## 5.6.2.3.3 Enable the SAP Event Mesh Service for Your Subaccount in SAP BTP
## Prerequisites
- Уou have created the SAP S/4HANA Cloud Extensibility service instance in the Cloud Foundry or Kyma environment. See:
- Create an SAP S/4HANA Extensibility Service Instance in the Cloud Foundry Environment [page 2141]
- Create an SAP S/4HANA Cloud Extensibility Service Instance in the Kyma Environment [page 2143]
- You have configured event topics for the channel inside SAP S/4HANA Cloud tenant. See Configure Event Topics in SAP S/4HANA Cloud [page 2153].
## Overview
To enable the SAP Event Mesh for your subaccount in SAP BTP, you have to create an instance of the SAP Event Mesh service with service plan default . This instance will specify the details of the namespace that you created in SAP Event Mesh for the SAP S/4HANA Cloud Extensibility service instance with the messaging plan. This way, you are setting up a contract between SAP Event Mesh and the Cloud Foundry, or the Kyma environment, and connect them to enable seamless event flow from the given SAP S/4HANA Cloud tenant.
Depending on the SAP BTP environment, to create an SAP Event Mesh service instance, you have to choose one of these:
- Create an SAP Event Mesh Service Instance in the Cloud Foundry Environment [page 2155]
- Create an SAP Event Mesh Service Instance in the Kyma Environment [page 2156]
Define the details of your message client in SAP Event Mesh as parameters in a dedicated JSON file. To map the message client to the client defined in the SAP S/4HANA Cloud JSON file, in the SAP Event Mesh JSON file, you must include the subscribeFilter parameter which specifies the sap/S4HANAOD/{emClientId} namespace you created for the SAP S/4 HANA Cloud Extensibility instance of the messaging plan. For more information about the structure of the JSON file, see Define SAP Event Mesh Service Descriptor JSON/YAML File [page 2158].
## Process Flow
| Process Step                                                                                                                                                                                             | Related Documentation                                                                                                                                                    |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| 1. Create an SAP Event Mesh service instance with service plan default .                                                                                                                                 | • Create an SAP Event Mesh Service Instance in the Cloud Foundry Environment [page 2155] • Create an SAP Event Mesh Service Instance in the Kyma Environment [page 2156] |
| 2. Define a dedicated JSON file that you add either when creating the SAP Event Mesh service instance, or after that.                                                                                    | Define SAP Event Mesh Service Descriptor JSON/YAML File [page 2158]                                                                                                      |
| 3. Create a queue in the message client that refers to the SAP Event Mesh service instance and then subscribe the topic of the namespace of the SAP S/4HANA Cloud Extensi- bility service to that queue. | Create Queues and Subscribe to Them [page 2164]                                                                                                                          |