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Content Length Check
x402
Content Length Check is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).
Compares a declared Content-Length header value against an observed byte count and returns a deterministic pass/advisory verdict with normalized evidence.
Price / call$0.001
Success—
StatusUnknown
How this service works
Content Length Check: Content Length Check compares declared Content-Length with an observed byte count from bounded caller-supplied values without an external provider. Call Content Length Check 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 Content Length Check as versioned deterministic JSON. Price: $0.001 USDC via x402 on Base. First-party, stateless, memor…
Output
Returns versioned deterministic JSON containing: normalized web evidence (declared and observed values), the computed finding (difference and match status), and an explicit pass or advisory status indicating whether the declared Content-Length matches the observed byte count.
Example use cases
Validate cached response before storing
“Before I cache this API response, check whether the declared Content-Length of 512 bytes matches the observed 512 bytes I counted — give me a clear pass or advisory result.”
Detect truncated download in agent pipeline
“I downloaded a file and my byte counter says 10240 but the server declared 10500 — can you run a content length check and tell me if the response was truncated?”
Pre-retry mismatch detection for resilient agent
“Before I retry this failed request, check if the declared Content-Length of 300 and my observed count of 0 represent a real mismatch that warrants a retry.”
Technical details
Endpoint
POSThttps://api.delx.ai/api/v1/x402/content-length-checkWhen to prefer
Use this endpoint when an AI agent needs a stateless, auditable, deterministic check that a Content-Length HTTP header matches the actual observed byte count before accepting, caching, redirecting, or retrying a web response. Prefer it over manual comparison when you need a versioned JSON record of the finding for audit trails or when operating in an agentic pipeline that requires explicit pass/advisory signals.
Side effects
- Missing or null declared/observed integers cause a validation error
- Non-integer values for declared or observed fields are rejected
- Negative byte counts may trigger an invalid-input error
- Payment failure via x402 prevents the call from completing
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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