{"uid":"cap_7kz7dDXbPDWefR_vAKbKI","slug":"compound-interest-projection-api-3e7fa996","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/v1/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_RXP8D3byzAodDRBIGcJJM","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":"Projects 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":"Can you project the compound interest growth for a $10,000 starting balance with $200 monthly contributions at a 6% annual rate compounded monthly over 20 years, and show me the full balance curve?","exampleUseCases":[{"title":"Retirement savings growth forecast","prompt":"I have $25,000 saved up and plan to add $500 every month. If I get a 7% annual return compounded monthly, what will my balance look like after 30 years — show me the year-by-year curve and how much of it is interest versus contributions."},{"title":"College fund planning projection","prompt":"My kid is 3 years old and I want to start a college fund with $5,000 now and put in $300 a month. Assuming a 5% annual rate compounded quarterly, how much will I have in 15 years and how much of that is from interest?"},{"title":"Emergency fund growth simulation","prompt":"If I put $2,000 in a high-yield savings account earning 4.5% annually compounded daily, and add $100 each month, what will my balance be at the end of 5 years and what's the total interest earned?"}],"resultDescription":"Returns a time-series balance curve showing the account value at each period, along with summary figures for total amount contributed and total interest earned over the investment horizon.","failureModes":["Invalid or negative interest rate returns a validation error","Non-positive compounding frequency (e.g. zero periods per year) causes a computation error","Missing required fields (principal, rate, years) results in a 400 bad request","Extremely large values or very long time horizons may cause numeric overflow errors","Invalid compounding frequency identifier returns an error"],"whenToPreferThis":"Choose this endpoint when you need a detailed time-series projection of investment or savings growth that combines a lump-sum principal with recurring contributions, especially when you need both the balance curve over time and a breakdown of contributed capital versus earned interest. Prefer this over simple future-value formulas when you need the full growth curve (not just the terminal value).","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T19:02:25.684Z","isFirstParty":false}