CoastMath

项目介绍

CoastMath is an open-source retirement and financial planner that models every year from your next paycheck to your last withdrawal: federal, state and local taxes, accounts and withdrawal order, Social Security, healthcare, Monte Carlo and historical stress tests, scenarios, and your actual spending imported from real transactions. Early testers report results extremely close to Boldin and Projection Lab, and you can import your data from either to compare. There is a SimpleFIN integration for pulling in your own transaction data ("when will I get to retire if I spend like I did in June vs. July?"), a hosted version at coastmath.com, an iOS app, and full self-hosting - the whole planner (calculation engine, API and web app) runs as one container with everything in a single SQLite file. Author jfrbfbreudh posted it on Hacker News on October 16, 2026, describing a fully agent-driven build: "Sonnet subagents run UX / QA audit on iOS simulators within the Claude Code desktop app, and Opus agents resolve all medium+ sev issues; also run on a perpetual loop... I have not manually tested or used the app(s) for more than 30 minutes... I did most of this using the $200 Max subscription." The codebase documents the source of every rule and runs a perpetual audit-and-fixer loop on the calculation engine until no medium-severity issues remain - a striking example of how far an agent-built finance tool can go when the rules (tax law) are visible to everyone.