{"uid":"cap_HNyDIvVrpN95hYG4Xown1","slug":"pennyrail-json-pick-select-object-keys-d04c8173","name":"PennyRail JSON Pick – Select Object Keys","description":"Machine-readable settlement service","url":"https://pennyrail.vercel.app/api/p/nano/json.pick--select-object-keys","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_CYzKfPwihRE6YEphL7UrK","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":"Accepts a JSON object and returns a new object containing only the specified subset of keys (pick/select operation)","exampleAgentPrompt":"I have a JSON object with lots of fields — can you pick just the 'name', 'email', and 'role' keys from it and give me back a clean object with only those three?","exampleUseCases":[{"title":"Trim API response to essential fields","prompt":"I'm getting back a huge user object from our auth API — can you pick just the 'id', 'email', and 'displayName' fields from it so I can pass a smaller payload to the next step?"},{"title":"Project config object for downstream service","prompt":"Here's a big config JSON with dozens of keys. I only need to forward 'host', 'port', and 'timeout' to the connection service — can you select just those keys from the object?"},{"title":"Extract billing fields from invoice record","prompt":"I have a full invoice record as a JSON object. Can you pick out only the 'invoiceNumber', 'amount', 'currency', and 'dueDate' fields so I can feed them into the billing report?"}],"resultDescription":"Returns a new JSON object containing only the key-value pairs from the input object whose keys were specified in the selection. All other keys from the input are omitted. The response is a plain JSON object with the picked fields.","failureModes":["Missing 'input' field in request body returns a validation error","If requested keys do not exist on the input object, those keys are silently omitted from the result","Malformed JSON body causes a parse error","Payment failure or insufficient USDC balance blocks the request via x402 payment protocol","Empty key selection may return an empty object"],"whenToPreferThis":"Use this endpoint when you need a lightweight, paid micro-service to programmatically project a subset of keys from a JSON object — especially in agent pipelines where you want a deterministic, stateless transformation without running custom code. Prefer this over general-purpose code execution when you want a simple, auditable pick operation with a clear x402 payment trail at $0.001 per call.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T07:04:04.452Z","isFirstParty":false}