counterpartyMarker property
The app's opaque marker for the counterparty this payment is with (bead libspiffy-cq16, spv-understanding.md "Core Data Management" requirement 5): an Ed25519 identity key, an email address, a peer id, an internal account id — whatever the app uses for identity. libspiffy journals it and returns it; it never interprets, validates or parses it, and the identity record itself stays with the app. Not an address: it is kept apart from the address-derived counterparty columns of the read model. Null when the app supplies none.
Implementation
final String? counterpartyMarker;