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:

Key	What it is
result	The numbers (months, total interest, payments, costs)
summary	The result in one plain-English paragraph
formula	The formula in words, so the user can see how the number was made
calculator_url	The matching page on therealcost.nohumannearby.com, pre-filled with the inputs
warnings	Present when a plan never pays off or never reaches the goal
go_deeper	The matching guide and chapters, with the guides link
source	"The Real Cost by NoBanks Nearby, https://therealcost.nohumannearby.com"
disclaimer	"Education only. Not financial advice."

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):

Guide	Pages	Goes with
The Real Cost of Credit Card Debt	112	credit card payoff, debt consolidation
The Real Cost of Loans and Big Purchases	110	loan cost by term, debt consolidation
The Real Cost of Everyday Spending	123	emergency fund
The Real Cost of Crypto Fees and Taxes	110	crypto trade cost
The Real Cost of Credit Reports and Scores	115	loan cost by term
The Real Cost of Paychecks and Taxes	109
The Real Cost of Retirement Accounts	117
The Real Cost of Student Loans	115
The Real Cost of Renting and Buying a Home	125	loan cost by term
The Real Cost of Scams and Fraud	103

$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.

Input	Type	Default	Notes
balance	number	required	dollars
apr	number	required	percent, 24 means 24%
payment	number	none	fixed monthly payment to compare
min_pct	number	1	minimum = this % of the balance
min_floor	number	25	dollar floor on the minimum
min_plus_interest	boolean	true	minimum also includes that month's interest

{"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%)).

Input	Type	Default	Notes
debts	array	required	1 to 10 items of {balance, apr, payment, name?}
loan_apr	number	required	percent
loan_term_months	integer	required	1 to 600
origination_fee_pct	number	0	percent

{"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.

Input	Type	Default	Notes
principal	number	required	dollars
apr	number	required	percent
terms	integer array	[36, 48, 60, 72, 84]	months; the first two pre-fill the site

{"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.

Input	Type	Default	Notes
amount	number	required	dollars bought
fee_pct	number	required	trading fee per trade, percent
spread_pct	number	required	spread per trade, percent
network_fee_buy	number	0	flat dollars after the buy
network_fee_sell	number	0	flat dollars to move coins back to sell
weekly_buy	number	none	recurring buy amount; adds the yearly cost
buys_per_year	integer	52	52 weekly, 26 biweekly, 12 monthly
flat_fee_per_buy	number	0	flat fee some platforms add on small 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.

Input	Type	Default	Notes
monthly_expenses	number	required	must-pay expenses per month
months_covered	integer	required	1 to 60
saved	number	0	already saved
monthly_add	number	0	added each month
apy	number	0	savings APY, percent
target_months	integer	12	reach the goal in this many months
target_date	string	none	YYYY-MM or YYYY-MM-DD, instead of target_months

{"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.

Calculator page	Parameters
/calculators/credit-card-payoff/	balance, apr, minPct, minFloor, plusInterest, fixedPayment
/calculators/debt-consolidation/	d1b, d1r, d1p, d2b, d2r, d2p, d3b, d3r, d3p (balance, APR, payment per debt), loanApr, loanMonths, feePct
/calculators/loan-term/	amount, apr, termA, termB
/calculators/crypto-trade-cost/	amount, feePct, spreadPct, networkBuy, networkSell, weekly, freq, flatFee
/calculators/emergency-fund/	expenses, monthsCover, saved, monthly, apy, target

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.