Upload a File to Document note.file.add

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.

Scope: note

Who can execute the method: a user with access to the Knowledge base module and "Edit" permissions for the document Knowledge base

The note.file.add method uploads a file to a document and returns a file object.

The method does not automatically insert the attachment into the document content. It only saves the file and links it to the document.

Method Parameters

Required parameters are marked with *

Name `type`	Description
documentId* `integer`	Identifier of the document to which the file should be attached. The identifier can be obtained using the note.document.tree.list method
fileName* `string`	File name with extension. Allowed extensions: `png`, `jpg`, `jpeg`, `gif`, `webp`, `svg`, `pdf`, `txt`, `md`, `csv`, `doc`, `docx`, `xls`, `xlsx`, `ppt`, `pptx`, `mp4`, `webm`, `mov`
fileContent* `string`	Binary file content in Base64 encoding. The maximum file size depends on the `main.max_file_size` setting in Bitrix24. If it is not set, the `25 MiB (25 * 1024 * 1024 bytes)` limit is used

Code Examples

How to Use Examples in Documentation

The new API call differs by adding the /api/ segment to the request URL:

https://{installation_address}/rest/api/{user_id}/{webhook_token}/note.file.add

cURL (Webhook)

cURL (OAuth)

JS (TS)

JS (UMD)

PHP

BX24.js

PHP CRest

curl -X POST \
        -H "Content-Type: application/json" \
        -H "Accept: application/json" \
        -d '{"documentId":77,"fileName":"diagram.png","fileContent":"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII="}' \
        https://**put_your_bitrix24_address**/rest/api/**put_your_user_id_here**/**put_your_webhook_here**/note.file.add

curl -X POST \
        -H "Content-Type: application/json" \
        -H "Accept: application/json" \
        -d '{"documentId":77,"fileName":"diagram.png","fileContent":"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII=","auth":"**put_access_token_here**"}' \
        https://**put_your_bitrix24_address**/rest/api/note.file.add

import { Text } from '@bitrix24/b24jssdk'
        import type { B24Frame } from '@bitrix24/b24jssdk'
        
        declare const $b24: B24Frame
        
        type FileAddResult = {
          item: {
            id: number
            documentId: number
            name: string
            size: number
            mimeType: string
            assetType: string
            assetMarkdown: string
          }
        }
        
        try {
          const response = await $b24.actions.v3.call.make<FileAddResult>({
            method: 'note.file.add',
            params: {
              documentId: 77,
              fileName: 'diagram.png',
              fileContent: 'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII=',
            },
            requestId: Text.getUuidRfc4122()
          })
        
          if (!response.isSuccess) {
            console.error(response.getErrorMessages().join('; '))
          } else {
            const result = response.getData()!.result
            console.info('File uploaded:', result.item.id, result.item.assetMarkdown)
          }
        } catch (error) {
          console.error(error)
        }

<script src="https://unpkg.com/@bitrix24/b24jssdk@1/dist/umd/index.min.js"></script>
        <script>
          async function addFile() {
            try {
              const $b24 = await B24Js.initializeB24Frame()
        
              const response = await $b24.actions.v3.call.make({
                method: 'note.file.add',
                params: {
                  documentId: 77,
                  fileName: 'diagram.png',
                  fileContent: 'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII=',
                },
                requestId: B24Js.Text.getUuidRfc4122()
              })
        
              if (!response.isSuccess) {
                console.error(response.getErrorMessages().join('; '))
                return
              }
        
              const result = response.getData().result
              console.info('File uploaded:', result.item.id, result.item.assetMarkdown)
            } catch (error) {
              console.error(error)
            }
          }
        
          document.addEventListener('DOMContentLoaded', addFile)
        </script>

SDKs do not yet support the /rest/api/ address in calls. Use direct HTTP requests, for example, via curl or fetch.

try {
            $response = $b24Service
                ->core
                ->call(
                    'note.file.add',
                    [
                        'documentId' => 77,
                        'fileName' => 'diagram.png',
                        'fileContent' => 'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII=',
                    ]
                );
        
            $result = $response
                ->getResponseData()
                ->getResult();
        
            echo 'Success: ' . print_r($result, true);
        
        } catch (Throwable $e) {
            error_log($e->getMessage());
            echo 'Error uploading file: ' . $e->getMessage();
        }

SDKs do not yet support the /rest/api/ address in calls. Use direct HTTP requests, for example, via curl or fetch.

BX24.callMethod(
            'note.file.add',
            {
                documentId: 77,
                fileName: 'diagram.png',
                fileContent: 'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII='
            },
            function(result){
                console.info(result.data());
                console.log(result);
            }
        );

SDKs do not yet support the /rest/api/ address in calls. Use direct HTTP requests, for example, via curl or fetch.

require_once('crest.php');
        
        $result = CRest::call(
            'note.file.add',
            [
                'documentId' => 77,
                'fileName' => 'diagram.png',
                'fileContent' => 'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII='
            ]
        );
        
        echo '<PRE>';
        print_r($result);
        echo '</PRE>';

Response Handling

HTTP status: 200

{
            "result": {
                "item": {
                    "id": 5001,
                    "documentId": 77,
                    "name": "diagram.png",
                    "size": 6321,
                    "mimeType": "image/png",
                    "assetType": "image",
                    "assetMarkdown": "[[image fileId=5001]]"
                }
            },
            "time": {
                "start": 1780392000,
                "finish": 1780392000.284521,
                "duration": 0.28452086448669434,
                "processing": 0.2413930892944336,
                "date_start": "2026-06-16T12:20:00+03:00",
                "date_finish": "2026-06-16T12:20:00+03:00",
                "operating_reset_at": 1780392600,
                "operating": 0
            }
        }

Returned Data

Name `type`	Description
result `object`	Object with the file upload result
item `object`	Object of the uploaded file
id `integer`	Identifier of the uploaded file
documentId `integer`	Identifier of the document to which the file is attached
name `string`	File name
size `integer`	File size in bytes
mimeType `string`	File MIME type
assetType `string`	Attachment type for the Markdown block
assetMarkdown `string`	Ready-to-use Markdown block for inserting the file into a document via note.document.update
time `time`	Information about the request execution time

Error Handling

HTTP status: 400

{
            "error": {
                "code": "BITRIX_REST_V3_EXCEPTION_VALIDATION_REQUESTVALIDATIONEXCEPTION",
                "message": "Error during request object validation",
                "validation": [
                    {
                        "message": "invalid base64 payload",
                        "field": "fileContent"
                    }
                ]
            }
        }

Name `type`	Description
error.code `string`	String error code. Use it to identify the type of exception
error.message `string`	Text description of the error
error.validation `array`	Array with error details. Present only in data validation errors `BITRIX_REST_V3_EXCEPTION_VALIDATION_REQUESTVALIDATIONEXCEPTION`
error.validation[].field `string`	Name of the field where the validation error occurred
error.validation[].message `string`	Description of the error related to the specified field

Possible Error Codes

Request Validation Errors

Error Code: BITRIX_REST_V3_EXCEPTION_VALIDATION_REQUESTVALIDATIONEXCEPTION

Field	Error description	How to Fix
`documentId` `fileName` `fileContent`	Required field `#FIELD#` is not specified	Add the specified field to the request body
`documentId` `fileName` `fileContent`	The field `#FIELD#` requires data type `#TYPE#` for this request	Ensure the provided value is of the correct type
`fileContent`	Incorrect Base64 content provided	Please ensure that `fileContent` contains a non-empty Base64 string without corrupted characters
`fileContent`	Failed to save the file	Retry the request later or check the correctness of the provided data

Error Code: NOTE_FILE_TOO_LARGE

Field	Error description	How to Fix
`fileContent`	File size exceeds the allowed value	Reduce the file size or change the `main.max_file_size` setting in Bitrix24

Error Code: NOTE_FILE_TYPE_NOT_ALLOWED

Field	Error description	How to Fix
`fileName`	File type is not supported	Use a file with an allowed extension

Access Errors

Error Code: BITRIX_REST_V3_EXCEPTION_ACCESSDENIEDEXCEPTION

Field	Error description	How to Fix
`-`	Access denied	The user does not have access to the Knowledge Base module or permissions to edit the document

Object Not Found Error

Error Code: BITRIX_REST_V3_EXCEPTION_ENTITYNOTFOUNDEXCEPTION

Field	Error description	How to Fix
`documentId`	Document not found	Please ensure that the document exists, is not archived, and is not in the trash

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 permitted for calls 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 HTTPS protocol is required for method calls
`503`	`OVERLOAD_LIMIT` REST API is blocked due to overload	The REST API is blocked due to overload. This is a manual individual block; please contact Bitrix24 technical support to lift it
`403`	`ACCESS_DENIED` REST API is available only on commercial plans	The REST API is only available on commercial plans
`403`	`INVALID_CREDENTIALS` Invalid request credentials	The user associated with the access token or webhook used to call the method lacks the necessary 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 portal administrator has restricted access to this application to specific users only
`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 "Temporary closure of the public part of the site" option. Path to the setting: Desktop > Settings > Product Settings > Module Settings > Main Module > Temporary closure of the public part of the site

Continue Learning

Overview of Methods

Get Document File Data

Upload a File to Document note.file.add

Method ParametersMethod Parameters

Code ExamplesCode Examples

Response HandlingResponse Handling

Returned DataReturned Data

Error HandlingError Handling

Possible Error CodesPossible Error Codes

Request Validation ErrorsRequest Validation Errors

Access ErrorsAccess Errors

Object Not Found ErrorObject Not Found Error

Statuses and System Error CodesStatuses and System Error Codes

Continue LearningContinue Learning

Method Parameters

Code Examples

Response Handling

Returned Data

Error Handling

Possible Error Codes

Request Validation Errors

Access Errors

Object Not Found Error

Statuses and System Error Codes

Continue Learning