{"name":"pricing-calc-api","version":"1.0.0","description":"Pricing & profitability engine for retail, e-commerce and freelancers: markup vs margin (and the conversion between them), stacked discount chains, tip & bill split, break-even / CVP analysis, full profit lines, and percent change. Deterministic, no DB, no external calls.","usage":"POST JSON or query params. Markup% is on cost; margin% is on price (revenue).","endpoints":{"POST /markup":"Markup math (on cost): solve any two of cost, price, markup%","POST /margin":"Margin math (on price): solve any two of cost, price, margin%","POST /convert":"Convert markup% ⇄ margin% (the one everyone gets wrong)","POST /discount":"Apply a chain of sequential discounts + true effective discount","POST /tip":"Tip amount + split a bill across N people","POST /breakeven":"Break-even units/revenue, target-profit units, margin of safety","POST /profit":"Revenue, COGS, gross profit, margin%, markup%, ROI%","POST /percent-change":"Percent change between two prices/values"},"example":"POST /markup {\"cost\":80,\"price\":100} → markup 25%, profit 20 (vs /margin → margin 20%)"}