# ModifyChimeMeetingAttendee (muting and unmuting audio)
<a name="mute-unmute"></a>

Allows the SIP media application to modify the status of a telephony attendee by providing the Amazon Chime SDK meeting ID and attendee list.

**Note**  
This action currently supports mute and unmute operations on telephony attendees. Also, the user must be joined into a meeting using the `JoinChimeMeeting` action. This action can be performed on a `participantTag=“LEG-B”`, or a corresponding `CallId`. 

This action only applies to the callLeg that joins from the SIP media application to `"+`*13605550122*`"`, LEG-B, or the leg joined from the SIP media application to the meeting.

```
{
"SchemaVersion": "1.0",
  "Actions": [
    {
      "Type" : "ModifyChimeMeetingAttendees",
      "Parameters" : {
        "Operation": "Mute",
        "MeetingId": "meeting-id",
        "CallId": "call-id",
        "ParticipantTag": LEG-B",
        "AttendeeList": ["attendee-id-1", "attendee-id-2"]
      }
    }
  ]
}
```

**Operation**  
*Description* – The operation to perform on the list of attendees  
*Allowed values* – Mute, Unmute  
*Required* – Yes  
*Default value* – None

**MeetingId**  
*Description* – The ID of the meeting to which the attendees belong  
*Allowed values* – A valid meeting ID. The person muting or unmuting must also belong to the meeting.  
*Required* – Yes  
*Default value* – None

**CallId**  
*Description* – The ID of the meeting to which the attendees belong  
*Allowed values* – A valid call ID.  
*Required* – No  
*Default value* – None

**ParticipantTag**  
*Description* – The tag assigned to the attendee.  
*Allowed values* – A valid tag.  
*Required* – No  
*Default value* – None

**AttendeeList**  
*Description* – List of attendee IDs to mute or unmute  
*Allowed values* – A list of valid attendee IDs  
*Required* – Yes  
*Default value* – None, maximum of 100

After running this action, Audio Service always invoke an AWS Lambda function with the `ACTION_SUCCESSFUL` or `ACTION_FAILED` invocation event type. The following example code shows a typical `ACTION_SUCCESSFUL` invocation event.

```
{
    "SchemaVersion": "1.0",
    "Sequence": INTEGER,
    "InvocationEventType": "ACTION_SUCCESSFUL",
    "ActionData": {
        "Type" : "ModifyChimeMeetingAttendees",
        "Parameters" : {
            "Operation": "Mute",
            "MeetingId": "meeting-id",
            "CallId": "call-id",
            "ParticipantTag": "LEG-B",
            "AttendeeList": ["attendee-id-1", "attendee-id-2"]
        }
    }
    "CallDetails": {
        ...
    }
}
```

**Error handling**  
In cases of invalid instruction parameters or API failures, SIP media applications call an AWS Lambda function with the error message specific to the failed instruction or API.


|  Error  |  Message  |  Reason  | 
| --- | --- | --- | 
|  `InvalidActionParameter`  |  The `ModifyChimeMeetingAttendees Operation` parameter value is invalid  |  The `Operation` value must be Mute or Unmute.  | 
|     |  Meeting ID parameter value is invalid.  |  Meeting ID is empty.  | 
|     |  Attendee List parameter value is invalid.  |  The Attendee ID list is empty, or it exceeds the maximum of 100.  | 
|     |  Invalid action on the call.  |  The call isn't bridged.  | 
|     |  Call is not connected to Chime Meeting.  |  The attendee is not connected to a Chime Meeting.  | 
|     |  One or more attendees are not part of this meeting. All attendees must be part of this meeting.  |  The attendee is not authorized to modify attendees in the meeting.  | 
|  `SystemException`  |  System error while running action.  |  A system error occurred while running an action.  | 

The following example code shows a typical failure event:

```
{
    "SchemaVersion": "1.0",
    "Sequence": INTEGER,
    "InvocationEventType": "ACTION_FAILED",
    "ActionData": {
        "Type" : "ModifyChimeMeetingAttendees",
        "Parameters" : {
            "Operation": "Mute",
            "MeetingId": "meeting-id",
            "CallId": "call-id",
            "ParticipantTag": "LEG-B",
            "AttendeeList": ["attendee-id-1", "attendee-id-2"]
        },
        "ErrorType": "",
        "ErrorMessage": "",
        "ErrorList": []
    }
    "CallDetails": {
        ...
    }
}
```

See working examples on GitHub:
+ [https://github.com/aws-samples/amazon-chime-sma-bridging](https://github.com/aws-samples/amazon-chime-sma-bridging).
+ [https://github.com/aws-samples/amazon-chime-sma-update-call](https://github.com/aws-samples/amazon-chime-sma-update-call)