{"uid":"cap_IqPMBp7Lsvqeu2nI_r3XD","slug":"one-engine-array-frequency-t9-a9233e19","name":"ONE Engine Array Frequency (T9)","description":"Low-cost pay-per-call utility APIs for autonomous agents using x402 on Base.","url":"https://one-search.one-engine.workers.dev/v3/array/frequency/t9?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","required":["values"],"properties":{"size":{"type":"integer"},"other":{"type":"array","description":"Optional comparison array"},"offset":{"type":"integer"},"values":{"type":"array","description":"JSON array with at most 1000 items"}}},"responseSchema":{"type":"object","additionalProperties":true},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.018","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":"$0.018/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.018","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.018","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_d_saKrHQdH43DJjyV7qbE","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.018","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes frequency distribution of elements in a JSON array, with optional comparison against a second array.","exampleAgentPrompt":"Can you count how many times each value appears in this list: [\"apple\",\"banana\",\"apple\",\"cherry\",\"banana\",\"apple\"] and also compare it against this reference list [\"apple\",\"banana\",\"date\"]?","exampleUseCases":[{"title":"Survey response tally","prompt":"I have survey responses in this array: [\"yes\",\"no\",\"yes\",\"maybe\",\"yes\",\"no\",\"yes\"] — count how often each answer appears so I can see which was most common."},{"title":"Log error frequency analysis","prompt":"Here's a list of error codes from our system logs: [\"404\",\"500\",\"404\",\"403\",\"500\",\"404\",\"200\",\"500\"] — give me a frequency breakdown of each error code, and compare it to last week's baseline [\"404\",\"404\",\"500\",\"200\"]."},{"title":"Product category ranking","prompt":"Count how many times each category appears in this product list: [\"electronics\",\"clothing\",\"electronics\",\"food\",\"clothing\",\"electronics\",\"food\",\"food\"] so I can rank them by popularity."}],"resultDescription":"Returns an object containing frequency counts for each unique element in the input array, and optionally a comparison breakdown when a second array is provided. The response includes occurrence tallies per element, enabling ranking or distribution analysis.","failureModes":["Array exceeds 1000 items — request rejected","Invalid JSON array format for values field — validation error","Missing required 'values' field — 400 error","Payment not included or insufficient — 402 Payment Required","Malformed comparison array in 'other' field — processing error"],"whenToPreferThis":"Choose this endpoint when you need to count element occurrences or compute a frequency distribution over a JSON array of up to 1000 items, especially when you also want to compare frequencies between two arrays. It is pay-per-call with no subscription needed, making it ideal for lightweight, on-demand statistical analysis in agent workflows.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-02T12:43:05.579Z","isFirstParty":false,"canonicalSlug":"one-engine-array-frequency-t9-a9233e19"}