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PennyRail JSON Keys Extractor
x402
PennyRail JSON Keys Extractor is a paid API for AI agents from pennyrail.vercel.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-22).
Extracts and returns the keys from a JSON object via a paid micro-transaction endpoint
Price / call$0.001
Success—
StatusUnknown
How this service works
Machine-readable settlement service
Output
A JSON object containing the extracted key names from the provided input object, returned as a machine-readable response with dynamic properties.
Example use cases
Inspect unknown API response structure
“I just got back this JSON blob from a third-party API and I have no idea what fields are in it — can you pull out all the keys so I know what I'm working with?”
Validate expected fields in JSON payload
“Here's a JSON object from our data pipeline — can you list all its keys so I can check whether the expected fields like 'id', 'timestamp', and 'status' are actually present?”
Auto-document JSON data schema
“I have a sample JSON record from our database export and I need to document its structure — can you extract all the key names from it so I can start building a schema?”
Technical details
Endpoint
POSThttps://pennyrail.vercel.app/api/p/nano/json.keys--json-keys?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need a quick, programmatic way to enumerate the keys of a JSON object without writing custom parsing logic, especially in agent pipelines where you want to inspect or validate the structure of an unknown JSON payload on the fly and are comfortable with micro-payment per call.
Side effects
- Missing or malformed 'input' field returns a validation error
- Input is not a JSON object (e.g. array or primitive) may return unexpected results
- Payment not fulfilled results in HTTP 402 and the call is not processed
- Network timeout on the Vercel edge function
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object |
Output
Schema · Response
{
"type": "object",
"additionalProperties": true
}Tags
x402
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