This is not a live API with request limits or an account, it's a single static JSON file with the formulas and default constants behind the Rate Calculator and a few other tools on this site. Fetch it, cache it, use it in your own project. Free, no key required.
fetch("https://obscuraos.com/rate-formulas.json")
.then(r => r.json())
.then(data => console.log(data));
hourlyRateFromAnnualTarget, the formula behind the main Rate CalculatorprojectRateFromHourly, converts an hourly rate into a flat-project quote with a risk bufferselfEmploymentTaxEstimate, a rough US self-employment tax formulakillFeeSuggested, the formula behind the Kill Fee CalculatorEach entry includes the formula, default constants, and notes on what the constants mean. See the raw file: /rate-formulas.json
Free to use, commercially or otherwise, attribution back to obscuraos.com appreciated but not required. No uptime guarantee, no versioning promise yet, treat it as a convenience, not infrastructure to build a business on. No warranty, this is not financial or tax advice, the constants are reasonable defaults, not universal truths.
Building something with it? Let us know, we'd like to hear about it.