Categories › Web & Browser › Web search engines & search APIs
Backtest S&P 500 stocks and ETFs on real prices, plus loan, savings, FIRE and retirement tools.
Remote server: your requests and data go to smartfin.fyi. Claude Code: claude mcp add --transport http smartfin https://smartfin.fyi/mcp · Claude app: Settings → Connectors → Add custom connector.
The tools this server listed when we connected to it, in its own words.
smartfin_compare_investment_strategies — Runs one amount through three ways of buying the same US stock or index ETF over a chosen period, on real daily closing prices (adjusted forsmartfin_calculate_investment_return — What an amount invested in a US stock or index ETF became over a past period under one strategy: lump_sum (all on the first trading day), mosmartfin_compare_time_periods — What a fixed amount in a US stock or index ETF became across reference periods ending today (or on as_of_date): since 2000, since the dot-cosmartfin_calculate_loan_payment — Monthly payment, total interest and total paid for a fixed-rate loan with monthly payments: mortgage, car, student or personal loan. Give eismartfin_project_savings_growth — Future balance of savings or an investment growing at a fixed yearly rate, with optional monthly contributions and a chosen compounding freqsmartfin_calculate_inflation_impact — What an amount will be worth in today's money after years of inflation at a fixed yearly rate, and what something costing that amount today smartfin_calculate_fire_number — Works the way SmartFin's FIRE calculator does. The FIRE number today is yearly expenses divided by a withdrawal-rate assumption. Each year ssmartfin_calculate_retirement_withdrawal — Works the way SmartFin's withdrawal calculator does, with withdrawals monthly, quarterly or annually and the balance earning a yearly returnsmartfin_calculate_simple_interest — The interest earned and the final amount on a principal at a fixed yearly rate over a number of years, when interest is not compounded (intesmartfin_calculate_future_value — What a single present amount grows to at a fixed yearly rate with interest added to the balance at a chosen frequency, and the growth over tsmartfin_calculate_missing_variable — Finds the one missing number among four that sit in the same equation, a single amount earning one fixed yearly rate with interest added at smartfin_calculate_present_value — What an amount due in the future is worth today at a fixed yearly discount rate, and the discount between the two (PV = FV / (1 + r/n)^(n x smartfin_calculate_roi — The profit or loss and the ROI percentage from an initial investment and a final value (ROI = (final - initial) / initial x 100). Negative rsmartfin_calculate_profit_margin — The profit and the profit margin percentage from revenue and total costs (margin = (revenue - costs) / revenue x 100). A negative margin is smartfin_compare_rent_vs_buy — Compares buying a home with a fixed-rate mortgage against renting a similar home and investing the money not spent on the home, over the yeasmartfin_calculate_savings_vs_investing — Compares the modeled balances of a savings account and of an investment after 1 to 50 years, from the same starting amount and the same montsmartfin_calculate_mortgage_payoff — How much sooner a fixed-rate mortgage (or other fixed-rate loan paid monthly) ends with an extra amount every month, a one-off payment, or bsmartfin_calculate_down_payment — How long savings take to reach a home down payment, from what is saved so far plus the same amount each month growing at a fixed yearly ratesmartfin_compare_two_stocks — Compares two US-listed stocks or index ETFs on identical dates with the same money, on daily closing prices adjusted for stock splits with dsmartfin_get_embed_code — The HTML to put one of SmartFin's free calculators on a website the user runs: a blog post, a class or library page, a client resources pageNot tested by KitScout yet. When our harness runs it, pros, cons and the tasks we tried appear here, with the date and evidence.