{"uid":"cap_Ncy2JFpDI7U8-Wo06Ld0E","slug":"compound-interest-projection-api-6c4ed3ee","name":"Compound Interest Projection API","description":"Future value of a lump sum plus recurring contributions: principal, annual rate, compounding frequency, contribution and years; returns balance curve, total contributed, total interest.","url":"https://api.24klabs.ai/api/compound-interest-projection","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"years":{"type":"number"},"principal":{"type":"number"},"annual_rate":{"type":"number"},"contribution":{"type":"number"},"compounds_per_year":{"type":"number"}}},"responseSchema":{"type":"json","example":{"final_balance":55172.5,"total_interest":21172.5,"total_contributed":34000}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_96f58MaIZkKdqBGurJCqJ","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Calculates the future value of a lump sum investment plus recurring contributions over time, returning a balance growth curve, total contributed, and total interest earned.","exampleAgentPrompt":"Project how my $10,000 investment will grow over 20 years with a 7% annual rate compounded monthly, and assume I'm adding $200 every month on top of that.","exampleUseCases":[{"title":"Retirement savings growth modeling","prompt":"I have $25,000 saved for retirement and I'm adding $500 a month. Assuming a 6% annual return compounded monthly, show me how my balance will grow over the next 30 years."},{"title":"College fund projection","prompt":"If I start a college fund with $5,000 today and contribute $150 a month for 18 years at a 5% annual rate compounded quarterly, how much will I have by the time my kid starts college?"},{"title":"Short-term savings goal check","prompt":"I'm putting $2,000 in a high-yield savings account at 4.5% annual interest compounded daily with no additional contributions — what will my balance look like month by month over 3 years?"}],"resultDescription":"Returns a time-series balance curve showing the projected account balance at each period, along with the total amount contributed (principal plus all recurring deposits) and total interest earned over the investment horizon.","failureModes":["Invalid or negative interest rate returns a validation error","Non-positive compounding frequency causes a bad request response","Missing required fields (principal, rate, years) result in a 400 error","Extremely large numbers or infinite values may cause computation errors","Unsupported compounding frequency string returns an error"],"whenToPreferThis":"Choose this endpoint when you need a structured, period-by-period breakdown of compound interest growth including recurring contributions — not just a single final value. Ideal for building savings dashboards, retirement projections, or financial planning tools where the balance curve over time is needed rather than a one-time calculation.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T19:02:12.435Z","isFirstParty":false}