settlement that resolves through every layer beneath it

A single act at the top of a layered system — one registration, one write, one listing that stays listed — touches a dozen components that each did some work. The easy answer is a central accountant that bills the caller once. That answer collapses as soon as the layers stop belonging to the same operator.

The tension is precision against independence. One bill is comprehensible; per-layer accounting is accurate. But if the top layer must know what every layer beneath it costs, then adding a layer means editing the biller, and every new participant reimplements the same arithmetic with slightly different rounding.

The decision is to flatten, then settle upward. Charges accumulated anywhere in a dependency tree collapse into one account per participant role, and value flows one level at a time: an object that references another carries the cost of that reference, the referencing layer settles with the layer it used, and each layer settles with the catalog above it. Each step knows only its neighbour. The record also fixes the private-public split for agreements between two identities: the terms stay sealed, while the settlement instruction is public and checkable, so a coordinator can reconcile two parties without reading either party's business.

What it costs is more accounts, more moving parts, and one boring invariant that has to hold everywhere — whoever triggers work is the one who carries its cost. What it proves is that compositional accounting was designed as a property rather than an afterthought.