# Delx Commerce — Vary Header Normalize

> Delx Commerce — Vary Header Normalize 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).

Parses and normalizes an HTTP Vary header string into a canonical, sorted list of header field tokens

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/vary-header-normalize?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-vary-header-normalize-c204e200
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_aUarCx6gccHbKHYVzhcHl

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-vary-header-normalize-c204e200 -d '<json body>'
```

Example prompt: Can you normalize this Vary header for me — 'Origin, Accept-Encoding, Accept' — and give me back the canonical sorted token list?

## When to prefer this

Use this endpoint when you need a deterministic, verifiable, privacy-preserving normalization of HTTP Vary headers — especially in automated pipelines where auditability matters (the SHA-256 evidence hash confirms the input processed). Prefer this over ad-hoc string splitting when you need consistent canonical output with no data retention guarantees and a pay-per-call model with no signup friction.

## Known failure modes

- Input header string exceeds 8192 character limit — request rejected
- Malformed or unparseable header content — may return empty token list or error status
- Payment failure or insufficient USDC balance — 402 response before processing
- Network timeout — no result returned

## 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: a list of normalized, lowercased header tokens (e.g. ['accept-encoding','origin']), a normalized comma-joined string, a status of 'pass', an operation identifier, and a verifiable evidence block including whether input was retained (always false), the SHA-256 hash of the input, and the count of external calls made (always 0).

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "tokens": [
    "accept-encoding",
    "origin"
   ],
   "normalized": "accept-encoding, origin"
  },
  "schema": "delx/util-vary-header-normalize/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "939169b314b2600276b55d910c792908209d28331261b7f22bab533cf1e6cd07",
   "external_calls": 0
  },
  "operation": "web_reliability:vary_header_normalize"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-vary-header-normalize-c204e200/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)