Background Handler on Every Page PAGE_BACKGROUND_WORKER

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: placement

Bitrix24 loads the handler of this placement on every page in a hidden frame, without a visible interface element. The user neither opens nor sees the widget: the application code runs in the background on any page the employee has open.

The placement is needed where the application has to react not to a click but to an external event: receive a signal from its own backend through interactive interaction, show an incoming call in a telephony integration, open the application slider with the openApplication method.

The placement code is specified in the PLACEMENT parameter of the placement.bind method. Registration requires the OPTIONS[errorHandlerUrl] parameter. It carries the address where Bitrix24 reports that the handler has been deactivated.

The widget is not displayed in the interface until the application installation is complete. Check the application installation

Where the Widget is Embedded

Placement Code

Location

PAGE_BACKGROUND_WORKER

A hidden frame on every Bitrix24 page

When the Handler is Called

The handler loads on every Bitrix24 page load. A page opened in a slider is a separate document, so the handler loads there once more, already with its own address in the URI key.

This leads to the main requirement for the handler: it has to respond quickly. If the response takes longer than five seconds and this happens more than ten times a day on the same Bitrix24, the handler registration is deleted.

Bitrix24 informs the application about the deletion: a request with the error ERROR_PLACEMENT_LOADING_OVERTIME and a description of the exceeded loading time arrives at the address from OPTIONS[errorHandlerUrl]. The request is sent without authorization tokens. To bring the widget back, the application registers the handler again with the placement.bind method.

What the Handler Receives

Data is sent in a POST request: some parameters come in the handler URL query string, the rest in the request body

Array
        (
            [DOMAIN] => xxx.bitrix24.com
            [PROTOCOL] => 1
            [LANG] => en
            [APP_SID] => 588b8a98e848778a4ffb38fbcf70f2b9
            [AUTH_ID] => 4172bb660070f28d001e30ba00000001f0f107c42ca5bd5f61030c5d9c3e4d60
            [AUTH_EXPIRES] => 3600
            [REFRESH_ID] => 31f1e2660070f28d001e30ba00000001f0f107b1918506d8a2ed9ecf76e8fdac
            [SERVER_ENDPOINT] => https://oauth.bitrix.info/rest/
            [APPLICATION_TOKEN] => ec1b2074a9d3f5c81b6e40d27a95cf38
            [APPLICATION_SCOPE] => placement
            [member_id] => da45a03b265edd8787f8a258d793cc5d
            [status] => L
            [PLACEMENT] => PAGE_BACKGROUND_WORKER
            [PLACEMENT_OPTIONS] => {"ID":"PAGE_BACKGROUND_WORKER","URI":"\/company\/personal\/user\/1\/blog\/"}
        )
        

Required parameters are marked with *

Parameters in the Handler URL Query String

Parameter
type

Description

DOMAIN*
string

The Bitrix24 address where the widget handler was invoked

PROTOCOL*
string

Secure or non-secure HTTP protocol:

  • 0 - HTTP
  • 1 - HTTPS

LANG*
string

The user interface language of Bitrix24 that invoked the widget. You can localize the interface language in your widget based on this value

APP_SID*
string

Application session identifier. Bitrix24 generates a new one each time the widget is rendered and uses it to link the js library with the application environment

Parameters in the POST Request Body

Parameter
type

Description

AUTH_ID
string

Authorization token OAuth 2 issued for the user who invoked the widget. Can be used for REST API calls on behalf of this user

AUTH_EXPIRES
integer

Time in seconds after which the authorization token will become invalid

REFRESH_ID
string

Refresh token OAuth 2 issued for the user who invoked the widget. Can be used to refresh the authorization token on behalf of this user

SERVER_ENDPOINT*
string

Address of the Bitrix24 authorization server needed to refresh OAuth 2 tokens

APPLICATION_TOKEN*
string

Application token. The same value is passed in the application_token parameter when event handlers are invoked. The widget handler can use it to verify that the request came from Bitrix24

APPLICATION_SCOPE*
string

List of scopes granted to the application, separated by commas. Shows which REST API methods are available with the authorization token received

member_id*
string

Unique string identifier of Bitrix24 where the widget handler was invoked.

status
string

Type of application that registered the handler for this widget. Accepts values:

  • L - local application
  • F - free mass-market application
  • D - demo version of a mass-market application
  • T - trial version of a mass-market application, time-limited
  • P - paid mass-market application

PLACEMENT*
string

The placement code. You can use the same handler URL for all your widgets. The value that Bitrix24 will report in the PLACEMENT parameter will help determine from which specific placement your handler was invoked in each case

PLACEMENT_OPTIONS
string

Additional data in the form of a JSON string that defines the context of the widget execution. For example, this could be an array containing the numeric identifier of the CRM object in the detail form where the widget handler was invoked, etc. The PLACEMENT_OPTIONS parameter, along with the PLACEMENT parameter, allows you to accurately determine for which specific placement and object the widget handler was invoked

Bitrix24 adds a URI key to PLACEMENT_OPTIONS — the path with the query string of the page from which the widget was opened. It arrives for any placement, along with the keys of that placement itself. The key is absent if the browser did not send the Referer header or if the widget was opened from a page on a different domain.

How to Parse the Call Context

PLACEMENT_OPTIONS arrives as a JSON string, not as an array: parse it on the handler side before use. The set of keys is specific to each placement and is described in the PLACEMENT_OPTIONS section of this page.

$placement = $_POST['PLACEMENT'] ?? '';
        $options = json_decode($_POST['PLACEMENT_OPTIONS'] ?? '{}', true);
        
options = json.loads(request.form.get("PLACEMENT_OPTIONS", "{}") or "{}")
        

In B24JsSDK, there is no need to parse the string: the $b24.placement.options property returns a ready object, and $b24.placement.placement returns the placement code.

What the Handler Must Return

The handler responds with a regular HTML page — Bitrix24 displays it in a frame in place of the widget. The page must allow embedding: if the application server sends the X-Frame-Options or Content-Security-Policy headers that prohibit framing, an empty area remains in place of the widget. How to fix it is described in the article Site Does Not Allow Connection.

PLACEMENT_OPTIONS

The value of PLACEMENT_OPTIONS is passed as a JSON string with the call context.

Parameter

Description

ID*
string

The placement code, always equal to PAGE_BACKGROUND_WORKER

URI*
string

The path with the query string of the page where the handler loaded. It tells the application where the user currently is

OPTIONS when registering via placement.bind

For PAGE_BACKGROUND_WORKER, the placement.bind method supports one OPTIONS parameter.

Required parameters are marked with *

Parameter
type

Description

errorHandlerUrl*
string

The address where Bitrix24 reports that the handler registration has been deleted.

The parameter is mandatory: without it placement.bind returns the error EMPTY_ERROR_HANDLER_URL. Other OPTIONS keys are not retained. The placement.get method returns only errorHandlerUrl

An application registers one handler for this placement. A repeated placement.bind call returns the error ERROR_PLACEMENT_MAX_COUNT. To change the handler address, first remove the registration with the placement.unbind method.

Code Examples

How to Use Examples in Documentation

curl -X POST \
          -H "Content-Type: application/json" \
          -H "Accept: application/json" \
          -d '{
            "PLACEMENT": "PAGE_BACKGROUND_WORKER",
            "HANDLER": "https://your-domain.com/widgets/background-handler.php",
            "OPTIONS": {
              "errorHandlerUrl": "https://your-domain.com/widgets/background-error.php"
            },
            "auth": "**put_access_token_here**"
          }' \
          https://**put_your_bitrix24_address**/rest/placement.bind
        
// This snippet is an ES module: top-level await requires type="module" or a bundler.
        // $b24 is an already-initialized SDK instance (see the SDK "Get started" guide).
        import { Text } from '@bitrix24/b24jssdk'
        import type { B24Frame } from '@bitrix24/b24jssdk'
        
        declare const $b24: B24Frame
        
        try {
          const response = await $b24.actions.v2.call.make<boolean>({
            method: 'placement.bind',
            params: {
              PLACEMENT: 'PAGE_BACKGROUND_WORKER',
              HANDLER: 'https://your-domain.com/widgets/background-handler.php',
              OPTIONS: {
                errorHandlerUrl: 'https://your-domain.com/widgets/background-error.php',
              },
            },
            requestId: Text.getUuidRfc4122()
          })
        
          // The payload is available only on a successful response
          if (!response.isSuccess) {
            console.error(response.getErrorMessages().join('; '))
          } else {
            const result = response.getData()!.result
            console.info('Placement bound successfully:', result)
          }
        } catch (error) {
          // Thrown on transport or SDK failures (AjaxError, SdkError, etc.)
          console.error(error)
        }
        
<!-- Load the SDK (UMD build); it is exposed as the global B24Js -->
        <script src="https://unpkg.com/@bitrix24/b24jssdk@1/dist/umd/index.min.js"></script>
        <script>
          async function bindBackgroundWorker() {
            try {
              // Initialize the SDK inside a Bitrix24 frame
              const $b24 = await B24Js.initializeB24Frame()
        
              const response = await $b24.actions.v2.call.make({
                method: 'placement.bind',
                params: {
                  PLACEMENT: 'PAGE_BACKGROUND_WORKER',
                  HANDLER: 'https://your-domain.com/widgets/background-handler.php',
                  OPTIONS: {
                    errorHandlerUrl: 'https://your-domain.com/widgets/background-error.php',
                  },
                },
                requestId: B24Js.Text.getUuidRfc4122()
              })
        
              // The payload is available only on a successful response
              if (!response.isSuccess) {
                console.error(response.getErrorMessages().join('; '))
                return
              }
        
              const result = response.getData().result
              console.info('Placement bound successfully:', result)
            } catch (error) {
              // Thrown on transport or SDK failures (AjaxError, SdkError, etc.)
              console.error(error)
            }
          }
        
          document.addEventListener('DOMContentLoaded', bindBackgroundWorker)
        </script>
        
try {
            $response = $b24Service
                ->core
                ->call(
                    'placement.bind',
                    [
                        'PLACEMENT' => 'PAGE_BACKGROUND_WORKER',
                        'HANDLER' => 'https://your-domain.com/widgets/background-handler.php',
                        'OPTIONS' => [
                            'errorHandlerUrl' => 'https://your-domain.com/widgets/background-error.php',
                        ],
                    ]
                );
        
            $result = $response->getResponseData()->getResult();
            if ($result->error()) {
                error_log($result->error());
            } else {
                echo 'Success: ' . print_r($result->data(), true);
            }
        } catch (Throwable $e) {
            error_log($e->getMessage());
            echo 'Error binding placement: ' . $e->getMessage();
        }
        
BX24.callMethod(
            'placement.bind',
            {
                PLACEMENT: 'PAGE_BACKGROUND_WORKER',
                HANDLER: 'https://your-domain.com/widgets/background-handler.php',
                OPTIONS: {
                    errorHandlerUrl: 'https://your-domain.com/widgets/background-error.php'
                }
            },
            function(result) {
                if (result.error()) {
                    console.error(result.error());
                } else {
                    console.log(result.data());
                }
            }
        );
        
require_once('crest.php');
        
        $result = CRest::call(
            'placement.bind',
            [
                'PLACEMENT' => 'PAGE_BACKGROUND_WORKER',
                'HANDLER' => 'https://your-domain.com/widgets/background-handler.php',
                'OPTIONS' => [
                    'errorHandlerUrl' => 'https://your-domain.com/widgets/background-error.php',
                ],
            ]
        );
        
        echo '<PRE>';
        print_r($result);
        echo '</PRE>';
        
// client and ctx are already created — see the Go SDK section
        res, err := client.Core().Call(ctx, "placement.bind", b24.Params{
        	"PLACEMENT": "PAGE_BACKGROUND_WORKER",
        	"HANDLER":   "https://your-domain.com/widgets/background-handler.php",
        	"OPTIONS": b24.Params{
        		"errorHandlerUrl": "https://your-domain.com/widgets/background-error.php",
        	},
        })
        if err != nil {
        	return fmt.Errorf("placement.bind: %w", err)
        }
        
        // The response arrives as json.RawMessage — unmarshal it into the response
        // shape of the placement.bind method, see "Response Handling" on its page.
        fmt.Printf("%s\n", res.Result)
        

A Handler for a Single User

PAGE_BACKGROUND_WORKER is the only placement that supports the USER_ID parameter of the placement.bind method. A handler registered with USER_ID loads only on the pages of that user. This is how background code is connected only for those who need it, for example for telephony operators.

The limit of one handler is counted separately for the general registration and for each user, so a personal handler and a handler for all employees can be registered at the same time.

Relationship With Other Objects

Call card. From the background handler, the application controls the call card: it changes the card state, buttons, and title, and subscribes to the operator actions. The methods and events are collected in the Manage the Call Card of a WebRTC Client: Overview of Commands and Events section, and the whole scenario is described in the WebRTC Embedding Scenario article.

Signals from the backend. The handler receives messages from the server side of the application through the interactive interaction mechanism and opens the application interface based on them with the JavaScript methods for widgets.

User. The identifier for the USER_ID parameter used when registering a personal handler is returned by the methods of the Users: Overview of Methods section.

Common Mistakes

Mistake

Solution

placement.bind returns EMPTY_ERROR_HANDLER_URL

Pass OPTIONS[errorHandlerUrl]: without an address for deactivation messages the placement is not registered

placement.bind returns ERROR_PLACEMENT_MAX_COUNT

The handler is already registered. Remove the old registration with the placement.unbind method

The handler stopped being called and is missing from placement.get

The registration was deleted because of slow loading. Speed up the handler response and register it again

The handler is called several times on one screen

Pages in sliders are separate documents, and the handler loads again in each of them. Check URI if the scenario has to run only once

Typical Use-Cases and Scenarios

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