{"uid":"cap_vM99l8dmzQ1T123Z9_aKk","slug":"pennyrail-json-keys-fields-extractor-8ea21d73","name":"PennyRail JSON Keys & Fields Extractor","description":"Machine-readable settlement service","url":"https://pennyrail.vercel.app/api/p/nano/json.keys--json-fields","method":"POST","headers":{},"bodySchema":{"type":"object","required":["input"],"properties":{"input":{"type":"object"}}},"responseSchema":{"type":"object","additionalProperties":true},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_eEjige0stRsCJHCQk9-YZ","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Extracts and returns the keys and fields present in a submitted JSON object, enabling machine-readable inspection of JSON structure","exampleAgentPrompt":"Can you pull out all the keys and field names from this JSON object for me? Here it is: {\"user\": {\"id\": 42, \"name\": \"Alice\", \"roles\": [\"admin\", \"editor\"]}, \"created_at\": \"2024-01-01\"}","exampleUseCases":[{"title":"Discover fields in unknown API response","prompt":"I got a JSON response back from a third-party API and I have no idea what fields are in it — can you extract all the keys and field names so I can understand its structure?"},{"title":"Validate expected fields exist","prompt":"I need to check that this JSON payload from our webhook actually contains the fields I expect — can you extract all the keys from it so I can compare them against my required list?"},{"title":"Auto-document a data payload","prompt":"I want to auto-generate a list of all fields in this JSON object so I can build documentation for it — please extract every key name from the payload I'm sending you."}],"resultDescription":"A JSON object containing the enumerated keys and field names found within the submitted input object, allowing the caller to inspect the structure and properties of the original JSON without needing to parse it manually.","failureModes":["Input object is missing or malformed — returns a 400-level error","Input is not a valid JSON object — schema validation failure","Payment not settled via x402 protocol — returns 402 Payment Required","Empty object submitted — may return an empty keys list","Deeply nested structures may only return top-level keys depending on implementation"],"whenToPreferThis":"Choose this endpoint when you need a lightweight, pay-per-call microservice to enumerate the keys or fields of a JSON object without setting up local parsing logic, or when operating in an agent pipeline that uses x402 micropayment-gated APIs. It is best suited for dynamic schema discovery, payload inspection, and cases where the JSON structure is unknown or variable.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T07:02:02.968Z","isFirstParty":false}