# Controlling and querying btcd via btcctl btcctl is a command line utility that can be used to both control and query btcd via [RPC](http://www.wikipedia.org/wiki/Remote_procedure_call). btcd does **not** enable its RPC server by default; You must configure at minimum both an RPC username and password or both an RPC limited username and password: * btcd.conf configuration file ```bash [Application Options] rpcuser=myuser rpcpass=SomeDecentp4ssw0rd rpclimituser=mylimituser rpclimitpass=Limitedp4ssw0rd ``` * btcctl.conf configuration file ```bash [Application Options] rpcuser=myuser rpcpass=SomeDecentp4ssw0rd ``` OR ```bash [Application Options] rpclimituser=mylimituser rpclimitpass=Limitedp4ssw0rd ``` For a list of available options, run: `$ btcctl --help`