Therealcost MCP Server

therealcost-mcp

Free money calculators for AI agents, from The Real Cost.

The Real Cost by NoBanks Nearby is a free set of US money calculators with the math shown: credit card payoff, debt consolidation, loan cost by term, crypto trading fees and emergency fund. This MCP server lets Claude and other AI assistants run those exact calculators and hand the user a link to the same calculator on the site, already filled in with their numbers, so they can check the math and keep adjusting it.

• Site: https://therealcost.nohumannearby.com
• All calculators: https://therealcost.nohumannearby.com/calculators/
• Guides: https://therealcost.nohumannearby.com/books/

Education only. Not financial advice. Results are estimates from the numbers entered.

What every result includes

Each calculator tool returns JSON with:

The math is a line-for-line port of the site's own calculator code, and the test suite reuses the site's hand-checked cases, so a number from this server matches the number on the site. No network calls, no API keys, no tracking.

The guides

The Real Cost also publishes ten plain-English guides that go deeper than any one calculation, with every number worked out step by step (PDF and EPUB):

$4.99 each at https://therealcost.nohumannearby.com/books/ . All ten come together as the complete set for $24.95 (10 for the price of 5). Guides 1-3 also come as a starter pack for $9.98 (3 for the price of 2); the starter pack does not include guides 4-10.

Free sample chapters (Chapter 1 of each guide, PDF):

• https://therealcost.nohumannearby.com/samples/the-real-cost-of-credit-card-debt-chapter-1.pdf
• https://therealcost.nohumannearby.com/samples/the-real-cost-of-loans-and-big-purchases-chapter-1.pdf
• https://therealcost.nohumannearby.com/samples/the-real-cost-of-everyday-spending-chapter-1.pdf
• https://therealcost.nohumannearby.com/samples/the-real-cost-of-crypto-fees-and-taxes-chapter-1.pdf
• https://therealcost.nohumannearby.com/samples/the-real-cost-of-credit-reports-and-scores-chapter-1.pdf
• https://therealcost.nohumannearby.com/samples/the-real-cost-of-paychecks-and-taxes-chapter-1.pdf
• https://therealcost.nohumannearby.com/samples/the-real-cost-of-retirement-accounts-chapter-1.pdf
• https://therealcost.nohumannearby.com/samples/the-real-cost-of-student-loans-chapter-1.pdf
• https://therealcost.nohumannearby.com/samples/the-real-cost-of-renting-and-buying-a-home-chapter-1.pdf
• https://therealcost.nohumannearby.com/samples/the-real-cost-of-scams-and-fraud-chapter-1.pdf

The server tells connected agents about the guides in its instructions, and each calculator result names the matching guide, its relevant chapters and its free sample chapter in a calm one-line go_deeper block. The calculators are free and complete on their own.

Install

Requires Python 3.10+. The easiest runner is uv.

Claude Code

claude mcp add therealcost -- uvx --from git+https://github.com/NoBanks/therealcost-mcp therealcost-mcp

Claude Desktop

Add this to claude_desktop_config.json (Settings, Developer, Edit Config), then restart Claude Desktop:

{
  "mcpServers": {
    "therealcost": {
      "command": "uvx",
      "args": ["--from", "git+https://github.com/NoBanks/therealcost-mcp", "therealcost-mcp"]
    }
  }
}

From a local clone

git clone https://github.com/NoBanks/therealcost-mcp
cd therealcost-mcp
pip install -e .
therealcost-mcp   # speaks MCP over stdio

Then point your client at the therealcost-mcp command (Claude Code: claude mcp add therealcost -- therealcost-mcp).

Tools

credit_card_payoff

Months and total interest to clear a card balance paying only the minimum, versus a fixed monthly payment.

{"name": "credit_card_payoff", "arguments": {"balance": 5000, "apr": 24, "payment": 200}}

Result (abridged): minimum only 234 months and $8,886.95 interest; $200 a month 36 months and $2,000.56 interest; link https://therealcost.nohumannearby.com/calculators/credit-card-payoff/?balance=5000&apr=24&minPct=1&minFloor=25&plusInterest=1&fixedPayment=200

debt_consolidation

Current debts versus one consolidation loan, including the origination fee (taken out of the loan, so the loan is sized up to total / (1 - fee%)).

{"name": "debt_consolidation", "arguments": {
  "debts": [{"balance": 6000, "apr": 24.99, "payment": 200},
            {"balance": 3000, "apr": 27.99, "payment": 110},
            {"balance": 2500, "apr": 19.99, "payment": 90}],
  "loan_apr": 13, "loan_term_months": 48, "origination_fee_pct": 5}}

loan_cost_by_term

Monthly payment, total interest and total paid for one loan over several terms.

{"name": "loan_cost_by_term", "arguments": {"principal": 25000, "apr": 8, "terms": [36, 60]}}

Result (abridged): 36 months $783.41 a month; 60 months $506.91 a month.

crypto_trade_cost

Trading fee, spread and network fees on a buy and a later sale at the same price, the price rise needed to break even, and the yearly cost of recurring buys.

{"name": "crypto_trade_cost", "arguments": {"amount": 1000, "fee_pct": 0.6, "spread_pct": 0.5,
  "network_fee_buy": 2.5, "network_fee_sell": 2.5, "weekly_buy": 25, "flat_fee_per_buy": 0.99}}

emergency_fund

Goal = monthly expenses x months to cover. Months to reach it, and the monthly amount needed to reach it by a target.

{"name": "emergency_fund", "arguments": {"monthly_expenses": 2500, "months_covered": 3,
  "saved": 500, "monthly_add": 300, "target_date": "2027-10"}}

Result (abridged): goal $7,500.00; 24 months to reach it at $300 a month; $583.33 a month reaches it in 12 months.

list_guides

No inputs. Returns the ten guides (title, subtitle, pages, what each covers, price), the complete set ($24.95 for all ten, 10 for the price of 5), the starter pack price (guides 1-3 only), and the guides link.

{"name": "list_guides", "arguments": {}}

Errors

Bad input never crashes the server. It returns:

{"error": {"type": "validation_error", "message": "Invalid input for credit_card_payoff.",
  "details": [{"field": "apr", "message": "Field required"}]},
 "disclaimer": "Education only. Not financial advice."}

Calculator link parameters (for the site)

calculator_url uses the site's own form field ids as query parameters, so the site can pre-fill each form by reading ?name=value into the field with that id. Numbers are plain (5000, 24.99); booleans are 1 or 0.

Notes: unused debt rows are sent as dNb=0 so the form's example rows are not counted. With more than 3 debts the link opens the plain page (the form has 3 rows) and the result says so. Some site fields are dropdowns (loan terms, months to cover, target, frequency); a value outside the dropdown's options needs the site to add that option or fall back to its default.

Development

pip install -e ".[dev]"
pytest

tests/test_calc.py is a port of the site's site/tests/calc-math.test.js (same hand-checked cases and the same cross-checks), and tests/test_server.py awaits list_tools and call_tool directly.

License

MIT. The Real Cost by NoBanks Nearby.