The versioned calculation API accepts a JSON POST at /api/v1/calculate. Supported tools: sip, lumpsum, emi and delay. No account or API key is required. This is a calculation service, not financial advice; returns are assumptions.
Request
{"tool":"sip","amount":5000,"rate":12,"years":10}Response
{"version":"1.0.0","tool":"sip","invested":600000,"value":1161695.38,"growth":561695.38}SIP uses beginning-of-month deposits and nominal annual return divided by 12. Lumpsum compounds annually. EMI uses monthly interest with a fixed annual nominal rate; amount is principal. Delay adds delayMonths and keeps the same end date. Values are unrounded in JSON.
Limits and privacy
Amount ₹1–₹1 billion; rate 0–40%; horizon 1–50 whole years; delay 0–one month before the goal. JSON body maximum 4 KB. Invalid inputs return 400; unsupported methods return 405. Send scenario amounts only, never names, account details or other personal information. No application database is used; hosting request logs may exist. Availability is best effort; no unlimited-service or uptime guarantee.
Browser SDK
The browser bundle at /assets/decision-math.js exposes DecisionMath.version, periodic() and loanComparison(). The API and browser conventions match.