# Delx Commerce — X402 Challenge Version Check

> Delx Commerce — X402 Challenge Version Check is a paid API for AI agents from commerce.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-02).

Checks whether a given x402 protocol version is supported among a list of supported versions, returning a verifiable result with cryptographic evidence.

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/x402-challenge-version-check?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-commerce-x402-challenge-version-check-5bc84983
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gLIqBXf5FiyQXpTSqYJli

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-challenge-version-check-5bc84983 -d '<json body>'
```

Example prompt: Check if x402 version 2 is supported among versions [1, 2, 3] and give me a verifiable result with evidence.

## When to prefer this

Use this endpoint when an AI agent or payment system needs a cheap, verifiable, tamper-evident check of x402 protocol version compatibility — especially when cryptographic evidence of the computation (input hash, no retention, no external calls) is required for audit or compliance. Prefer this over a local check when you need an on-chain-payable, verifiable delivery proof rather than a simple in-process comparison.

## Known failure modes

- Version integer not found in supported_versions list — returns supported: false
- Malformed input (non-integer version or array exceeding 256 items) — likely 400 Bad Request
- Payment not completed via x402 — 402 Payment Required before result is returned
- Empty supported_versions array — result may return supported: false with no match

## 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 containing: the matched version integer, a boolean indicating if it is supported, the full list of supported versions, a pass/fail status, the operation name, the schema identifier, and an evidence block with a SHA-256 hash of the input, a flag confirming no data was retained, and a count of zero external calls made.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "version": {
   "type": "integer",
   "description": "Version supplied to X402 Challenge Version Check; used only for this bounded calculation and processed in memory without retention."
  },
  "supported_versions": {
   "type": "array",
   "items": {
    "type": "integer"
   },
   "maxItems": 256,
   "description": "Supported Versions supplied to X402 Challenge Version Check; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "version": 2,
   "supported": true,
   "supported_versions": [
    1,
    2
   ]
  },
  "schema": "delx/util-x402-challenge-version-check/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "19a97d5b88dfc156ec9b3f1ff4cfb324dd9d18bb96d5ff480a3478193db0eeab",
   "external_calls": 0
  },
  "operation": "delivery_contract:x402_challenge_version_check"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-x402-challenge-version-check-5bc84983/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)