# Delx Commerce — Range Header Parse

> Delx Commerce — Range Header Parse 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).

Parses an HTTP Range header string and resolves the concrete byte range (start, end, length, satisfiable) given a resource size

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/range-header-parse?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-range-header-parse-a04faf93
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_atY7PjQfUY4gOF_bmQKhI

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-range-header-parse-a04faf93 -d '<json body>'
```

Example prompt: Parse the HTTP Range header 'bytes=0-499' for a resource that is 1024 bytes total and tell me the start offset, end offset, length, and whether it's satisfiable.

## When to prefer this

Use this endpoint when you need a quick, pay-per-call, no-signup computation to parse and validate HTTP Range headers into concrete byte offsets — particularly in agent workflows that handle partial content delivery, streaming, or resumable downloads. Prefer this over rolling your own parser when you need verifiable, in-memory-only processing with cryptographic evidence of input and no data retention.

## Known failure modes

- Malformed Range header string returns an unsatisfiable or error result
- Resource size of 0 may yield unsatisfiable ranges for most headers
- Range header exceeding 8192 characters is rejected at input validation
- Suffix ranges (bytes=-N) require correct resource_size to resolve properly
- Missing resource_size may cause incorrect or incomplete range resolution

## 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 the resolved byte range: start offset, end offset, byte length, and a satisfiable boolean indicating whether the range can be fulfilled. Also includes schema identifier, status, and evidence metadata (input hash, no data retention, zero external calls).

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "end": 499,
   "start": 0,
   "length": 500,
   "satisfiable": true
  },
  "schema": "delx/util-range-header-parse/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "b8cf82c3de152f6483e2bcdb69d68b8857f068e1b199d6c5fe801bbb24ff9086",
   "external_calls": 0
  },
  "operation": "web_reliability:range_header_parse"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-range-header-parse-a04faf93/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)