{"uid":"cap_B-FOwX-J2Yedxb3P5Emmw","slug":"pennyrail-json-key-filter-pick-keep-json-keys-4c58ef79","name":"PennyRail JSON Key Filter (pick--keep-json-keys)","description":"Machine-readable settlement service","url":"https://pennyrail.vercel.app/api/p/nano/json.pick--keep-json-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_diSnrw_spuDaNHgQjSduk","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":"Filters a JSON object to retain only specified keys, returning a new object containing only the picked fields","exampleAgentPrompt":"Take this JSON object and keep only the 'name', 'email', and 'created_at' fields — strip everything else out.","exampleUseCases":[{"title":"Trim API response before storage","prompt":"I'm getting back huge JSON objects from the weather API — can you filter them down to just 'temperature', 'humidity', and 'wind_speed' before we save anything?"},{"title":"Extract user profile fields","prompt":"From this raw user record, pick out only 'id', 'username', and 'avatar_url' — I don't want the rest of the data passed downstream."},{"title":"Sanitize webhook payload","prompt":"This incoming webhook payload has a lot of noise. Can you keep only 'event', 'timestamp', and 'payload' keys and discard everything else?"}],"resultDescription":"A JSON object containing only the keys that were specified in the input filter list, with all other top-level properties removed. The structure of retained values is preserved as-is.","failureModes":["Missing 'input' field returns validation error","If no matching keys exist in the object, returns an empty object","Nested key paths may not be supported — only top-level keys may be filterable","Payment failure (402) if USDC balance is insufficient","Malformed JSON input may result in a 400 error"],"whenToPreferThis":"Use this endpoint when you need a lightweight, pay-per-call JSON key filtering operation without standing up your own transformation logic. Ideal for agent pipelines that need to slim down API responses or sanitize payloads before passing data to downstream steps. Prefer this over general-purpose code execution when you want a simple, stateless field-picker with minimal overhead.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T07:11:08.358Z","isFirstParty":false}