Status. Proposed design only. Nothing in this vault is DG client approval. No application, service or test has been executed; every scenario is Not executed. Fees and dates are open.

ADR-0004 UUIDv7 Identifiers and Idempotency Keys

Status: Proposed. The owner accepts by merging the PR that introduces it.

Context

Repeatable commands must not create duplicates (T18); identifiers must not leak existence (T27).

Decision

Primary keys are UUIDv7. Repeatable commands accept an Idempotency-Key; the server stores key, actor company, route and a request hash, and replays the stored result for a repeat.

Consequences

Time-ordered keys index well and reveal little. Binding the key to the actor company prevents cross-company replay.

Revisit trigger

Key retention period is Blocked by Q09. Revisit if a provider mandates another identifier.

Change history

Date	Change
2026-10-20	Created (bootstrap Phase 2)