The Real Cost

What The Real Cost does

The Real Cost MCP server exposes free US personal-finance calculators to MCP-compatible AI clients. It is intended for education, not financial advice, and produces estimates based on the values supplied by the user. The calculations cover revolving debt, consolidation loans, loan repayment terms, crypto transaction costs, and emergency-fund targets.

Each calculator result includes the computed figures, a plain-English explanation, and the formula described in words. Results also provide a pre-filled link to the matching calculator on the The Real Cost website, allowing users to inspect the inputs and continue adjusting them. When relevant, the response includes warnings, related reading, a free sample chapter link, and the source and education-only disclaimer.

How it works

The server runs locally and communicates over MCP using standard input and output. Its calculation logic is a port of the website’s calculator code, so the returned figures are intended to match the corresponding site calculator. It does not require network calls or API keys, and the README states that it does not track users.

The tools accept structured numeric inputs such as balances, annual percentage rates, payment amounts, loan terms, fees, expenses, and savings contributions. The server then returns structured JSON containing the result and supporting context. Inputs are used for calculations only; the material does not describe account access, lender connections, transaction execution, or market data retrieval.

Setup and configuration

Python 3.10 or newer is required. The documented installation path uses uvx to run the package directly from its GitHub repository. Claude Code can register the server with claude mcp add, while Claude Desktop requires an entry in claude_desktop_config.json followed by a restart.

A local checkout can also be installed with pip install -e . and started with the therealcost-mcp command. The process speaks MCP over stdio. No environment variables, API keys, or external service configuration are documented.

Tools and capabilities

• credit_card_payoff compares minimum-payment repayment with a fixed monthly payment, including months and interest.
• debt_consolidation compares existing debts with one loan and accounts for an origination fee deducted from loan proceeds.
• loan_cost_by_term calculates monthly payments, total interest, and total repayment across selected terms.
• crypto_trade_cost estimates trading fees, spreads, network charges, break-even price growth, and recurring-buy costs.
• emergency_fund calculates a savings goal, time to reach it, or the monthly contribution needed by a target.
• list_guides returns the ten related guides and their coverage, with links and pricing information.

The Real Cost also connects calculator outputs to relevant guides and chapters. The guides cover topics including credit cards, loans, everyday spending, crypto fees and taxes, credit reports, taxes, retirement accounts, student loans, housing, and scams.

Limitations and notes

The Real Cost MCP server is limited to the calculator topics and inputs documented by the project. Results depend on the supplied assumptions and are estimates, not personalized financial recommendations. A warning may appear when a repayment plan never clears a balance or a savings plan never reaches its goal. Crypto calculations describe specified fees and price scenarios; they do not execute trades or predict prices. The calculators are free, while the related guides are sold separately.