@mainr gattc is automatic to 'subscribe' the notification, client will get ESP_GATTC_SRVC_CHG_EVT

Thanks for the response @Weijian-Espressif .

To clarify:
Say my 'gatt_server' is an ESP32, and the 'client' is an android phone.
Say my 'gatt_server' device has an attribute table:

SERVER 1
  +- service 1
  |  +- characteristic 1
  |  +- characteristic 2
  +- service 2
     +- characteristic 3

Now some conditions arise that cause the STRUCTURE of the attribute table to change, such as exposing a new service (or removing an existing one, etc.). If adding, say the attributes now look like:

SERVER 1
  +- service 1
  |  +- characteristic 1
  |  +- characteristic 2
  +- service 2
  |  +- characteristic 3
  +- service 3
     +- characteristic 4

I understand the function of the 'service changed' notification is to inform the client that changes have occured, and it should flush its internal cache (GAP/GATT) for this device, and re-discover services.

What I don't understand is what does the gatt server code running on the ESP32 need to do after modifying the GATT structure to trigger the notify/indicate to the client?

Surely the notification is not automatic so that EVERY change to the GATT triggers notification?
If so, the client-side discovery would be triggered every time a change was made?
What I expect is the server would make whatever changes are necessary, then issue some kind of 'commit' or 'update' or 'notify' command to trigger the 'service changed' notification.

service_change_demo.zip
please refer to the service change demo

service_change_demo.zip
please refer to the service change demo

Hi, is there the Arduino Framework version of this?

service_change_demo.zip
please refer to the service change demo

Hi, is there the Arduino Framework version of this?

Nothing?

@Sladerix I don't find anything specific either 'range of...' is ambiguous at best

but I 'guess' that in the end one sends a notify on this characteristic, which triggers the host side action.
I'm going to add that to my arduino code and see what happens...

well, after starting to add the code, it seems u send a notify, then the client READS the 'range of'
so I'm guessing its the characteristic ID... hm.. but my service UUID changed... so does that mean the read is empty or....