{ "schemaVersion": "1.0", "experimentId": "gk-contribution-api-acceptance-2026-10-04-v1", "author": "George Kelly", "inputProvenance": "All amounts and caller metadata are deliberately authored synthetic examples; they are not merchant or employer records.", "selection": "Eight arithmetic controls and six malformed HTTP requests, selected before execution; five separate local caller-metadata cases. This is an editorial acceptance panel, not a random sample.", "httpCases": [ { "id": "positive-control", "question": "Can a caller obtain all results and the original inputs for the published worked example?", "query": "netRevenue=1000&costOfGoods=550&variableCosts=150&adSpend=200", "expected": { "status": 200, "result": { "grossProfit": "450", "contributionBeforeAds": "300", "contributionAfterAds": "100", "revenueRoas": "5", "grossProfitReturn": "9/4", "contributionReturn": "3/2", "breakEvenRoas": "10/3", "contributionMarginBeforeAds": "3/10" } } }, { "id": "negative-contribution", "question": "Does a loss remain negative instead of being clipped to zero?", "query": "netRevenue=1000&costOfGoods=700&variableCosts=400&adSpend=200", "expected": { "status": 200, "result": { "grossProfit": "300", "contributionBeforeAds": "-100", "contributionAfterAds": "-300", "revenueRoas": "5", "grossProfitReturn": "3/2", "contributionReturn": "-1/2", "breakEvenRoas": null, "contributionMarginBeforeAds": "-1/10" } } }, { "id": "zero-ad-spend", "question": "Do undefined spend ratios remain null while monetary contribution remains available?", "query": "netRevenue=1000&costOfGoods=550&variableCosts=150&adSpend=0", "expected": { "status": 200, "result": { "grossProfit": "450", "contributionBeforeAds": "300", "contributionAfterAds": "300", "revenueRoas": null, "grossProfitReturn": null, "contributionReturn": null, "breakEvenRoas": "10/3", "contributionMarginBeforeAds": "3/10" } } }, { "id": "zero-revenue", "question": "Are zero ROAS and undefined revenue-based margin distinguished?", "query": "netRevenue=0&costOfGoods=55&variableCosts=15&adSpend=20", "expected": { "status": 200, "result": { "grossProfit": "-55", "contributionBeforeAds": "-70", "contributionAfterAds": "-90", "revenueRoas": "0", "grossProfitReturn": "-11/4", "contributionReturn": "-7/2", "breakEvenRoas": null, "contributionMarginBeforeAds": null } } }, { "id": "zero-pre-ad-margin", "question": "Does zero pre-ad contribution yield null break-even ROAS?", "query": "netRevenue=1000&costOfGoods=700&variableCosts=300&adSpend=200", "expected": { "status": 200, "result": { "grossProfit": "300", "contributionBeforeAds": "0", "contributionAfterAds": "-200", "revenueRoas": "5", "grossProfitReturn": "3/2", "contributionReturn": "0", "breakEvenRoas": null, "contributionMarginBeforeAds": "0" } } }, { "id": "all-zero", "question": "Does the empty arithmetic scenario preserve undefined denominators?", "query": "netRevenue=0&costOfGoods=0&variableCosts=0&adSpend=0", "expected": { "status": 200, "result": { "grossProfit": "0", "contributionBeforeAds": "0", "contributionAfterAds": "0", "revenueRoas": null, "grossProfitReturn": null, "contributionReturn": null, "breakEvenRoas": null, "contributionMarginBeforeAds": null } } }, { "id": "decimal-inputs", "question": "Are decimal amounts accepted without integer truncation or display rounding?", "query": "netRevenue=100.50&costOfGoods=55.25&variableCosts=15.25&adSpend=20.00", "expected": { "status": 200, "result": { "grossProfit": "45.25", "contributionBeforeAds": "30", "contributionAfterAds": "10", "revenueRoas": "201/40", "grossProfitReturn": "181/80", "contributionReturn": "3/2", "breakEvenRoas": "67/20", "contributionMarginBeforeAds": "20/67" } } }, { "id": "upper-input-bound", "question": "Is the inclusive 1e12 input limit distinct from a limit on output magnitudes?", "query": "netRevenue=1000000000000&costOfGoods=1000000000000&variableCosts=1000000000000&adSpend=1000000000000", "expected": { "status": 200, "result": { "grossProfit": "0", "contributionBeforeAds": "-1000000000000", "contributionAfterAds": "-2000000000000", "revenueRoas": "1", "grossProfitReturn": "0", "contributionReturn": "-1", "breakEvenRoas": null, "contributionMarginBeforeAds": "-1" } } }, { "id": "missing-ad-spend", "question": "Is missing input rejected rather than filled with zero?", "query": "netRevenue=1000&costOfGoods=550&variableCosts=150", "expected": { "status": 400, "error": "adSpend is required exactly once as a non-negative decimal number." } }, { "id": "duplicate-ad-spend", "question": "Is a duplicate rejected even when both values agree?", "query": "netRevenue=1000&costOfGoods=550&variableCosts=150&adSpend=200&adSpend=200", "expected": { "status": 400, "error": "adSpend is required exactly once as a non-negative decimal number." } }, { "id": "negative-input", "question": "Are negative inputs rejected while negative outputs remain possible?", "query": "netRevenue=1000&costOfGoods=550&variableCosts=150&adSpend=-1", "expected": { "status": 400, "error": "adSpend is required exactly once as a non-negative decimal number." } }, { "id": "exponent-input", "question": "Is exponent notation rejected even when it represents 200?", "query": "netRevenue=1000&costOfGoods=550&variableCosts=150&adSpend=2e2", "expected": { "status": 400, "error": "adSpend is required exactly once as a non-negative decimal number." } }, { "id": "above-input-bound", "question": "Is an amount immediately above the bound rejected?", "query": "netRevenue=1000&costOfGoods=550&variableCosts=150&adSpend=1000000000001", "expected": { "status": 400, "error": "Advertising spend must be a finite number between 0 and 1,000,000,000,000." } }, { "id": "unknown-currency-parameter", "question": "Does the HTTP contract reject a made-up currency field rather than imply currency verification?", "query": "netRevenue=1000&costOfGoods=550&variableCosts=150&adSpend=200¤cy=USD", "expected": { "status": 400, "error": "Unknown parameter. Use netRevenue, costOfGoods, variableCosts, and adSpend only." } } ], "callerCases": [ { "id": "matching-labels-ready", "question": "Four complete, agreeing metadata labels permit a request to be prepared; no request is sent in this caller check.", "records": { "netRevenue": { "amount": "1000", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" }, "costOfGoods": { "amount": "550", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" }, "variableCosts": { "amount": "150", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" }, "adSpend": { "amount": "200", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" } }, "expectedStatus": "ready" }, { "id": "mixed-currency-hold", "question": "Revenue in USD and cost of goods in EUR need reconciliation before arithmetic.", "records": { "netRevenue": { "amount": "1000", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" }, "costOfGoods": { "amount": "550", "currency": "EUR", "cohortId": "fictional-orders-2026-09-settled-v1" }, "variableCosts": { "amount": "150", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" }, "adSpend": { "amount": "200", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" } }, "expectedStatus": "hold" }, { "id": "missing-currency-hold", "question": "An absent currency label is unknown, not an implied USD amount.", "records": { "netRevenue": { "amount": "1000", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" }, "costOfGoods": { "amount": "550", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" }, "variableCosts": { "amount": "150", "cohortId": "fictional-orders-2026-09-settled-v1" }, "adSpend": { "amount": "200", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" } }, "expectedStatus": "hold" }, { "id": "different-cohort-hold", "question": "Advertising spend assigned to another cohort must be reconciled.", "records": { "netRevenue": { "amount": "1000", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" }, "costOfGoods": { "amount": "550", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" }, "variableCosts": { "amount": "150", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" }, "adSpend": { "amount": "200", "currency": "USD", "cohortId": "fictional-orders-2026-08-settled-v1" } }, "expectedStatus": "hold" }, { "id": "missing-cohort-hold", "question": "Missing cohort evidence must not be inferred from the other values.", "records": { "netRevenue": { "amount": "1000", "currency": "USD" }, "costOfGoods": { "amount": "550", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" }, "variableCosts": { "amount": "150", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" }, "adSpend": { "amount": "200", "currency": "USD", "cohortId": "fictional-orders-2026-09-settled-v1" } }, "expectedStatus": "hold" } ], "notTested": [ "Independent integrations, adoption, repeat use, or audience demand", "Any language model, tool-selection policy, or model performance", "Correctness, settlement, authenticity, currency conversion, or cohort assignment of real business data", "Advertising incrementality, forecasting, profit after fixed overhead, or a spend recommendation", "Exhaustive input space, load, uptime, latency, security, or compatibility with every API client", "Provider validation of an OpenAPI document or admission to any tool directory" ] }