State Machines

Settld relies on deterministic state transitions and idempotent retries.

1) Paid execution flow

create -> quote(optional) -> authorize -> verify -> settlement

Terminal outcomes:

• released
• refunded
• reversed
• locked (until operator/dispute action)

2) Escalation flow

triggered -> pending -> approved|denied -> resumed|voided

Rules:

• Escalation decisions are signed and one-time.
• Retry does not double-settle or double-resolve.

3) Agent lifecycle flow

active -> frozen -> unwind -> archived

Used when insolvency/risk controls require immediate containment.

4) Queue and retry guarantees

• At-least-once delivery with idempotency keys
• Backoff + dead-letter protection
• Replay-safe processing for settlement/dispute transitions