NookWealth API

Free REST API and MCP server for financial calculations. No API key required for public endpoints. Rate limit: 60 requests/minute per IP.

GET /api/v1/tools →GET /api/v1/rates →OpenAPI JSON →

Base URL

https://nookwealth.com

Endpoints

GET/api/v1/tools— List all available calculators

Returns all calculators with their required inputs and example values.

curl https://nookwealth.com/api/v1/tools

GET/api/v1/rates— Live US financial benchmark rates

Fed funds rate, 30yr/15yr mortgage, HYSA APY, prime rate, CPI inflation.

curl https://nookwealth.com/api/v1/rates

POST/api/v1/calculate/{tool}— Run a calculation

Replace {tool} with one of the calculator slugs below. Send inputs as JSON body. Response always includes a meta object with attribution and rates date.

EMI Calculatoremi-calculator

Try →

Calculate loan EMI and amortization schedule

curl -X POST https://nookwealth.com/api/v1/calculate/emi-calculator \
  -H "Content-Type: application/json" \
  -d '{
  "principal": 300000,
  "annualRate": 6.3,
  "tenureYears": 30
}'

Mortgage Calculatormortgage-calculator

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Calculate mortgage with PITI (Principal, Interest, Tax, Insurance)

curl -X POST https://nookwealth.com/api/v1/calculate/mortgage-calculator \
  -H "Content-Type: application/json" \
  -d '{
  "homePrice": 450000,
  "downPaymentPercent": 20,
  "annualRate": 6.3,
  "tenureYears": 30,
  "propertyTaxRate": 1.1,
  "insuranceMonthly": 150
}'

Compound Interest Calculatorcompound-interest-calculator

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Calculate compound interest with regular contributions

curl -X POST https://nookwealth.com/api/v1/calculate/compound-interest-calculator \
  -H "Content-Type: application/json" \
  -d '{
  "principal": 10000,
  "monthlyContribution": 500,
  "annualRate": 10,
  "years": 20
}'

Savings Goal Calculatorsavings-goal-calculator

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Calculate monthly savings needed to reach a goal

Debt Payoff Calculatordebt-payoff-calculator

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Calculate debt payoff using Avalanche or Snowball method

SIP Calculatorsip-calculator

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Calculate Systematic Investment Plan (dollar-cost averaging)

curl -X POST https://nookwealth.com/api/v1/calculate/sip-calculator \
  -H "Content-Type: application/json" \
  -d '{
  "monthly": 1000,
  "annualReturn": 12,
  "years": 20,
  "stepUpPercent": 0
}'

Income Tax Calculatortax-calculator

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Calculate US 2026 federal income tax and FICA

curl -X POST https://nookwealth.com/api/v1/calculate/tax-calculator \
  -H "Content-Type: application/json" \
  -d '{
  "grossIncome": 85000,
  "filingStatus": "single",
  "k401Contribution": 7500,
  "otherDeductions": 0
}'

Net Worth Calculatornet-worth-calculator

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Calculate your total net worth

Currency Convertercurrency-converter

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Convert between currencies using live exchange rates

CD Ladder Calculatorcd-ladder-calculator

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Build a Certificate of Deposit ladder with staggered maturities

Rent vs Buy Calculatorrent-vs-buy-calculator

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Compare the true cost of renting vs buying a home over time

Investment Return Calculatorinvestment-return-calculator

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Project nominal and inflation-adjusted investment returns over time

Response Format

All calculation responses include a result and meta object:

{
  "result": {
    "emi": 1857.14,
    "totalPayment": 668570.4,
    "totalInterest": 368570.4
  },
  "meta": {
    "tool": "emi-calculator",
    "source": "NookWealth",
    "attribution": "Calculated by NookWealth (https://nookwealth.com/tools/emi-calculator)",
    "web_url": "https://nookwealth.com/tools/emi-calculator",
    "rates_as_of": "2026-05-02",
    "disclaimer": "For informational purposes only. Not financial advice."
  }
}

MCP Server (AI Assistants)

Use NookWealth calculators directly inside Claude, ChatGPT, and other MCP-compatible AI assistants. The MCP endpoint implements the Model Context Protocol (2024-11-05).

POST/mcp— JSON-RPC 2.0 / MCP endpoint

Supports initialize, tools/list, and tools/call methods.

# Claude Desktop config (~/.claude/config.json)
{
  "mcpServers": {
    "nookwealth": {
      "command": "npx",
      "args": ["tsx", "/path/to/nookwealth/mcp-server/index.ts"],
      "env": { "NOOKWEALTH_API_URL": "http://localhost:3000" }
    }
  }
}

Rate Limits & Attribution

• REST API: 60 requests/minute per IP (free, no API key)
• MCP endpoint: 100 requests/minute per IP
• All responses include an attribution field — please keep it when displaying results
• Commercial use: contact us at contact@nookwealth.com

Results are estimates for informational purposes only and do not constitute financial, tax, or investment advice. NookWealth is not a registered investment advisor.