Specs

Minimum shape

---
type: spec
id: SPEC-checkout
title: Expired checkout sessions
status: ready
owner: checkout-team
sources:
  - SHOP-4012
---

# Expired checkout sessions

## Intent

Reject expired checkout sessions without converting an expected client condition into a server
failure.

## Requirements

### AC-001 - Expired session returns 409
- When: a checkout session is older than 30 minutes
- Then: the API MUST return `409 SESSION_EXPIRED`, never a 5xx
- Verify with: `npm run test:integration -- expired-session`

Intent and Requirements are required. Add Non-goals, Open questions, Affected areas, Dropped from sources, or Execution only when they carry information. Empty headings prove nothing.

Requirements

Each requirement:

• has a stable AC-NNN ID;
• has exactly one non-empty When, Then, and Verify with item, in that order;
• states one observable behavior in Then;
• names its actor or system in Then;
• uses exactly one binding word in Then;
• contains no unresolved uncertainty.

Resolve discoverable facts and reversible conventions. Put unresolved material decisions under Open questions, keep the spec draft, and block dependent work. ready is a claim: no blocking decision or unresolved marker remains. C007 enforces that floor; C021 rejects a missing or empty Intent.

Exact frontmatter and optional sections: artifact formats.

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