statetakehome-mcp

A Model Context Protocol (MCP) server that puts a full US paycheck-tax engine directly at your AI assistant's fingertips: federal brackets, all 50 states + DC, FICA, self-employment tax, and capital gains — all for the 2026 tax year, and all sourced from the same engine that powers statetakehome.com.

Why it's different: most take-home-pay calculators stop at "gross minus taxes." This one also understands the 2026 OBBBA (One Big Beautiful Bill Act) landscape — the current-year federal brackets and thresholds it ships with already reflect the post-OBBBA baseline, so estimates stay accurate as the rules that shaped the 2026 tax year continue to roll out.

Quick Start

No installation needed — run it with npx.

Claude Desktop / Claude Code

Add to your MCP config (claude_desktop_config.json or .mcp.json):

{
  "mcpServers": {
    "statetakehome": {
      "command": "npx",
      "args": ["-y", "statetakehome-mcp"]
    }
  }
}

Cursor

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "statetakehome": {
      "command": "npx",
      "args": ["-y", "statetakehome-mcp"]
    }
  }
}

Restart your client and the three tools below become available.

Tools

1. us_take_home_pay

Net pay for a US W-2 employee: federal income tax, state income tax (all 50 states + DC), Social Security, Medicare, Additional Medicare, and state-specific extras (CA SDI, OR transit tax, etc.). Handles pre-tax 401(k) and health-insurance deductions and returns a per-paycheck breakdown for every pay frequency.

Example call:

{
  "gross": 75000,
  "state": "CA",
  "filingStatus": "single"
}

Response (abridged, from the live engine):

{
  "result": {
    "gross": 75000,
    "federalTax": 7670,
    "stateTax": 2940.85,
    "socialSecurity": 4650,
    "medicare": 1087.5,
    "totalTax": 17323.35,
    "takeHome": 57676.65,
    "effectiveRate": 0.2310,
    "perPaycheck": { "biweekly": 2218.33, "monthly": 4806.39 }
  }
}

The same input with "state": "TX" (no state income tax) returns stateTax: 0 and takeHome: 61592.5 — $3,915.85 higher on the same gross pay.

2. self_employment_tax

Schedule SE self-employment tax (15.3% on 92.35% of net profit, split into the Social Security and Medicare portions), the 0.9% Additional Medicare surtax, federal income tax, an optional state income tax, and a quarterly estimated-payment figure.

Example call:

{
  "netProfit": 90000,
  "filingStatus": "single",
  "state": "TX"
}

Response (abridged, from the live engine):

{
  "result": {
    "netProfit": 90000,
    "seTax": 12716.6,
    "seTaxDeduction": 6358.3,
    "federalIncomeTax": 9571.17,
    "totalTax": 22287.77,
    "quarterlyEstimate": 5571.94,
    "setAsidePct": 0.2477
  }
}

3. capital_gains_tax

Federal capital gains tax — long-term stacked 0%/15%/20% bands or short-term ordinary rates — plus the 3.8% Net Investment Income Tax (NIIT) above the MAGI threshold, and an optional state estimate (most states tax gains as ordinary income).

Example call:

{
  "gain": 50000,
  "ordinaryTaxableIncome": 80000,
  "filingStatus": "single",
  "term": "long"
}

Response (abridged, from the live engine):

{
  "result": {
    "gain": 50000,
    "taxableGain": 50000,
    "federalTax": 7500,
    "niit": 0,
    "totalTax": 7500,
    "netProceeds": 42500,
    "ltcgRate": 0.15
  }
}

Data & Methodology

• Tax year: 2026.
• Federal brackets & standard deduction: IRS Rev. Proc. 2025-32.
• State brackets & standard deductions: Tax Foundation — State Individual Income Tax Rates and Brackets, as of January 1, 2026, cross-checked against individual state Departments of Revenue.
• FICA: current Social Security wage base and Medicare rates, including the 0.9% Additional Medicare surtax.
• Capital gains: long-term bands and the NIIT threshold per Rev. Proc. 2025-32, cross-checked against Tax Foundation and Schwab.
• Every response includes a source block naming the underlying publication and a reference_url pointing to the matching calculator on the live site for further reading and methodology notes:
  • https://statetakehome.com/
  • https://statetakehome.com/self-employment-tax-calculator
  • https://statetakehome.com/capital-gains-tax-calculator

The calculation code in this package is the same engine that runs statetakehome.com, kept in sync by hand — it is not a reimplementation.

Disclaimer

This tool produces estimates for planning purposes only. It is not tax advice. Tax situations vary; consult a licensed CPA or tax professional before making financial decisions.

License

MIT © tresor4k