# Range Header Parse

> Range Header Parse is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-20).

Parses a single bounded HTTP Range header into normalized start and end byte offsets given a known resource size, returning a deterministic pass/advisory status.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/range-header-parse?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/range-header-parse-3e21a885
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_p01AaXhwPPAt7y1ekHBeE

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 range-header-parse-3e21a885 -d '<json body>'
```

Example prompt: Parse the HTTP Range header 'bytes=0-1023' for a resource that is 5242880 bytes total, and give me the normalized start and end byte offsets with a pass or advisory status.

## When to prefer this

Choose this endpoint when you need a stateless, deterministic, pay-per-call HTTP Range header parser with no external dependencies — especially useful in agentic pipelines that must validate or normalize byte ranges before accepting, caching, redirecting, or retrying partial content responses. Prefer it over custom parsing logic when you need a normalized, versioned JSON result with explicit pass/advisory status for auditability.

## Known failure modes

- Malformed Range header string produces an advisory/error status rather than a hard failure
- Resource size of zero or negative may result in advisory status
- Range values exceeding the resource size return out-of-bounds advisory
- Unsupported range unit (non-bytes) may not be parsed correctly
- Missing required fields (header or resource_size) returns a validation error
- Payment failure via x402 prevents the call from completing

## How this service works

Range Header Parse: Range Header Parse parses one bounded HTTP byte range into start and end offsets from bounded caller-supplied values without an external provider. Call Range Header Parse before accepting, caching, redirecting, or retrying a caller-supplied web response. Returns normalized web evidence, the computed finding, and an explicit pass or advisory status for Range Header Parse as versioned deterministic JSON. Price: $0.001 USDC via x402 on Base. First-party, stateless, memory-only…

## Output

Returns versioned deterministic JSON containing the normalized byte range (start and end offsets), the original web evidence (the input header and resource size), the computed finding, and an explicit pass or advisory status indicating whether the parsed range is valid and within bounds.

## 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/range-header-parse-3e21a885/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)