{"uid":"cap_bB3zmBOUpXgoGUU4_6ENl","slug":"pairs-z-score-89e6aa8a","name":"Pairs Z-Score","description":"Z-score of spread series for pairs trading. Call when mean-reversion signals from a price-spread series. Returns zscore, mean, stdev as deterministic JSON for $0.001 USDC via x402 on Base. First-party local math only—no RPC, live market feed, API keys, storage, or mediagen. Advisory only; the caller owns capital, risk, and production controls.","url":"https://api.delx.ai/api/v1/x402/pairs-zscore","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"spread":{"type":"array","description":"Spread series for pairs z-score"}}},"responseSchema":{"type":"json","example":{"mean":1,"stdev":0.1290994448735805,"schema":"delx/util-pairs-zscore/v1","zscore":0}},"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_P0B01KTROG8qYyqOw22PU","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":"Computes the z-score, mean, and standard deviation of a price-spread series for pairs trading mean-reversion analysis.","exampleAgentPrompt":"Calculate the z-score for this pairs trading spread series so I can see how far it is from the mean: [12.3, 12.8, 11.9, 13.1, 14.2, 15.0, 14.7, 13.5, 12.1, 11.5].","exampleUseCases":[{"title":"Pairs trade entry signal detection","prompt":"I'm tracking the price spread between two correlated stocks and want to know if the spread is at a statistically significant extreme — can you compute the z-score for this spread series: [5.1, 5.3, 4.9, 5.5, 6.2, 7.0, 6.8, 5.9, 5.2, 4.8]?"},{"title":"Mean reversion exit timing","prompt":"My pairs trade has been open for a while and I want to know if the spread has reverted close enough to the mean to close the position — here's the spread series, can you give me the z-score, mean, and standard deviation: [2.1, 2.4, 2.0, 1.8, 1.5, 1.2, 1.0, 0.9]?"},{"title":"Automated stat arb screening","prompt":"I'm screening several spread series for mean-reversion signals — compute the z-score for this spread: [100.2, 99.8, 101.1, 102.5, 104.0, 103.7, 102.1, 100.5, 99.3, 98.7]."}],"resultDescription":"Returns a deterministic JSON object containing the z-score of the latest spread value (or the full series), the mean of the spread series, and the standard deviation — all computed locally with no external data dependencies.","failureModes":["Empty or missing spread array returns an error","Spread array with insufficient data points (e.g. fewer than 2) may yield undefined standard deviation","Non-numeric values in the spread array cause a validation or computation error","Payment failure or insufficient USDC balance prevents the call from executing"],"whenToPreferThis":"Use this endpoint when you need a fast, cheap, deterministic z-score computation for a pairs trading spread series without any external market data dependencies. Ideal for AI agents running statistical arbitrage workflows that need to evaluate mean-reversion signals programmatically. Prefer this over rolling your own math when you want a reliable, payable microservice with consistent JSON output. Not appropriate for live price fetching or portfolio management — the caller must supply the spread series.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T07:07:19.969Z","isFirstParty":false}