diff --git a/apps/api/src/api/v1/stats.py b/apps/api/src/api/v1/stats.py
new file mode 100644
index 00000000..8471a3bc
--- /dev/null
+++ b/apps/api/src/api/v1/stats.py
@@ -0,0 +1,385 @@
+# =============================================================================
+# AWOOOI Statistics API - Phase 6.5
+# =============================================================================
+# 統計分析 API - 從 Episodic Memory 萃取洞察
+#
+# 核心價值:
+# - 識別常見問題模式
+# - 評估 AI 建議效能
+# - 支援 Playbook 萃取
+# =============================================================================
+
+from datetime import datetime, timedelta
+from typing import Any
+
+from fastapi import APIRouter, Depends, Query
+from pydantic import BaseModel, Field
+from sqlalchemy import func, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from src.core.logging import get_logger
+from src.db.database import get_db
+from src.db.models import IncidentRecord
+from src.models.incident import IncidentStatus
+
+logger = get_logger(__name__)
+
+router = APIRouter(prefix="/stats", tags=["Statistics"])
+
+
+# =============================================================================
+# Response Models
+# =============================================================================
+
+
+class StatusCount(BaseModel):
+    """狀態計數"""
+
+    status: str
+    count: int
+
+
+class SeverityCount(BaseModel):
+    """嚴重度計數"""
+
+    severity: str
+    count: int
+
+
+class IncidentSummary(BaseModel):
+    """事件總覽"""
+
+    total_incidents: int = Field(description="總事件數")
+    status_distribution: list[StatusCount] = Field(description="狀態分佈")
+    severity_distribution: list[SeverityCount] = Field(description="嚴重度分佈")
+    resolved_rate: float = Field(description="解決率 (%)")
+    avg_signals_per_incident: float = Field(description="平均告警聚合數")
+
+
+class ResolutionStats(BaseModel):
+    """解決時間統計"""
+
+    avg_minutes: float | None = Field(description="平均解決時間 (分鐘)")
+    p50_minutes: float | None = Field(description="P50 解決時間")
+    p95_minutes: float | None = Field(description="P95 解決時間")
+    fastest_minutes: float | None = Field(description="最快解決時間")
+    slowest_minutes: float | None = Field(description="最慢解決時間")
+    sample_size: int = Field(description="樣本數")
+
+
+class TrendPoint(BaseModel):
+    """趨勢數據點"""
+
+    date: str
+    count: int
+
+
+class IncidentTrends(BaseModel):
+    """事件趨勢"""
+
+    period: str = Field(description="週期 (daily/weekly/monthly)")
+    data: list[TrendPoint]
+
+
+class AIPerformance(BaseModel):
+    """AI 效能統計"""
+
+    total_proposals: int = Field(description="總提案數")
+    executed_count: int = Field(description="已執行數")
+    execution_rate: float = Field(description="執行率 (%)")
+    success_count: int = Field(description="成功數")
+    success_rate: float = Field(description="成功率 (%)")
+    avg_effectiveness: float | None = Field(description="平均有效性評分 (1-5)")
+    effectiveness_distribution: dict[int, int] = Field(
+        description="有效性評分分佈 {1: count, 2: count, ...}"
+    )
+
+
+class ServiceImpact(BaseModel):
+    """服務影響統計"""
+
+    service: str
+    incident_count: int
+    severity_breakdown: dict[str, int] = Field(description="{P0: 5, P1: 10, ...}")
+
+
+class FeedbackSummary(BaseModel):
+    """人類回饋摘要"""
+
+    total_feedback: int
+    positive_count: int = Field(description="正面回饋 (score >= 4)")
+    neutral_count: int = Field(description="中性回饋 (score == 3)")
+    negative_count: int = Field(description="負面回饋 (score <= 2)")
+    common_themes: list[str] = Field(description="常見主題 (從 learning_notes 萃取)")
+
+
+# =============================================================================
+# API Endpoints
+# =============================================================================
+
+
+@router.get(
+    "/incidents/summary",
+    response_model=IncidentSummary,
+    summary="事件總覽統計",
+)
+async def get_incident_summary(
+    days: int = Query(30, ge=1, le=365, description="統計區間 (天)"),
+    db: AsyncSession = Depends(get_db),  # noqa: B008
+) -> IncidentSummary:
+    """
+    取得事件總覽統計
+
+    包含:
+    - 總事件數
+    - 狀態分佈
+    - 嚴重度分佈
+    - 解決率
+    """
+    since = datetime.utcnow() - timedelta(days=days)
+
+    # 總數
+    total_result = await db.execute(
+        select(func.count(IncidentRecord.incident_id)).where(
+            IncidentRecord.created_at >= since
+        )
+    )
+    total = total_result.scalar() or 0
+
+    # 狀態分佈
+    status_result = await db.execute(
+        select(IncidentRecord.status, func.count(IncidentRecord.incident_id))
+        .where(IncidentRecord.created_at >= since)
+        .group_by(IncidentRecord.status)
+    )
+    status_dist = [
+        StatusCount(status=str(row[0]), count=row[1]) for row in status_result.all()
+    ]
+
+    # 嚴重度分佈
+    severity_result = await db.execute(
+        select(IncidentRecord.severity, func.count(IncidentRecord.incident_id))
+        .where(IncidentRecord.created_at >= since)
+        .group_by(IncidentRecord.severity)
+    )
+    severity_dist = [
+        SeverityCount(severity=str(row[0]), count=row[1])
+        for row in severity_result.all()
+    ]
+
+    # 解決率
+    resolved_result = await db.execute(
+        select(func.count(IncidentRecord.incident_id)).where(
+            IncidentRecord.created_at >= since,
+            IncidentRecord.status.in_(
+                [IncidentStatus.RESOLVED, IncidentStatus.CLOSED]
+            ),
+        )
+    )
+    resolved_count = resolved_result.scalar() or 0
+    resolved_rate = (resolved_count / total * 100) if total > 0 else 0.0
+
+    # 平均告警聚合數
+    signals_result = await db.execute(
+        select(func.avg(func.json_array_length(IncidentRecord.signals))).where(
+            IncidentRecord.created_at >= since
+        )
+    )
+    avg_signals = signals_result.scalar() or 0.0
+
+    logger.info(
+        "stats_incident_summary",
+        total=total,
+        resolved_rate=resolved_rate,
+        days=days,
+    )
+
+    return IncidentSummary(
+        total_incidents=total,
+        status_distribution=status_dist,
+        severity_distribution=severity_dist,
+        resolved_rate=round(resolved_rate, 2),
+        avg_signals_per_incident=round(float(avg_signals), 2),
+    )
+
+
+@router.get(
+    "/incidents/resolution",
+    response_model=ResolutionStats,
+    summary="解決時間統計",
+)
+async def get_resolution_stats(
+    days: int = Query(30, ge=1, le=365, description="統計區間 (天)"),
+    db: AsyncSession = Depends(get_db),  # noqa: B008
+) -> ResolutionStats:
+    """
+    取得解決時間統計
+
+    計算已解決事件的:
+    - 平均解決時間
+    - P50/P95 解決時間
+    - 最快/最慢解決時間
+    """
+    since = datetime.utcnow() - timedelta(days=days)
+
+    # 取得已解決事件的時間差
+    result = await db.execute(
+        select(
+            IncidentRecord.created_at,
+            IncidentRecord.resolved_at,
+        ).where(
+            IncidentRecord.created_at >= since,
+            IncidentRecord.resolved_at.isnot(None),
+        )
+    )
+    rows = result.all()
+
+    if not rows:
+        return ResolutionStats(
+            avg_minutes=None,
+            p50_minutes=None,
+            p95_minutes=None,
+            fastest_minutes=None,
+            slowest_minutes=None,
+            sample_size=0,
+        )
+
+    # 計算解決時間 (分鐘)
+    durations = []
+    for row in rows:
+        if row.resolved_at and row.created_at:
+            delta = row.resolved_at - row.created_at
+            durations.append(delta.total_seconds() / 60)
+
+    if not durations:
+        return ResolutionStats(
+            avg_minutes=None,
+            p50_minutes=None,
+            p95_minutes=None,
+            fastest_minutes=None,
+            slowest_minutes=None,
+            sample_size=0,
+        )
+
+    durations.sort()
+    n = len(durations)
+
+    return ResolutionStats(
+        avg_minutes=round(sum(durations) / n, 2),
+        p50_minutes=round(durations[n // 2], 2),
+        p95_minutes=round(durations[min(int(n * 0.95), n - 1)], 2),
+        fastest_minutes=round(min(durations), 2),
+        slowest_minutes=round(max(durations), 2),
+        sample_size=n,
+    )
+
+
+@router.get(
+    "/ai-performance",
+    response_model=AIPerformance,
+    summary="AI 效能統計",
+)
+async def get_ai_performance(
+    days: int = Query(30, ge=1, le=365, description="統計區間 (天)"),
+    db: AsyncSession = Depends(get_db),  # noqa: B008
+) -> AIPerformance:
+    """
+    取得 AI 提案效能統計
+
+    評估指標:
+    - 提案執行率
+    - 執行成功率
+    - 有效性評分分佈
+    """
+    since = datetime.utcnow() - timedelta(days=days)
+
+    # 取得有 outcome 的事件
+    result = await db.execute(
+        select(IncidentRecord.outcome).where(
+            IncidentRecord.created_at >= since,
+            IncidentRecord.outcome.isnot(None),
+        )
+    )
+    outcomes = [row[0] for row in result.all() if row[0]]
+
+    total = len(outcomes)
+    executed = sum(1 for o in outcomes if o.get("proposal_executed"))
+    success = sum(
+        1 for o in outcomes if o.get("proposal_executed") and o.get("execution_success")
+    )
+
+    # 有效性評分分佈
+    effectiveness_dist: dict[int, int] = {1: 0, 2: 0, 3: 0, 4: 0, 5: 0}
+    scores = []
+    for o in outcomes:
+        score = o.get("effectiveness_score")
+        if score and 1 <= score <= 5:
+            effectiveness_dist[score] += 1
+            scores.append(score)
+
+    avg_effectiveness = sum(scores) / len(scores) if scores else None
+
+    return AIPerformance(
+        total_proposals=total,
+        executed_count=executed,
+        execution_rate=round((executed / total * 100) if total > 0 else 0, 2),
+        success_count=success,
+        success_rate=round((success / executed * 100) if executed > 0 else 0, 2),
+        avg_effectiveness=round(avg_effectiveness, 2) if avg_effectiveness else None,
+        effectiveness_distribution=effectiveness_dist,
+    )
+
+
+@router.get(
+    "/services/affected",
+    response_model=list[ServiceImpact],
+    summary="受影響服務排名",
+)
+async def get_affected_services(
+    days: int = Query(30, ge=1, le=365, description="統計區間 (天)"),
+    limit: int = Query(10, ge=1, le=50, description="返回數量"),
+    db: AsyncSession = Depends(get_db),  # noqa: B008
+) -> list[ServiceImpact]:
+    """
+    取得最常受影響的服務排名
+
+    包含:
+    - 事件計數
+    - 嚴重度分佈
+    """
+    since = datetime.utcnow() - timedelta(days=days)
+
+    # 取得所有事件的 affected_services 和 severity
+    result = await db.execute(
+        select(
+            IncidentRecord.affected_services,
+            IncidentRecord.severity,
+        ).where(IncidentRecord.created_at >= since)
+    )
+
+    # 統計每個服務
+    service_stats: dict[str, dict[str, Any]] = {}
+    for row in result.all():
+        services = row[0] or []
+        severity = str(row[1])
+        for svc in services:
+            if svc not in service_stats:
+                service_stats[svc] = {"count": 0, "severity": {}}
+            service_stats[svc]["count"] += 1
+            service_stats[svc]["severity"][severity] = (
+                service_stats[svc]["severity"].get(severity, 0) + 1
+            )
+
+    # 排序並返回 top N
+    sorted_services = sorted(
+        service_stats.items(), key=lambda x: x[1]["count"], reverse=True
+    )[:limit]
+
+    return [
+        ServiceImpact(
+            service=svc,
+            incident_count=stats["count"],
+            severity_breakdown=stats["severity"],
+        )
+        for svc, stats in sorted_services
+    ]
diff --git a/apps/api/src/main.py b/apps/api/src/main.py
index f77554d8..31740d74 100644
--- a/apps/api/src/main.py
+++ b/apps/api/src/main.py
@@ -33,6 +33,7 @@ from src.api.v1 import health as health_v1
 from src.api.v1 import incidents as incidents_v1  # Phase 6.4: Decision Proposal
 from src.api.v1 import metrics as metrics_v1  # Phase 7: Gold Metrics (真實血脈)
 from src.api.v1 import proposals as proposals_v1  # Phase 6.4h: Proposals CRUD API
+from src.api.v1 import stats as stats_v1  # Phase 6.5: Statistics Analytics
 from src.api.v1 import telegram as telegram_v1  # Phase 5.4: Telegram Gateway
 from src.api.v1 import timeline as timeline_v1
 from src.api.v1 import webhooks as webhooks_v1
@@ -88,7 +89,9 @@ async def lifespan(_app: FastAPI) -> AsyncGenerator[None, None]:
     # CTO-201: Initialize PostgreSQL database (統帥鐵律: 禁止 SQLite)
     await init_db()
     db_url = settings.DATABASE_URL
-    logger.info("database_initialized", url=db_url.split("@")[-1] if "@" in db_url else db_url)
+    logger.info(
+        "database_initialized", url=db_url.split("@")[-1] if "@" in db_url else db_url
+    )
 
     # Phase 5: Initialize HTTP Clients (ClickHouse, Ollama)
     # 統帥鐵律: 連線池在啟動時建立，關閉時回收
@@ -242,6 +245,7 @@ async def request_logging_middleware(request: Request, call_next):
 # Exception Handlers
 # =============================================================================
 
+
 @app.exception_handler(Exception)
 async def global_exception_handler(_request: Request, exc: Exception) -> JSONResponse:
     """
@@ -277,24 +281,42 @@ app.include_router(ai_v1.router, prefix="/api/v1", tags=["AI Decision"])
 app.include_router(webhooks_v1.router, prefix="/api/v1", tags=["Webhooks"])
 app.include_router(timeline_v1.router, prefix="/api/v1", tags=["Timeline"])
 app.include_router(audit_logs_v1.router, prefix="/api/v1", tags=["Audit Logs"])
-app.include_router(telegram_v1.router, prefix="/api/v1", tags=["Telegram Gateway"])  # Phase 5.4
-app.include_router(metrics_v1.router, prefix="/api/v1", tags=["Gold Metrics"])  # Phase 7: 真實血脈
-app.include_router(incidents_v1.router, prefix="/api/v1", tags=["Incidents"])  # Phase 6.4: Decision Proposal
-app.include_router(proposals_v1.router, prefix="/api/v1", tags=["Proposals"])  # Phase 6.4h: Proposals CRUD
-app.include_router(agents_v1.router, prefix="/api/v1", tags=["Agent Teams"])  # Phase 9.5: Agent Teams
-app.include_router(proposals_router.router, tags=["Proposals (Legacy)"])  # Phase 6.4g: lewooogo-brain (舊版)
+app.include_router(
+    telegram_v1.router, prefix="/api/v1", tags=["Telegram Gateway"]
+)  # Phase 5.4
+app.include_router(
+    metrics_v1.router, prefix="/api/v1", tags=["Gold Metrics"]
+)  # Phase 7: 真實血脈
+app.include_router(
+    incidents_v1.router, prefix="/api/v1", tags=["Incidents"]
+)  # Phase 6.4: Decision Proposal
+app.include_router(
+    proposals_v1.router, prefix="/api/v1", tags=["Proposals"]
+)  # Phase 6.4h: Proposals CRUD
+app.include_router(
+    agents_v1.router, prefix="/api/v1", tags=["Agent Teams"]
+)  # Phase 9.5: Agent Teams
+app.include_router(
+    stats_v1.router, prefix="/api/v1", tags=["Statistics"]
+)  # Phase 6.5: Statistics Analytics
+app.include_router(
+    proposals_router.router, tags=["Proposals (Legacy)"]
+)  # Phase 6.4g: lewooogo-brain (舊版)
 
 # Legacy routes (to be migrated to api/v1/)
 app.include_router(plugins.router, prefix="/api/v1/plugins", tags=["Plugins"])
 app.include_router(pipelines.router, prefix="/api/v1/pipelines", tags=["Pipelines"])
 app.include_router(agent.router, prefix="/api/v1/agent", tags=["Agent"])
-app.include_router(notifications.router, prefix="/api/v1/notifications", tags=["Notifications"])
+app.include_router(
+    notifications.router, prefix="/api/v1/notifications", tags=["Notifications"]
+)
 
 
 # =============================================================================
 # Root Endpoint
 # =============================================================================
 
+
 @app.get("/", include_in_schema=False)
 async def root() -> dict:
     """Root endpoint with API info"""
diff --git a/apps/api/src/services/decision_manager.py b/apps/api/src/services/decision_manager.py
index 999d12c3..1f8d2244 100644
--- a/apps/api/src/services/decision_manager.py
+++ b/apps/api/src/services/decision_manager.py
@@ -300,12 +300,23 @@ class DecisionManager:
 
         # 1. 檢查現有 token
         existing_token = await self._find_existing_token(incident.incident_id)
-        if existing_token and existing_token.state in (
-            DecisionState.READY,
-            DecisionState.EXECUTING,
-            DecisionState.COMPLETED,
-        ):
-            return existing_token
+        if existing_token:
+            # READY 或 EXECUTING 狀態: 直接返回
+            if existing_token.state in (DecisionState.READY, DecisionState.EXECUTING):
+                return existing_token
+            # COMPLETED 狀態: 只有 incident 也已解決才返回，否則創建新 decision
+            # 修復: 避免 incident 未解決但 decision 已完成導致 Y/n 按鈕永久禁用
+            if existing_token.state == DecisionState.COMPLETED:
+                from src.models.incident import IncidentStatus
+                if incident.status in (IncidentStatus.RESOLVED, IncidentStatus.CLOSED):
+                    return existing_token
+                # incident 仍在處理中，需要新的 decision
+                logger.info(
+                    "decision_reset_for_active_incident",
+                    token=existing_token.token,
+                    incident_id=incident.incident_id,
+                    incident_status=incident.status.value,
+                )
 
         # 2. 建立新 token
         token = DecisionToken(
@@ -539,12 +550,21 @@ class DecisionManager:
 
         # 檢查現有 token
         existing_token = await self._find_existing_token(incident.incident_id)
-        if existing_token and existing_token.state in (
-            DecisionState.READY,
-            DecisionState.EXECUTING,
-            DecisionState.COMPLETED,
-        ):
-            return existing_token
+        if existing_token:
+            # READY 或 EXECUTING 狀態: 直接返回
+            if existing_token.state in (DecisionState.READY, DecisionState.EXECUTING):
+                return existing_token
+            # COMPLETED 狀態: 只有 incident 也已解決才返回
+            if existing_token.state == DecisionState.COMPLETED:
+                from src.models.incident import IncidentStatus
+                if incident.status in (IncidentStatus.RESOLVED, IncidentStatus.CLOSED):
+                    return existing_token
+                logger.info(
+                    "decision_reset_for_active_incident_consensus",
+                    token=existing_token.token,
+                    incident_id=incident.incident_id,
+                    incident_status=incident.status.value,
+                )
 
         # 建立新 token
         token = DecisionToken(