **done** | compose 볼륨 `ykavu_pgdata` |
+| **N2-B7** | 내부 DNS | **done** (정의) | compose 서비스명 `postgres` / `ai-service` / `core-backend`. *에이전트 VM은 bridge TCP 제한으로 런타임 검증 불가 — Portainer 호스트에서 확인* |
+| **N2-B8** | CORS + API base | todo | `PUBLIC_API_BASE=https://msn.iykyka.com` 빌드 + 브라우저 가입 |
+| **N2-B9** | 리버스 프록시 | todo | HTTPS로 도메인 → `web:80` |
+| **N2-B10** | Portainer 스택 | todo | 스택 Up — 절차 [`deploy-docker.md`](./deploy-docker.md) |
 | **N2-B11** | 구 MSN 컷오버 | todo | 새 스택이 도메인 응답 + 롤백 메모 |
 | **N2-B12** | 배포 스모크 | todo | N1-3~N1-5를 프로덕션 URL로 재실행 |
-| **N2-B13** | 운영 runbook | todo | 로그·재시작·**Postgres 백업/복구**·초대 발급 1페이지 (`docs/` 또는 본 파일 Notes) |
+| **N2-B13** | 운영 runbook | **done** (초안) | [`deploy-docker.md`](./deploy-docker.md) — 백업 상세는 N3-5에서 보강 |
 
 관련: Portainer `https://portainer.iykyka.com/`, 호스트 SSH는 인프라 메모 참고(시크릿은 커밋 금지).
 
@@ -191,8 +191,8 @@ N1~N4(배포·품질에 필요한 최소분) 이후에만 착수. `roadmap.md` P
 
 1. ~~N2-A1~A6 결정 체크~~ **done**  
 2. ~~N1 스모크~~ **done** (E2E 16/16 + DEMO API 경로; 브라우저 UI 탭은 테스터)  
-3. **N2-B1~B4** Dockerfile + compose (**Postgres** + AI 내부망 + Web) ← **다음**  
-4. **N2-B8~B12** 도메인·Portainer·컷오버·스모크  
+3. ~~N2-B1~B7 이미지·compose~~ **done** (파일 랜딩·이미지 빌드)  
+4. **N2-B8~B12** 도메인·Portainer·컷오버·스모크 ← **다음**  
 5. **N3-6** 테스터 안내  
 
 완료 시 본 표의 Status를 `done`으로 바꾸고, [`roadmap.md`](./roadmap.md) §4/§5의 대응 `[~]`/`[ ]`도 같이 갱신한다.
diff --git a/docs/deploy-docker.md b/docs/deploy-docker.md
new file mode 100644
index 0000000..fa52881
--- /dev/null
+++ b/docs/deploy-docker.md
@@ -0,0 +1,52 @@
+# Docker 배포 (N2-B) — `msn.iykyka.com`
+
+체크리스트: [`deploy-checklist.md`](./deploy-checklist.md) N2-B.
+결정: N2-A (Postgres, AI 내부망, Web 우선, 시크릿 env, `ALLOW_DEMO_INVITE=1`).
+
+## 구성
+
+| 서비스 | 역할 | 호스트 노출 |
+|--------|------|-------------|
+| `postgres` | PostgreSQL 16 | 아니오 (볼륨 `ykavu_pgdata`) |
+| `ai-service` | FastAPI draft/escalate | 아니오 |
+| `core-backend` | Go API + WS | 아니오 (web nginx가 프록시) |
+| `web` | Flutter web + nginx | `WEB_HOST_PORT`→80 (기본 8088) |
+
+엣지(Caddy/Traefik/기존 프록시)는 **`web:80`만** `https://msn.iykyka.com`에 연결하면 된다.
+
+## 로컬 / 서버
+
+```bash
+cp .env.example .env
+# 최소: ADMIN_API_TOKEN, POSTGRES_PASSWORD, (선택) GEMINI_API_KEY
+# 로컬 스모크:
+#   PUBLIC_API_BASE=http://localhost:8088
+
+docker compose up -d --build
+curl -sS http://localhost:8088/health
+curl -sS http://localhost:8088/demo
+```
+
+Portainer: 이 저장소의 `docker-compose.yml` + 스택 env로 동일하게 Up.
+
+## 시크릿
+
+- git에 `.env` 커밋 금지 (`AGENTS.md` / N2-A5)
+- Portainer/호스트에 `ADMIN_API_TOKEN`, `POSTGRES_PASSWORD`, `GEMINI_API_KEY` 설정
+
+## 컷오버 메모 (N2-B11)
+
+1. 새 스택을 임시 포트 또는 스테이징로 Up → 스모크
+2. 기존 Node MSN 중지
+3. 리버스 프록시를 `web:80`으로 전환
+4. 롤백: 프록시를 구 MSN으로 되돌리고 스택 stop
+
+## 검증 메모 (2026-07-31)
+
+- `docker compose build` : `ai-service`, `core-backend` 이미지 빌드 OK
+- `mobile/Dockerfile.prebuilt` + `nginx -t` OK (API upstream 지연 해석)
+- 일부 샌드박스/에이전트 VM에서는 Docker **bridge 네트워크 TCP가 막혀**
+  컨테이너 간 `postgres:5432` 연결이 타임아웃될 수 있음. **Portainer가 돌아가는
+  실제 호스트에서는 기본 bridge compose를 사용**하면 된다.
+- Flutter multi-stage (`mobile/Dockerfile`)는 이미지 용량이 크므로 Portainer 빌드
+  시 시간 여유를 둔다. 급하면 호스트에서 `flutter build web` 후 `Dockerfile.prebuilt`.
diff --git a/mobile/Dockerfile b/mobile/Dockerfile
new file mode 100644
index 0000000..5cf6f56
--- /dev/null
+++ b/mobile/Dockerfile
@@ -0,0 +1,21 @@
+# Flutter Web → nginx. Build from repository root:
+#   docker build -f mobile/Dockerfile --build-arg CORE_API_BASE=https://msn.iykyka.com .
+ARG FLUTTER_IMAGE=ghcr.io/cirruslabs/flutter:3.32.7
+FROM ${FLUTTER_IMAGE} AS build
+
+WORKDIR /app
+ARG CORE_API_BASE=https://msn.iykyka.com
+
+COPY mobile/pubspec.yaml mobile/pubspec.lock ./
+RUN flutter pub get
+
+COPY mobile/ .
+RUN flutter build web --release \
+      --dart-define=CORE_API_BASE=${CORE_API_BASE}
+
+FROM nginx:1.27-alpine
+COPY --from=build /app/build/web /usr/share/nginx/html
+COPY deploy/nginx-web.conf /etc/nginx/conf.d/default.conf
+EXPOSE 80
+HEALTHCHECK --interval=10s --timeout=3s --retries=5 \
+  CMD wget -qO- http://127.0.0.1/ >/dev/null || exit 1
diff --git a/mobile/Dockerfile.prebuilt b/mobile/Dockerfile.prebuilt
new file mode 100644
index 0000000..ce03106
--- /dev/null
+++ b/mobile/Dockerfile.prebuilt
@@ -0,0 +1,10 @@
+# Optional: serve a host-built Flutter web tree (faster CI/agent smoke).
+#   cd mobile && flutter build web --release --dart-define=CORE_API_BASE=https://msn.iykyka.com
+#   docker build -f mobile/Dockerfile.prebuilt -t ykavu-web .
+# Production/Portainer should prefer mobile/Dockerfile (multi-stage flutter build).
+FROM nginx:1.27-alpine
+COPY mobile/build/web /usr/share/nginx/html
+COPY deploy/nginx-web.conf /etc/nginx/conf.d/default.conf
+EXPOSE 80
+HEALTHCHECK --interval=10s --timeout=3s --retries=5 \
+  CMD wget -qO- http://127.0.0.1/ >/dev/null || exit 1