The getzmqnotifications RPC returns information about the active ZeroMQ notifications.
getzmqnotifications none
*bitcoin-cli help getzmqnotifications
getzmqnotifications Returns information about the active ZeroMQ notifications. Result: [ { (json object) "type": "pubhashtx", (string) Type of notification "address": "..." (string) Address of the publisher }, ... ] Examples: > bitcoin-cli getzmqnotifications > curl --user myusername --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "getzmqnotifications", "params": [] }' -H 'content-type: text/plain;' http://127.0.0.1:8332/