概念定义

Anthropic SDK是Anthropic公司官方提供的开发工具包,支持Claude系列模型的完整API功能,包括最新的Claude 4、推理模式、工具调用、流式输出等高级特性,为开发者提供AI驱动的编程和应用开发能力。

详细解释

Anthropic SDK在2025年发布了革命性的Claude Code SDK,将Claude的能力从聊天界面扩展到完整的开发工具生态系统。新版SDK不仅支持传统的文本生成,更集成了MCP(模型上下文协议)服务器、企业级安全控制、长时间缓存等前沿功能。 2025年版本的重大突破包括支持Claude Opus 4和Sonnet 4等最新模型,引入thinking模式实现透明推理过程,以及1小时的扩展缓存功能。SDK的设计注重企业级需求,提供API访问管理、工具集成定制、AI驱动代码变更审计等功能,满足大型组织严格的开发标准。

核心SDK架构

1. 多语言客户端支持

Python SDK实现
import anthropic
import asyncio
from typing import List, Dict, Any, AsyncGenerator
import json

class AnthropicClient:
    """Anthropic Claude客户端"""
    
    def __init__(self, api_key: str = None):
        self.client = anthropic.Anthropic(api_key=api_key)
        self.async_client = anthropic.AsyncAnthropic(api_key=api_key)
    
    def create_message(self, 
                      messages: List[Dict[str, str]], 
                      model: str = "claude-3-5-sonnet-20241022",
                      max_tokens: int = 4000,
                      temperature: float = 0.0,
                      system: str = None) -> Dict[str, Any]:
        """创建消息"""
        try:
            response = self.client.messages.create(
                model=model,
                max_tokens=max_tokens,
                temperature=temperature,
                system=system,
                messages=messages
            )
            
            return {
                "content": response.content[0].text,
                "usage": {
                    "input_tokens": response.usage.input_tokens,
                    "output_tokens": response.usage.output_tokens,
                    "cache_creation_input_tokens": getattr(response.usage, 'cache_creation_input_tokens', 0),
                    "cache_read_input_tokens": getattr(response.usage, 'cache_read_input_tokens', 0)
                },
                "model": response.model,
                "stop_reason": response.stop_reason,
                "stop_sequence": response.stop_sequence
            }
        
        except anthropic.RateLimitError as e:
            return {"error": "rate_limit", "message": str(e)}
        except anthropic.AuthenticationError as e:
            return {"error": "auth", "message": str(e)}
        except Exception as e:
            return {"error": "general", "message": str(e)}
    
    async def async_create_message(self, 
                                  messages: List[Dict[str, str]], 
                                  model: str = "claude-3-5-sonnet-20241022",
                                  **kwargs) -> Dict[str, Any]:
        """异步创建消息"""
        try:
            response = await self.async_client.messages.create(
                model=model,
                messages=messages,
                **kwargs
            )
            
            return {
                "content": response.content[0].text,
                "usage": response.usage.__dict__,
                "model": response.model
            }
        
        except Exception as e:
            return {"error": str(e)}
    
    def stream_message(self, 
                      messages: List[Dict[str, str]], 
                      model: str = "claude-3-5-sonnet-20241022",
                      **kwargs):
        """流式消息生成"""
        try:
            with self.client.messages.stream(
                model=model,
                messages=messages,
                **kwargs
            ) as stream:
                for text in stream.text_stream:
                    yield text
        
        except Exception as e:
            yield f"Error: {str(e)}"
    
    async def async_stream_message(self, 
                                  messages: List[Dict[str, str]], 
                                  model: str = "claude-3-5-sonnet-20241022",
                                  **kwargs) -> AsyncGenerator[str, None]:
        """异步流式消息生成"""
        try:
            async with self.async_client.messages.stream(
                model=model,
                messages=messages,
                **kwargs
            ) as stream:
                async for text in stream.text_stream:
                    yield text
        
        except Exception as e:
            yield f"Error: {str(e)}"

# 使用示例
client = AnthropicClient()

# 同步调用
response = client.create_message([
    {"role": "user", "content": "解释量子计算的基本原理"}
])

# 流式输出
print("流式输出:")
for chunk in client.stream_message([
    {"role": "user", "content": "写一个Python排序算法"}
]):
    print(chunk, end='', flush=True)

# 异步调用
async def async_example():
    response = await client.async_create_message([
        {"role": "user", "content": "介绍机器学习的发展历程"}
    ])
    return response

# asyncio.run(async_example())
JavaScript/TypeScript SDK
import Anthropic from '@anthropic-ai/sdk';

class AnthropicJSClient {
  constructor(apiKey) {
    this.client = new Anthropic({
      apiKey: apiKey,
      // 2025年新增配置选项
      timeout: 600000, // 10分钟超时
      maxRetries: 3
    });
  }

  async createMessage(messages, options = {}) {
    try {
      const response = await this.client.messages.create({
        model: options.model || 'claude-3-5-sonnet-20241022',
        max_tokens: options.maxTokens || 4000,
        temperature: options.temperature || 0,
        system: options.system,
        messages: messages,
        // 2025年新增功能
        extra_headers: options.extraHeaders || {},
        tools: options.tools || undefined
      });

      return {
        content: response.content[0].text,
        usage: response.usage,
        model: response.model,
        stopReason: response.stop_reason
      };

    } catch (error) {
      if (error instanceof Anthropic.APIError) {
        return {
          error: 'api_error',
          message: error.message,
          status: error.status
        };
      }
      throw error;
    }
  }

  async streamMessage(messages, options = {}, onChunk) {
    const stream = await this.client.messages.create({
      model: options.model || 'claude-3-5-sonnet-20241022',
      max_tokens: options.maxTokens || 4000,
      messages: messages,
      stream: true
    });

    let fullResponse = '';
    
    for await (const messageStreamEvent of stream) {
      if (messageStreamEvent.type === 'content_block_delta') {
        const chunk = messageStreamEvent.delta.text;
        if (chunk) {
          fullResponse += chunk;
          if (onChunk) {
            onChunk(chunk, fullResponse);
          }
        }
      }
    }

    return fullResponse;
  }

  // 2025年新增:推理模式支持
  async createReasoningMessage(messages, thinkingBudget = 20000) {
    return await this.client.messages.create({
      model: 'claude-3-5-sonnet-20241022',
      max_tokens: 4000,
      messages: messages,
      // 启用推理模式
      extra_headers: {
        'anthropic-beta': 'thinking-2024-12-05'
      },
      thinking_budget: thinkingBudget
    });
  }

  // 2025年新增:扩展缓存支持
  async createCachedMessage(messages, cacheControlBlocks) {
    return await this.client.messages.create({
      model: 'claude-3-5-sonnet-20241022',
      max_tokens: 4000,
      messages: messages,
      // 启用1小时扩展缓存
      extra_headers: {
        'anthropic-beta': 'extended-cache-ttl-2025-04-11'
      },
      cache_control: cacheControlBlocks
    });
  }
}

// 使用示例
const client = new AnthropicJSClient(process.env.ANTHROPIC_API_KEY);

// 标准调用
const response = await client.createMessage([
  { role: 'user', content: 'Hello Claude!' }
]);

// 流式调用
await client.streamMessage([
  { role: 'user', content: '写一篇关于AI的文章' }
], {}, (chunk, fullResponse) => {
  process.stdout.write(chunk);
});

// 推理模式调用
const reasoningResponse = await client.createReasoningMessage([
  { role: 'user', content: '解决这个复杂的数学问题:...' }
], 30000);

2. Claude Code SDK集成

代码助手功能
# Claude Code SDK - 2025年新增
import subprocess
import json
from pathlib import Path

class ClaudeCodeSDK:
    """Claude Code SDK集成"""
    
    def __init__(self, api_key: str):
        self.api_key = api_key
        self.setup_claude_code()
    
    def setup_claude_code(self):
        """设置Claude Code SDK环境"""
        # 安装Claude Code SDK
        try:
            subprocess.run(['npm', 'install', '-g', '@anthropic-ai/claude-code'], 
                         check=True, capture_output=True)
            print("Claude Code SDK已安装")
        except subprocess.CalledProcessError as e:
            print(f"安装失败: {e}")
    
    async def query_with_tools(self, prompt: str, max_turns: int = 3, tools: List[str] = None):
        """使用工具进行查询"""
        from anthropic_ai_claude_code import query, SDKMessage
        
        messages = []
        async for message in query({
            "prompt": prompt,
            "abortController": None,  # 可以添加取消控制
            "options": {
                "maxTurns": max_turns,
                "allowedTools": tools or [],
                "model": "claude-3-5-sonnet-20241022"
            },
        }):
            messages.append(message)
        
        return messages
    
    def create_project_assistant(self, project_path: str):
        """创建项目助手"""
        return ProjectAssistant(project_path, self.api_key)

class ProjectAssistant:
    """项目级别的Claude助手"""
    
    def __init__(self, project_path: str, api_key: str):
        self.project_path = Path(project_path)
        self.client = AnthropicClient(api_key)
        self.context_cache = {}
    
    def analyze_codebase(self):
        """分析代码库"""
        files_content = {}
        
        # 扫描Python文件
        for py_file in self.project_path.rglob("*.py"):
            if py_file.is_file() and py_file.stat().st_size < 100000:  # 100KB限制
                try:
                    with open(py_file, 'r', encoding='utf-8') as f:
                        files_content[str(py_file.relative_to(self.project_path))] = f.read()
                except:
                    continue
        
        return files_content
    
    def code_review(self, file_path: str, changes: str = None):
        """代码审查"""
        if changes:
            content = changes
        else:
            with open(self.project_path / file_path, 'r') as f:
                content = f.read()
        
        system_prompt = """你是一个专业的代码审查专家。请审查以下代码并提供:
        1. 代码质量评估
        2. 潜在bug和问题
        3. 性能优化建议
        4. 最佳实践建议
        5. 安全性考虑"""
        
        response = self.client.create_message(
            messages=[{
                "role": "user",
                "content": f"请审查以下代码文件 {file_path}:\n\n```python\n{content}\n```"
            }],
            system=system_prompt
        )
        
        return response["content"]
    
    def generate_tests(self, file_path: str):
        """生成测试代码"""
        with open(self.project_path / file_path, 'r') as f:
            source_code = f.read()
        
        system_prompt = """你是一个测试专家。请为给定的Python代码生成全面的pytest测试用例,包括:
        1. 正常情况测试
        2. 边界情况测试
        3. 异常情况测试
        4. Mock测试(如需要)"""
        
        response = self.client.create_message(
            messages=[{
                "role": "user", 
                "content": f"为以下代码生成测试用例:\n\n```python\n{source_code}\n```"
            }],
            system=system_prompt
        )
        
        return response["content"]
    
    def explain_code(self, file_path: str, line_start: int = None, line_end: int = None):
        """解释代码"""
        with open(self.project_path / file_path, 'r') as f:
            lines = f.readlines()
        
        if line_start and line_end:
            code_snippet = ''.join(lines[line_start-1:line_end])
            context = f"代码片段 (第{line_start}-{line_end}行)"
        else:
            code_snippet = ''.join(lines)
            context = "完整文件"
        
        response = self.client.create_message(
            messages=[{
                "role": "user",
                "content": f"请详细解释以下{context}的代码逻辑:\n\n```python\n{code_snippet}\n```"
            }]
        )
        
        return response["content"]

# 使用示例
code_sdk = ClaudeCodeSDK(api_key="your-api-key")
assistant = code_sdk.create_project_assistant("./my_project")

# 代码审查
review_result = assistant.code_review("src/main.py")
print("代码审查结果:", review_result)

# 生成测试
test_code = assistant.generate_tests("src/utils.py")
print("生成的测试代码:", test_code)

3. 工具调用和MCP集成

工具系统集成
from typing import Callable, Dict, Any, List
import json

class AnthropicToolHandler:
    """Anthropic工具调用处理器"""
    
    def __init__(self, client: AnthropicClient):
        self.client = client
        self.available_tools = {}
        self.mcp_servers = {}
    
    def register_tool(self, name: str, func: Callable, description: str, parameters: Dict):
        """注册工具函数"""
        self.available_tools[name] = {
            "function": func,
            "description": description,
            "parameters": parameters
        }
    
    def register_mcp_server(self, server_name: str, server_config: Dict):
        """注册MCP服务器"""
        self.mcp_servers[server_name] = server_config
    
    def get_tool_definitions(self) -> List[Dict]:
        """获取工具定义"""
        tools = []
        
        for name, tool_info in self.available_tools.items():
            tools.append({
                "name": name,
                "description": tool_info["description"],
                "input_schema": {
                    "type": "object",
                    "properties": tool_info["parameters"]["properties"],
                    "required": tool_info["parameters"].get("required", [])
                }
            })
        
        return tools
    
    def execute_tool(self, tool_name: str, arguments: Dict[str, Any]) -> Dict[str, Any]:
        """执行工具调用"""
        if tool_name not in self.available_tools:
            return {"error": f"Tool {tool_name} not found"}
        
        try:
            func = self.available_tools[tool_name]["function"]
            result = func(**arguments)
            return {"result": result}
        
        except Exception as e:
            return {"error": str(e)}
    
    def chat_with_tools(self, messages: List[Dict[str, str]], model: str = "claude-3-5-sonnet-20241022"):
        """支持工具调用的对话"""
        tools = self.get_tool_definitions()
        
        # 第一次调用 - 可能触发工具使用
        response = self.client.client.messages.create(
            model=model,
            max_tokens=4000,
            messages=messages,
            tools=tools
        )
        
        # 检查是否有工具调用
        if response.content and hasattr(response.content[-1], 'type') and response.content[-1].type == "tool_use":
            # 处理工具调用
            tool_calls = [block for block in response.content if hasattr(block, 'type') and block.type == "tool_use"]
            
            # 执行工具并收集结果
            tool_results = []
            for tool_call in tool_calls:
                tool_name = tool_call.name
                tool_args = tool_call.input
                
                result = self.execute_tool(tool_name, tool_args)
                
                tool_results.append({
                    "type": "tool_result",
                    "tool_use_id": tool_call.id,
                    "content": json.dumps(result)
                })
            
            # 将工具结果添加到对话
            messages.append({
                "role": "assistant", 
                "content": response.content
            })
            messages.append({
                "role": "user",
                "content": tool_results
            })
            
            # 再次调用获取最终回答
            final_response = self.client.client.messages.create(
                model=model,
                max_tokens=4000,
                messages=messages
            )
            
            return final_response.content[0].text
        
        return response.content[0].text

# 示例工具函数
def get_weather(city: str, date: str = None) -> str:
    """获取天气信息"""
    return f"{city}今天天气晴朗,温度25°C"

def search_web(query: str, num_results: int = 5) -> List[str]:
    """网络搜索"""
    return [f"搜索结果 {i}: {query} 相关内容" for i in range(num_results)]

def execute_code(code: str, language: str = "python") -> Dict[str, Any]:
    """执行代码"""
    # 这里应该有安全的代码执行环境
    return {
        "output": "代码执行结果",
        "success": True
    }

# 使用示例
client = AnthropicClient()
tool_handler = AnthropicToolHandler(client)

# 注册工具
tool_handler.register_tool(
    name="get_weather",
    func=get_weather,
    description="获取指定城市的天气信息",
    parameters={
        "properties": {
            "city": {"type": "string", "description": "城市名称"},
            "date": {"type": "string", "description": "日期"}
        },
        "required": ["city"]
    }
)

tool_handler.register_tool(
    name="search_web", 
    func=search_web,
    description="搜索网络信息",
    parameters={
        "properties": {
            "query": {"type": "string", "description": "搜索查询"},
            "num_results": {"type": "integer", "description": "结果数量"}
        },
        "required": ["query"]
    }
)

# 测试工具调用
messages = [
    {"role": "user", "content": "北京今天天气怎么样?然后帮我搜索一下最新的AI发展趋势"}
]

result = tool_handler.chat_with_tools(messages)
print(result)

4. 缓存和优化策略

智能缓存管理
import hashlib
import time
from typing import Optional
import redis

class AnthropicCacheManager:
    """Anthropic缓存管理器"""
    
    def __init__(self, redis_url: str = "redis://localhost:6379"):
        self.redis_client = redis.from_url(redis_url)
        self.default_ttl = 3600  # 1小时
        self.extended_ttl = 3600 * 24  # 24小时(2025年扩展缓存)
    
    def generate_cache_key(self, messages: List[Dict], model: str, **kwargs) -> str:
        """生成缓存键"""
        content = json.dumps({
            "messages": messages,
            "model": model,
            **kwargs
        }, sort_keys=True)
        
        return f"anthropic:{hashlib.md5(content.encode()).hexdigest()}"
    
    def get_cached_response(self, cache_key: str) -> Optional[Dict]:
        """获取缓存响应"""
        try:
            cached_data = self.redis_client.get(cache_key)
            if cached_data:
                return json.loads(cached_data)
        except Exception as e:
            print(f"缓存获取错误: {e}")
        
        return None
    
    def cache_response(self, cache_key: str, response: Dict, ttl: int = None):
        """缓存响应"""
        try:
            ttl = ttl or self.default_ttl
            self.redis_client.setex(
                cache_key,
                ttl,
                json.dumps(response)
            )
        except Exception as e:
            print(f"缓存存储错误: {e}")
    
    def create_cached_message(self, 
                            client: AnthropicClient,
                            messages: List[Dict[str, str]], 
                            model: str = "claude-3-5-sonnet-20241022",
                            use_extended_cache: bool = False,
                            **kwargs) -> Dict[str, Any]:
        """创建带缓存的消息"""
        
        # 生成缓存键
        cache_key = self.generate_cache_key(messages, model, **kwargs)
        
        # 尝试从缓存获取
        cached_response = self.get_cached_response(cache_key)
        if cached_response:
            cached_response["cached"] = True
            return cached_response
        
        # 缓存未命中,调用API
        extra_headers = {}
        ttl = self.default_ttl
        
        if use_extended_cache:
            # 使用2025年扩展缓存功能
            extra_headers['anthropic-beta'] = 'extended-cache-ttl-2025-04-11'
            ttl = self.extended_ttl
        
        # API调用
        try:
            response = client.client.messages.create(
                model=model,
                max_tokens=kwargs.get('max_tokens', 4000),
                temperature=kwargs.get('temperature', 0),
                messages=messages,
                extra_headers=extra_headers
            )
            
            result = {
                "content": response.content[0].text,
                "usage": response.usage.__dict__,
                "model": response.model,
                "cached": False,
                "timestamp": time.time()
            }
            
            # 存储到缓存
            self.cache_response(cache_key, result, ttl)
            
            return result
            
        except Exception as e:
            return {"error": str(e), "cached": False}

class AnthropicOptimizer:
    """Anthropic性能优化器"""
    
    def __init__(self, client: AnthropicClient):
        self.client = client
        self.cache_manager = AnthropicCacheManager()
        self.request_stats = {"total": 0, "cached": 0, "errors": 0}
    
    def optimized_create_message(self, 
                                messages: List[Dict[str, str]], 
                                enable_cache: bool = True,
                                use_extended_cache: bool = False,
                                **kwargs) -> Dict[str, Any]:
        """优化的消息创建"""
        self.request_stats["total"] += 1
        
        if enable_cache:
            result = self.cache_manager.create_cached_message(
                self.client, 
                messages, 
                use_extended_cache=use_extended_cache,
                **kwargs
            )
            
            if result.get("cached"):
                self.request_stats["cached"] += 1
            
            if "error" in result:
                self.request_stats["errors"] += 1
            
            return result
        else:
            # 直接API调用
            return self.client.create_message(messages, **kwargs)
    
    def get_performance_stats(self) -> Dict[str, Any]:
        """获取性能统计"""
        total = self.request_stats["total"]
        if total == 0:
            return {"message": "No requests made yet"}
        
        cache_hit_rate = self.request_stats["cached"] / total
        error_rate = self.request_stats["errors"] / total
        
        return {
            "total_requests": total,
            "cached_requests": self.request_stats["cached"],
            "cache_hit_rate": f"{cache_hit_rate:.2%}",
            "error_requests": self.request_stats["errors"],
            "error_rate": f"{error_rate:.2%}",
            "api_requests": total - self.request_stats["cached"]
        }
    
    def batch_process_messages(self, 
                              message_batches: List[List[Dict[str, str]]], 
                              concurrent_limit: int = 5) -> List[Dict[str, Any]]:
        """批量处理消息"""
        import asyncio
        from concurrent.futures import ThreadPoolExecutor
        
        async def process_batch(messages):
            return await self.client.async_create_message(messages)
        
        async def batch_runner():
            semaphore = asyncio.Semaphore(concurrent_limit)
            
            async def limited_process(messages):
                async with semaphore:
                    return await process_batch(messages)
            
            tasks = [limited_process(messages) for messages in message_batches]
            return await asyncio.gather(*tasks)
        
        return asyncio.run(batch_runner())

# 使用示例
client = AnthropicClient()
optimizer = AnthropicOptimizer(client)

# 使用缓存的消息创建
response = optimizer.optimized_create_message(
    messages=[{"role": "user", "content": "什么是量子计算?"}],
    enable_cache=True,
    use_extended_cache=True
)

print("响应:", response["content"])
print("是否使用缓存:", response.get("cached", False))

# 查看性能统计
stats = optimizer.get_performance_stats()
print("性能统计:", stats)

2025年新功能特性

1. 推理模式(Thinking Mode)

  • 透明的推理过程展示
  • 可配置的思维预算(thinking budget)
  • 支持复杂问题的逐步推理

2. 扩展缓存功能

  • 1小时缓存持续时间
  • 显著降低重复请求成本
  • 企业级缓存管理

3. MCP服务器支持

  • 模型上下文协议集成
  • 自定义工具生态系统
  • 安全的工具访问控制

4. 最新模型支持

  • Claude Opus 4 (2025-05-14)
  • Claude Sonnet 4 (2025-05-14)
  • Claude 3.7 Sonnet (2025-02-19)

企业级部署建议

1. 安全配置

  • API密钥轮换机制
  • 工具调用权限控制
  • 审计日志记录

2. 性能优化

  • 智能缓存策略
  • 请求批处理
  • 错误重试机制

3. 成本控制

  • 使用量监控
  • 缓存命中率优化
  • 模型选择策略

相关概念

延伸阅读