For programs that support it, the keyset file can be provided via the command line (see program usage for details). Alternatively a keyset file located in ___$HOME/.switch/prod.keys___ (or ___$HOME/.switch/dev.keys___ for dev) will be imported automatically if one is not provided at the command line.
Keyset files are ASCII text files containing one key per line, in the form "__key_name = HEXADECIMALKEY__". Case and whitespace do not matter, ';' character can be used to insert comments.