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PennyRail MIME Type Lookup
x402
PennyRail MIME Type Lookup is a paid API for AI agents from pennyrail.vercel.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).
Looks up the MIME type for a given file extension or filename, returning the corresponding content-type string
Price / call$0.001
Success—
StatusUnknown
How this service works
Machine-readable settlement service
Output
Returns an object containing the resolved MIME type string (e.g. 'image/png', 'application/pdf') corresponding to the provided file extension or filename. If the extension is unrecognized, may return null or a default fallback type.
Example use cases
Set correct content-type for uploads
“I'm building a file upload handler and need to know the correct MIME type for .xlsx files so I can set the right content-type header in my response.”
Validate file extension before serving
“Before I serve this .webm file from my server, can you look up what MIME type it should be so I can configure the response headers correctly?”
Map filename to media type in pipeline
“I have a file called 'report.pdf' going through my data pipeline — what MIME type should be associated with it so downstream consumers know how to handle it?”
Technical details
Endpoint
POSThttps://pennyrail.vercel.app/api/p/nano/mime.lookup--mime-type-lookupWhen to prefer
Use this endpoint when you need a quick, paid, machine-readable MIME type resolution as part of an automated pipeline or agent workflow, particularly when already operating within the x402 micropayment ecosystem on PennyRail. Prefer alternatives (local npm mime package, free APIs) for high-volume lookups where per-call cost adds up.
Side effects
- Unknown or unrecognized file extension returns null or empty result
- Missing 'input' field in request body causes validation error
- Malformed input object causes 400-level error
- Extension provided without leading dot may not resolve correctly
- Payment failure (402) if USDC balance insufficient
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object |
Output
Schema · Response
{
"type": "object",
"additionalProperties": true
}Tags
x402
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