How to Create a Comment in a Task and Attach a File

Scope: disk, tasks

Who can execute the method: users with access to Drive and Task sections

If you are developing integrations for Bitrix24 using AI tools (Codex, Claude Code, Cursor), connect to the MCP server so that the assistant can utilize the official REST documentation.

Bitrix24 has two types of file fields:

File. This field is not linked to Drive; files are uploaded directly via a Base64 format string
File (Drive). This field is linked to Drive and stores the Drive object ID. Base64 format is not processed in this field, so the file must first be uploaded to Bitrix24 Drive

Task comments are stored in the Task chat. To create a comment with a file, perform the following methods sequentially:

disk.folder.uploadfile — uploads a file to Drive
tasks.task.get — returns the chatId of the Task chat
im.disk.file.commit — attaches a Drive file to the Task chat along with the comment text

1. Uploading a File to Bitrix24 Drive

To upload a file to Drive, use the disk.folder.uploadfile method with the following parameters:

id — specify the 1739 value — the identifier of the Drive folder where the file is being uploaded
data — specify the filename NAME; the file will be saved on Bitrix24 Drive with this name
fileContent — pass the file in the format ['filename.extension', 'file as a Base64 encoded string']

Uploading a file to Drive is a required step because the im.disk.file.commit method only attaches files to a comment that have already been uploaded to Bitrix24 Drive.

How to Use Examples in Documentation

PHP

Python

import { B24Hook } from '@bitrix24/b24jssdk'
        
        const $b24 = B24Hook.fromWebhookUrl('https://your-domain.bitrix24.com/rest/USER_ID/TOKEN/')
        
        const response = await $b24.actions.v2.call.make({
            method: 'disk.folder.uploadfile',
            params: {
                id: 1739,
                data: {
                    NAME: 'file.pdf'
                },
                fileContent: [
                    'file555.pdf',
                    '/9j/4AAQSkZJRgABAQEASABIAAD/2wBDAAQDAwQDAwQEAwQ///+dAYq6YFKoAv/AFnAa6ArKv8AAtFJVppxCEAulxQ2DWgfMR//2Q=='
                ]
            },
            requestId: 'disk-uploadfile'
        })
        
        if (!response.isSuccess) {
            throw new Error(response.getErrorMessages().join('; '))
        }
        
        const result = response.getData().result

require_once 'vendor/autoload.php';
        
        use Bitrix24\SDK\Services\ServiceBuilderFactory;
        use Symfony\Component\EventDispatcher\EventDispatcher;
        
        $serviceBuilder = (new ServiceBuilderFactory(new EventDispatcher(), $log))
            ->initFromWebhook('https://your-domain.bitrix24.com/rest/USER_ID/TOKEN/');
        
        $result = $serviceBuilder->getDiskScope()->folder()->uploadFile(
            1739,
            ['NAME' => 'file.pdf'],
            [
                'file555.pdf',
                '/9j/4AAQSkZJRgABAQEASABIAAD/2wBDAAQDAwQDAwQEAwQ///+dAYq6YFKoAv/AFnAa6ArKv8AAtFJVppxCEAulxQ2DWgfMR//2Q=='
            ]
        );

from b24pysdk import BitrixWebhook, Client
        
        client = Client(
            BitrixWebhook(
                domain="your-domain.bitrix24.com",
                webhook_token="user_id/webhook_key",
            )
        )
        
        response = client.disk.folder.uploadfile(
            bitrix_id=1739,
            data={
                "NAME": "file.pdf",
            },
            file_content=[
                "file555.pdf",
                "/9j/4AAQSkZJRgABAQEASABIAAD/2wBDAAQDAwQDAwQEAwQ///+dAYq6YFKoAv/AFnAa6ArKv8AAtFJVppxCEAulxQ2DWgfMR//2Q==",
            ],
        ).response

As a result of uploading the file to Drive, you receive two different file ID values:

FILE_ID: 28073 — the internal file ID value
ID: 6687 — the Drive object ID; use this value in methods when working with "File (Drive)" type fields
If you pass the FILE_ID value in a request to change a "File (Drive)" field, the file will either not be attached to the task because no Drive object exists with that ID, or the wrong file will be attached

{
            "result": {
                "ID": 6687,
                "NAME": "file.pdf",
                "CODE": null,
                "STORAGE_ID": "1",
                "TYPE": "file",
                "PARENT_ID": "1739",
                "DELETED_TYPE": 0,
                "GLOBAL_CONTENT_VERSION": 1,
                "FILE_ID": 28073,
                "SIZE": "405559",
                "CREATE_TIME": "2024-11-01T17:00:55+03:00",
                "UPDATE_TIME": "2024-11-01T17:00:55+03:00",
                "DELETE_TIME": null,
                "CREATED_BY": "1",
                "UPDATED_BY": "1",
                "DELETED_BY": null,
                "DOWNLOAD_URL": "https://your-domain.bitrix24.com/rest/download.json?sessid=9dd90ed5a58ccc41af81f5f0043739db&token=disk%7CaWQ9NjY4NyZfPTJ5ZXdvN2Fsb09SMGw1b0FHTkRMSGR5MFJkN1pLTjNS%7CImRvd25sb2FkfGRpc2t8YVdROU5qWTROeVpmUFRKNVpYZHZOMkZzYjA5U01HdzFiMEZIVGtSTVNHUjVNRkprTjFwTFRqTlN8OWRkOTBlZDVhNThjY2M0MWFmODFmNWYwMDQzNzM5ZGIi.Lup1vDbibL6twiCPfCMFnLSoDLleNX0cfMHGv5PFaJw%3D",
                "DETAIL_URL": "https://your-domain.bitrix24.com/company/personal/user/1/disk/file/Created files/New folder for process test/file.pdf"
            }
        }

2. Retrieving the Task Chat chatId

To attach a file to a comment, you need the Task chat identifier. Retrieve it using the tasks.task.get method with the following parameters:

taskId — the Task ID. To retrieve a Task ID, use the tasks.task.list method
select — specify the CHAT_ID field; the tasks.task.get method will not return the chat identifier without CHAT_ID in select

PHP

Python

const response = await $b24.actions.v2.call.make({
            method: 'tasks.task.get',
            params: {
                taskId: 3711,
                select: ['ID', 'CHAT_ID']
            },
            requestId: 'task-get'
        })
        
        if (!response.isSuccess) {
            throw new Error(response.getErrorMessages().join('; '))
        }
        
        const chatId = response.getData().result.task.chatId

$task = $serviceBuilder->core->call(
            'tasks.task.get',
            [
                'taskId' => 3711,
                'select' => ['ID', 'CHAT_ID']
            ]
        )->getResponseData()->getResult()['task'];
        
        $chatId = $task['chatId'];

task = client.tasks.task.get(
            bitrix_id=3711,
            select=["ID", "CHAT_ID"],
        ).response.result["task"]
        
        chat_id = task["chatId"]

As a result, you receive the chatId of the Task chat.

{
            "result": {
                "task": {
                    "id": "3711",
                    "chatId": 861
                }
            }
        }

3. Create a Comment with a File

The im.disk.file.commit method adds a Drive file to the task chat as a separate message — this is the comment with a file. Use the following parameters:

CHAT_ID — the chatId of the task chat from the previous method's result
FILE_ID — the ID of the Drive object 6687 from the disk.folder.uploadfile method result
MESSAGE — the comment text that will be sent along with the file

PHP

Python

const response = await $b24.actions.v2.call.make({
            method: 'im.disk.file.commit',
            params: {
                CHAT_ID: 861,
                FILE_ID: 6687,
                MESSAGE: 'comment for test'
            },
            requestId: 'im-disk-file-commit'
        })
        
        if (!response.isSuccess) {
            throw new Error(response.getErrorMessages().join('; '))
        }
        
        const result = response.getData().result

$result = $serviceBuilder->getIMScope()->disk()->commitFile(
            chatId: 861,
            fileId: 6687,
            message: 'comment for test'
        );

token = BitrixWebhook(
            domain="your-domain.bitrix24.com",
            webhook_token="user_id/webhook_key",
        )
        
        result = token.call_method(
            "im.disk.file.commit",
            {
                "CHAT_ID": 861,
                "FILE_ID": 6687,
                "MESSAGE": "comment for test",
            },
        )

The comment with a file has been created. The method returns the MESSAGE_ID of the message in the task chat and the DISK_ID of the file added to the chat.

{
            "result": {
                "FILES": {
                    "disk1899": {
                        "id": 1903,
                        "chatId": 861,
                        "type": "file",
                        "name": "file.pdf",
                        "extension": "pdf",
                        "size": 70,
                        "status": "done",
                        "authorId": 1
                    }
                },
                "DISK_ID": [
                    1903
                ],
                "MESSAGE_ID": 6175
            }
        }

The MESSAGE_ID field is the identifier of the message with the file in the task chat, and DISK_ID is the identifier of the file in the chat. The comment with a file is displayed in the task chat.

Code Example

PHP

Python

import { B24Hook } from '@bitrix24/b24jssdk'
        
        const $b24 = B24Hook.fromWebhookUrl('https://your-domain.bitrix24.com/rest/USER_ID/TOKEN/')
        
        // Function for uploading a file
        async function uploadFileToDisk() {
            // Folder ID where the file needs to be uploaded
            const folderId = 'folder_ID';
            // File name and its content in Base64 format
            const fileName = 'file_name';
            const fileContentBase64 = 'file_content_Base64';
        
            // Calling the disk.folder.uploadfile method
            const response = await $b24.actions.v2.call.make({
                method: 'disk.folder.uploadfile',
                params: {
                    id: folderId,
                    data: {
                        NAME: fileName
                    },
                    fileContent: [
                        fileName,
                        fileContentBase64
                    ]
                },
                requestId: 'disk-uploadfile'
            });
        
            if (!response.isSuccess) {
                console.error('Error while uploading the file:', response.getErrorMessages().join('; '));
                return;
            }
        
            console.log('File uploaded successfully!', response.getData().result);
            const fileId = response.getData().result.ID; // Using the ID from the result
            await createCommentWithFile(fileId);
        }
        
        // Function for creating a comment with a file
        async function createCommentWithFile(fileId) {
            // Comment parameters
            const taskID = 'task_ID';
            const commentMessage = 'comment_text';
        
            // Getting the task chat's chatId
            const taskResponse = await $b24.actions.v2.call.make({
                method: 'tasks.task.get',
                params: {
                    taskId: taskID,
                    select: ['ID', 'CHAT_ID']
                },
                requestId: 'task-get'
            });
        
            if (!taskResponse.isSuccess) {
                console.error('Error while getting the task:', taskResponse.getErrorMessages().join('; '));
                return;
            }
        
            const chatId = taskResponse.getData().result.task.chatId;
        
            // Attaching the file to the task chat along with the comment text
            const fileResponse = await $b24.actions.v2.call.make({
                method: 'im.disk.file.commit',
                params: {
                    CHAT_ID: chatId,
                    FILE_ID: fileId,
                    MESSAGE: commentMessage
                },
                requestId: 'im-disk-file-commit'
            });
        
            if (!fileResponse.isSuccess) {
                console.error('Error while creating a comment:', fileResponse.getErrorMessages().join('; '));
                return;
            }
        
            console.log('Comment with file created successfully!', fileResponse.getData().result);
        }
        
        // Calling the function to upload a file and create a comment
        await uploadFileToDisk();
        
        $b24.destroy();

require_once 'vendor/autoload.php';
        
        use Bitrix24\SDK\Services\ServiceBuilderFactory;
        use Bitrix24\SDK\Core\Exceptions\BaseException;
        use Symfony\Component\EventDispatcher\EventDispatcher;
        
        $serviceBuilder = (new ServiceBuilderFactory(new EventDispatcher(), $log))
            ->initFromWebhook('https://your-domain.bitrix24.com/rest/USER_ID/TOKEN/');
        
        // Function for uploading a file
        function uploadFileToDisk($serviceBuilder) {
            // Folder ID where the file needs to be uploaded
            $folderId = 'folder_ID';
            // The name of the file you want to upload
            $fileName = 'file_name';
            // Path to the file on your file system
            $filePath = '/path/to/your/file';
        
            // Reading the file content and encoding it in Base64
            $fileContentBase64 = base64_encode(file_get_contents($filePath));
        
            // Calling the disk.folder.uploadfile method
            try {
                $result = $serviceBuilder->getDiskScope()->folder()->uploadFile(
                    (int)$folderId,
                    ['NAME' => $fileName],
                    [
                        $fileName,
                        $fileContentBase64
                    ]
                );
            } catch (BaseException $e) {
                echo 'Error while uploading the file: ' . $e->getMessage();
                return;
            }
        
            echo 'File uploaded successfully!';
            $fileId = $result->getId(); // Using the ID from the result
            createCommentWithFile($serviceBuilder, $fileId);
        }
        
        // Function for creating a comment with a file
        function createCommentWithFile($serviceBuilder, $fileId) {
            // Comment parameters
            $taskID = 'task_ID';
            $commentMessage = 'comment_text';
        
            // Getting the task chat's chatId
            try {
                $task = $serviceBuilder->core->call(
                    'tasks.task.get',
                    [
                        'taskId' => $taskID,
                        'select' => ['ID', 'CHAT_ID']
                    ]
                )->getResponseData()->getResult()['task'];
            } catch (BaseException $e) {
                echo 'Error while getting the task: ' . $e->getMessage();
                return;
            }
        
            $chatId = $task['chatId'];
        
            // Attaching the file to the task chat along with the comment text
            try {
                $serviceBuilder->getIMScope()->disk()->commitFile(
                    chatId: (int)$chatId,
                    fileId: $fileId,
                    message: $commentMessage
                );
            } catch (BaseException $e) {
                echo 'Error while creating a comment: ' . $e->getMessage();
                return;
            }
        
            echo 'Comment with file created successfully!';
        }
        
        // Calling the function to upload a file and create a comment
        uploadFileToDisk($serviceBuilder);

from b24pysdk import BitrixWebhook, Client
        from b24pysdk.errors import BitrixAPIError
        
        webhook = BitrixWebhook(
            domain="your-domain.bitrix24.com",
            webhook_token="user_id/webhook_key",
        )
        client = Client(webhook)
        
        def upload_file_to_drive(client):
            folder_id = 1739
            file_name = "file_name"
            file_content_base64 = "file_content_Base64"
        
            try:
                result = client.disk.folder.uploadfile(
                    bitrix_id=folder_id,
                    data={"NAME": file_name},
                    file_content=[file_name, file_content_base64],
                ).response.result
            except BitrixAPIError as error:
                print(f"File upload error: {error}")
            else:
                print("File uploaded successfully!")
                file_id = result["ID"]
                create_comment_with_file(client, file_id)
        
        def create_comment_with_file(client, file_id):
            task_id = "task_ID"
            comment_message = "comment_text"
        
            # Getting the task chat's chatId
            try:
                task = client.tasks.task.get(
                    bitrix_id=task_id,
                    select=["ID", "CHAT_ID"],
                ).response.result["task"]
            except BitrixAPIError as error:
                print(f"Task retrieval error: {error}")
                return
        
            chat_id = task["chatId"]
        
            # Attaching the file to the task chat along with the comment text
            try:
                webhook.call_method(
                    "im.disk.file.commit",
                    {
                        "CHAT_ID": chat_id,
                        "FILE_ID": file_id,
                        "MESSAGE": comment_message,
                    },
                )
            except BitrixAPIError as error:
                print(f"Comment creation error: {error}")
            else:
                print("Comment with file created successfully!")
        
        upload_file_to_drive(client)

Was the article helpful?

How to upload a file to a task

How to attach a task to an SPA

How to Create a Comment in a Task and Attach a File

1. Uploading a File to Bitrix24 Drive1. Uploading a File to Bitrix24 Drive

2. Retrieving the Task Chat chatId2. Retrieving the Task Chat chatId

3. Create a Comment with a File3. Create a Comment with a File

Code ExampleCode Example

Was the article helpful?

1. Uploading a File to Bitrix24 Drive

2. Retrieving the Task Chat chatId

3. Create a Comment with a File

Code Example