feat: 添加缓存监控和使用量统计 API 端点

src/api/admin/usage/routes.py

@@ -800,3 +800,184 @@ class AdminUsageDetailAdapter(AdminApiAdapter):
             "tiers": tiers,
             "source": pricing_source,  # 定价来源: 'provider' 或 'global'
         }
+
+
+# ==================== 缓存亲和性分析 ====================
+
+
+@router.get("/cache-affinity/ttl-analysis")
+async def analyze_cache_affinity_ttl(
+    request: Request,
+    user_id: Optional[str] = Query(None, description="指定用户 ID"),
+    api_key_id: Optional[str] = Query(None, description="指定 API Key ID"),
+    hours: int = Query(168, ge=1, le=720, description="分析最近多少小时的数据"),
+    db: Session = Depends(get_db),
+):
+    """
+    分析用户请求间隔分布，推荐合适的缓存亲和性 TTL。
+
+    通过分析同一用户连续请求之间的时间间隔，判断用户的使用模式：
+    - 高频用户（间隔短）：5 分钟 TTL 足够
+    - 中频用户：15-30 分钟 TTL
+    - 低频用户（间隔长）：需要 60 分钟 TTL
+    """
+    adapter = CacheAffinityTTLAnalysisAdapter(
+        user_id=user_id,
+        api_key_id=api_key_id,
+        hours=hours,
+    )
+    return await pipeline.run(adapter=adapter, http_request=request, db=db, mode=adapter.mode)
+
+
+@router.get("/cache-affinity/hit-analysis")
+async def analyze_cache_hit(
+    request: Request,
+    user_id: Optional[str] = Query(None, description="指定用户 ID"),
+    api_key_id: Optional[str] = Query(None, description="指定 API Key ID"),
+    hours: int = Query(168, ge=1, le=720, description="分析最近多少小时的数据"),
+    db: Session = Depends(get_db),
+):
+    """
+    分析缓存命中情况。
+
+    返回缓存命中率、节省的费用等统计信息。
+    """
+    adapter = CacheHitAnalysisAdapter(
+        user_id=user_id,
+        api_key_id=api_key_id,
+        hours=hours,
+    )
+    return await pipeline.run(adapter=adapter, http_request=request, db=db, mode=adapter.mode)
+
+
+class CacheAffinityTTLAnalysisAdapter(AdminApiAdapter):
+    """缓存亲和性 TTL 分析适配器"""
+
+    def __init__(
+        self,
+        user_id: Optional[str],
+        api_key_id: Optional[str],
+        hours: int,
+    ):
+        self.user_id = user_id
+        self.api_key_id = api_key_id
+        self.hours = hours
+
+    async def handle(self, context):  # type: ignore[override]
+        db = context.db
+
+        result = UsageService.analyze_cache_affinity_ttl(
+            db=db,
+            user_id=self.user_id,
+            api_key_id=self.api_key_id,
+            hours=self.hours,
+        )
+
+        context.add_audit_metadata(
+            action="cache_affinity_ttl_analysis",
+            user_id=self.user_id,
+            api_key_id=self.api_key_id,
+            hours=self.hours,
+            total_users_analyzed=result.get("total_users_analyzed", 0),
+        )
+
+        return result
+
+
+class CacheHitAnalysisAdapter(AdminApiAdapter):
+    """缓存命中分析适配器"""
+
+    def __init__(
+        self,
+        user_id: Optional[str],
+        api_key_id: Optional[str],
+        hours: int,
+    ):
+        self.user_id = user_id
+        self.api_key_id = api_key_id
+        self.hours = hours
+
+    async def handle(self, context):  # type: ignore[override]
+        db = context.db
+
+        result = UsageService.get_cache_hit_analysis(
+            db=db,
+            user_id=self.user_id,
+            api_key_id=self.api_key_id,
+            hours=self.hours,
+        )
+
+        context.add_audit_metadata(
+            action="cache_hit_analysis",
+            user_id=self.user_id,
+            api_key_id=self.api_key_id,
+            hours=self.hours,
+        )
+
+        return result
+
+
+@router.get("/cache-affinity/interval-timeline")
+async def get_interval_timeline(
+    request: Request,
+    hours: int = Query(168, ge=1, le=720, description="分析最近多少小时的数据"),
+    limit: int = Query(1000, ge=100, le=5000, description="最大返回数据点数量"),
+    user_id: Optional[str] = Query(None, description="指定用户 ID"),
+    include_user_info: bool = Query(False, description="是否包含用户信息（用于管理员多用户视图）"),
+    db: Session = Depends(get_db),
+):
+    """
+    获取请求间隔时间线数据，用于散点图展示。
+
+    返回每个请求的时间点和与上一个请求的间隔（分钟），
+    可用于可视化用户请求模式。
+
+    当 include_user_info=true 且未指定 user_id 时，返回数据会包含:
+    - points 中每个点包含 user_id 字段
+    - users 字段包含 user_id -> username 的映射
+    """
+    adapter = IntervalTimelineAdapter(
+        hours=hours,
+        limit=limit,
+        user_id=user_id,
+        include_user_info=include_user_info,
+    )
+    return await pipeline.run(adapter=adapter, http_request=request, db=db, mode=adapter.mode)
+
+
+class IntervalTimelineAdapter(AdminApiAdapter):
+    """请求间隔时间线适配器"""
+
+    def __init__(
+        self,
+        hours: int,
+        limit: int,
+        user_id: Optional[str] = None,
+        include_user_info: bool = False,
+    ):
+        self.hours = hours
+        self.limit = limit
+        self.user_id = user_id
+        self.include_user_info = include_user_info
+
+    async def handle(self, context):  # type: ignore[override]
+        db = context.db
+
+        result = UsageService.get_interval_timeline(
+            db=db,
+            hours=self.hours,
+            limit=self.limit,
+            user_id=self.user_id,
+            include_user_info=self.include_user_info,
+        )
+
+        context.add_audit_metadata(
+            action="interval_timeline",
+            hours=self.hours,
+            limit=self.limit,
+            user_id=self.user_id,
+            include_user_info=self.include_user_info,
+            total_points=result.get("total_points", 0),
+        )
+
+        return result

src/api/user_me/routes.py

@@ -121,6 +121,18 @@ async def get_my_active_requests(
     return await pipeline.run(adapter=adapter, http_request=request, db=db, mode=adapter.mode)
 
 
+@router.get("/usage/interval-timeline")
+async def get_my_interval_timeline(
+    request: Request,
+    hours: int = Query(168, ge=1, le=720, description="分析最近多少小时的数据"),
+    limit: int = Query(1000, ge=100, le=5000, description="最大返回数据点数量"),
+    db: Session = Depends(get_db),
+):
+    """获取当前用户的请求间隔时间线数据，用于散点图展示"""
+    adapter = GetMyIntervalTimelineAdapter(hours=hours, limit=limit)
+    return await pipeline.run(adapter=adapter, http_request=request, db=db, mode=adapter.mode)
+
+
 @router.get("/providers")
 async def list_available_providers(request: Request, db: Session = Depends(get_db)):
     adapter = ListAvailableProvidersAdapter()
@@ -676,6 +688,27 @@ class GetActiveRequestsAdapter(AuthenticatedApiAdapter):
         return {"requests": requests}
 
 
+@dataclass
+class GetMyIntervalTimelineAdapter(AuthenticatedApiAdapter):
+    """获取当前用户的请求间隔时间线适配器"""
+
+    hours: int
+    limit: int
+
+    async def handle(self, context):  # type: ignore[override]
+        db = context.db
+        user = context.user
+
+        result = UsageService.get_interval_timeline(
+            db=db,
+            hours=self.hours,
+            limit=self.limit,
+            user_id=str(user.id),
+        )
+
+        return result
+
+
 class ListAvailableProvidersAdapter(AuthenticatedApiAdapter):
     async def handle(self, context):  # type: ignore[override]
         from sqlalchemy.orm import selectinload

src/services/cache/aware_scheduler.py

@@ -862,13 +862,14 @@ class CacheAwareScheduler:
 
         # Key 级别的能力匹配检查
         # 注意：模型级别的能力检查已在 _check_model_support 中完成
-        if capability_requirements:
-            from src.core.key_capabilities import check_capability_match
+        # 始终执行检查，即使 capability_requirements 为空
+        # 因为 check_capability_match 会检查 Key 的 EXCLUSIVE 能力是否被浪费
+        from src.core.key_capabilities import check_capability_match
 
-            key_caps: Dict[str, bool] = dict(key.capabilities or {})
-            is_match, skip_reason = check_capability_match(key_caps, capability_requirements)
-            if not is_match:
-                return False, skip_reason
+        key_caps: Dict[str, bool] = dict(key.capabilities or {})
+        is_match, skip_reason = check_capability_match(key_caps, capability_requirements)
+        if not is_match:
+            return False, skip_reason
 
         return True, None
 

src/services/orchestration/error_classifier.py

@@ -67,12 +67,13 @@ class ErrorClassifier:
 
     # 表示客户端请求错误的关键词（不区分大小写）
     # 这些错误是由用户请求本身导致的，换 Provider 也无济于事
+    # 注意：标准 API 返回的 error.type 已在 CLIENT_ERROR_TYPES 中处理
+    # 这里主要用于匹配非标准格式或第三方代理的错误消息
     CLIENT_ERROR_PATTERNS: Tuple[str, ...] = (
         "could not process image",  # 图片处理失败
         "image too large",  # 图片过大
         "invalid image",  # 无效图片
         "unsupported image",  # 不支持的图片格式
-        "invalid_request_error",  # OpenAI/Claude 通用客户端错误类型
         "content_policy_violation",  # 内容违规
         "invalid_api_key",  # 无效的 API Key（不同于认证失败）
         "context_length_exceeded",  # 上下文长度超限
@@ -85,6 +86,7 @@ class ErrorClassifier:
         "image exceeds",  # 图片超出限制
         "pdf too large",  # PDF 过大
         "file too large",  # 文件过大
+        "tool_use_id",  # tool_result 引用了不存在的 tool_use（兼容非标准代理）
     )
 
     def __init__(
@@ -105,10 +107,22 @@ class ErrorClassifier:
         self.adaptive_manager = adaptive_manager or get_adaptive_manager()
         self.cache_scheduler = cache_scheduler
 
+    # 表示客户端错误的 error type（不区分大小写）
+    # 这些 type 表明是请求本身的问题，不应重试
+    CLIENT_ERROR_TYPES: Tuple[str, ...] = (
+        "invalid_request_error",  # Claude/OpenAI 标准客户端错误类型
+        "invalid_argument",  # Gemini 参数错误
+        "failed_precondition",  # Gemini 前置条件错误
+    )
+
     def _is_client_error(self, error_text: Optional[str]) -> bool:
         """
         检测错误响应是否为客户端错误（不应重试）
 
+        判断逻辑：
+        1. 检查 error.type 是否为已知的客户端错误类型
+        2. 检查错误文本是否包含已知的客户端错误模式
+
         Args:
             error_text: 错误响应文本
 
@@ -118,6 +132,19 @@ class ErrorClassifier:
         if not error_text:
             return False
 
+        # 尝试解析 JSON 并检查 error type
+        try:
+            data = json.loads(error_text)
+            if isinstance(data.get("error"), dict):
+                error_type = data["error"].get("type", "")
+                if error_type and any(
+                    t.lower() in error_type.lower() for t in self.CLIENT_ERROR_TYPES
+                ):
+                    return True
+        except (json.JSONDecodeError, TypeError, KeyError):
+            pass
+
+        # 回退到关键词匹配
         error_lower = error_text.lower()
         return any(pattern.lower() in error_lower for pattern in self.CLIENT_ERROR_PATTERNS)
 

src/services/usage/service.py

@@ -1394,3 +1394,461 @@ class UsageService:
             }
             for r in records
         ]
+
+    # ========== 缓存亲和性分析方法 ==========
+
+    @staticmethod
+    def analyze_cache_affinity_ttl(
+        db: Session,
+        user_id: Optional[str] = None,
+        api_key_id: Optional[str] = None,
+        hours: int = 168,
+    ) -> Dict[str, Any]:
+        """
+        分析用户请求间隔分布，推荐合适的缓存亲和性 TTL
+
+        通过分析同一用户连续请求之间的时间间隔，判断用户的使用模式：
+        - 高频用户（间隔短）：5 分钟 TTL 足够
+        - 中频用户：15-30 分钟 TTL
+        - 低频用户（间隔长）：需要 60 分钟 TTL
+
+        Args:
+            db: 数据库会话
+            user_id: 指定用户 ID（可选，为空则分析所有用户）
+            api_key_id: 指定 API Key ID（可选）
+            hours: 分析最近多少小时的数据
+
+        Returns:
+            包含分析结果的字典
+        """
+        from sqlalchemy import text
+
+        # 计算时间范围
+        start_date = datetime.now(timezone.utc) - timedelta(hours=hours)
+
+        # 构建 SQL 查询 - 使用窗口函数计算请求间隔
+        # 按 user_id 或 api_key_id 分组，计算同一组内连续请求的时间差
+        group_by_field = "api_key_id" if api_key_id else "user_id"
+
+        # 构建过滤条件
+        filter_clause = ""
+        if user_id or api_key_id:
+            filter_clause = f"AND {group_by_field} = :filter_id"
+
+        sql = text(f"""
+            WITH user_requests AS (
+                SELECT
+                    {group_by_field} as group_id,
+                    created_at,
+                    LAG(created_at) OVER (
+                        PARTITION BY {group_by_field}
+                        ORDER BY created_at
+                    ) as prev_request_at
+                FROM usage
+                WHERE status = 'completed'
+                  AND created_at > :start_date
+                  AND {group_by_field} IS NOT NULL
+                  {filter_clause}
+            ),
+            intervals AS (
+                SELECT
+                    group_id,
+                    EXTRACT(EPOCH FROM (created_at - prev_request_at)) / 60.0 as interval_minutes
+                FROM user_requests
+                WHERE prev_request_at IS NOT NULL
+            ),
+            user_stats AS (
+                SELECT
+                    group_id,
+                    COUNT(*) as request_count,
+                    COUNT(*) FILTER (WHERE interval_minutes <= 5) as within_5min,
+                    COUNT(*) FILTER (WHERE interval_minutes > 5 AND interval_minutes <= 15) as within_15min,
+                    COUNT(*) FILTER (WHERE interval_minutes > 15 AND interval_minutes <= 30) as within_30min,
+                    COUNT(*) FILTER (WHERE interval_minutes > 30 AND interval_minutes <= 60) as within_60min,
+                    COUNT(*) FILTER (WHERE interval_minutes > 60) as over_60min,
+                    PERCENTILE_CONT(0.5) WITHIN GROUP (ORDER BY interval_minutes) as median_interval,
+                    PERCENTILE_CONT(0.75) WITHIN GROUP (ORDER BY interval_minutes) as p75_interval,
+                    PERCENTILE_CONT(0.90) WITHIN GROUP (ORDER BY interval_minutes) as p90_interval,
+                    AVG(interval_minutes) as avg_interval,
+                    MIN(interval_minutes) as min_interval,
+                    MAX(interval_minutes) as max_interval
+                FROM intervals
+                GROUP BY group_id
+                HAVING COUNT(*) >= 2
+            )
+            SELECT * FROM user_stats
+            ORDER BY request_count DESC
+        """)
+
+        params: Dict[str, Any] = {
+            "start_date": start_date,
+        }
+        if user_id:
+            params["filter_id"] = user_id
+        elif api_key_id:
+            params["filter_id"] = api_key_id
+
+        result = db.execute(sql, params)
+        rows = result.fetchall()
+
+        # 收集所有 user_id 以便批量查询用户信息
+        group_ids = [row[0] for row in rows]
+
+        # 如果是按 user_id 分组，查询用户信息
+        user_info_map: Dict[str, Dict[str, str]] = {}
+        if group_by_field == "user_id" and group_ids:
+            users = db.query(User).filter(User.id.in_(group_ids)).all()
+            for user in users:
+                user_info_map[str(user.id)] = {
+                    "username": user.username,
+                    "email": user.email or "",
+                }
+
+        # 处理结果
+        users_analysis = []
+        for row in rows:
+            # row 是一个 tuple，按查询顺序访问
+            (
+                group_id,
+                request_count,
+                within_5min,
+                within_15min,
+                within_30min,
+                within_60min,
+                over_60min,
+                median_interval,
+                p75_interval,
+                p90_interval,
+                avg_interval,
+                min_interval,
+                max_interval,
+            ) = row
+
+            # 计算推荐 TTL
+            recommended_ttl = UsageService._calculate_recommended_ttl(
+                p75_interval, p90_interval
+            )
+
+            # 获取用户信息
+            user_info = user_info_map.get(str(group_id), {})
+
+            # 计算各区间占比
+            total_intervals = request_count
+            users_analysis.append({
+                "group_id": group_id,
+                "username": user_info.get("username"),
+                "email": user_info.get("email"),
+                "request_count": request_count,
+                "interval_distribution": {
+                    "within_5min": within_5min,
+                    "within_15min": within_15min,
+                    "within_30min": within_30min,
+                    "within_60min": within_60min,
+                    "over_60min": over_60min,
+                },
+                "interval_percentages": {
+                    "within_5min": round(within_5min / total_intervals * 100, 1),
+                    "within_15min": round(within_15min / total_intervals * 100, 1),
+                    "within_30min": round(within_30min / total_intervals * 100, 1),
+                    "within_60min": round(within_60min / total_intervals * 100, 1),
+                    "over_60min": round(over_60min / total_intervals * 100, 1),
+                },
+                "percentiles": {
+                    "p50": round(float(median_interval), 2) if median_interval else None,
+                    "p75": round(float(p75_interval), 2) if p75_interval else None,
+                    "p90": round(float(p90_interval), 2) if p90_interval else None,
+                },
+                "avg_interval_minutes": round(float(avg_interval), 2) if avg_interval else None,
+                "min_interval_minutes": round(float(min_interval), 2) if min_interval else None,
+                "max_interval_minutes": round(float(max_interval), 2) if max_interval else None,
+                "recommended_ttl_minutes": recommended_ttl,
+                "recommendation_reason": UsageService._get_ttl_recommendation_reason(
+                    recommended_ttl, p75_interval, p90_interval
+                ),
+            })
+
+        # 汇总统计
+        ttl_distribution = {"5min": 0, "15min": 0, "30min": 0, "60min": 0}
+        for analysis in users_analysis:
+            ttl = analysis["recommended_ttl_minutes"]
+            if ttl <= 5:
+                ttl_distribution["5min"] += 1
+            elif ttl <= 15:
+                ttl_distribution["15min"] += 1
+            elif ttl <= 30:
+                ttl_distribution["30min"] += 1
+            else:
+                ttl_distribution["60min"] += 1
+
+        return {
+            "analysis_period_hours": hours,
+            "total_users_analyzed": len(users_analysis),
+            "ttl_distribution": ttl_distribution,
+            "users": users_analysis,
+        }
+
+    @staticmethod
+    def _calculate_recommended_ttl(
+        p75_interval: Optional[float],
+        p90_interval: Optional[float],
+    ) -> int:
+        """
+        根据请求间隔分布计算推荐的缓存 TTL
+
+        策略：
+        - 如果 90% 的请求间隔都在 5 分钟内 → 5 分钟 TTL
+        - 如果 75% 的请求间隔在 15 分钟内 → 15 分钟 TTL
+        - 如果 75% 的请求间隔在 30 分钟内 → 30 分钟 TTL
+        - 否则 → 60 分钟 TTL
+        """
+        if p90_interval is None or p75_interval is None:
+            return 5  # 默认值
+
+        # 如果 90% 的间隔都在 5 分钟内
+        if p90_interval <= 5:
+            return 5
+
+        # 如果 75% 的间隔在 15 分钟内
+        if p75_interval <= 15:
+            return 15
+
+        # 如果 75% 的间隔在 30 分钟内
+        if p75_interval <= 30:
+            return 30
+
+        # 低频用户，需要更长的 TTL
+        return 60
+
+    @staticmethod
+    def _get_ttl_recommendation_reason(
+        ttl: int,
+        p75_interval: Optional[float],
+        p90_interval: Optional[float],
+    ) -> str:
+        """生成 TTL 推荐理由"""
+        if p75_interval is None or p90_interval is None:
+            return "数据不足，使用默认值"
+
+        if ttl == 5:
+            return f"高频用户：90% 的请求间隔在 {p90_interval:.1f} 分钟内"
+        elif ttl == 15:
+            return f"中高频用户：75% 的请求间隔在 {p75_interval:.1f} 分钟内"
+        elif ttl == 30:
+            return f"中频用户：75% 的请求间隔在 {p75_interval:.1f} 分钟内"
+        else:
+            return f"低频用户：75% 的请求间隔为 {p75_interval:.1f} 分钟，建议使用长 TTL"
+
+    @staticmethod
+    def get_cache_hit_analysis(
+        db: Session,
+        user_id: Optional[str] = None,
+        api_key_id: Optional[str] = None,
+        hours: int = 168,
+    ) -> Dict[str, Any]:
+        """
+        分析缓存命中情况
+
+        Args:
+            db: 数据库会话
+            user_id: 指定用户 ID（可选）
+            api_key_id: 指定 API Key ID（可选）
+            hours: 分析最近多少小时的数据
+
+        Returns:
+            缓存命中分析结果
+        """
+        start_date = datetime.now(timezone.utc) - timedelta(hours=hours)
+
+        # 基础查询
+        query = db.query(
+            func.count(Usage.id).label("total_requests"),
+            func.sum(Usage.input_tokens).label("total_input_tokens"),
+            func.sum(Usage.cache_read_input_tokens).label("total_cache_read_tokens"),
+            func.sum(Usage.cache_creation_input_tokens).label("total_cache_creation_tokens"),
+            func.sum(Usage.cache_read_cost_usd).label("total_cache_read_cost"),
+            func.sum(Usage.cache_creation_cost_usd).label("total_cache_creation_cost"),
+        ).filter(
+            Usage.status == "completed",
+            Usage.created_at >= start_date,
+        )
+
+        if user_id:
+            query = query.filter(Usage.user_id == user_id)
+        if api_key_id:
+            query = query.filter(Usage.api_key_id == api_key_id)
+
+        result = query.first()
+
+        total_requests = result.total_requests or 0
+        total_input_tokens = result.total_input_tokens or 0
+        total_cache_read_tokens = result.total_cache_read_tokens or 0
+        total_cache_creation_tokens = result.total_cache_creation_tokens or 0
+        total_cache_read_cost = float(result.total_cache_read_cost or 0)
+        total_cache_creation_cost = float(result.total_cache_creation_cost or 0)
+
+        # 计算缓存命中率（按 token 数）
+        # 总输入上下文 = input_tokens + cache_read_tokens（因为 input_tokens 不含 cache_read）
+        # 或者如果 input_tokens 已经包含 cache_read，则直接用 input_tokens
+        # 这里假设 cache_read_tokens 是额外的，命中率 = cache_read / (input + cache_read)
+        total_context_tokens = total_input_tokens + total_cache_read_tokens
+        cache_hit_rate = 0.0
+        if total_context_tokens > 0:
+            cache_hit_rate = total_cache_read_tokens / total_context_tokens * 100
+
+        # 计算节省的费用
+        # 缓存读取价格是正常输入价格的 10%，所以节省了 90%
+        # 节省 = cache_read_tokens * (正常价格 - 缓存价格) = cache_read_cost * 9
+        # 因为 cache_read_cost 是按 10% 价格算的，如果按 100% 算就是 10 倍
+        estimated_savings = total_cache_read_cost * 9  # 节省了 90%
+
+        # 统计有缓存命中的请求数
+        requests_with_cache_hit = db.query(func.count(Usage.id)).filter(
+            Usage.status == "completed",
+            Usage.created_at >= start_date,
+            Usage.cache_read_input_tokens > 0,
+        )
+        if user_id:
+            requests_with_cache_hit = requests_with_cache_hit.filter(Usage.user_id == user_id)
+        if api_key_id:
+            requests_with_cache_hit = requests_with_cache_hit.filter(Usage.api_key_id == api_key_id)
+        requests_with_cache_hit = requests_with_cache_hit.scalar() or 0
+
+        return {
+            "analysis_period_hours": hours,
+            "total_requests": total_requests,
+            "requests_with_cache_hit": requests_with_cache_hit,
+            "request_cache_hit_rate": round(requests_with_cache_hit / total_requests * 100, 2) if total_requests > 0 else 0,
+            "total_input_tokens": total_input_tokens,
+            "total_cache_read_tokens": total_cache_read_tokens,
+            "total_cache_creation_tokens": total_cache_creation_tokens,
+            "token_cache_hit_rate": round(cache_hit_rate, 2),
+            "total_cache_read_cost_usd": round(total_cache_read_cost, 4),
+            "total_cache_creation_cost_usd": round(total_cache_creation_cost, 4),
+            "estimated_savings_usd": round(estimated_savings, 4),
+        }
+
+    @staticmethod
+    def get_interval_timeline(
+        db: Session,
+        hours: int = 168,
+        limit: int = 1000,
+        user_id: Optional[str] = None,
+        include_user_info: bool = False,
+    ) -> Dict[str, Any]:
+        """
+        获取请求间隔时间线数据，用于散点图展示
+
+        Args:
+            db: 数据库会话
+            hours: 分析最近多少小时的数据
+            limit: 最大返回数据点数量
+            user_id: 指定用户 ID（可选，为空则返回所有用户）
+            include_user_info: 是否包含用户信息（用于管理员多用户视图）
+
+        Returns:
+            包含时间线数据点的字典
+        """
+        from sqlalchemy import text
+
+        start_date = datetime.now(timezone.utc) - timedelta(hours=hours)
+
+        # 构建用户过滤条件
+        user_filter = "AND u.user_id = :user_id" if user_id else ""
+
+        # 根据是否需要用户信息选择不同的查询
+        if include_user_info and not user_id:
+            # 管理员视图：返回带用户信息的数据点
+            sql = text(f"""
+                WITH request_intervals AS (
+                    SELECT
+                        u.created_at,
+                        u.user_id,
+                        usr.username,
+                        LAG(u.created_at) OVER (
+                            PARTITION BY u.user_id
+                            ORDER BY u.created_at
+                        ) as prev_request_at
+                    FROM usage u
+                    LEFT JOIN users usr ON u.user_id = usr.id
+                    WHERE u.status = 'completed'
+                      AND u.created_at > :start_date
+                      AND u.user_id IS NOT NULL
+                      {user_filter}
+                )
+                SELECT
+                    created_at,
+                    user_id,
+                    username,
+                    EXTRACT(EPOCH FROM (created_at - prev_request_at)) / 60.0 as interval_minutes
+                FROM request_intervals
+                WHERE prev_request_at IS NOT NULL
+                  AND EXTRACT(EPOCH FROM (created_at - prev_request_at)) / 60.0 <= 120
+                ORDER BY created_at
+                LIMIT :limit
+            """)
+        else:
+            # 普通视图：只返回时间和间隔
+            sql = text(f"""
+                WITH request_intervals AS (
+                    SELECT
+                        u.created_at,
+                        u.user_id,
+                        LAG(u.created_at) OVER (
+                            PARTITION BY u.user_id
+                            ORDER BY u.created_at
+                        ) as prev_request_at
+                    FROM usage u
+                    WHERE u.status = 'completed'
+                      AND u.created_at > :start_date
+                      AND u.user_id IS NOT NULL
+                      {user_filter}
+                )
+                SELECT
+                    created_at,
+                    EXTRACT(EPOCH FROM (created_at - prev_request_at)) / 60.0 as interval_minutes
+                FROM request_intervals
+                WHERE prev_request_at IS NOT NULL
+                  AND EXTRACT(EPOCH FROM (created_at - prev_request_at)) / 60.0 <= 120
+                ORDER BY created_at
+                LIMIT :limit
+            """)
+
+        params: Dict[str, Any] = {"start_date": start_date, "limit": limit}
+        if user_id:
+            params["user_id"] = user_id
+
+        result = db.execute(sql, params)
+        rows = result.fetchall()
+
+        # 转换为时间线数据点
+        points = []
+        users_map: Dict[str, str] = {}  # user_id -> username
+
+        if include_user_info and not user_id:
+            for row in rows:
+                created_at, row_user_id, username, interval_minutes = row
+                points.append({
+                    "x": created_at.isoformat(),
+                    "y": round(float(interval_minutes), 2),
+                    "user_id": str(row_user_id),
+                })
+                if row_user_id and username:
+                    users_map[str(row_user_id)] = username
+        else:
+            for row in rows:
+                created_at, interval_minutes = row
+                points.append({
+                    "x": created_at.isoformat(),
+                    "y": round(float(interval_minutes), 2)
+                })
+
+        response: Dict[str, Any] = {
+            "analysis_period_hours": hours,
+            "total_points": len(points),
+            "points": points,
+        }
+
+        if include_user_info and not user_id:
+            response["users"] = users_map
+
+        return response