530A Model calculator

530A Model

530amodel.com — a free, privacy-first, mobile-first scenario-planning calculator for 530A custodial retirement accounts ("Trump Accounts").

No login. No email capture. No monetization. All calculation runs in your browser.

Use the public API / MCP server

The engine is free to call — no key, nothing stored, attribution to 530amodel.com asked:

• JSON API — https://api.530amodel.com (POST /v1/project, GET /v1/rules, GET /v1/returns; OpenAPI 3.1 with full request/response schemas)
• MCP server — https://mcp.530amodel.com (streamable HTTP; tools project_530a, explain_530a, search, fetch; registry name com.530amodel/calculator). Works as a custom connector in Claude and ChatGPT, and with the Anthropic/OpenAI agent APIs.
• Docs & platform quickstarts — 530amodel.com/api · machine-readable maps: llms.txt, llms-full.txt
• Contact — api@530amodel.com

Structure

packages/
  engine/     # pure TS calculation engine — zero deps, deterministic, integer-cents money
  config/     # legal figures + sources + verifiedAt + feature flags (single source of truth)
  ui/         # design tokens, shared components, charts
apps/
  web/        # Astro static site (widget, advanced model, content pages)
  workers/    # Cloudflare Workers: analytics beacon, rollup cron, newsfeed cron, email
  api/        # public calculator API (wraps the engine; OpenAPI; cache-by-input-hash)
  mcp/        # read-only MCP server (project_530a / explain_530a)
reference/    # Python reference implementation + golden-vector generator
e2e/          # Playwright specs (user journeys UC-1..UC-7)

Non-negotiables

1. Financial math is exact, deterministic, and independently tested (golden vectors from the Python reference implementation must match the TS engine to the cent).
2. Static-first: calculation is client-side; a million users cost the same as one.
3. Minimal dependencies, no PII, small attack surface, everything scanned in CI.
4. Every user-facing claim is honest: ranges are labeled estimates, legal figures cite sources, unverified items live behind OFF feature flags (packages/config/src/flags.ts).

Development

pnpm install
pnpm check     # lint + typecheck + test + build (same as CI)
pnpm --filter @530a/web dev

Node ≥ 22, pnpm ≥ 11. Engine numeric contract: money is integer cents (bigint), balances are quantized round-half-to-even every monthly step, display formatting only via formatMoney.

Disclaimer

This tool provides educational estimates only, not financial, tax, or legal advice. Market projections are probabilistic and not guarantees.