# Delx Commerce X402 Refund Amount Check

> Delx Commerce X402 Refund Amount Check is a paid API for AI agents from commerce.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-01).

Verifies whether a settled payment amount matches the requested amount within acceptable tolerance for X402 protocol refund calculations

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/x402-refund-amount-check?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-commerce-x402-refund-amount-check-230e5ef6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_GjG-ObsKQSnKPe9N2jwJw

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability delx-commerce-x402-refund-amount-check-230e5ef6 -d '<json body>'
```

Example prompt: Check whether the settled payment amount '1000' matches the requested payment amount '1000' in the X402 refund check — I want to know if there's any drift and whether it's within tolerance.

## When to prefer this

Use this endpoint when you need a verifiable, cryptographically evidenced check of whether a settled X402 payment amount matches the requested amount — particularly when building refund logic, auditing agent payment pipelines, or confirming delivery fidelity in pay-per-result architectures on Base or Solana. Prefer this over manual calculation when you need the tamper-evident evidence hash and explicit tolerance logic baked in.

## Known failure modes

- Invalid or non-numeric raw values cause validation to fail
- Missing settled_raw or requested_raw fields return an error
- Strings exceeding 8192 characters are rejected
- Malformed JSON body returns a 400 error
- Large drift beyond tolerance returns within_tolerance: false with a fail status

## How this service works

Pay-per-result APIs for agents. No signup. Exact price. Verifiable delivery. USDC on Base + Solana via x402.

## Output

Returns a JSON object with drift_raw (difference between expected and actual), actual_raw, expected_raw, within_tolerance boolean, an overall status (pass/fail), operation identifier, and an evidence block containing the input SHA-256 hash and confirmation that no external calls were made and no data was retained.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "settled_raw": {
   "type": "string",
   "maxLength": 8192,
   "description": "Settled Raw supplied to X402 Refund Amount Check; used only for this bounded calculation and processed in memory without retention."
  },
  "requested_raw": {
   "type": "string",
   "maxLength": 8192,
   "description": "Requested Raw supplied to X402 Refund Amount Check; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "drift_raw": "0",
   "actual_raw": "1000",
   "expected_raw": "1000",
   "within_tolerance": true
  },
  "schema": "delx/util-x402-refund-amount-check/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "8f2b3a0b094ceb2d8c75d4ce4b7f179347769e2b9645666d7c973aae510291f0",
   "external_calls": 0
  },
  "operation": "delivery_contract:x402_refund_amount_check"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-x402-refund-amount-check-230e5ef6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from commerce.delx.ai](https://www.zero.xyz/host/commerce.delx.ai/llms.txt)