We're building a matrix client and trying to enable push notifications. I've already got our client's push gateway set up with some modifications to create a notification body for FCM (our client doesn't support silent data-only notifications yet). Push notifications are working, but the content within them is limited.
The problem is that, we want to include information about the particular event, but that information doesn't seem to always be sent from Synapse to our push gateway.
For instance, we want to add the sender of the message to the notification body sent to FCM.
As outlined here in the Push Gateway spec, the synapse server will communicate with the push gateway via this POST endpoint. In the notification body, there may be the field "sender_display_name", but that field isn't showing up in the notification body being sent to Sygnal, even when our users have a display name set.
Modifying synapse doesn't seem like the way to go, as users of the client may be on different homeservers.
Is there something we need to change in our client to ensure that particular fields like "sender_display_name" are always within the notification body that gets passed along?
When I send the example request notification body to our push gateway endpoint, the "sender_display_name" is indeed present in the actual push notification on my phone. This indicates to me that our setup is working, but for some reason, not all the information we would want from our client is coming through synapse to the push gateway.
