Submitted to HACS, repo at https://github.com/michael-adler/ha-ocpp-relay/.
EV chargers are typically controlled by the Open Charge Point Protocol (OCPP). The protocol includes metering. For some users, connecting to a particular remote OCPP server is essential for electrical billing discounts or access control. The code here monitors OCPP traffic to track energy use but acts only as a relay between an EV charger and the remote Charge Point Management System (CPMS). The relay exposes a second socket where OCPP traffic can be monitored. Multiple clients may connect to the snoop service and each one receives the same read-only OCPP JSON stream.
Use this project if you want to continue using your vendor's OCPP server while monitoring energy use.
Multiple chargers may connect through the relay simultaneously. They will be identified by serial number.
More details in the README.