# Delx Commerce — Accept-Encoding Rank

> Delx Commerce — Accept-Encoding Rank 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).

Ranks and selects the best HTTP Accept-Encoding compression format from a list of offers given an Accept-Encoding header value

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/accept-encoding-rank?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-accept-encoding-rank-b9eac80e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mshhw__GAmWwOcoulMQeI

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-accept-encoding-rank-b9eac80e -d '<json body>'
```

Example prompt: Given the Accept-Encoding header 'br;q=1.0, gzip;q=0.8, deflate;q=0.5' and available encodings ['br','gzip','deflate','identity'], which compression format should I use for the response?

## When to prefer this

Use this endpoint when you need a deterministic, verifiable, auditable computation of HTTP Accept-Encoding negotiation without any side effects or external calls. It is ideal for AI agents that need a provably correct answer (with SHA-256 evidence) at extremely low cost ($0.001 USDC) without requiring signup or session management. Prefer it over implementing Accept-Encoding parsing in-process when auditability or correctness guarantees matter, or when running in a sandboxed agent environment.

## Known failure modes

- Malformed or empty Accept-Encoding header string may produce unexpected rankings or an error
- Encoding offers list exceeding 256 items is rejected by schema validation
- Header string exceeding 8192 characters is rejected
- Payment failure via x402 protocol results in 402 response before computation begins
- Unrecognized or non-standard encoding token names may be passed through without quality normalization

## How this service works

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

## Output

A JSON object containing a ranked array of encoding offers (each with offer name and quality score), the selected best encoding string, the operation name, pass/fail status, and evidence metadata including input SHA-256 hash, a flag confirming no data retention, and a count of zero external calls made.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "header": {
   "type": "string",
   "maxLength": 8192,
   "description": "Header supplied to Accept Encoding Rank; used only for this bounded calculation and processed in memory without retention."
  },
  "offers": {
   "type": "array",
   "items": {
    "type": "string",
    "maxLength": 8192
   },
   "maxItems": 256,
   "description": "Offers supplied to Accept Encoding Rank; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "ranked": [
    {
     "offer": "br",
     "quality": 1
    },
    {
     "offer": "gzip",
     "quality": 0.8
    }
   ],
   "selected": "br"
  },
  "schema": "delx/util-accept-encoding-rank/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "38b764e7204eb17f82ed20cce029e6a2c8cd6149a609fe91d9a2ab05143350ab",
   "external_calls": 0
  },
  "operation": "web_reliability:accept_encoding_rank"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-accept-encoding-rank-b9eac80e/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)