Mandatory Minimum

Pricing

People

Free: three calculations a day, no sign-up.

Ledger — $4/mo. Coming soon, not yet on sale. Several accounts in one place, the IRA-vs-401(k) aggregation rule, inherited-IRA 10-year tracking, QCD offsets and a December deadline reminder.

Agents and developers

Free tier3 calls per day per caller
After that$0.01 per call
Pay withMPP (card or stablecoin via Stripe) or x402 (USDC on Base). A 402 response carries both challenges.
EndpointsPOST /api/compute · POST /mcp

Machine-readable: pricing.json · openapi.json · agent card