# \Api20100401UserDefinedMessageSubscriptionApi
All URIs are relative to *https://api.twilio.com*
[**create_user_defined_message_subscription**](Api20100401UserDefinedMessageSubscriptionApi.md#create_user_defined_message_subscription) | **POST** /2010-04-01/Accounts/{AccountSid}/Calls/{CallSid}/UserDefinedMessageSubscriptions.json |
[**delete_user_defined_message_subscription**](Api20100401UserDefinedMessageSubscriptionApi.md#delete_user_defined_message_subscription) | **DELETE** /2010-04-01/Accounts/{AccountSid}/Calls/{CallSid}/UserDefinedMessageSubscriptions/{Sid}.json |
## create_user_defined_message_subscription
> models::ApiPeriodV2010PeriodAccountPeriodCallPeriodUserDefinedMessageSubscription create_user_defined_message_subscription(account_sid, call_sid, callback, idempotency_key, method)
Subscribe to User Defined Messages for a given Call SID.
### Parameters
**account_sid** | **String** | The SID of the [Account](https://www.twilio.com/docs/iam/api/account) that subscribed to the User Defined Messages. | [required] |
**call_sid** | **String** | The SID of the [Call](https://www.twilio.com/docs/voice/api/call-resource) the User Defined Messages subscription is associated with. This refers to the Call SID that is producing the user defined messages. | [required] |
**callback** | **String** | The URL we should call using the `method` to send user defined events to your application. URLs must contain a valid hostname (underscores are not permitted). | [required] |
**idempotency_key** | Option<**String**> | A unique string value to identify API call. This should be a unique string value per API call and can be a randomly generated. | |
**method** | Option<**String**> | The HTTP method Twilio will use when requesting the above `Url`. Either `GET` or `POST`. Default is `POST`. | |
### Return type
[**models::ApiPeriodV2010PeriodAccountPeriodCallPeriodUserDefinedMessageSubscription**](api.v2010.account.call.user_defined_message_subscription.md)
### Authorization
[accountSid_authToken](../README.md#accountSid_authToken)
### HTTP request headers
- **Content-Type**: application/x-www-form-urlencoded
- **Accept**: application/json
[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to Model list]](../README.md#documentation-for-models) [[Back to README]](../README.md)
## delete_user_defined_message_subscription
> delete_user_defined_message_subscription(account_sid, call_sid, sid)
Delete a specific User Defined Message Subscription.
### Parameters
**account_sid** | **String** | The SID of the [Account](https://www.twilio.com/docs/iam/api/account) that subscribed to the User Defined Messages. | [required] |
**call_sid** | **String** | The SID of the [Call](https://www.twilio.com/docs/voice/api/call-resource) the User Defined Message Subscription is associated with. This refers to the Call SID that is producing the User Defined Messages. | [required] |
**sid** | **String** | The SID that uniquely identifies this User Defined Message Subscription. | [required] |
### Return type
(empty response body)
### Authorization
[accountSid_authToken](../README.md#accountSid_authToken)
### HTTP request headers
- **Content-Type**: Not defined
- **Accept**: Not defined
[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to Model list]](../README.md#documentation-for-models) [[Back to README]](../README.md)