Create rpc json format for my altcoin

[widecash]

Hi all,

How can i create rpc json format for my altcoin ? is there any open source web url ?

{"jsonrpc": "2.0", "error": {"code": -32700, "message": "cannot decode JSON: Expecting value: line 1 column 1 (char 0)"}, "id": null}
{"jsonrpc": "2.0", "error": {"code": -32700, "message": "cannot decode JSON: Expecting value: line 1 column 1 (char 0)"}, "id": null}
{"jsonrpc": "2.0", "error": {"code": -32700, "message": "cannot decode JSON: Expecting value: line 1 column 1 (char 0)"}, "id": null}
{"jsonrpc": "2.0", "error": {"code": -32700, "message": "cannot decode JSON: Expecting value: line 1 column 1 (char 0)"}, "id": null}

Regards,