FIX Protocol
The messaging standard for electronic trade communication — orders, executions, allocations and post-trade — in continuous use since the early 1990s and underpinning most institutional order flow.
Why it matters for autonomous finance
FIX is the existence proof that this is a solved genre. It carries order provenance, party identification, timestamps and a sequenced message log that reconstructs a trade's full lifecycle — precisely the properties AI governance says it wants and keeps designing from scratch. Anyone specifying an agent audit trail should start by reading how FIX handles party roles and sequence gaps, because regulators already read FIX logs and do not yet read anything else.
What it does not cover
FIX reconstructs the order, not the reasoning. It tells you an order was sent by a party at a time with certain characteristics. It cannot tell you what model produced the intent, on what evidence, or under whose authority — the gap between an execution record and a decision record is exactly where agent governance lives.
No model identity, no decision provenance, no drift signal. Every entry in this register carries this section. A standard read past its scope is worse than no standard, because it produces confidence without coverage.