---
title: "A correct payment is answered with a server error — x402 defect class settlement-error"
description: "A correct payment is answered with a server error (settlement-error), an x402 defect class: A valid, sufficient payment is answered with a 2xx and the goods. Detectable by an paid probe. Money may move with nothing delivered. The failure is invisible to the free preflight, which never pays."
canonical: "https://scvd.store/defects/settlement-error"
url: "https://scvd.store/defects/settlement-error"
term_code: "settlement-error"
defined_in: "https://scvd.store/defects"
data: "https://scvd.store/defects.json"
vocabulary_version: "22"
license: "https://creativecommons.org/licenses/by/4.0/"
---

# A correct payment is answered with a server error

`settlement-error` — an x402 defect class.

**Asserts:** A valid, sufficient payment is answered with a 2xx and the goods.

**Costs:** Money may move with nothing delivered. The failure is invisible to the free preflight, which never pays.

**Detectable:** paid — only a settled payment reveals it

**Falsified by:** A correctly-formed payment settling and returning a 2xx at the stated moment.

**How an operator clears it:** Read your settle-path logs: the failure sits after payment verification, most often a facilitator timeout, an unhandled fulfillment exception, or a dead upstream. Fail BEFORE money moves or deliver after it — never answer a settled payment with a 500.

**What a buyer does:** Do not retry with a fresh nonce: money may already have moved once. Check the chain for your settlement first; if it settled, present the same payment again or ask for a paid retry against that settlement, and if it did not, only then pay again.

**Our signal:** `launch_check stage: settle`

**Also known as:** `settlement-server-error` (Cairn (cairnwake.com)). Check: cairnwake.com/scoreboard.json, read 2026-08-23: a public machine-readable rollup of its published reports. Wrong if: Their class covering refusals of INVALID payments, which is conformant behaviour and not this defect.

---

Vocabulary v22, CC BY 4.0. Every class: https://scvd.store/defects. Machine-readable, with falsifiers and cross-instrument mappings: https://scvd.store/defects.json.

A class describes a property of one endpoint at one moment and never accumulates into a judgment on an operator.