Anthropic | 提示词缓存

提示缓存允许您在 API 调用之间缓存常用上下文,在缓存读取时最多可降低 90% 的成本并改善延迟。缓存内容通过 cache_control 参数标记,并在缓存 TTL 窗口内跨请求复用。

系统提示缓存

缓存长系统提示以避免每次请求都重新处理。将 SystemCacheControl 设置为 True 可自动用 cache_control 包装系统提示。


Anthropic := TsgcHTTP_API_Anthropic.Create(nil);
Anthropic.AnthropicOptions.ApiKey := 'API_KEY';

oRequest := TsgcAnthropicClass_Request_Messages.Create;
Try
  oRequest.Model := 'claude-sonnet-4-20250514';
  oRequest.MaxTokens := 4096;
  oRequest.System := 'You are an expert legal assistant... (long system prompt)';
  oRequest.SystemCacheControl := True;  // Enable caching for system prompt

  oMessage := TsgcAnthropicClass_Request_Message.Create;
  oMessage.Role := 'user';
  oMessage.Content := 'Analyze this contract clause.';
  oMessages := oRequest.Messages;
  SetLength(oMessages, 1);
  oMessages[0] := oMessage;
  oRequest.Messages := oMessages;

  oResponse := Anthropic.CreateMessage(oRequest);
  Try
    // Check cache usage in response
    WriteLn('Cache created: ' +
      IntToStr(oResponse.Usage.CacheCreationInputTokens));
    WriteLn('Cache read: ' +
      IntToStr(oResponse.Usage.CacheReadInputTokens));
    WriteLn(oResponse.Content[0].Text);
  Finally
    oResponse.Free;
  End;
Finally
  oMessage.Free;
  oRequest.Free;
End;

内容块缓存

通过在单个内容块上将 CacheControl 设置为 'ephemeral',可以缓存特定内容块(例如大型文档或上下文)。


oBlock := TsgcAnthropicClass_Request_Content_Block.Create;
oBlock.ContentType := 'text';
oBlock.Text := '(large reference text to cache)';
oBlock.CacheControl := 'ephemeral';  // Mark for caching

工具定义缓存

缓存工具定义,避免在每次请求时重新处理。当您有许多在请求间保持不变的工具定义时,此功能非常有用。


oTool := TsgcAnthropicClass_Request_Tool.Create;
oTool.Name := 'search_database';
oTool.Description := 'Search the database for records.';
oTool.InputSchema := '{"type":"object","properties":{"query":{"type":"string"}}}';
oTool.CacheControl := 'ephemeral';  // Cache this tool definition

属性

定价