configUrl is the parameter name on the IDL definition but it's url on the description below.
nonce has a TODO explaining how it's used. That's okay maybe but:
A random number of the choice of the RP. If it's random, it should not be the choice of the RP then? Does it have to be unique among different requests? I don't know what this is used for, but if it's a nonce like in cryptography, please explicitly say that it MUST be cryptographically random (or maybe that it doesn't have to be!).
configUrlis the parameter name on the IDL definition but it'surlon the description below.noncehas a TODO explaining how it's used. That's okay maybe but:A random number of the choice of the RP. If it's random, it should not be the choice of the RP then? Does it have to be unique among different requests? I don't know what this is used for, but if it's a nonce like in cryptography, please explicitly say that it MUST be cryptographically random (or maybe that it doesn't have to be!).