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Delx Commerce — Content Length Check
x402
Delx Commerce — Content Length Check 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).
Verifies whether a declared HTTP Content-Length header value matches the observed byte length of a response body, returning a pass/fail result with a delta.
Price / call$0.001
Success—
StatusUnknown
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 a boolean 'matched' field, the 'delta' between declared and observed values, the original declared and observed integers, an operation status ('pass'/'fail'), and an evidence block containing a SHA-256 hash of the input, a flag confirming no data retention, and a count of external calls made (always 0).
Example use cases
Detecting corrupted HTTP downloads
“I downloaded a file and the server said the Content-Length was 204800 bytes, but I only received 198432 bytes — can you check if those match and tell me the delta?”
Web scraper response integrity check
“My scraper is seeing inconsistent responses — the declared content length is 512 bytes but the observed is 512 bytes. Can you confirm they match before I process the payload?”
API reliability monitoring audit
“As part of our uptime checks, verify that the declared content length of 2048 bytes matches the observed 1900 bytes and flag whether there's a mismatch so I can alert the team.”
Technical details
Endpoint
POSThttps://commerce.delx.ai/api/v1/x402/content-length-check?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a verifiable, auditable, pay-per-use check of whether an HTTP Content-Length header matches the actual observed body size — particularly when you need cryptographic evidence (SHA-256 input hash) that no data was retained and no external calls were made. Prefer it over custom validation logic when you want tamper-evident results or when operating in an agent pipeline that requires provable, per-call billing via USDC on Base or Solana.
Side effects
- Missing or non-integer 'declared' or 'observed' fields return a validation error
- Negative integer inputs may be rejected or produce unexpected deltas
- Network or payment failures (x402 protocol) prevent the call from completing
- Malformed request body returns a 4xx error before processing
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| declared | integer | Declared supplied to Content Length Check; used only for this bounded calculation and processed in memory without retention. |
| observed | integer | Observed supplied to Content Length Check; used only for this bounded calculation and processed in memory without retention. |
Output
Schema · Response
{
"type": "json",
"example": {
"result": {
"delta": 0,
"matched": true,
"declared": 128,
"observed": 128
},
"schema": "delx/util-content-length-check/v1",
"status": "pass",
"evidence": {
"retained": false,
"input_sha256": "c55f65a8b217d1823723eaaef27fb2baf48c4cfd7f20ccc0fecf75ec925d4da5",
"external_calls": 0
},
"operation": "web_reliability:content_length_check"
}
}Tags
x402
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