Todo Lists

Track and display todos using the Claude Agent SDK for organized task management

Todo tracking provides a structured way to manage tasks and display progress to users. The Claude Agent SDK includes built-in todo functionality that helps organize complex workflows and keep users informed about task progression.

As of TypeScript Agent SDK 0.3.142 and Claude Code v2.1.142, sessions use the structured Task tools TaskCreate, TaskUpdate, TaskGet, and TaskList instead of TodoWrite. The Python SDK gets this change from the Claude Code CLI it launches, not from the Python package version: the switch applies once that CLI — the copy bundled inside the pip package, or one you point to with cli_path — is v2.1.142 or later. See Migrate to Task tools for how monitoring code changes. The examples on this page set CLAUDE_CODE_ENABLE_TASKS=0 to keep showing TodoWrite for sessions that have not migrated yet.

Todo Lifecycle

Todos follow a predictable lifecycle:

1. Created as pending when tasks are identified
2. Activated to in_progress when work begins
3. Completed when the task finishes successfully
4. Removed when all tasks in a group are completed

When Todos Are Used

The SDK creates todos for most multi-step work, such as:

• Complex multi-step tasks requiring 3 or more distinct actions
• User-provided task lists when multiple items are mentioned
• Non-trivial operations that benefit from progress tracking
• Explicit requests when users ask for todo organization

It may skip todos for very short or single-step requests.

Examples

Before running these examples, install the Claude Agent SDK by following the quickstart.

Each example runs until the agent finishes and yields its final result message. If a session reaches its turn limit first, that result message has the error_max_turns subtype. Check subtype to detect that ending.

These examples use single-shot query() calls. After yielding an error_max_turns result, query() raises an error that includes Reached maximum number of turns. Each example wraps its loop in a try block to exit cleanly when that happens.

See Handle the result for the result subtypes.

Monitoring Todo Changes

TypeScript

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

try {
  for await (const message of query({
    prompt: "Optimize my React app performance and track progress with todos",
    // Re-enable TodoWrite, which this example monitors. Without it, the SDK uses
    // Task tools instead and these tool_use blocks never appear.
    options: { maxTurns: 15, env: { ...process.env, CLAUDE_CODE_ENABLE_TASKS: "0" } }
  })) {
    // Todo updates are reflected in the message stream
    if (message.type === "assistant") {
      for (const block of message.message.content) {
        if (block.type === "tool_use" && block.name === "TodoWrite") {
          const todos = block.input.todos;

          console.log("Todo Status Update:");
          todos.forEach((todo, index) => {
            const status =
              todo.status === "completed" ? "✅" : todo.status === "in_progress" ? "🔧" : "❌";
            console.log(`${index + 1}. ${status} ${todo.content}`);
          });
        }
      }
    }
  }
} catch (error) {
  // A single-shot query() throws after yielding an error result,
  // such as when the maxTurns limit is hit.
  console.log(`Session ended with an error: ${error}`);
}

import asyncio

from claude_agent_sdk import query, ClaudeAgentOptions, AssistantMessage, ToolUseBlock


async def main():
    try:
        async for message in query(
            prompt="Optimize my React app performance and track progress with todos",
            # Re-enable TodoWrite, which this example monitors. Without it, the SDK uses
            # Task tools instead and these tool_use blocks never appear.
            options=ClaudeAgentOptions(max_turns=15, env={"CLAUDE_CODE_ENABLE_TASKS": "0"}),
        ):
            # Todo updates are reflected in the message stream
            if isinstance(message, AssistantMessage):
                for block in message.content:
                    if isinstance(block, ToolUseBlock) and block.name == "TodoWrite":
                        todos = block.input["todos"]

                        print("Todo Status Update:")
                        for i, todo in enumerate(todos):
                            status = (
                                "✅"
                                if todo["status"] == "completed"
                                else "🔧"
                                if todo["status"] == "in_progress"
                                else "❌"
                            )
                            print(f"{i + 1}. {status} {todo['content']}")
    except Exception as error:
        # A single-shot query() raises after yielding an error result,
        # such as when the max_turns limit is hit.
        print(f"Session ended with an error: {error}")


asyncio.run(main())

Real-time Progress Display

TypeScript

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

class TodoTracker {
  private todos: any[] = [];

  displayProgress() {
    if (this.todos.length === 0) return;

    const completed = this.todos.filter((t) => t.status === "completed").length;
    const inProgress = this.todos.filter((t) => t.status === "in_progress").length;
    const total = this.todos.length;

    console.log(`\nProgress: ${completed}/${total} completed`);
    console.log(`Currently working on: ${inProgress} task(s)\n`);

    this.todos.forEach((todo, index) => {
      const icon =
        todo.status === "completed" ? "✅" : todo.status === "in_progress" ? "🔧" : "❌";
      const text = todo.status === "in_progress" ? todo.activeForm : todo.content;
      console.log(`${index + 1}. ${icon} ${text}`);
    });
  }

  async trackQuery(prompt: string) {
    try {
      for await (const message of query({
        prompt,
        // Re-enable TodoWrite, which this tracker watches for.
        options: { maxTurns: 20, env: { ...process.env, CLAUDE_CODE_ENABLE_TASKS: "0" } }
      })) {
        if (message.type === "assistant") {
          for (const block of message.message.content) {
            if (block.type === "tool_use" && block.name === "TodoWrite") {
              this.todos = block.input.todos;
              this.displayProgress();
            }
          }
        }
      }
    } catch (error) {
      // A single-shot query() throws after yielding an error result,
      // such as when the maxTurns limit is hit.
      console.log(`Session ended with an error: ${error}`);
    }
  }
}

// Usage
const tracker = new TodoTracker();
await tracker.trackQuery("Build a complete authentication system with todos");

import asyncio

from claude_agent_sdk import query, ClaudeAgentOptions, AssistantMessage, ToolUseBlock
from typing import List, Dict


class TodoTracker:
    def __init__(self):
        self.todos: List[Dict] = []

    def display_progress(self):
        if not self.todos:
            return

        completed = len([t for t in self.todos if t["status"] == "completed"])
        in_progress = len([t for t in self.todos if t["status"] == "in_progress"])
        total = len(self.todos)

        print(f"\nProgress: {completed}/{total} completed")
        print(f"Currently working on: {in_progress} task(s)\n")

        for i, todo in enumerate(self.todos):
            icon = (
                "✅"
                if todo["status"] == "completed"
                else "🔧"
                if todo["status"] == "in_progress"
                else "❌"
            )
            text = (
                todo["activeForm"]
                if todo["status"] == "in_progress"
                else todo["content"]
            )
            print(f"{i + 1}. {icon} {text}")

    async def track_query(self, prompt: str):
        try:
            async for message in query(
                prompt=prompt,
                # Re-enable TodoWrite, which this tracker watches for.
                options=ClaudeAgentOptions(max_turns=20, env={"CLAUDE_CODE_ENABLE_TASKS": "0"}),
            ):
                if isinstance(message, AssistantMessage):
                    for block in message.content:
                        if isinstance(block, ToolUseBlock) and block.name == "TodoWrite":
                            self.todos = block.input["todos"]
                            self.display_progress()
        except Exception as error:
            # A single-shot query() raises after yielding an error result,
            # such as when the max_turns limit is hit.
            print(f"Session ended with an error: {error}")


# Usage
async def main():
    tracker = TodoTracker()
    await tracker.track_query("Build a complete authentication system with todos")


asyncio.run(main())

Migrate to Task tools

The Task tools split the single TodoWrite call into TaskCreate for each new item and TaskUpdate for each status change, with TaskList and TaskGet available for the model to read back the current list. Your monitoring code still inspects tool_use blocks in the assistant stream, but maintains a map keyed by task ID instead of replacing the whole list on every call. The Task tools are the default as of TypeScript Agent SDK 0.3.142 and Claude Code v2.1.142, so no options.env change is needed.

With TodoWrite	With Task tools
One tool call rewrites the full todos array	TaskCreate adds one item, TaskUpdate patches one item by taskId
Match block.name === "TodoWrite"	Match block.name === "TaskCreate" or "TaskUpdate"
Item shape: { content, status, activeForm }	TaskCreate input: { subject, description, activeForm?, metadata? }. TaskUpdate input: { taskId, status?, subject?, description?, activeForm?, addBlocks?, addBlockedBy?, owner?, metadata? }. status is "pending", "in_progress", or "completed"; set status: "deleted" to delete
Render block.input.todos directly	Accumulate items across calls, or read a snapshot from a TaskList tool result

The assigned task ID is not in the TaskCreate input. It comes back in the matching tool_result as { task: { id, subject } }, so capture it from the result block to key your map. The following example shows the minimal change to the Monitoring Todo Changes loop. It reads only tool_use inputs and skips capturing IDs from tool_result blocks. To render a complete list, watch for a TaskList tool result in the stream or accumulate TaskCreate results and TaskUpdate inputs into a map.

The streamed tool_use input is the raw shape the model emitted. Claude Code repairs some close-but-incorrect key names before execution, mapping id or task_id to taskId and active_form to activeForm, but that repair is not reflected in the stream. Read TaskUpdate input fields defensively, as the samples below do, rather than assuming the canonical name is always present.

TypeScript

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

try {
  for await (const message of query({
    prompt: "Optimize my React app performance and track progress with todos",
    options: { maxTurns: 15 },
  })) {
    if (message.type !== "assistant") continue;
    for (const block of message.message.content) {
      if (block.type !== "tool_use") continue;
      if (block.name === "TaskCreate") {
        const input = block.input as { subject: string };
        console.log(`+ ${input.subject}`);
      } else if (block.name === "TaskUpdate") {
        const input = block.input as {
          taskId?: string;
          id?: string;
          task_id?: string;
          status?: string;
        };
        const taskId = input.taskId ?? input.id ?? input.task_id;
        if (taskId && input.status) console.log(`  ${taskId} -> ${input.status}`);
      }
    }
  }
} catch (error) {
  // A single-shot query() throws after yielding an error result.
  console.log(`Session ended with an error: ${error}`);
}

import asyncio

from claude_agent_sdk import query, ClaudeAgentOptions, AssistantMessage, ToolUseBlock

async def main():
    try:
        async for message in query(
            prompt="Optimize my React app performance and track progress with todos",
            options=ClaudeAgentOptions(max_turns=15),
        ):
            if not isinstance(message, AssistantMessage):
                continue
            for block in message.content:
                if not isinstance(block, ToolUseBlock):
                    continue
                if block.name == "TaskCreate":
                    print(f"+ {block.input['subject']}")
                elif block.name == "TaskUpdate" and block.input.get("status"):
                    task_id = (
                        block.input.get("taskId")
                        or block.input.get("id")
                        or block.input.get("task_id")
                    )
                    if task_id:
                        print(f"  {task_id} -> {block.input['status']}")
    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())

Related Documentation

• TypeScript SDK Reference
• Python SDK Reference
• Streaming vs Single Mode
• Custom Tools