Attach Files to Task tasks.task.files.attach

Scope: task

Who can execute the method: task Creator or a user with edit access to the task

The method tasks.task.files.attach adds a file from Disk to a task. The user must have read access or higher to the file.

Method Parameters

Required parameters are marked with *

Name
type

Description

taskId*
integer

The identifier of the task to which the file needs to be attached.

The task identifier can be obtained when creating a new task or by using the getting the list of tasks method.

fileId*
integer

The identifier of the file on Disk.

The file identifier can be obtained in two ways.

Use one of the file upload methods:

Use one of the methods to get the list of files:

Code Examples

How to Use Examples in Documentation

cURL (Webhook)

cURL (OAuth)

PHP

BX24.js

PHP CRest

curl -X POST \
        -H "Content-Type: application/json" \
        -H "Accept: application/json" \
        -d '{"taskId":8017,"fileId":1065}' \
        https://**put_your_bitrix24_address**/rest/**put_your_user_id_here**/**put_your_webhook_here**/tasks.task.files.attach

curl -X POST \
        -H "Content-Type: application/json" \
        -H "Accept: application/json" \
        -d '{"taskId":8017,"fileId":1065,"auth":"**put_access_token_here**"}' \
        https://**put_your_bitrix24_address**/rest/tasks.task.files.attach

try
        {
            const response = await $b24.callMethod(
                'tasks.task.files.attach',
                {
                    taskId: 8017,
                    fileId: 1065
                }
            );
            
            const result = response.getData().result;
            console.log('File attached:', result);
            
            processResult(result);
        }
        catch( error )
        {
            console.error('Error:', error);
        }

try {
            $response = $b24Service
                ->core
                ->call(
                    'tasks.task.files.attach',
                    [
                        'taskId' => 8017,
                        'fileId' => 1065
                    ]
                );
        
            $result = $response
                ->getResponseData()
                ->getResult();
        
            echo 'Success: ' . print_r($result, true);
            processData($result);
        
        } catch (Throwable $e) {
            error_log($e->getMessage());
            echo 'Error attaching file: ' . $e->getMessage();
        }

BX24.callMethod(
            'tasks.task.files.attach',
            {
                taskId: 8017,
                fileId: 1065
            },
            function(result){
                console.info(result.data());
                console.log(result);
            }
        );

require_once('crest.php');
        
        $result = CRest::call(
            'tasks.task.files.attach',
            [
                'taskId' => 8017,
                'fileId' => 1065
            ]
        );
        
        echo '<PRE>';
        print_r($result);
        echo '</PRE>';

Response Handling

HTTP Status: 200

{
            "result": {
                "attachmentId": 1079
            },
            "time": {
                "start": 1758806783,
                "finish": 1758806783.609955,
                "duration": 0.6099550724029541,
                "processing": 0,
                "date_start": "2025-09-25T16:26:23+02:00",
                "date_finish": "2025-09-25T16:26:23+02:00",
                "operating_reset_at": 1758807383,
                "operating": 0.4156019687652588
            }
        }

Returned Data

Name `type`	Description
result `object`	The root element of the response. Contains an object with the description of the attached file
attachmentId `integer`	The identifier of the file attachment to the task. Data about the file can be obtained by the attachment identifier using the disk.attachedObject.get method
time `time`	Information about the execution time of the request

Error Handling

HTTP Status: 400

{
            "error": "100",
            "error_description": "Could not find value for parameter {fileId} (internal error)"
        }

Name `type`	Description
error `string`	String error code. It may consist of digits, Latin letters, and underscores
error_description `error_description`	Textual description of the error. The description is not intended to be shown to the end user in its raw form

Possible Error Codes

Code	Description	Value
`100`	CTaskItem All parameters in the constructor must have real class type (internal error)	Required parameter `taskId` is missing
`0`	wrong task id (internal error)	The value in the `taskId` parameter is of an incorrect type
`100`	Could not find value for parameter {fileId} (internal error)	Required parameter `fileId` is missing
`100`	Invalid value {value} to match with parameter {fileId}. Should be value of type int. (internal error)	The value in the `fileId` parameter is of an incorrect type
`ERROR_CORE`	Insufficient permissions.\u003Cbr\u003E	No access to the specified file
`0`	Access denied (internal error)	Insufficient permissions to modify the task

Statuses and System Error Codes

HTTP Status: 20x, 40x, 50x

The errors described below may occur when calling any method.

Status	Code Error Message	Description
`500`	`INTERNAL_SERVER_ERROR` Internal server error	An internal server error has occurred, please contact the server administrator or Bitrix24 technical support
`500`	`ERROR_UNEXPECTED_ANSWER` Server returned an unexpected response	An internal server error has occurred, please contact the server administrator or Bitrix24 technical support
`503`	`QUERY_LIMIT_EXCEEDED` Too many requests	The request intensity limit has been exceeded
`405`	`ERROR_BATCH_METHOD_NOT_ALLOWED` Method is not allowed for batch usage	The current method is not allowed to be called using batch
`400`	`ERROR_BATCH_LENGTH_EXCEEDED` Max batch length exceeded	The maximum length of parameters passed to the batch method has been exceeded
`401`	`NO_AUTH_FOUND` Wrong authorization data	Invalid access token or webhook code
`400`	`INVALID_REQUEST` Https required	The methods must be called using the HTTPS protocol
`503`	`OVERLOAD_LIMIT` REST API is blocked due to overload	The REST API is blocked due to overload. This is a manual individual block, to remove it you need to contact Bitrix24 technical support
`403`	`ACCESS_DENIED` REST API is available only on commercial plans	The REST API is available only on commercial plans
`403`	`INVALID_CREDENTIALS` Invalid request credentials	The user whose access token or webhook was used to call the method lacks permissions
`404`	`ERROR_MANIFEST_IS_NOT_AVAILABLE` Manifest is not available	The manifest is not available
`403`	`insufficient_scope` The request requires higher privileges than provided by the webhook token	The request requires higher privileges than those provided by the webhook token
`401`	`expired_token` The access token provided has expired	The provided access token has expired
`403`	`user_access_error` The user does not have access to the application	The user does not have access to the application. This means that the application is installed, but the account administrator has allowed access to this application only for specific users
`500`	`PORTAL_DELETED` Portal was deleted	The public part of the site is closed. To open the public part of the site on an on-premise installation, disable the option "Temporary closure of the public part of the site". Path to the setting: Desktop > Settings > Product Settings > Module Settings > Main Module > Temporary closure of the public part of the site

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Check Access to Task

Get User Counters

Attach Files to Task tasks.task.files.attach

Method ParametersMethod Parameters

Code ExamplesCode Examples

Response HandlingResponse Handling

Returned DataReturned Data

Error HandlingError Handling

Possible Error CodesPossible Error Codes

Statuses and System Error CodesStatuses and System Error Codes

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