If I understand well, TTN HHTP integration is able to post data to a endpoint. However, the data format to be posted by TTN is defined, i.e.:
{
"app_id": "my-app-id", // Same as in the topic
"dev_id": "my-dev-id", // Same as in the topic
"hardware_serial": "0102030405060708", // In case of LoRaWAN: the DevEUI
"port": 1, // LoRaWAN FPort
...
Which means that you have to modify your endpoints to get the payload fields in your (backend) application. Is there a way to post completely redefined data? That would be a kind of TTN decoder working not only on the payload, but also on the other fields?
Thanks.