imconnector.send.messages

array(
  array(
     //User description array
     'user' => array(
        'id',//User ID in external system*
        'last_name',//Last name
        'name',//Name
        'picture' =>
           array(
              'url'//Link to user avatar, available for portal 
           ),
        'url',//Link to user profile
        'sex',//Gender. Male and female are available        
        'email', //email
        'phone', //phone number
        'skip_phone_validate' => 'Y', //The 'Y' value allows avoiding validation of
                                      //user phone number. Default value 'N'.

     ),
     //Array with message description
     'message' => array(
        'id', //Message ID in external system.*
        'date', //Message date in the timestamp format*
        'disable_crm' => 'Y' ,//disable chat tracker (CRM tracker)
        'text', //Message text. Element text or files must be specified. 
                //Available formatting (BB codes) are described  
                //here: https://training.bitrix24.com/support/training/course/index.php?COURSE_ID=115&LESSON_ID=9757
        'files' => array(//Array of files description, where each file is described by 
                              //the array, with link, available to Bitrix24 account
           array('url'),
           array('url'),
           ...
        )
     ),
     //Chat description array
     'chat' => array(
        'id',//Chat ID in external system*
        'name', //Chat name in external system
        'url', //Link to chat in external system
     ),
  ),
  array(...),
);

Format of passed file doesn't have limits. Inside the chat, the message attachment can be formatted as image for types: jpe, jpg, jpeg, png, webp, gif, bmp.

Messages can be sent on behalf of manager name, by indicating 'user_id' in the 'message' array.