How to use JSON-RPC in C++ in Linux? Which library I must use for JSON? Where is RPC call example ?
How to use RPC of bitcoind or bitcoin-cli? or better Electrum API to get all new (maybe pending) transactions which appears in Bitcoin net?
Even though it is a C library, you could use Jansson in C++ apps, too. See: https://en.bitcoin.it/wiki/API_reference_(JSON-RPC)#C