# Delx Commerce — X402 Payment Header Shape Validator

> Delx Commerce — X402 Payment Header Shape Validator 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).

Validates the structural shape and encoding of an X402 payment header, returning a pass/fail result with verifiable evidence of in-memory-only processing.

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/x402-payment-header-shape?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-payment-header-shape-validator-2376b351
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nehDvutbOhIN9WuWBKjWR

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-payment-header-shape-validator-2376b351 -d '<json body>'
```

Example prompt: Can you check whether this x402 payment header is correctly shaped and has valid base64_json encoding? Here's the header string: 'eyJ0eXBlIjoieDQwMiIsInBheW1lbnQiOnsidG9rZW4iOiJVU0RDIn19'

## When to prefer this

Choose this endpoint when you need a lightweight, privacy-preserving, verifiable check of an x402 payment header's structural validity before submitting a payment. It is ideal for agent payment pipelines that need cryptographic evidence (SHA-256 of input, zero external calls, no data retention) that validation was performed correctly. Prefer this over manual parsing when auditability and verifiable delivery matter.

## Known failure modes

- Header string exceeds 8192 character limit — request rejected
- Malformed or non-base64 header returns shape_valid: false rather than an error
- Missing or empty header field causes validation failure
- Invalid JSON structure in request body returns HTTP 400
- Network timeout on the Delx Commerce endpoint

## 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 indicating whether the x402 payment header shape is valid (shape_valid boolean), the encoding type detected (e.g. base64_json), a pass/fail status, and a verifiable evidence block containing the SHA-256 hash of the input, confirmation that no data was retained, and the count of external calls made (always 0). Also includes the schema version and operation identifier.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "header": {
   "type": "string",
   "maxLength": 8192,
   "description": "Header supplied to X402 Payment Header Shape; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "encoding": "base64_json",
   "shape_valid": true
  },
  "schema": "delx/util-x402-payment-header-shape/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "d2df40bf50f271956773fe4254a5de1a334515afca29fda6e60cd96f1ec08c63",
   "external_calls": 0
  },
  "operation": "delivery_contract:x402_payment_header_shape"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-x402-payment-header-shape-validator-2376b351/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)