即時串流回應
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。
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 AssistantMessage 和 ResultMessage。
您的程式碼需要:
- 檢查每個訊息的類型以區分
StreamEvent和其他訊息類型 - 對於
StreamEvent,提取event欄位並檢查其type - 尋找
content_block_delta事件,其中delta.type是text_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:
- Python:
StreamEvent(從claude_agent_sdk.types匯入) - TypeScript:
SDKPartialAssistantMessage,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 # Parent tool ID if from a subagent
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
};
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" 的 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.type 是 text_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: