Settlement Domain Discovery
1. ABSTRACT
Describes how Settlement Domains advertise liquidity capability and how routers discover which domains are eligible destinations for a given obligation.
2. MOTIVATION
Obligations cannot be routed without a shared mechanism for domains to declare what they can settle, and at what capacity, without requiring routers to trust a single centralized registry.
3. TERMINOLOGY
DomainCapability — a signed, periodically published record of a Settlement Domain's advertised liquidity and exposure.
4. SPECIFICATION
Each Settlement Domain periodically publishes a signed capability record:
DomainCapability {
domainId: DomainID
currency: CurrencyCode
availableLiquidity: Decimal // as reported, not independently verified
openObligations: Integer
exposure: SignedDecimal
status: BALANCED | SURPLUS | DEFICIT
}
Routers MUST treat availableLiquidity as advisory rather than authoritative and MUST re-validate capacity at the point of HSC assignment (NIP-0004).
5. INVARIANTS
Routers MUST treat `availableLiquidity` as advisory, never authoritative, and MUST re-validate capacity at HSC assignment.
6. FAILURE CONDITIONS
A domain that over-reports liquidity causes obligations routed toward it to fail at assignment; no penalty mechanism for repeated over-reporting is yet defined.
7. SECURITY CONSIDERATIONS
A domain that over-reports liquidity can cause obligations to be routed toward it and subsequently fail at assignment. NIP-0003 does not currently define a penalty mechanism for repeated over-reporting; this is tracked as an open question for a future proposal.
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.