[Open Question] Atomicity across heterogeneous-finality ledgers

[pv-sarvesh]

Context

Atomic DvP/PvP is naturally a single-ledger property (Whitepaper §3.3, §6.1). Spanning two ledgers requires a shared platform, a trusted coordinator, or a cross-chain protocol (HTLC, escrow/notary, messaging bridges) — each with its own trust and finality assumptions. The whitepaper proposes a rail-neutral AtomicLeg primitive with a canonical SettlementProposed -> Settled | Aborted event lifecycle, deliberately without prescribing a bridging mechanism.

The question

What minimal cross-ledger settlement interface can the community endorse without privileging one bridging trust model?

How to contribute

• Propose interface requirements an AtomicLeg must satisfy to be coordinated across ledgers with different finality guarantees (probabilistic vs. deterministic, instant vs. delayed).
• Map how existing mechanisms (HTLC, escrow/notary, shared-ledger, Ownera-style routers) would implement or fail the interface.
• Identify the failure/abort semantics that must be standardized vs. left to the coordinator.

Reference: Whitepaper §3.3, §5.2, §6.1, Flow A (§8).