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即時串流回應

官方中文文件· 查看原文 ↗ ·官方譯文,未經機器翻譯

當文字和工具呼叫串流進來時,從 Agent SDK 取得即時回應

根據預設,Agent SDK 會在 Claude 完成生成每個回應後產生完整的 AssistantMessage 物件。若要在文字和工具呼叫生成時接收增量更新,請在選項中將 include_partial_messages(Python)或 includePartialMessages(TypeScript)設定為 true 來啟用部分訊息串流。

建议

本頁涵蓋輸出串流(即時接收權杖)。如需輸入模式(如何傳送訊息),請參閱傳送訊息給代理。您也可以透過 CLI 使用 Agent SDK 串流回應

啟用串流輸出

若要啟用串流,請在選項中將 include_partial_messages(Python)或 includePartialMessages(TypeScript)設定為 true。這會導致 SDK 產生包含原始 API 事件的 StreamEvent 訊息(當它們到達時),以及通常的 AssistantMessageResultMessage

您的程式碼需要:

  1. 檢查每個訊息的類型以區分 StreamEvent 和其他訊息類型
  2. 對於 StreamEvent,提取 event 欄位並檢查其 type
  3. 尋找 content_block_delta 事件,其中 delta.typetext_delta,其中包含實際的文字區塊

下面的範例啟用串流並在文字區塊到達時列印它們。注意巢狀類型檢查:首先是 StreamEvent,然後是 content_block_delta,然後是 text_delta

  from claude_agent_sdk import query, ClaudeAgentOptions
  from claude_agent_sdk.types import StreamEvent
  import asyncio

  async def stream_response():
      options = ClaudeAgentOptions(
          include_partial_messages=True,
          allowed_tools=["Bash", "Read"],
      )

      async for message in query(prompt="List the files in my project", options=options):
          if isinstance(message, StreamEvent):
              event = message.event
              if event.get("type") == "content_block_delta":
                  delta = event.get("delta", {})
                  if delta.get("type") == "text_delta":
                      print(delta.get("text", ""), end="", flush=True)

  asyncio.run(stream_response())
import { query } from "@anthropic-ai/claude-agent-sdk";

for await (const message of query({
  prompt: "List the files in my project",
  options: {
    includePartialMessages: true,
    allowedTools: ["Bash", "Read"]
  }
})) {
  if (message.type === "stream_event") {
    const event = message.event;
    if (event.type === "content_block_delta") {
      if (event.delta.type === "text_delta") {
        process.stdout.write(event.delta.text);
      }
    }
  }
}

StreamEvent 參考

啟用部分訊息時,您會收到包裝在物件中的原始 Claude API 串流事件。該類型在每個 SDK 中有不同的名稱:

  • PythonStreamEvent(從 claude_agent_sdk.types 匯入)
  • TypeScriptSDKPartialAssistantMessage,其中 type: 'stream_event'

兩者都包含原始 Claude API 事件,而不是累積的文字。您需要自己提取和累積文字增量。以下是每種類型的結構:

  @dataclass
  class StreamEvent:
      uuid: str  # Unique identifier for this event
      session_id: str  # Session identifier
      event: dict[str, Any]  # The raw Claude API stream event
      parent_tool_use_id: str | None  # Always None
type SDKPartialAssistantMessage = {
  type: "stream_event";
  event: BetaRawMessageStreamEvent; // From Anthropic SDK
  parent_tool_use_id: string | null;
  uuid: UUID;
  session_id: string;
  ttft_ms?: number; // Time to first token in ms, present only on message_start events
};

parent_tool_use_id 欄位在 Python 中始終為 None,在 TypeScript 中始終為 null。串流事件僅針對主工作階段發出;來自子代理的令牌級增量不會被轉發。若要將輸出歸因於子代理,請使用完整訊息,其中包含 parent_tool_use_id。請參閱偵測子代理叫用

event 欄位包含來自 Claude API 的原始串流事件。常見的事件類型包括:

事件類型 說明
message_start 新訊息的開始
content_block_start 新內容區塊的開始(文字或工具使用)
content_block_delta 內容的增量更新
content_block_stop 內容區塊的結束
message_delta 訊息層級的更新(停止原因、使用情況)
message_stop 訊息的結束

訊息流

啟用部分訊息後,您會按此順序接收訊息:

StreamEvent (message_start)
StreamEvent (content_block_start) - text block
StreamEvent (content_block_delta) - text chunks...
StreamEvent (content_block_stop)
StreamEvent (content_block_start) - tool_use block
StreamEvent (content_block_delta) - tool input chunks...
StreamEvent (content_block_stop)
StreamEvent (message_delta)
StreamEvent (message_stop)
AssistantMessage - complete message with all content
... tool executes ...
... more streaming events for next turn ...
ResultMessage - final result

未啟用部分訊息(Python 中的 include_partial_messages、TypeScript 中的 includePartialMessages)時,您會收到除 StreamEvent 外的所有訊息類型。常見類型包括 SystemMessage(工作階段初始化)、AssistantMessage(完整回應)、ResultMessage(最終結果)和指示何時壓縮對話歷史記錄的緊湊邊界訊息(TypeScript 中的 SDKCompactBoundaryMessage;Python 中具有子類型 "compact_boundary"SystemMessage)。

串流文字回應

若要在生成文字時顯示它,請尋找 content_block_delta 事件,其中 delta.typetext_delta。這些包含增量文字區塊。下面的範例在每個區塊到達時列印它:

  from claude_agent_sdk import query, ClaudeAgentOptions
  from claude_agent_sdk.types import StreamEvent
  import asyncio

  async def stream_text():
      options = ClaudeAgentOptions(include_partial_messages=True)

      async for message in query(prompt="Explain how databases work", options=options):
          if isinstance(message, StreamEvent):
              event = message.event
              if event.get("type") == "content_block_delta":
                  delta = event.get("delta", {})
                  if delta.get("type") == "text_delta":
                      # Print each text chunk as it arrives
                      print(delta.get("text", ""), end="", flush=True)

      print()  # Final newline

  asyncio.run(stream_text())
import { query } from "@anthropic-ai/claude-agent-sdk";

for await (const message of query({
  prompt: "Explain how databases work",
  options: { includePartialMessages: true }
})) {
  if (message.type === "stream_event") {
    const event = message.event;
    if (event.type === "content_block_delta" && event.delta.type === "text_delta") {
      process.stdout.write(event.delta.text);
    }
  }
}

console.log(); // Final newline

串流工具呼叫

工具呼叫也會增量串流。您可以追蹤工具何時開始、在生成時接收其輸入,以及查看何時完成。下面的範例追蹤目前被呼叫的工具並在串流進來時累積 JSON 輸入。它使用三種事件類型:

  • content_block_start:工具開始
  • content_block_delta 搭配 input_json_delta:輸入區塊到達
  • content_block_stop:工具呼叫完成
  from claude_agent_sdk import query, ClaudeAgentOptions
  from claude_agent_sdk.types import StreamEvent
  import asyncio

  async def stream_tool_calls():
      options = ClaudeAgentOptions(
          include_partial_messages=True,
          allowed_tools=["Read", "Bash"],
      )

      # Track the current tool and accumulate its input JSON
      current_tool = None
      tool_input = ""

      async for message in query(prompt="Read the README.md file", options=options):
          if isinstance(message, StreamEvent):
              event = message.event
              event_type = event.get("type")

              if event_type == "content_block_start":
                  # New tool call is starting
                  content_block = event.get("content_block", {})
                  if content_block.get("type") == "tool_use":
                      current_tool = content_block.get("name")
                      tool_input = ""
                      print(f"Starting tool: {current_tool}")

              elif event_type == "content_block_delta":
                  delta = event.get("delta", {})
                  if delta.get("type") == "input_json_delta":
                      # Accumulate JSON input as it streams in
                      chunk = delta.get("partial_json", "")
                      tool_input += chunk
                      print(f"  Input chunk: {chunk}")

              elif event_type == "content_block_stop":
                  # Tool call complete - show final input
                  if current_tool:
                      print(f"Tool {current_tool} called with: {tool_input}")
                      current_tool = None

  asyncio.run(stream_tool_calls())
import { query } from "@anthropic-ai/claude-agent-sdk";

// Track the current tool and accumulate its input JSON
let currentTool: string | null = null;
let toolInput = "";

for await (const message of query({
  prompt: "Read the README.md file",
  options: {
    includePartialMessages: true,
    allowedTools: ["Read", "Bash"]
  }
})) {
  if (message.type === "stream_event") {
    const event = message.event;

    if (event.type === "content_block_start") {
      // New tool call is starting
      if (event.content_block.type === "tool_use") {
        currentTool = event.content_block.name;
        toolInput = "";
        console.log(`Starting tool: ${currentTool}`);
      }
    } else if (event.type === "content_block_delta") {
      if (event.delta.type === "input_json_delta") {
        // Accumulate JSON input as it streams in
        const chunk = event.delta.partial_json;
        toolInput += chunk;
        console.log(`  Input chunk: ${chunk}`);
      }
    } else if (event.type === "content_block_stop") {
      // Tool call complete - show final input
      if (currentTool) {
        console.log(`Tool ${currentTool} called with: ${toolInput}`);
        currentTool = null;
      }
    }
  }
}

建立串流 UI

此範例將文字和工具串流結合成一個有凝聚力的 UI。它追蹤代理目前是否正在執行工具(使用 in_tool 旗標)以顯示狀態指示器,例如在工具執行時顯示 [Using Read...]。文字在不在工具中時正常串流,工具完成會觸發「完成」訊息。此模式對於需要在多步驟代理任務期間顯示進度的聊天介面很有用。

  from claude_agent_sdk import query, ClaudeAgentOptions, ResultMessage
  from claude_agent_sdk.types import StreamEvent
  import asyncio
  import sys

  async def streaming_ui():
      options = ClaudeAgentOptions(
          include_partial_messages=True,
          allowed_tools=["Read", "Bash", "Grep"],
      )

      # Track whether we're currently in a tool call
      in_tool = False

      async for message in query(
          prompt="Find all TODO comments in the codebase", options=options
      ):
          if isinstance(message, StreamEvent):
              event = message.event
              event_type = event.get("type")

              if event_type == "content_block_start":
                  content_block = event.get("content_block", {})
                  if content_block.get("type") == "tool_use":
                      # Tool call is starting - show status indicator
                      tool_name = content_block.get("name")
                      print(f"\n[Using {tool_name}...]", end="", flush=True)
                      in_tool = True

              elif event_type == "content_block_delta":
                  delta = event.get("delta", {})
                  # Only stream text when not executing a tool
                  if delta.get("type") == "text_delta" and not in_tool:
                      sys.stdout.write(delta.get("text", ""))
                      sys.stdout.flush()

              elif event_type == "content_block_stop":
                  if in_tool:
                      # Tool call finished
                      print(" done", flush=True)
                      in_tool = False

          elif isinstance(message, ResultMessage):
              # Agent finished all work
              print(f"\n\n--- Complete ---")

  asyncio.run(streaming_ui())
import { query } from "@anthropic-ai/claude-agent-sdk";

// Track whether we're currently in a tool call
let inTool = false;

for await (const message of query({
  prompt: "Find all TODO comments in the codebase",
  options: {
    includePartialMessages: true,
    allowedTools: ["Read", "Bash", "Grep"]
  }
})) {
  if (message.type === "stream_event") {
    const event = message.event;

    if (event.type === "content_block_start") {
      if (event.content_block.type === "tool_use") {
        // Tool call is starting - show status indicator
        process.stdout.write(`\n[Using ${event.content_block.name}...]`);
        inTool = true;
      }
    } else if (event.type === "content_block_delta") {
      // Only stream text when not executing a tool
      if (event.delta.type === "text_delta" && !inTool) {
        process.stdout.write(event.delta.text);
      }
    } else if (event.type === "content_block_stop") {
      if (inTool) {
        // Tool call finished
        console.log(" done");
        inTool = false;
      }
    }
  } else if (message.type === "result") {
    // Agent finished all work
    console.log("\n\n--- Complete ---");
  }
}

已知限制

  • 結構化輸出:JSON 結果僅出現在最終 ResultMessage.structured_output 中,而不是作為串流增量。如需詳細資訊,請參閱結構化輸出

後續步驟

現在您可以即時串流文字和工具呼叫,請探索這些相關主題: