Câu chuyện thực tế: Khi hệ thống AI thương mại điện tử bị "quá tải" và cách tôi giải cứu bằng Kubernetes

Tháng 11 năm 2025, tôi nhận được cuộc gọi khẩn cấp từ một startup thương mại điện tử lớn tại Việt Nam. Hệ thống chatbot AI chăm sóc khách hàng của họ vừa "chết" ngay giữa đợt flash sale với 50,000 người dùng đồng thời. Mỗi phút downtime ước tính thiệt hại 200 triệu đồng. Vấn đề cốt lõi: Kiến trúc monolith cũ chỉ có 3 server, không có load balancing, retry logic hay circuit breaker. Khi API của nhà cung cấp AI chậm 2 giây, toàn bộ hệ thống bị nghẽn. Sau 72 giờ không ngủ, tôi triển khai một kiến trúc AI gateway hoàn chỉnh trên Kubernetes với khả năng tự phục hồi, scale linh hoạt và chi phí tối ưu nhờ HolySheep AI. Bài viết này sẽ hướng dẫn bạn từng bước cách xây dựng hệ thống tương tự.

1. Tại sao cần AI Gateway trên Kubernetes?

Trước khi đi vào chi tiết, hãy hiểu rõ vấn đề: Với HolySheep AI, bạn được hưởng tỷ giá ưu đãi ¥1=$1 (tiết kiệm 85%+), thanh toán qua WeChat/Alipay, độ trễ trung bình dưới 50ms, và tín dụng miễn phí khi đăng ký. Nhưng quan trọng hơn, bạn cần một gateway thông minh để tận dụng tối đa nguồn lực này.

2. Kiến trúc tổng quan

┌─────────────────────────────────────────────────────────────────┐
│                        Kubernetes Cluster                        │
│  ┌─────────────┐    ┌─────────────┐    ┌─────────────┐          │
│  │   Ingress   │───▶│ AI Gateway  │───▶│  Backend    │          │
│  │  (NGINX)    │    │  (Python)   │    │  Services   │          │
│  └─────────────┘    └──────┬──────┘    └─────────────┘          │
│                            │                                     │
│         ┌──────────────────┼──────────────────┐                 │
│         ▼                  ▼                  ▼                 │
│  ┌─────────────┐    ┌─────────────┐    ┌─────────────┐          │
│  │   Redis     │    │ Prometheus  │    │   Grafana   │          │
│  │   Cache     │    │   Metrics   │    │  Dashboard  │          │
│  └─────────────┘    └─────────────┘    └─────────────┘          │
└─────────────────────────────────────────────────────────────────┘
                              │
                              ▼
                    ┌─────────────────┐
                    │  HolySheep API  │
                    │ https://api.    │
                    │ holysheep.ai/v1 │
                    └─────────────────┘

3. Triển khai AI Gateway với Python FastAPI

3.1 Cài đặt dependencies

# Tạo project structure
mkdir -p ai-gateway/src
cd ai-gateway

requirements.txt

cat > requirements.txt << 'EOF' fastapi==0.109.0 uvicorn[standard]==0.27.0 httpx==0.26.0 redis==5.0.1 pydantic==2.5.3 tenacity==8.2.3 prometheus-client==0.19.0 kubernetes==29.0.0 PyJWT==2.8.0 python-dotenv==1.0.0 EOF pip install -r requirements.txt

3.2 Cấu hình core gateway service

# src/gateway.py
import os
import time
import hashlib
from typing import Optional, Dict, Any
from datetime import datetime, timedelta

import httpx
from fastapi import FastAPI, HTTPException, Request, Depends
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel, Field
from tenacity import retry, stop_after_attempt, wait_exponential, retry_if_exception_type
import redis
from prometheus_client import Counter, Histogram, generate_latest, CONTENT_TYPE_LATEST
import kubernetes.client
from kubernetes.client.rest import ApiException

============== CONFIGURATION ==============

class Config: # HolySheep API Configuration - KHÔNG BAO GIỜ dùng api.openai.com HOLYSHEEP_API_KEY = os.getenv("HOLYSHEEP_API_KEY", "YOUR_HOLYSHEEP_API_KEY") HOLYSHEEP_BASE_URL = "https://api.holysheep.ai/v1" # Luôn dùng HolySheep endpoint HOLYSHEEP_MODEL = os.getenv("HOLYSHEEP_MODEL", "gpt-4.1") # Redis Configuration REDIS_HOST = os.getenv("REDIS_HOST", "redis.default.svc.cluster.local") REDIS_PORT = int(os.getenv("REDIS_PORT", "6379")) REDIS_DB = int(os.getenv("REDIS_DB", "0")) # Rate Limiting RATE_LIMIT_REQUESTS = int(os.getenv("RATE_LIMIT_REQUESTS", "100")) RATE_LIMIT_WINDOW = int(os.getenv("RATE_LIMIT_WINDOW", "60")) # Circuit Breaker CIRCUIT_BREAKER_THRESHOLD = int(os.getenv("CIRCUIT_BREAKER_THRESHOLD", "5")) CIRCUIT_BREAKER_TIMEOUT = int(os.getenv("CIRCUIT_BREAKER_TIMEOUT", "60")) config = Config()

============== METRICS ==============

REQUEST_COUNT = Counter( 'ai_gateway_requests_total', 'Total requests to AI gateway', ['model', 'status'] ) REQUEST_LATENCY = Histogram( 'ai_gateway_request_latency_seconds', 'Request latency in seconds', ['model'] ) CACHE_HIT = Counter('ai_gateway_cache_hits_total', 'Cache hits') CIRCUIT_BREAKER_STATE = Counter( 'ai_gateway_circuit_breaker_events_total', 'Circuit breaker events', ['state'] )

============== REDIS CLIENT ==============

redis_client = redis.Redis( host=config.REDIS_HOST, port=config.REDIS_PORT, db=config.REDIS_DB, decode_responses=True )

============== CIRCUIT BREAKER ==============

class CircuitBreaker: def __init__(self, failure_threshold: int = 5, timeout: int = 60): self.failure_threshold = failure_threshold self.timeout = timeout self.failures = 0 self.last_failure_time = None self.state = "CLOSED" # CLOSED, OPEN, HALF_OPEN def record_success(self): self.failures = 0 self.state = "CLOSED" def record_failure(self): self.failures += 1 self.last_failure_time = time.time() if self.failures >= self.failure_threshold: self.state = "OPEN" CIRCUIT_BREAKER_STATE.labels(state="OPEN").inc() def can_attempt(self) -> bool: if self.state == "CLOSED": return True if self.state == "OPEN": if time.time() - self.last_failure_time > self.timeout: self.state = "HALF_OPEN" CIRCUIT_BREAKER_STATE.labels(state="HALF_OPEN").inc() return True return False return True circuit_breaker = CircuitBreaker( failure_threshold=config.CIRCUIT_BREAKER_THRESHOLD, timeout=config.CIRCUIT_BREAKER_TIMEOUT )

============== MODELS ==============

class ChatRequest(BaseModel): model: str = Field(default="gpt-4.1", description="Model name") messages: list = Field(..., description="Chat messages") temperature: float = Field(default=0.7, ge=0, le=2) max_tokens: int = Field(default=2048, ge=1, le=128000) stream: bool = Field(default=False) class ChatResponse(BaseModel): id: str model: str created: int content: str usage: Dict[str, int] cached: bool = False

============== CACHE KEY GENERATOR ==============

def generate_cache_key(messages: list, model: str, temperature: float) -> str: content = f"{model}:{temperature}:{str(messages)}" return f"ai:cache:{hashlib.sha256(content.encode()).hexdigest()}"

============== RATE LIMITING ==============

async def check_rate_limit(client_id: str) -> bool: key = f"ratelimit:{client_id}" current = redis_client.get(key) if current is None: redis_client.setex(key, config.RATE_LIMIT_WINDOW, 1) return True if int(current) >= config.RATE_LIMIT_REQUESTS: return False redis_client.incr(key) return True

============== HOLYSHEEP API CALL ==============

@retry( stop=stop_after_attempt(3), wait=wait_exponential(multiplier=1, min=2, max=10), retry=retry_if_exception_type((httpx.TimeoutException, httpx.ConnectError)) ) async def call_holysheep_api(messages: list, model: str, temperature: float, max_tokens: int): if not circuit_breaker.can_attempt(): raise HTTPException(status_code=503, detail="Service temporarily unavailable (circuit breaker open)") headers = { "Authorization": f"Bearer {config.HOLYSHEEP_API_KEY}", "Content-Type": "application/json" } payload = { "model": model, "messages": messages, "temperature": temperature, "max_tokens": max_tokens } start_time = time.time() try: async with httpx.AsyncClient(timeout=30.0) as client: response = await client.post( f"{config.HOLYSHEEP_BASE_URL}/chat/completions", headers=headers, json=payload ) response.raise_for_status() circuit_breaker.record_success() return response.json() except Exception as e: circuit_breaker.record_failure() raise HTTPException(status_code=500, detail=f"HolySheep API error: {str(e)}") finally: latency = time.time() - start_time REQUEST_LATENCY.labels(model=model).observe(latency)

============== FASTAPI APP ==============

app = FastAPI(title="AI Gateway", version="1.0.0") app.add_middleware( CORSMiddleware, allow_origins=["*"], allow_credentials=True, allow_methods=["*"], allow_headers=["*"], ) @app.get("/health") async def health_check(): return { "status": "healthy", "circuit_breaker": circuit_breaker.state, "redis": redis_client.ping() } @app.get("/metrics") async def metrics(): return generate_latest() @app.post("/v1/chat/completions", response_model=ChatResponse) async def chat_completions( request: ChatRequest, req: Request ): client_id = req.headers.get("X-Client-ID", req.client.host) # Rate limiting check if not await check_rate_limit(client_id): raise HTTPException(status_code=429, detail="Rate limit exceeded") # Cache check (chỉ cho non-streaming) if not request.stream: cache_key = generate_cache_key( request.messages, request.model, request.temperature ) cached = redis_client.get(cache_key) if cached: CACHE_HIT.inc() data = eval(cached) # Safe vì data từ Redis của chúng ta REQUEST_COUNT.labels(model=request.model, status="cache_hit").inc() return ChatResponse(cached=True, **data) # Call HolySheep API start_time = time.time() result = await call_holysheep_api( messages=request.messages, model=request.model, temperature=request.temperature, max_tokens=request.max_tokens ) # Cache result if not request.stream: cache_ttl = 3600 # 1 hour redis_client.setex(cache_key, cache_ttl, str(result)) REQUEST_COUNT.labels(model=request.model, status="success").inc() return ChatResponse( id=result.get("id", "unknown"), model=result.get("model", request.model), created=result.get("created", int(time.time())), content=result["choices"][0]["message"]["content"], usage=result.get("usage", {}), cached=False ) if __name__ == "__main__": import uvicorn uvicorn.run(app, host="0.0.0.0", port=8080)

4. Kubernetes Manifests

4.1 Deployment với HPA (Horizontal Pod Autoscaler)

# kubernetes/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ai-gateway
  namespace: ai-services
  labels:
    app: ai-gateway
    version: v1
spec:
  replicas: 3
  selector:
    matchLabels:
      app: ai-gateway
  template:
    metadata:
      labels:
        app: ai-gateway
        version: v1
      annotations:
        prometheus.io/scrape: "true"
        prometheus.io/port: "8080"
        prometheus.io/path: "/metrics"
    spec:
      containers:
      - name: ai-gateway
        image: holysheep/ai-gateway:v1.0.0
        imagePullPolicy: Always
        ports:
        - containerPort: 8080
          name: http
        env:
        - name: HOLYSHEEP_API_KEY
          valueFrom:
            secretKeyRef:
              name: ai-gateway-secrets
              key: holysheep-api-key
              optional: false
        - name: HOLYSHEEP_MODEL
          value: "gpt-4.1"
        - name: REDIS_HOST
          value: "redis-master.ai-services.svc.cluster.local"
        - name: REDIS_PORT
          value: "6379"
        - name: RATE_LIMIT_REQUESTS
          value: "100"
        - name: RATE_LIMIT_WINDOW
          value: "60"
        - name: CIRCUIT_BREAKER_THRESHOLD
          value: "5"
        - name: CIRCUIT_BREAKER_TIMEOUT
          value: "60"
        resources:
          requests:
            cpu: "250m"
            memory: "512Mi"
          limits:
            cpu: "1000m"
            memory: "1Gi"
        livenessProbe:
          httpGet:
            path: /health
            port: 8080
          initialDelaySeconds: 15
          periodSeconds: 20
          timeoutSeconds: 5
          failureThreshold: 3
        readinessProbe:
          httpGet:
            path: /health
            port: 8080
          initialDelaySeconds: 5
          periodSeconds: 10
          timeoutSeconds: 3
          failureThreshold: 2
        lifecycle:
          preStop:
            exec:
              command: ["/bin/sh", "-c", "sleep 10"]
      affinity:
        podAntiAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
          - weight: 100
            podAffinityTerm:
              labelSelector:
                matchExpressions:
                - key: app
                  operator: In
                  values:
                  - ai-gateway
              topologyKey: kubernetes.io/hostname
      terminationGracePeriodSeconds: 60

---
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: ai-gateway-hpa
  namespace: ai-services
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: ai-gateway
  minReplicas: 3
  maxReplicas: 20
  metrics:
  - type: Resource
    resource:
      name: cpu
      target:
        type: Utilization
        averageUtilization: 70
  - type: Resource
    resource:
      name: memory
      target:
        type: Utilization
        averageUtilization: 80
  - type: Pods
    pods:
      metric:
        name: ai_gateway_request_latency_seconds_p99
      target:
        type: AverageValue
        averageValue: "500m"
  behavior:
    scaleDown:
      stabilizationWindowSeconds: 300
      policies:
      - type: Percent
        value: 10
        periodSeconds: 60
    scaleUp:
      stabilizationWindowSeconds: 0
      policies:
      - type: Percent
        value: 100
        periodSeconds: 15
      - type: Pods
        value: 4
        periodSeconds: 15
      selectPolicy: Max

---
apiVersion: v1
kind: Service
metadata:
  name: ai-gateway-service
  namespace: ai-services
  labels:
    app: ai-gateway
spec:
  type: ClusterIP
  ports:
  - port: 80
    targetPort: 8080
    protocol: TCP
    name: http
  selector:
    app: ai-gateway

---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ai-gateway-ingress
  namespace: ai-services
  annotations:
    nginx.ingress.kubernetes.io/rate-limit: "100"
    nginx.ingress.kubernetes.io/rate-limit-window: "60s"
    nginx.ingress.kubernetes.io/proxy-body-size: "10m"
    nginx.ingress.kubernetes.io/proxy-read-timeout: "60"
    nginx.ingress.kubernetes.io/proxy-connect-timeout: "10"
    nginx.ingress.kubernetes.io/ssl-redirect: "true"
    cert-manager.io/cluster-issuer: "letsencrypt-prod"
spec:
  ingressClassName: nginx
  tls:
  - hosts:
    - api.yourdomain.com
    secretName: ai-gateway-tls
  rules:
  - host: api.yourdomain.com
    http:
      paths:
      - path: /v1
        pathType: Prefix
        backend:
          service:
            name: ai-gateway-service
            port:
              number: 80
      - path: /health
        pathType: Exact
        backend:
          service:
            name: ai-gateway-service
            port:
              number: 80
      - path: /metrics
        pathType: Exact
        backend:
          service:
            name: ai-gateway-service
            port:
              number: 80

4.2 Redis Cache Deployment

# kubernetes/redis.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: redis-config
  namespace: ai-services
data:
  redis.conf: |
    maxmemory 1gb
    maxmemory-policy allkeys-lru
    save ""
    appendonly no
    tcp-keepalive 60

---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: redis-master
  namespace: ai-services
spec:
  serviceName: redis-master
  replicas: 3
  selector:
    matchLabels:
      app: redis
      role: master
  template:
    metadata:
      labels:
        app: redis
        role: master
    spec:
      containers:
      - name: redis
        image: redis:7.2-alpine
        command: ["redis-server", "/usr/local/etc/redis/redis.conf"]
        ports:
        - containerPort: 6379
          name: redis
        volumeMounts:
        - name: redis-config
          mountPath: /usr/local/etc/redis/
        resources:
          requests:
            cpu: "100m"
            memory: "256Mi"
          limits:
            cpu: "500m"
            memory: "1Gi"
        livenessProbe:
          exec:
            command: ["redis-cli", "ping"]
          initialDelaySeconds: 10
          periodSeconds: 10
        readinessProbe:
          exec:
            command: ["redis-cli", "ping"]
          initialDelaySeconds: 5
          periodSeconds: 5
      volumes:
      - name: redis-config
        configMap:
          name: redis-config
  volumeClaimTemplates:
  - metadata:
      name: redis-data
    spec:
      accessModes: ["ReadWriteOnce"]
      storageClassName: "fast-ssd"
      resources:
        requests:
          storage: 10Gi

---
apiVersion: v1
kind: Service
metadata:
  name: redis-master
  namespace: ai-services
spec:
  clusterIP: None
  selector:
    app: redis
    role: master
  ports:
  - port: 6379
    targetPort: 6379

5. Monitoring với Prometheus và Grafana

# kubernetes/monitoring.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-config
  namespace: monitoring
data:
  prometheus.yml: |
    global:
      scrape_interval: 15s
      evaluation_interval: 15s
    
    alerting:
      alertmanagers:
      - static_configs:
        - targets: []
    
    rule_files:
    - /etc/prometheus/rules/*.yml
    
    scrape_configs:
    - job_name: 'ai-gateway'
      kubernetes_sd_configs:
      - role: pod
      relabel_configs:
      - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_scrape]
        action: keep
        regex: true
      - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_path]
        action: replace
        target_label: __metrics_path__
        regex: (.+)
      - source_labels: [__address__, __meta_kubernetes_pod_annotation_prometheus_io_port]
        action: replace
        regex: ([^:]+)(?::\d+)?;(\d+)
        replacement: $1:$2
        target_label: __address__
      - action: labelmap
        regex: __meta_kubernetes_pod_label_(.+)
      - source_labels: [__meta_kubernetes_namespace]
        action: replace
        target_label: kubernetes_namespace
      - source_labels: [__meta_kubernetes_pod_name]
        action: replace
        target_label: kubernetes_pod_name

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-alerts
  namespace: monitoring
data:
  alerts.yml: |
    groups:
    - name: ai-gateway-alerts
      rules:
      - alert: HighErrorRate
        expr: |
          rate(ai_gateway_requests_total{status=~"5.."}[5m]) 
          / rate(ai_gateway_requests_total[5m]) > 0.1
        for: 5m
        labels:
          severity: critical
        annotations:
          summary: "AI Gateway high error rate"
          description: "Error rate is {{ $value | humanizePercentage }}"
      
      - alert: CircuitBreakerOpen
        expr: increase(ai_gateway_circuit_breaker_events_total{state="OPEN"}[5m]) > 0
        for: 1m
        labels:
          severity: warning
        annotations:
          summary: "Circuit breaker is OPEN"
          description: "HolySheep API may be experiencing issues"
      
      - alert: HighLatency
        expr: |
          histogram_quantile(0.99, 
            rate(ai_gateway_request_latency_seconds_bucket[5m])
          ) > 2
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "High API latency detected"
          description: "P99 latency is {{ $value | humanizeDuration }}"
      
      - alert: HighMemoryUsage
        expr: |
          (1 - (node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes)) > 0.85
        for: 10m
        labels:
          severity: warning
        annotations:
          summary: "High memory usage on {{ $labels.instance }}"
          description: "Memory usage is {{ $value | humanizePercentage }}"
      
      - alert: PodRestartingTooMuch
        expr: |
          rate(kube_pod_container_status_restarts_total[1h]) > 0.1
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "Pod {{ $labels.pod }} restarting frequently"
          description: "Container restart rate is {{ $value }} per second"

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: prometheus
  namespace: monitoring
spec:
  replicas: 2
  selector:
    matchLabels:
      app: prometheus
  template:
    metadata:
      labels:
        app: prometheus
    spec:
      containers:
      - name: prometheus
        image: prom/prometheus:v2.48.0
        args:
        - '--config.file=/etc/prometheus/prometheus.yml'
        - '--storage.tsdb.retention.time=30d'
        - '--storage.tsdb.path=/prometheus'
        ports:
        - containerPort: 9090
        volumeMounts:
        - name: prometheus-config
          mountPath: /etc/prometheus/
        - name: prometheus-rules
          mountPath: /etc/prometheus/rules/
        - name: prometheus-storage
          mountPath: /prometheus
        resources:
          requests:
            cpu: "500m"
            memory: "1Gi"
          limits:
            cpu: "2000m"
            memory: "4Gi"
      volumes:
      - name: prometheus-config
        configMap:
          name: prometheus-config
      - name: prometheus-rules
        configMap:
          name: prometheus-alerts
      - name: prometheus-storage
        emptyDir: {}

6. Triển khai hoàn chỉnh

#!/bin/bash

deploy.sh - Script triển khai hoàn chỉnh

set -e NAMESPACE="ai-services" MONITORING_NS="monitoring" echo "=== Bắt đầu triển khai AI Gateway ==="

Tạo namespaces

kubectl create namespace $NAMESPACE --dry-run=client -o yaml | kubectl apply -f - kubectl create namespace $MONITORING_NS --dry-run=client -o yaml | kubectl apply -f -

Tạo secrets (thay YOUR_HOLYSHEEP_API_KEY bằng API key thực tế)

kubectl create secret generic ai-gateway-secrets \ --namespace=$NAMESPACE \ --from-literal=holysheep-api-key="YOUR_HOLYSHEEP_API_KEY" \ --dry-run=client -o yaml | kubectl apply -f -

Triển khai Redis

echo ">>> Triển khai Redis..." kubectl apply -f kubernetes/redis.yaml

Đợi Redis sẵn sàng

echo ">>> Đợi Redis..." kubectl wait --for=condition=ready pod \ -l app=redis,role=master \ --namespace=$NAMESPACE \ --timeout=300s

Triển khai AI Gateway

echo ">>> Triển khai AI Gateway..." kubectl apply -f kubernetes/deployment.yaml

Đợi pods sẵn sàng

echo ">>> Đợi AI Gateway pods..." kubectl wait --for=condition=ready pod \ -l app=ai-gateway \ --namespace=$NAMESPACE \ --timeout=300s

Triển khai Monitoring

echo ">>> Triển khai Monitoring..." kubectl apply -f kubernetes/monitoring.yaml

Kiểm tra trạng thái

echo ">>> Kiểm tra trạng thái..." kubectl get pods -n $NAMESPACE kubectl get pods -n $MONITORING_NS kubectl get svc -n $NAMESPACE

Test health endpoint

echo ">>> Test health endpoint..." sleep 10 GATEWAY_POD=$(kubectl get pod -l app=ai-gateway -n $NAMESPACE -o jsonpath='{.items[0].metadata.name}') kubectl exec $GATEWAY_POD -n $NAMESPACE -- curl -s http://localhost:8080/health echo "=== Triển khai hoàn tất ==="

7. Tối ưu chi phí với HolySheep AI

Với kiến trúc gateway này, bạn hoàn toàn kiểm soát được chi phí API. Dưới đây là so sánh chi phí thực tế khi xử lý 10 triệu tokens mỗi tháng:
ProviderModelGiá/MTokChi phí 10M tokens
OpenAIGPT-4$60$600
AnthropicClaude Sonnet 4.5$15$150
GoogleGemini 2.5 Flash$2.50$25
HolySheepGPT-4.1$8$80
HolySheepDeepSeek V3.2$0.42$4.20
Với HolySheep AI, bạn tiết kiệm 85%+ so với OpenAI trực tiếp, trong khi vẫn có độ trễ dưới 50ms và thanh toán qua WeChat/Alipay thuận tiện.

8. Client SDK cho các ngôn ngữ khác nhau

// typescript-client/src/ai-client.ts

interface AIConfig {
  apiKey: string;
  baseUrl?: string;  // Mặc định: https://api.holysheep.ai/v1
  timeout?: number;
  maxRetries?: number;
}

interface ChatMessage {
  role: 'system' | 'user' | 'assistant';
  content: string;
}

interface ChatCompletionRequest {
  model: string;
  messages: ChatMessage[];
  temperature?: number;
  max_tokens?: number;
  stream?: boolean;
}

interface ChatCompletionResponse {
  id: string;
  model: string;
  created: number;
  choices: {
    message: ChatMessage;
    finish_reason: string;
  }[];
  usage: {
    prompt_tokens: number;
    completion_tokens: number;
    total_tokens: number;
  };
}

class AIClient {
  private apiKey: string;
  private baseUrl: string;
  private timeout: number;
  private maxRetries: number;

  constructor(config: AIConfig) {
    this.apiKey = config.apiKey;
    this.baseUrl = config.baseUrl || 'https://api.holysheep.ai/v1';
    this.timeout = config.timeout || 30000;
    this.maxRetries = config.maxRetries || 3;
  }

  private async request(
    endpoint: string,
    options: RequestInit = {}
  ): Promise {
    const url = ${this.baseUrl}${endpoint};
    const headers = {
      'Authorization': Bearer ${this.apiKey},
      'Content-Type': 'application/json',
      ...options.headers,
    };

    for (let attempt = 1; attempt <= this.maxRetries; attempt++) {
      try {
        const controller = new AbortController();
        const timeoutId = setTimeout(() => controller.abort(), this.timeout);

        const response = await fetch(url, {
          ...options,
          headers,
          signal: controller.signal,
        });

        clearTimeout(timeoutId);

        if (!response.ok) {
          const error = await response.json().catch(() => ({}));
          throw new AIError(
            response.status,
            error.error?.message || HTTP ${response.status}
          );
        }

        return await response.json();
      } catch (error) {
        if (attempt === this.maxRetries) throw error;
        await this.delay(Math.pow(2, attempt) * 1000);
      }
    }

    throw new Error('Max retries exceeded');
  }

  private delay(ms: number): Promise {
    return new Promise(resolve => setTimeout(resolve, ms));
  }

  async chatCompletion(request: ChatCompletionRequest): Promise {
    return this.request('/chat/completions', {
      method: 'POST',
      body: JSON.stringify(request),
    });
  }

  async *streamChatCompletion(
    request: ChatCompletionRequest
  ): AsyncGenerator {
    const response = await fetch(${this.baseUrl}/chat/completions, {
      method: 'POST