{"uid":"cap_GycMCT_R6MjjxYxvVCoug","slug":"x402toll-capital-gains-tax-calculator-9772dcb6","name":"x402toll Capital Gains Tax Calculator","description":"Federal capital-gains tax: long-term stacked across the 2026 0%/15%/20% breakpoints, short-term at ordinary marginal rates, plus the 3.8% Net Investment Income Tax.","url":"https://x402toll.com/v1/tax/capital-gains","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"magi":{"type":"number"},"filingStatus":{"enum":["single","mfj","hoh","mfs"],"type":"string","default":"single"},"longTermGain":{"type":"number","default":0},"shortTermGain":{"type":"number","default":0},"ordinaryTaxableIncome":{"type":"number","default":0}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.1","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":"$0.1/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_1mwFy_X-4V4Iy5mHhtxwa","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.1","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Calculates US federal capital gains tax using 2026 long-term bracket stacking (0%/15%/20%), short-term ordinary rates, and the 3.8% Net Investment Income Tax","exampleAgentPrompt":"I sold some stock this year — I have $80,000 in long-term capital gains and $15,000 in short-term gains. My MAGI is $220,000 and my ordinary taxable income is $175,000 and I file as single. What's my total federal capital gains tax including NIIT for 2026?","exampleUseCases":null,"resultDescription":"A breakdown of federal capital gains tax liability: long-term tax computed by stacking gains atop ordinary income across the 2026 0%/15%/20% bracket thresholds, short-term tax at applicable ordinary marginal rates, the 3.8% NIIT if MAGI exceeds applicable threshold, and a combined total federal capital gains tax owed.","failureModes":["Missing required 'magi' field returns validation error","Invalid filing status enum value returns 400 bad request","Negative gain values may produce unexpected results if not handled","Payment failure or insufficient USDC balance returns 402 Payment Required","Extremely large gain values may hit numerical precision limits"],"whenToPreferThis":"Use this endpoint when you need a precise, 2026-current federal capital gains tax estimate that correctly stacks long-term gains atop ordinary income across bracket breakpoints and applies NIIT — ideal when both long-term and short-term gains are present, or when MAGI may push income over the NIIT threshold. Prefer this over a generic tax calculator when you specifically need capital gains breakdown rather than a full income tax estimate.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T18:38:23.852Z","isFirstParty":false}