Agent SDK 会话管理：continue、resume 与 fork

import asyncio
from claude_agent_sdk import (
    ClaudeSDKClient,
    ClaudeAgentOptions,
    AssistantMessage,
    ResultMessage,
    TextBlock,
)


def print_response(message):
    """Print only the human-readable parts of a message."""
    if isinstance(message, AssistantMessage):
        for block in message.content:
            if isinstance(block, TextBlock):
                print(block.text)
    elif isinstance(message, ResultMessage):
        cost = (
            f"${message.total_cost_usd:.4f}"
            if message.total_cost_usd is not None
            else "N/A"
        )
        print(f"[done: {message.subtype}, cost: {cost}]")


async def main():
    options = ClaudeAgentOptions(
        allowed_tools=["Read", "Edit", "Glob", "Grep"],
    )

    async with ClaudeSDKClient(options=options) as client:
        # First query: client captures the session ID internally
        await client.query("Analyze the auth module")
        async for message in client.receive_response():
            print_response(message)

        # Second query: automatically continues the same session
        await client.query("Now refactor it to use JWT")
        async for message in client.receive_response():
            print_response(message)


asyncio.run(main())

import { query } from "@anthropic-ai/claude-agent-sdk";

// First query: creates a new session
try {
  for await (const message of query({
    prompt: "Analyze the auth module",
    options: { allowedTools: ["Read", "Glob", "Grep"] }
  })) {
    if (message.type === "result" && message.subtype === "success") {
      console.log(message.result);
    }
  }
} catch (error) {
  // A single-shot query() throws after yielding an error result,
  // so the follow-up query below still runs.
  console.error(`Session ended with an error: ${error}`);
}

// Second query: continue: true resumes the most recent session
for await (const message of query({
  prompt: "Now refactor it to use JWT",
  options: {
    continue: true,
    allowedTools: ["Read", "Edit", "Write", "Glob", "Grep"]
  }
})) {
  if (message.type === "result" && message.subtype === "success") {
    console.log(message.result);
  }
}

import asyncio
from claude_agent_sdk import query, ClaudeAgentOptions, ResultMessage


async def main():
    session_id = None

    try:
        async for message in query(
            prompt="Analyze the auth module and suggest improvements",
            options=ClaudeAgentOptions(
                allowed_tools=["Read", "Glob", "Grep"],
            ),
        ):
            if isinstance(message, ResultMessage):
                session_id = message.session_id
                if message.subtype == "success":
                    print(message.result)
    except Exception as error:
        # A single-shot query() raises after yielding an error result. If the
        # failure was an error result, the loop above already captured session_id;
        # connection or process failures yield no result message, so session_id stays None.
        print(f"Session ended with an error: {error}")

    print(f"Session ID: {session_id}")
    return session_id


session_id = asyncio.run(main())

import { query } from "@anthropic-ai/claude-agent-sdk";

let sessionId: string | undefined;

try {
  for await (const message of query({
    prompt: "Analyze the auth module and suggest improvements",
    options: { allowedTools: ["Read", "Glob", "Grep"] }
  })) {
    if (message.type === "result") {
      sessionId = message.session_id;
      if (message.subtype === "success") {
        console.log(message.result);
      }
    }
  }
} catch (error) {
  // A single-shot query() throws after yielding an error result. If the
  // failure was an error result, the loop above already captured sessionId;
  // connection or process failures yield no result message, so sessionId stays undefined.
  console.error(`Session ended with an error: ${error}`);
}

console.log(`Session ID: ${sessionId}`);

import asyncio
from claude_agent_sdk import query, ClaudeAgentOptions, ResultMessage

session_id = "..."  # The ID you captured in the previous example


async def main():
    # Earlier session analyzed the code; now build on that analysis
    async for message in query(
        prompt="Now implement the refactoring you suggested",
        options=ClaudeAgentOptions(
            resume=session_id,
            allowed_tools=["Read", "Edit", "Write", "Glob", "Grep"],
        ),
    ):
        if isinstance(message, ResultMessage) and message.subtype == "success":
            print(message.result)


asyncio.run(main())

import { query } from "@anthropic-ai/claude-agent-sdk";

const sessionId = "..."; // The ID you captured in the previous example

// Earlier session analyzed the code; now build on that analysis
for await (const message of query({
  prompt: "Now implement the refactoring you suggested",
  options: {
    resume: sessionId,
    allowedTools: ["Read", "Edit", "Write", "Glob", "Grep"]
  }
})) {
  if (message.type === "result" && message.subtype === "success") {
    console.log(message.result);
  }
}

import asyncio
from claude_agent_sdk import query, ClaudeAgentOptions, ResultMessage

session_id = "..."  # The ID you captured in the previous example


async def main():
    # Fork: branch from session_id into a new session
    forked_id = None
    try:
        async for message in query(
            prompt="Instead of JWT, outline how OAuth2 would work for the auth module",
            options=ClaudeAgentOptions(
                resume=session_id,
                fork_session=True,
                max_turns=5,
            ),
        ):
            if isinstance(message, ResultMessage):
                forked_id = message.session_id  # The fork's ID, distinct from session_id
                if message.subtype == "success":
                    print(message.result)
    except Exception as error:
        # A single-shot query() raises after yielding an error result. If the
        # failure was an error result, forked_id was already captured by the
        # loop above; connection or process failures yield no result message.
        print(f"Session ended with an error: {error}")

    print(f"Forked session: {forked_id}")

    # Original session is untouched; resuming it continues the JWT thread
    try:
        async for message in query(
            prompt="Continue with the JWT approach",
            options=ClaudeAgentOptions(resume=session_id),
        ):
            if isinstance(message, ResultMessage) and message.subtype == "success":
                print(message.result)
    except Exception as error:
        # A single-shot query() raises after yielding an error result.
        print(f"Session ended with an error: {error}")


asyncio.run(main())

import { query } from "@anthropic-ai/claude-agent-sdk";

const sessionId = "..."; // The ID you captured in the previous example

// Fork: branch from sessionId into a new session
let forkedId: string | undefined;

try {
  for await (const message of query({
    prompt: "Instead of JWT, outline how OAuth2 would work for the auth module",
    options: {
      resume: sessionId,
      forkSession: true,
      maxTurns: 5
    }
  })) {
    if (message.type === "system" && message.subtype === "init") {
      forkedId = message.session_id; // The fork's ID, distinct from sessionId
    }
    if (message.type === "result" && message.subtype === "success") {
      console.log(message.result);
    }
  }
} catch (error) {
  // A single-shot query() throws after yielding an error result. If the
  // failure was an error result, forkedId was already captured by the loop
  // above; connection or process failures yield no result message.
  console.error(`Session ended with an error: ${error}`);
}

console.log(`Forked session: ${forkedId}`);

// Original session is untouched; resuming it continues the JWT thread
try {
  for await (const message of query({
    prompt: "Continue with the JWT approach",
    options: { resume: sessionId }
  })) {
    if (message.type === "result" && message.subtype === "success") {
      console.log(message.result);
    }
  }
} catch (error) {
  // A single-shot query() throws after yielding an error result.
  console.error(`Session ended with an error: ${error}`);
}