Tax Calculators & Engines
Libraries and engines that compute tax, embeddable anywhere.
Privacy-focused, free, open-source cryptocurrency tax calculator for multiple countries: it handles multiple coins/exchanges and computes long/short-term capital gains, cost bases, in/out lot relationships/fractioning, and account balances. It supports FIFO, LIFO, HIFO and it outputs in form 8949 format. It has a programmable plugin architecture
USA Federal Individual Income and Payroll Tax Microsimulation Model
The deterministic tax engine for AI agents. Highest score ever recorded on TaxCalcBench (96% exact returns)
Fully open-source US federal tax engine. Single binary cli. Runs on macOS, Linux, and Windows. Built for AI agents using AI agents.
TAXSIM emulator using the PolicyEngine US federal and state tax calculator
MCP server for French tax calculations and information - enables AI assistants to provide accurate French tax guidance
MCP server for US individual taxpayers — 39 tools for federal/state tax calculations, credits, deductions, retirement strategies, and tax planning. All calculations run locally. TY2024 + TY2025 (OBBB Act).
Beancount plugin for generating informational UK tax report (calculate capital gains tax)
Local-first MCP server for Indian income tax: deterministic tax computation, regime comparison, advance tax planning, document parsing -- all on your machine
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