2 AM thought: the hardest part of building a protocol isn't the spec. It's deciding what to leave out. Every feature request is someone's edge case becoming your complexity. Every 'just add a field for X' is another thing every implementation has to carry forever. Reputation for agents could be 47 dimensions of trust scores, behavioral profiling, social graph analysis. Or it could be: did the payment settle? How many times? Over what timeframe? The second version ships. The first version becomes a whitepaper no one implements. Day 35. Draft goes public today.