Track file changes during agent sessions and restore files to any previous state
File checkpointing tracks file modifications made through the Write, Edit, and NotebookEdit tools during an agent session, allowing you to rewind files to any previous state. Want to try it out? Jump to the interactive example.With checkpointing, you can:
Undo unwanted changes by restoring files to a known good state
Explore alternatives by restoring to a checkpoint and trying a different approach
Recover from errors when the agent makes incorrect modifications
Only changes made through the Write, Edit, and NotebookEdit tools are tracked. Changes made through Bash commands (like echo > file.txt or sed -i) are not captured by the checkpoint system.
When you enable file checkpointing, the SDK creates backups of files before modifying them through the Write, Edit, or NotebookEdit tools. User messages in the response stream include a checkpoint UUID that you can use as a restore point.Checkpoint works with these built-in tools that the agent uses to modify files:
Tool
Description
Write
Creates a new file or overwrites an existing file with new content
Edit
Makes targeted edits to specific parts of an existing file
NotebookEdit
Modifies cells in Jupyter notebooks (.ipynb files)
File rewinding restores files on disk to a previous state. It does not rewind the conversation itself. The conversation history and context remain intact after calling rewindFiles() (TypeScript) or rewind_files() (Python).
The checkpoint system tracks:
Files created during the session
Files modified during the session
The original content of modified files
When you rewind to a checkpoint, created files are deleted and modified files are restored to their content at that point.
To use file checkpointing, enable it in your options, capture checkpoint UUIDs from the response stream, then call rewindFiles() (TypeScript) or rewind_files() (Python) when you need to restore.The following example shows the complete flow: enable checkpointing, capture the checkpoint UUID and session ID from the response stream, then resume the session later to rewind files. Each step is explained in detail below. The examples in this section use the prompt “Refactor the authentication module”. Run them in a project that contains an authentication module, or change the prompt to name files that exist in your project, so you can watch files change and see the rewind restore them.
import asynciofrom claude_agent_sdk import ( ClaudeSDKClient, ClaudeAgentOptions, UserMessage, ResultMessage,)async def main(): # Step 1: Enable checkpointing options = ClaudeAgentOptions( enable_file_checkpointing=True, permission_mode="acceptEdits", # Auto-accept file edits without prompting extra_args={ "replay-user-messages": None }, # Required to receive checkpoint UUIDs in the response stream ) checkpoint_id = None session_id = None # Run the query and capture checkpoint UUID and session ID async with ClaudeSDKClient(options) as client: await client.query("Refactor the authentication module") # Step 2: Capture checkpoint UUID from the first user message async for message in client.receive_response(): if isinstance(message, UserMessage) and message.uuid and not checkpoint_id: checkpoint_id = message.uuid if isinstance(message, ResultMessage) and not session_id: session_id = message.session_id # Step 3: Later, rewind by resuming the session with an empty prompt if checkpoint_id and session_id: async with ClaudeSDKClient( ClaudeAgentOptions(enable_file_checkpointing=True, resume=session_id) ) as client: await client.query("") # Empty prompt to open the connection async for message in client.receive_response(): await client.rewind_files(checkpoint_id) break print(f"Rewound to checkpoint: {checkpoint_id}")asyncio.run(main())
import { query } from "@anthropic-ai/claude-agent-sdk";async function main() { // Step 1: Enable checkpointing const opts = { enableFileCheckpointing: true, permissionMode: "acceptEdits" as const, // Auto-accept file edits without prompting extraArgs: { "replay-user-messages": null } // Required to receive checkpoint UUIDs in the response stream }; const response = query({ prompt: "Refactor the authentication module", options: opts }); let checkpointId: string | undefined; let sessionId: string | undefined; // Step 2: Capture checkpoint UUID from the first user message for await (const message of response) { if (message.type === "user" && message.uuid && !checkpointId) { checkpointId = message.uuid; } if ("session_id" in message && !sessionId) { sessionId = message.session_id; } } // Step 3: Later, rewind by resuming the session with an empty prompt if (checkpointId && sessionId) { const rewindQuery = query({ prompt: "", // Empty prompt to open the connection options: { ...opts, resume: sessionId } }); for await (const msg of rewindQuery) { await rewindQuery.rewindFiles(checkpointId); break; } console.log(`Rewound to checkpoint: ${checkpointId}`); }}main();
1
Enable checkpointing
Configure your SDK options to enable checkpointing and receive checkpoint UUIDs:
Option
Python
TypeScript
Description
Enable checkpointing
enable_file_checkpointing=True
enableFileCheckpointing: true
Tracks file changes for rewinding
Receive checkpoint UUIDs
extra_args={"replay-user-messages": None}
extraArgs: { 'replay-user-messages': null }
Required to get user message UUIDs in the stream
options = ClaudeAgentOptions( enable_file_checkpointing=True, permission_mode="acceptEdits", extra_args={"replay-user-messages": None},)async with ClaudeSDKClient(options) as client: await client.query("Refactor the authentication module")
With the replay-user-messages option set (shown above), each user message in the response stream has a UUID that serves as a checkpoint.For most use cases, capture the first user message UUID (message.uuid); rewinding to it restores all files to their original state. To store multiple checkpoints and rewind to intermediate states, see Multiple restore points.Capturing the session ID (message.session_id) is optional; you only need it if you want to rewind later, after the stream completes. If you’re calling rewindFiles() immediately while still processing messages (as the example in Checkpoint before risky operations does), you can skip capturing the session ID.
checkpoint_id = Nonesession_id = Noneasync for message in client.receive_response(): # Capture the first user message UUID as the checkpoint if isinstance(message, UserMessage) and message.uuid and checkpoint_id is None: checkpoint_id = message.uuid # Capture session ID from the result message if isinstance(message, ResultMessage): session_id = message.session_id
let checkpointId: string | undefined;let sessionId: string | undefined;for await (const message of response) { // Capture the first user message UUID as the checkpoint if (message.type === "user" && message.uuid && !checkpointId) { checkpointId = message.uuid; } // Capture session ID from any message that has it if ("session_id" in message) { sessionId = message.session_id; }}
3
Rewind files
To rewind after the stream completes, resume the session with an empty prompt and call rewind_files() (Python) or rewindFiles() (TypeScript) with your checkpoint UUID. You can also rewind during the stream; see Checkpoint before risky operations for that pattern.
async with ClaudeSDKClient( ClaudeAgentOptions(enable_file_checkpointing=True, resume=session_id)) as client: await client.query("") # Empty prompt to open the connection async for message in client.receive_response(): await client.rewind_files(checkpoint_id) break
const rewindQuery = query({ prompt: "", // Empty prompt to open the connection options: { ...opts, resume: sessionId }});for await (const msg of rewindQuery) { await rewindQuery.rewindFiles(checkpointId); break;}
If you capture the session ID and checkpoint ID, you can also rewind from the CLI. This command requires the claude executable, which comes from installing Claude Code and is not installed by the SDK package. The SDK enables checkpointing for you, but when you run claude -p directly you must set the CLAUDE_CODE_ENABLE_SDK_FILE_CHECKPOINTING environment variable:
CLAUDE_CODE_ENABLE_SDK_FILE_CHECKPOINTING=true claude -p --resume <session-id> --rewind-files <checkpoint-uuid>
The --rewind-files flag does not appear in claude --help output, but the CLI accepts it as shown.
This pattern keeps only the most recent checkpoint UUID, updating it before each agent turn. If something goes wrong during processing, you can immediately rewind to the last safe state and break out of the loop.Before running this example, replace your_revert_condition (Python) or yourRevertCondition (TypeScript) with your own check, such as error detection or a validation failure; the placeholder is not defined in the example.
import asynciofrom claude_agent_sdk import ClaudeSDKClient, ClaudeAgentOptions, UserMessageasync def main(): options = ClaudeAgentOptions( enable_file_checkpointing=True, permission_mode="acceptEdits", extra_args={"replay-user-messages": None}, ) safe_checkpoint = None async with ClaudeSDKClient(options) as client: await client.query("Refactor the authentication module") async for message in client.receive_response(): # Update checkpoint before each agent turn starts # This overwrites the previous checkpoint. Only keep the latest if isinstance(message, UserMessage) and message.uuid: safe_checkpoint = message.uuid # Decide when to revert based on your own logic # For example: error detection, validation failure, or user input if your_revert_condition and safe_checkpoint: await client.rewind_files(safe_checkpoint) # Exit the loop after rewinding, files are restored breakasyncio.run(main())
import { query } from "@anthropic-ai/claude-agent-sdk";async function main() { const response = query({ prompt: "Refactor the authentication module", options: { enableFileCheckpointing: true, permissionMode: "acceptEdits" as const, extraArgs: { "replay-user-messages": null } } }); let safeCheckpoint: string | undefined; for await (const message of response) { // Update checkpoint before each agent turn starts // This overwrites the previous checkpoint. Only keep the latest if (message.type === "user" && message.uuid) { safeCheckpoint = message.uuid; } // Decide when to revert based on your own logic // For example: error detection, validation failure, or user input if (yourRevertCondition && safeCheckpoint) { await response.rewindFiles(safeCheckpoint); // Exit the loop after rewinding, files are restored break; } }}main();
If Claude makes changes across multiple turns, you might want to rewind to a specific point rather than all the way back. For example, if Claude refactors a file in turn one and adds tests in turn two, you might want to keep the refactor but undo the tests.This pattern stores all checkpoint UUIDs in an array with metadata. After the session completes, you can rewind to any previous checkpoint:
import asynciofrom dataclasses import dataclassfrom datetime import datetimefrom claude_agent_sdk import ( ClaudeSDKClient, ClaudeAgentOptions, UserMessage, ResultMessage,)# Store checkpoint metadata for better tracking@dataclassclass Checkpoint: id: str description: str timestamp: datetimeasync def main(): options = ClaudeAgentOptions( enable_file_checkpointing=True, permission_mode="acceptEdits", extra_args={"replay-user-messages": None}, ) checkpoints = [] session_id = None async with ClaudeSDKClient(options) as client: await client.query("Refactor the authentication module") async for message in client.receive_response(): if isinstance(message, UserMessage) and message.uuid: checkpoints.append( Checkpoint( id=message.uuid, description=f"After turn {len(checkpoints) + 1}", timestamp=datetime.now(), ) ) if isinstance(message, ResultMessage) and not session_id: session_id = message.session_id # Later: rewind to any checkpoint by resuming the session if checkpoints and session_id: target = checkpoints[0] # Pick any checkpoint async with ClaudeSDKClient( ClaudeAgentOptions(enable_file_checkpointing=True, resume=session_id) ) as client: await client.query("") # Empty prompt to open the connection async for message in client.receive_response(): await client.rewind_files(target.id) break print(f"Rewound to: {target.description}")asyncio.run(main())
import { query } from "@anthropic-ai/claude-agent-sdk";// Store checkpoint metadata for better trackinginterface Checkpoint { id: string; description: string; timestamp: Date;}async function main() { const opts = { enableFileCheckpointing: true, permissionMode: "acceptEdits" as const, extraArgs: { "replay-user-messages": null } }; const response = query({ prompt: "Refactor the authentication module", options: opts }); const checkpoints: Checkpoint[] = []; let sessionId: string | undefined; for await (const message of response) { if (message.type === "user" && message.uuid) { checkpoints.push({ id: message.uuid, description: `After turn ${checkpoints.length + 1}`, timestamp: new Date() }); } if ("session_id" in message && !sessionId) { sessionId = message.session_id; } } // Later: rewind to any checkpoint by resuming the session if (checkpoints.length > 0 && sessionId) { const target = checkpoints[0]; // Pick any checkpoint const rewindQuery = query({ prompt: "", // Empty prompt to open the connection options: { ...opts, resume: sessionId } }); for await (const msg of rewindQuery) { await rewindQuery.rewindFiles(target.id); break; } console.log(`Rewound to: ${target.description}`); }}main();
This complete example creates a small utility file, has the agent add documentation comments, shows you the changes, then asks if you want to rewind.Before you begin, make sure you have the Claude Agent SDK installed.
1
Create a test file
Create a new file called utils.py (Python) or utils.ts (TypeScript) and paste the following code:
def add(a, b): return a + bdef subtract(a, b): return a - bdef multiply(a, b): return a * bdef divide(a, b): if b == 0: raise ValueError("Cannot divide by zero") return a / b
export function add(a: number, b: number): number { return a + b;}export function subtract(a: number, b: number): number { return a - b;}export function multiply(a: number, b: number): number { return a * b;}export function divide(a: number, b: number): number { if (b === 0) { throw new Error("Cannot divide by zero"); } return a / b;}
2
Run the interactive example
Create a new file called try_checkpointing.py (Python) or try_checkpointing.ts (TypeScript) in the same directory as your utility file, and paste the following code.This script asks Claude to add doc comments to your utility file, then gives you the option to rewind and restore the original.
import asynciofrom claude_agent_sdk import ( ClaudeSDKClient, ClaudeAgentOptions, UserMessage, ResultMessage,)async def main(): # Configure the SDK with checkpointing enabled # - enable_file_checkpointing: Track file changes for rewinding # - permission_mode: Auto-accept file edits without prompting # - extra_args: Required to receive user message UUIDs in the stream options = ClaudeAgentOptions( enable_file_checkpointing=True, permission_mode="acceptEdits", extra_args={"replay-user-messages": None}, ) checkpoint_id = None # Store the user message UUID for rewinding session_id = None # Store the session ID for resuming print("Running agent to add doc comments to utils.py...\n") # Run the agent and capture checkpoint data from the response stream async with ClaudeSDKClient(options) as client: await client.query("Add doc comments to utils.py") async for message in client.receive_response(): # Capture the first user message UUID - this is our restore point if isinstance(message, UserMessage) and message.uuid and not checkpoint_id: checkpoint_id = message.uuid # Capture the session ID so we can resume later if isinstance(message, ResultMessage): session_id = message.session_id print("Done! Open utils.py to see the added doc comments.\n") # Ask the user if they want to rewind the changes if checkpoint_id and session_id: response = input("Rewind to remove the doc comments? (y/n): ") if response.lower() == "y": # Resume the session with an empty prompt, then rewind async with ClaudeSDKClient( ClaudeAgentOptions(enable_file_checkpointing=True, resume=session_id) ) as client: await client.query("") # Empty prompt opens the connection async for message in client.receive_response(): await client.rewind_files(checkpoint_id) # Restore files break print( "\n✓ File restored! Open utils.py to verify the doc comments are gone." ) else: print("\nKept the modified file.")asyncio.run(main())
import { query } from "@anthropic-ai/claude-agent-sdk";import * as readline from "readline";async function main() { // Configure the SDK with checkpointing enabled // - enableFileCheckpointing: Track file changes for rewinding // - permissionMode: Auto-accept file edits without prompting // - extraArgs: Required to receive user message UUIDs in the stream const opts = { enableFileCheckpointing: true, permissionMode: "acceptEdits" as const, extraArgs: { "replay-user-messages": null } }; let sessionId: string | undefined; // Store the session ID for resuming let checkpointId: string | undefined; // Store the user message UUID for rewinding console.log("Running agent to add doc comments to utils.ts...\n"); // Run the agent and capture checkpoint data from the response stream const response = query({ prompt: "Add doc comments to utils.ts", options: opts }); for await (const message of response) { // Capture the first user message UUID - this is our restore point if (message.type === "user" && message.uuid && !checkpointId) { checkpointId = message.uuid; } // Capture the session ID so we can resume later if ("session_id" in message) { sessionId = message.session_id; } } console.log("Done! Open utils.ts to see the added doc comments.\n"); // Ask the user if they want to rewind the changes if (checkpointId && sessionId) { const rl = readline.createInterface({ input: process.stdin, output: process.stdout }); const answer = await new Promise<string>((resolve) => { rl.question("Rewind to remove the doc comments? (y/n): ", resolve); }); rl.close(); if (answer.toLowerCase() === "y") { // Resume the session with an empty prompt, then rewind const rewindQuery = query({ prompt: "", // Empty prompt opens the connection options: { ...opts, resume: sessionId } }); for await (const msg of rewindQuery) { await rewindQuery.rewindFiles(checkpointId); // Restore files break; } console.log("\n✓ File restored! Open utils.ts to verify the doc comments are gone."); } else { console.log("\nKept the modified file."); } }}main();
This example demonstrates the complete checkpointing workflow:
Enable checkpointing: configure the SDK with enable_file_checkpointing=True and permission_mode="acceptEdits" to auto-approve file edits
Capture checkpoint data: as the agent runs, store the first user message UUID (your restore point) and the session ID
Prompt for rewind: after the agent finishes, check your utility file to see the doc comments, then decide if you want to undo the changes
Resume and rewind: if yes, resume the session with an empty prompt and call rewind_files() to restore the original file
3
Run the example
Run the script from the same directory as your utility file.
Open your utility file (utils.py or utils.ts) in your IDE or editor before running the script. You’ll see the file update in real-time as the agent adds doc comments, then revert back to the original when you choose to rewind.
Python
TypeScript
python try_checkpointing.py
npx tsx try_checkpointing.ts
You’ll see the agent add doc comments, then a prompt asking if you want to rewind. If you choose yes, the file is restored to its original state.
If message.uuid is undefined or missing, you’re not receiving checkpoint UUIDs.Cause: The replay-user-messages option isn’t set.Solution: Add extra_args={"replay-user-messages": None} (Python) or extraArgs: { 'replay-user-messages': null } (TypeScript) to your options.
This error occurs when the checkpoint data doesn’t exist for the specified user message UUID.Common causes:
File checkpointing was not enabled on the original session (enable_file_checkpointing or enableFileCheckpointing was not set to true)
The session wasn’t properly completed before attempting to resume and rewind
Solution: Ensure enable_file_checkpointing=True (Python) or enableFileCheckpointing: true (TypeScript) was set on the original session, then use the pattern shown in the examples: capture the first user message UUID, complete the session fully, then resume with an empty prompt and call rewindFiles() once.
This error occurs when you attempt a non-interactive rewind without checkpointing enabled: running bare claude -p with --rewind-files, or running an SDK session, including a resumed one, whose options don’t enable checkpointing. The SDK sets the CLAUDE_CODE_ENABLE_SDK_FILE_CHECKPOINTING environment variable internally only when enable_file_checkpointing (Python) or enableFileCheckpointing (TypeScript) is enabled on the session performing the rewind; the bare CLI never sets it.Solution: For the bare CLI, set the environment variable when running the command:
CLAUDE_CODE_ENABLE_SDK_FILE_CHECKPOINTING=true claude -p --resume <session-id> --rewind-files <checkpoint-uuid>
For the SDK, set enable_file_checkpointing=True (Python) or enableFileCheckpointing: true (TypeScript) on the resumed session, as the examples on this page do.
This error occurs when you call rewindFiles() or rewind_files() after you’ve finished iterating through the response. The connection to the CLI process closes when the loop completes.Solution: Resume the session with an empty prompt, then call rewind on the new query:
# Resume session with empty prompt, then rewindasync with ClaudeSDKClient( ClaudeAgentOptions(enable_file_checkpointing=True, resume=session_id)) as client: await client.query("") async for message in client.receive_response(): await client.rewind_files(checkpoint_id) break
// Resume session with empty prompt, then rewindconst rewindQuery = query({ prompt: "", options: { ...opts, resume: sessionId }});for await (const msg of rewindQuery) { await rewindQuery.rewindFiles(checkpointId); break;}
Sessions: learn how to resume sessions, which is required for rewinding after the stream completes. Covers session IDs, resuming conversations, and session forking.
Permissions: configure which tools Claude can use and how file modifications are approved. Useful if you want more control over when edits happen.
TypeScript SDK reference: complete API reference including all options for query() and the rewindFiles() method.
Python SDK reference: complete API reference including all options for ClaudeAgentOptions and the rewind_files() method.