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Vary Header Normalize
x402
Vary Header Normalize is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-19).
Normalizes and deduplicates HTTP Vary header field names from a caller-supplied header string, returning a cleaned canonical form with pass/advisory status.
Price / call$0.001
Success—
StatusUnknown
How this service works
Vary Header Normalize: Vary Header Normalize normalizes and deduplicates Vary header field names from bounded caller-supplied values without an external provider. Call Vary Header Normalize 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 Vary Header Normalize as versioned deterministic JSON. Price: $0.001 USDC via x402 on Base. First-party, stateless, memory-onl…
Output
Returns versioned deterministic JSON containing the normalized Vary header field names (deduplicated and canonicalized), the computed finding describing what was changed or confirmed, and an explicit pass or advisory status indicating whether the header is acceptable for use in caching, redirecting, or retrying scenarios.
Example use cases
Pre-cache Vary header validation
“Before I store this web response in my cache, can you normalize and deduplicate its Vary header? The raw header value is 'Accept-Encoding, Accept, accept-encoding, Accept-Language'.”
Redirect pipeline header cleanup
“I'm about to follow a redirect and want to make sure the Vary header is clean first — can you normalize 'User-Agent, Accept, user-agent, Accept-Encoding' for me?”
Retry logic header audit
“My retry logic needs a canonical Vary header before deciding whether to reuse a cached response — please normalize and deduplicate 'Accept, Accept-Encoding, accept, Cache-Control' and tell me if it passes.”
Technical details
Endpoint
POSThttps://api.delx.ai/api/v1/x402/vary-header-normalize?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need a deterministic, stateless, zero-retention normalization of HTTP Vary headers before making caching, redirecting, or retrying decisions — especially in agentic pipelines where consistent cache-key computation depends on canonical header field names. Prefer it over manual string manipulation when deduplication and case-normalization correctness matter and you want an explicit pass/advisory audit trail.
Side effects
- Header string exceeds 8192 character limit — request rejected
- Malformed or unparseable header value — advisory status returned with finding detail
- Empty header string — may return pass with empty normalized output
- Payment failure via x402 — request not processed
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| header | string | Header supplied to Vary Header Normalize; used only for this bounded calculation and processed in memory without retention. |
Output
Schema · Response
{
"type": "json",
"example": {
"result": {
"tokens": [
"accept-encoding",
"origin"
],
"normalized": "accept-encoding, origin"
},
"schema": "delx/util-vary-header-normalize/v1",
"status": "pass",
"evidence": {
"retained": false,
"input_sha256": "939169b314b2600276b55d910c792908209d28331261b7f22bab533cf1e6cd07",
"external_calls": 0
},
"operation": "web_reliability:vary_header_normalize"
}
}Tags
x402
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