Trong bài viết này, tôi sẽ chia sẻ cách triển khai hệ thống kiểm toán token用量 và budget alerting cho doanh nghiệp sử dụng HolySheep AI — giải pháp unified API gateway với độ trễ dưới 50ms và khả năng tiết kiệm chi phí đến 85% so với các nhà cung cấp trực tiếp.

Tại sao cần kiểm toán Token theo Department/Project?

Khi team của bạn mở rộng từ 5 lên 50+ kỹ sư sử dụng LLM API, chi phí có thể tăng từ $500/tháng lên $15,000/tháng chỉ trong vài tuần. Không ai biết ai đang tiêu tốn bao nhiêu, model nào đang được gọi, và tại sao hóa đơn lại cao như vậy.

Bằng kinh nghiệm triển khai cho 20+ enterprise customer, tôi nhận ra rằng 3 nguyên nhân chính gây thâm hụt ngân sách LLM:

Kiến trúc tổng quan

Hệ thống audit của chúng ta bao gồm 4 thành phần chính:

┌─────────────────────────────────────────────────────────────────┐
│                      HOLYSHEEP API GATEWAY                       │
│  ┌──────────────┐  ┌──────────────┐  ┌──────────────────────┐   │
│  │ Token Counter│  │ Metadata     │  │ Cost Aggregator     │   │
│  │ (per call)   │→ │ Extractor    │→ │ (department/project) │   │
│  └──────────────┘  └──────────────┘  └──────────────────────┘   │
│         ↓                                     ↓                   │
│  ┌──────────────┐                    ┌──────────────┐            │
│  │ Audit Logger │                    │ Alert Engine │            │
│  │ (ClickHouse) │                    │ (Prometheus) │            │
│  └──────────────┘                    └──────────────┘            │
└─────────────────────────────────────────────────────────────────┘
                            ↓
                 ┌──────────────────────┐
                 │   Dashboard (Grafana)│
                 │   + Slack/PagerDuty  │
                 └──────────────────────┘

Triển khai Code Production

1. Unified API Client với Metadata Tracking

"""
HolySheep AI - Token Usage Audit Client
Production-ready với per-department, per-project tracking
"""
import asyncio
import httpx
import json
from datetime import datetime, timedelta
from typing import Optional, Dict, Any, List
from dataclasses import dataclass, field
from collections import defaultdict
import hashlib

@dataclass
class UsageRecord:
    """Bản ghi sử dụng cho audit"""
    timestamp: datetime
    department: str
    project: str
    model: str
    input_tokens: int
    output_tokens: int
    cost_usd: float
    latency_ms: float
    request_id: str

@dataclass
class BudgetAlert:
    """Cấu hình alert cho department/project"""
    department: str
    project: Optional[str]
    monthly_limit_usd: float
    daily_limit_usd: float
    warning_threshold: float = 0.8  # Alert khi 80% budget used

class HolySheepAuditClient:
    """
    HolySheep AI Client với built-in token auditing và budget tracking.
    
    Features:
    - Automatic token counting và cost calculation
    - Per-department, per-project cost allocation
    - Real-time budget alerting
    - Monthly/weekly/daily aggregation
    
    Pricing Reference (2026):
    - GPT-4.1: $8.00/1M tokens
    - Claude Sonnet 4.5: $15.00/1M tokens
    - Gemini 2.5 Flash: $2.50/1M tokens
    - DeepSeek V3.2: $0.42/1M tokens
    """
    
    # HolySheep unified pricing (2026) - save 85%+ vs direct
    PRICING = {
        "gpt-4.1": {"input": 8.00, "output": 8.00, "currency": "USD"},
        "claude-sonnet-4.5": {"input": 15.00, "output": 15.00, "currency": "USD"},
        "gemini-2.5-flash": {"input": 2.50, "output": 2.50, "currency": "USD"},
        "deepseek-v3.2": {"input": 0.42, "output": 0.42, "currency": "USD"},
    }
    
    def __init__(
        self,
        api_key: str,
        base_url: str = "https://api.holysheep.ai/v1",
        department: str = "default",
        project: str = "default",
        alert_callback: Optional[callable] = None
    ):
        self.api_key = api_key
        self.base_url = base_url
        self.department = department
        self.project = project
        self.alert_callback = alert_callback
        
        # In-memory storage cho demo - production nên dùng ClickHouse/TimescaleDB
        self.usage_records: List[UsageRecord] = []
        self.budget_configs: Dict[str, BudgetAlert] = {}
        self.daily_spend: Dict[str, float] = defaultdict(float)
        self.monthly_spend: Dict[str, float] = defaultdict(float)
        
        self.client = httpx.AsyncClient(
            timeout=httpx.Timeout(60.0, connect=10.0),
            headers={
                "Authorization": f"Bearer {api_key}",
                "Content-Type": "application/json"
            }
        )
    
    def _generate_request_id(self, messages: List[Dict]) -> str:
        """Tạo unique request ID từ content hash"""
        content_str = json.dumps(messages, sort_keys=True)
        return hashlib.sha256(content_str.encode()).hexdigest()[:16]
    
    def _calculate_cost(self, model: str, input_tokens: int, output_tokens: int) -> float:
        """Tính chi phí theo model pricing"""
        pricing = self.PRICING.get(model, {"input": 8.0, "output": 8.0})
        input_cost = (input_tokens / 1_000_000) * pricing["input"]
        output_cost = (output_tokens / 1_000_000) * pricing["output"]
        return round(input_cost + output_cost, 6)
    
    def _get_spend_key(self, department: str, project: str) -> str:
        return f"{department}:{project}"
    
    async def chat_completion(
        self,
        messages: List[Dict[str, str]],
        model: str = "deepseek-v3.2",
        department: Optional[str] = None,
        project: Optional[str] = None,
        temperature: float = 0.7,
        max_tokens: Optional[int] = None,
        **kwargs
    ) -> Dict[str, Any]:
        """
        Gọi HolySheep Chat Completions API với automatic usage tracking.
        
        Args:
            messages: List of message objects
            model: Model name (default: deepseek-v3.2 - cheapest option)
            department: Department identifier for cost allocation
            project: Project identifier for cost allocation
            temperature: Sampling temperature
            max_tokens: Maximum tokens to generate
        """
        dept = department or self.department
        proj = project or self.project
        
        request_id = self._generate_request_id(messages)
        
        # Build request payload
        payload = {
            "model": model,
            "messages": messages,
            "temperature": temperature,
        }
        if max_tokens:
            payload["max_tokens"] = max_tokens
        
        start_time = datetime.utcnow()
        
        try:
            response = await self.client.post(
                f"{self.base_url}/chat/completions",
                json=payload
            )
            response.raise_for_status()
            result = response.json()
            
            end_time = datetime.utcnow()
            latency_ms = (end_time - start_time).total_seconds() * 1000
            
            # Extract token usage từ response
            usage = result.get("usage", {})
            input_tokens = usage.get("prompt_tokens", 0)
            output_tokens = usage.get("completion_tokens", 0)
            cost_usd = self._calculate_cost(model, input_tokens, output_tokens)
            
            # Create usage record
            record = UsageRecord(
                timestamp=start_time,
                department=dept,
                project=proj,
                model=model,
                input_tokens=input_tokens,
                output_tokens=output_tokens,
                cost_usd=cost_usd,
                latency_ms=latency_ms,
                request_id=request_id
            )
            
            # Store record và update aggregations
            await self._record_and_check_budget(record)
            
            return result
            
        except httpx.HTTPStatusError as e:
            # Log failed request với cost = 0
            record = UsageRecord(
                timestamp=start_time,
                department=dept,
                project=proj,
                model=model,
                input_tokens=0,
                output_tokens=0,
                cost_usd=0.0,
                latency_ms=(datetime.utcnow() - start_time).total_seconds() * 1000,
                request_id=request_id
            )
            await self._record_and_check_budget(record)
            raise
    
    async def _record_and_check_budget(self, record: UsageRecord):
        """Lưu record và kiểm tra budget alert"""
        self.usage_records.append(record)
        
        spend_key = self._get_spend_key(record.department, record.project)
        today = datetime.utcnow().strftime("%Y-%m-%d")
        month_key = datetime.utcnow().strftime("%Y-%m")
        
        # Update aggregations
        self.daily_spend[f"{spend_key}:{today}"] += record.cost_usd
        self.monthly_spend[f"{spend_key}:{month_key}"] += record.cost_usd
        
        # Check budget alerts
        await self._check_budget_alerts(record.department, record.project)
    
    async def _check_budget_alerts(self, department: str, project: str):
        """Kiểm tra và trigger budget alerts nếu cần"""
        spend_key = self._get_spend_key(department, project)
        today = datetime.utcnow().strftime("%Y-%m-%d")
        month_key = datetime.utcnow().strftime("%Y-%m")
        
        daily_spend = self.daily_spend.get(f"{spend_key}:{today}", 0)
        monthly_spend = self.monthly_spend.get(f"{spend_key}:{month_key}", 0)
        
        # Check alerts
        for key, alert in self.budget_configs.items():
            if alert.department != department:
                continue
            if alert.project and alert.project != project:
                continue
            
            # Daily alert
            if daily_spend >= alert.daily_limit_usd * alert.warning_threshold:
                await self._trigger_alert(
                    "DAILY_BUDGET_WARNING",
                    department,
                    project,
                    daily_spend,
                    alert.daily_limit_usd,
                    "daily"
                )
            
            # Monthly alert
            if monthly_spend >= alert.monthly_limit_usd * alert.warning_threshold:
                await self._trigger_alert(
                    "MONTHLY_BUDGET_WARNING",
                    department,
                    project,
                    monthly_spend,
                    alert.monthly_limit_usd,
                    "monthly"
                )
    
    async def _trigger_alert(
        self,
        alert_type: str,
        department: str,
        project: str,
        current_spend: float,
        limit: float,
        period: str
    ):
        """Trigger budget alert via callback"""
        if self.alert_callback:
            await self.alert_callback({
                "type": alert_type,
                "department": department,
                "project": project,
                "current_spend_usd": round(current_spend, 2),
                "limit_usd": limit,
                "percentage": round((current_spend / limit) * 100, 1),
                "period": period,
                "timestamp": datetime.utcnow().isoformat()
            })
    
    def set_budget_alert(self, alert: BudgetAlert):
        """Cấu hình budget alert cho department/project"""
        key = self._get_spend_key(alert.department, alert.project or "all")
        self.budget_configs[key] = alert
    
    async def get_cost_summary(
        self,
        department: Optional[str] = None,
        project: Optional[str] = None,
        period: str = "month"
    ) -> Dict[str, Any]:
        """
        Lấy tổng hợp chi phí theo department/project.
        
        Args:
            department: Filter by department (None = all)
            project: Filter by project (None = all)
            period: 'day', 'week', 'month'
        """
        records = self.usage_records
        
        if department:
            records = [r for r in records if r.department == department]
        if project:
            records = [r for r in records if r.project == project]
        
        # Filter by period
        now = datetime.utcnow()
        if period == "day":
            cutoff = now - timedelta(days=1)
        elif period == "week":
            cutoff = now - timedelta(days=7)
        else:  # month
            cutoff = now - timedelta(days=30)
        
        records = [r for r in records if r.timestamp >= cutoff]
        
        # Aggregate
        total_cost = sum(r.cost_usd for r in records)
        total_input_tokens = sum(r.input_tokens for r in records)
        total_output_tokens = sum(r.output_tokens for r in records)
        avg_latency = sum(r.latency_ms for r in records) / len(records) if records else 0
        
        by_model = defaultdict(lambda: {"cost": 0, "requests": 0, "tokens": 0})
        for r in records:
            by_model[r.model]["cost"] += r.cost_usd
            by_model[r.model]["requests"] += 1
            by_model[r.model]["tokens"] += r.input_tokens + r.output_tokens
        
        by_department = defaultdict(lambda: {"cost": 0, "requests": 0})
        for r in records:
            by_department[r.department]["cost"] += r.cost_usd
            by_department[r.department]["requests"] += 1
        
        return {
            "period": period,
            "total_cost_usd": round(total_cost, 2),
            "total_input_tokens": total_input_tokens,
            "total_output_tokens": total_output_tokens,
            "total_requests": len(records),
            "avg_latency_ms": round(avg_latency, 2),
            "by_model": dict(by_model),
            "by_department": dict(by_department)
        }
    
    async def close(self):
        await self.client.aclose()


============================================================

USAGE EXAMPLE - Production Implementation

============================================================

async def slack_alert_handler(alert: Dict): """Handler gửi alert qua Slack webhook""" import os webhook_url = os.environ.get("SLACK_WEBHOOK_URL") if not webhook_url: print(f"[ALERT] {alert}") return import httpx await httpx.AsyncClient().post(webhook_url, json={ "text": f"🚨 Budget Alert: {alert['department']}/{alert['project']}", "blocks": [ { "type": "section", "text": { "type": "mrkdwn", "text": f"*Budget Warning*\n" f"Department: {alert['department']}\n" f"Project: {alert['project']}\n" f"Spend: ${alert['current_spend_usd']:.2f} / ${alert['limit_usd']:.2f}\n" f"Usage: {alert['percentage']}%" } } ] }) async def main(): """Example usage với multi-department tracking""" client = HolySheepAuditClient( api_key="YOUR_HOLYSHEEP_API_KEY", # Thay bằng API key thực tế department="engineering", project="ai-features", alert_callback=slack_alert_handler ) # Cấu hình budget alerts client.set_budget_alert(BudgetAlert( department="engineering", project="ai-features", monthly_limit_usd=5000.0, # $5000/tháng daily_limit_usd=300.0, # $300/ngày warning_threshold=0.8 )) client.set_budget_alert(BudgetAlert( department="data-science", project=None, # Áp dụng cho tất cả projects monthly_limit_usd=2000.0, daily_limit_usd=100.0 )) # Example: Gọi DeepSeek V3.2 (cheapest: $0.42/1M tokens) response = await client.chat_completion( messages=[ {"role": "system", "content": "Bạn là trợ lý AI hữu ích."}, {"role": "user", "content": "Giải thích về kiến trúc microservices"} ], model="deepseek-v3.2", # $0.42/1M tokens - tiết kiệm 85% vs GPT-4.1 department="engineering", project="backend-api" ) print(f"Response: {response['choices'][0]['message']['content']}") # Get cost summary summary = await client.get_cost_summary(period="month") print(f"Monthly spend: ${summary['total_cost_usd']}") print(f"By model: {summary['by_model']}") await client.close() if __name__ == "__main__": asyncio.run(main())

2. Dashboard Aggregation với ClickHouse

Để scale lên production với hàng triệu requests, chúng ta cần persistent storage. Dưới đây là schema ClickHouse và query aggregation:

-- ============================================================
-- HOLYSHEEP TOKEN USAGE AUDIT - ClickHouse Schema
-- Deploy: chcloud instance hoặc self-hosted ClickHouse
-- ============================================================

-- Database creation
CREATE DATABASE IF NOT EXISTS holysheep_audit;

-- Main usage table (partitioned by month, sorted by timestamp)
CREATE TABLE IF NOT EXISTS holysheep_audit.usage_log
(
    -- Primary keys
    request_id String DEFAULT generateUUIDv4(),
    timestamp DateTime64(3) DEFAULT now64(3),
    
    -- Cost allocation
    department LowCardinality(String),
    project LowCardinality(String),
    user_id String DEFAULT '',
    
    -- Model info
    model String,
    provider String DEFAULT 'holy-sheep',  -- holy-sheep, openai, anthropic
    
    -- Token usage
    input_tokens UInt32,
    output_tokens UInt32,
    total_tokens UInt32 ALIAS input_tokens + output_tokens,
    
    -- Cost calculation (USD)
    cost_usd Float64,
    
    -- Performance metrics
    latency_ms Float32,
    time_to_first_token_ms Float32 DEFAULT 0,
    
    -- Request metadata
    prompt_tokens_detail String DEFAULT '{}',
    completion_tokens_detail String DEFAULT '{}',
    
    -- Error tracking
    error_code UInt16 DEFAULT 0,
    error_message String DEFAULT ''
)
ENGINE = MergeTree()
PARTITION BY toYYYYMM(timestamp)
ORDER BY (department, project, timestamp)
TTL timestamp + INTERVAL 90 DAY
SETTINGS index_granularity = 8192;

-- Materialized View cho real-time department aggregation
CREATE MATERIALIZED VIEW IF NOT EXISTS holysheep_audit.dept_daily_mv
ENGINE = SummingMergeTree()
PARTITION BY (department, toYYYYMMDD(day))
ORDER BY (department, project, day)
AS SELECT
    department,
    project,
    toDate(timestamp) AS day,
    count() AS request_count,
    sum(input_tokens) AS total_input_tokens,
    sum(output_tokens) AS total_output_tokens,
    sum(cost_usd) AS total_cost_usd,
    avg(latency_ms) AS avg_latency_ms,
    quantile(0.95)(latency_ms) AS p95_latency_ms,
    quantile(0.99)(latency_ms) AS p99_latency_ms
FROM holysheep_audit.usage_log
GROUP BY department, project, toDate(timestamp);

-- Materialized View cho model-level cost analysis
CREATE MATERIALIZED VIEW IF NOT EXISTS holysheep_audit.model_cost_mv
ENGINE = SummingMergeTree()
PARTITION BY (model, toYYYYMMDD(day))
ORDER BY (model, day)
AS SELECT
    model,
    toDate(timestamp) AS day,
    count() AS request_count,
    sum(input_tokens) AS total_input_tokens,
    sum(output_tokens) AS total_output_tokens,
    sum(cost_usd) AS total_cost_usd,
    sumIf(cost_usd, error_code > 0) AS failed_cost_usd,
    sumIf(cost_usd, error_code = 0) AS success_cost_usd
FROM holysheep_audit.usage_log
GROUP BY model, toDate(timestamp);

-- ============================================================
-- KEY QUERIES FOR DASHBOARD
-- ============================================================

-- 1. Monthly spend by department
SELECT 
    department,
    project,
    sum(total_cost_usd) AS spend_usd,
    sum(request_count) AS requests,
    round(spend_usd / sum(request_count) * 1000, 4) AS cost_per_1k_requests
FROM holysheep_audit.dept_daily_mv
WHERE day >= DATE_TRUNC('month', now())
GROUP BY department, project
ORDER BY spend_usd DESC
FORMAT PrettyCompact;

-- 2. Daily trend comparison (current vs last month)
SELECT
    toStartOfDay(day) AS date,
    sum(total_cost_usd) AS daily_spend,
    sum(request_count) AS daily_requests,
    sum(total_input_tokens + total_output_tokens) / 1000000 AS total_mtok
FROM holysheep_audit.dept_daily_mv
WHERE day >= now() - INTERVAL 60 DAY
GROUP BY date
ORDER BY date
FORMAT PrettyCompact;

-- 3. Model cost efficiency analysis
SELECT
    model,
    sum(request_count) AS requests,
    sum(total_input_tokens) / 1000000 AS input_mtok,
    sum(total_output_tokens) / 1000000 AS output_mtok,
    sum(total_cost_usd) AS total_cost,
    round(total_cost / (input_mtok + output_mtok), 4) AS cost_per_mtok,
    round(avg_latency_ms, 2) AS avg_latency,
    round(p95_latency_ms, 2) AS p95_latency
FROM holysheep_audit.dept_daily_mv
WHERE day >= DATE_TRUNC('month', now())
GROUP BY model
ORDER BY total_cost DESC
FORMAT PrettyCompact;

-- 4. Department budget vs actual (monthly)
WITH 
    -- Budget configuration (có thể store trong separate table)
    budget_table AS (
        SELECT 'engineering' AS department, 5000.0 AS budget_usd
        UNION ALL SELECT 'data-science', 2000.0
        UNION ALL SELECT 'product', 1500.0
    ),
    actual AS (
        SELECT department, sum(total_cost_usd) AS actual_spend
        FROM holysheep_audit.dept_daily_mv
        WHERE day >= DATE_TRUNC('month', now())
        GROUP BY department
    )
SELECT
    b.department,
    b.budget_usd,
    a.actual_spend,
    b.budget_usd - a.actual_spend AS remaining_usd,
    round(a.actual_spend / b.budget_usd * 100, 1) AS usage_pct,
    CASE 
        WHEN a.actual_spend > b.budget_usd THEN '🔴 OVER BUDGET'
        WHEN a.actual_spend > b.budget_usd * 0.8 THEN '🟡 WARNING'
        ELSE '🟢 OK'
    END AS status
FROM budget_table b
LEFT JOIN actual a ON b.department = a.department
FORMAT PrettyCompact;

-- 5. Anomaly detection: Spike detection
SELECT
    department,
    project,
    day,
    total_cost_usd,
    lagInFrame(total_cost_usd) AS prev_day_cost,
    total_cost_usd - lagInFrame(total_cost_usd) AS cost_delta,
    round((total_cost_usd - lagInFrame(total_cost_usd)) / lagInFrame(total_cost_usd) * 100, 1) AS pct_change
FROM holysheep_audit.dept_daily_mv
WHERE day >= now() - INTERVAL 7 DAY
QUALIFY pct_change > 50  -- Flag increases > 50% day-over-day
ORDER BY pct_change DESC
FORMAT PrettyCompact;

3. Prometheus Metrics Export

"""
HolySheep Token Usage - Prometheus Metrics Exporter
Integrate với Grafana dashboard
"""
from fastapi import FastAPI, Response
from prometheus_client import (
    Counter, Histogram, Gauge, generate_latest, CONTENT_TYPE_LATEST
)
import asyncio
from datetime import datetime

Define Prometheus metrics

TOKEN_USAGE = Counter( 'holysheep_token_usage_total', 'Total tokens used', ['department', 'project', 'model', 'token_type'] ) COST_USD = Counter( 'holysheep_cost_usd_total', 'Total cost in USD', ['department', 'project', 'model'] ) REQUEST_LATENCY = Histogram( 'holysheep_request_latency_seconds', 'Request latency in seconds', ['department', 'project', 'model'], buckets=[0.05, 0.1, 0.25, 0.5, 1.0, 2.5, 5.0, 10.0] ) MONTHLY_BUDGET_USED = Gauge( 'holysheep_monthly_budget_used_usd', 'Monthly budget used by department', ['department'] ) MONTHLY_BUDGET_LIMIT = Gauge( 'holysheep_monthly_budget_limit_usd', 'Monthly budget limit by department', ['department'] )

FastAPI app for metrics endpoint

app = FastAPI(title="HolySheep Audit Metrics") @app.get("/metrics") async def metrics(): """Prometheus /metrics endpoint""" return Response( content=generate_latest(), media_type=CONTENT_TYPE_LATEST )

Usage in your audit client

async def record_metrics(record: UsageRecord): """Record usage to Prometheus""" TOKEN_USAGE.labels( department=record.department, project=record.project, model=record.model, token_type='input' ).inc(record.input_tokens) TOKEN_USAGE.labels( department=record.department, project=record.project, model=record.model, token_type='output' ).inc(record.output_tokens) COST_USD.labels( department=record.department, project=record.project, model=record.model ).inc(record.cost_usd) REQUEST_LATENCY.labels( department=record.department, project=record.project, model=record.model ).observe(record.latency_ms / 1000) # Convert to seconds

Grafana Dashboard JSON (import vào Grafana)

GRAFANA_DASHBOARD = """ { "dashboard": { "title": "HolySheep AI - Token Usage & Cost", "panels": [ { "title": "Monthly Spend by Department", "type": "piechart", "targets": [ { "expr": "sum(increase(holysheep_cost_usd_total[30d])) by (department)", "legendFormat": "{{department}}" } ] }, { "title": "Token Usage Trend", "type": "timeseries", "targets": [ { "expr": "sum(rate(holysheep_token_usage_total[5m])) by (department)", "legendFormat": "{{department}}" } ] }, { "title": "P95 Latency by Model", "type": "timeseries", "targets": [ { "expr": "histogram_quantile(0.95, rate(holysheep_request_latency_seconds_bucket[5m])) by (model)", "legendFormat": "p95 - {{model}}" } ] }, { "title": "Budget Utilization %", "type": "gauge", "targets": [ { "expr": "holysheep_monthly_budget_used_usd / holysheep_monthly_budget_limit_usd * 100", "legendFormat": "{{department}}" } ] } ] } } """ if __name__ == "__main__": import uvicorn uvicorn.run(app, host="0.0.0.0", port=9090)

Bảng so sánh chi phí - HolySheep vs Direct Providers

Model Giá Direct (USD/1M tokens) Giá HolySheep (USD/1M tokens) Tiết kiệm Độ trễ P50 Độ trễ P99
GPT-4.1 $60.00 $8.00 86.7% <45ms <120ms
Claude Sonnet 4.5 $90.00 $15.00 83.3% <48ms <130ms
Gemini 2.5 Flash $15.00 $2.50 83.3% <35ms <80ms
DeepSeek V3.2 $2.80 $0

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