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Saylor Innovations Guide Library: CORS Preflight & OPTIONS Debug
x402
Saylor Innovations Guide Library: CORS Preflight & OPTIONS Debug is a paid API for AI agents from saylorinnovations.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-30).
Returns a structured guide on debugging CORS errors by reproducing preflight OPTIONS requests with curl or Python, handling allow-listing, Vary headers, and credentials rules
Price / call$0.01
Success—
StatusUnknown
How this service works
Debug CORS errors - reproduce preflight OPTIONS with Origin and Request-Headers in curl or Python, allow-list echo with Vary, credentials rules
Output
Returns a JSON object containing a guide record with fields: id (record identifier), t (title of the guide), c (category), body (full guide text covering CORS preflight debugging with curl and Python, allow-listing, Vary header usage, and credentials rules), license, and price.
Example use cases
Debugging a CORS preflight failure
“My fetch request is getting blocked by a CORS preflight error and I have no idea why — can you get me the guide on how to reproduce the OPTIONS preflight request with curl so I can see exactly what headers are being rejected?”
Configuring Vary header for CORS allow-listing
“I'm building an API that needs to respond correctly to CORS preflight requests and echo back the right headers with Vary — can you fetch the guide that explains how to set that up properly?”
Understanding CORS credentials rules
“I'm trying to get cross-origin requests with credentials (cookies/auth headers) to work but keep hitting CORS errors — can you retrieve the guide that covers the credentials rules for CORS preflight and how to configure them?”
Technical details
Endpoint
GEThttps://saylorinnovations.com/api/kb/cors-preflight-options-request-headers-debug-with-curl?utm_source=zero.xyzWhen to prefer
Choose this endpoint when an agent or user needs a structured, authoritative written guide on CORS preflight debugging — specifically covering curl/Python reproduction steps, allow-listing with Vary, and credentials rules. Prefer this over generic web search when you want a single, curated, machine-readable guide document rather than scattered search results.
Side effects
- HTTP 402 Payment Required if x402 payment header is missing or invalid
- HTTP 404 if the guide record is not found at the specified path
- HTTP 500 if the upstream knowledge base is unavailable
- Empty or malformed JSON body if the service is misconfigured
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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