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Crypto Tax Calculator
x402
Crypto Tax Calculator is a paid API for AI agents from tax-api-production-eb93.up.railway.app, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-23).
Calculates US capital gains tax (LTCG, STCG, and NIIT) on cryptocurrency trades using 2026 tax brackets, paid per calculation on Base via x402.
Price / call$0.05
Success—
StatusUnknown
How this service works
US capital gains tax calculation. 2026 brackets. LTCG, STCG, NIIT. Pay per calculation on Base.
Output
Returns the computed US capital gains tax breakdown for the submitted trades, including short-term capital gains (STCG) taxed as ordinary income, long-term capital gains (LTCG) at preferential rates, and net investment income tax (NIIT) where applicable — all calculated against 2026 US tax brackets.
Example use cases
Year-end crypto tax liability estimate
“I made several crypto trades this year — I sold 0.5 BTC bought at $20,000 for $55,000 (held over a year), and sold 10 ETH bought at $2,000 each for $3,200 each last week. Can you calculate my total capital gains tax including long-term, short-term, and net investment income tax using 2026 brackets?”
DCA portfolio cost basis calculation
“I've been dollar-cost averaging into Ethereum all year with 12 separate purchases and I just sold my whole position. Here are all my buy and sell trades — can you calculate my cost basis and figure out what I owe in capital gains taxes under 2026 rules?”
Tax-loss harvesting impact check
“I want to see how my realized crypto gains and losses net out for tax purposes. I have some winning trades and some losses I already took — can you run the numbers on all my trades and tell me my net LTCG and STCG tax liability including any NIIT I might owe?”
Technical details
Endpoint
POSThttps://tax-api-production-eb93.up.railway.app/cost-basis?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need automated, per-calculation US cryptocurrency capital gains tax computation using current 2026 bracket rates, specifically requiring LTCG/STCG/NIIT breakdown. Prefer this over generic tax APIs when working with crypto-specific trade histories and needing cost-basis-aware computation on Base with micropayment pricing at $0.05/call.
Side effects
- Missing or empty trades array returns validation error
- Malformed trade objects (missing buy price, sell price, or dates) cause computation failure
- Insufficient USDC balance or payment failure via x402 results in 402 Payment Required
- Trades with ambiguous or missing holding period data may produce incorrect LTCG vs STCG classification
- Unsupported asset types or missing cost basis data may return null or incomplete results
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| tradesrequired | array |
Tags
x402
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