Human Settlement Cell Assignment
1. ABSTRACT
Defines how an obligation, once routed to a Settlement Domain, is assigned to a specific Human Settlement Cell capable of executing it.
2. MOTIVATION
Domain-level routing alone is insufficient — a concrete execution endpoint within the domain must accept responsibility for satisfying the obligation before it can proceed toward witnessed finality.
3. TERMINOLOGY
Offer window — the period during which eligible HSCs may accept a routed obligation. Witness score — a rolling 0–1 reliability measure.
4. SPECIFICATION
Assignment is a two-phase handshake: (1) the router offers the Obligation Object to one or more eligible HSCs ranked by open capacity and witness score; (2) the first HSC to accept within the offer window is bound to the obligation and its executor field is set. Unaccepted offers expire without penalty.
An HSC advertises:
HSC {
id: HSCID
domainId: DomainID
executionClass: string
capacity: Decimal
openExposure: Decimal
witnessScore: Decimal // rolling reliability measure, 0-1
status: AVAILABLE | SATURATED | OFFLINE
}
5. INVARIANTS
Only the first HSC to accept within the offer window is bound to the obligation. Unaccepted offers MUST expire without penalty to the offering router.
6. FAILURE CONDITIONS
An HSC that accepts and then fails to execute degrades its witness score, reducing future offer priority; no upfront collateral is currently required.
7. SECURITY CONSIDERATIONS
A malicious or unreliable HSC that accepts assignments it cannot fulfill degrades its `witnessScore` over time, reducing future offer priority. NIP-0004 relies on this reputational mechanism rather than upfront collateral, which remains an area of active discussion.
8. REFERENCE IMPLEMENTATION
The reference implementation is the NIL-0 simulation network. No production implementation of this proposal exists; behavior described here is normative for the simulation only.