{"uid":"cap_Fh-AXr_DP8vJvr-35f4ys","slug":"leap-year-check-09d58375","name":"Leap Year Check","description":"Leap year check. Use for date validation and calendar math without external data. Returns a boolean leap-year result for a Gregorian year. $0.001 USDC per successful call via x402 on Base—deterministic first-party JSON, no API key, no subscription, and nothing is billed on structured validation errors.","url":"https://api.delx.ai/api/v1/x402/is-leap-year","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"year":{"type":"integer","maximum":9999,"minimum":1,"description":"Gregorian calendar year."}}},"responseSchema":{"type":"json","example":{"year":2028,"schema":"delx/is-leap-year/v1","is_leap_year":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_kAaKVj6lamgB1ydRqfgYh","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":"Returns a boolean indicating whether a given Gregorian calendar year is a leap year","exampleAgentPrompt":"Is 2100 a leap year? Just give me a true or false answer.","exampleUseCases":[{"title":"Date validation in scheduling pipeline","prompt":"Before I generate the schedule for February 2096, can you confirm whether 2096 is a leap year so I know if February 29th is a valid date?"},{"title":"Historical calendar research check","prompt":"I'm writing about Julius Caesar's calendar reforms — can you tell me if the year 46 BC (year 46 in Gregorian) was a leap year?"},{"title":"Automated form field validation","prompt":"A user just entered February 29, 1900 as their birthday — is 1900 actually a leap year so I can tell them if that date is valid?"}],"resultDescription":"A JSON object containing a boolean field indicating whether the supplied year is a leap year under Gregorian calendar rules (divisible by 4, except century years unless also divisible by 400). Response is deterministic and first-party; no external data sources are consulted.","failureModes":["Year out of range (below 1 or above 9999) returns a structured validation error with no charge","Non-integer or missing year field returns a structured validation error","Payment not provided or insufficient returns an x402 payment-required error before processing"],"whenToPreferThis":"Choose this endpoint when you need a deterministic, authoritative leap-year answer for a single year without shipping your own calendar logic, relying on a math library, or handling edge cases like century years. Ideal for agents that need to validate calendar dates, compute February day counts, or perform date arithmetic as part of a larger workflow, especially when operating in environments where a lightweight, pay-per-call model is preferable to maintaining a dependency.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T19:02:29.403Z","isFirstParty":false}