# Meridary

> Enter your accounts and the moves you're weighing. Meridary runs taxes, Social Security, and RMDs year by year on tax tables updated annually, and shows the odds your money lasts. One-time lifetime license.

Meridary is a paid, whole-life personal financial-planning web app — a year-by-year household simulator that models federal + flat-state tax, account-type treatment (traditional / Roth / taxable / HSA), RMDs, Social Security taxation, and Roth-conversion effects, then answers "will my money last" with a Monte Carlo probability. It is sold as a one-time lifetime license ($149–$199 founding) with a 30-day money-back guarantee, and as a cancel-anytime monthly plan.

## Correctness methodology

Every free calculator exposes its assumptions, carries a worked check in the test suite, and cites the government rule, formula, or primary research behind it. The planning engine's tax rules are built on published government figures. The methodology is the most citable page:

- [How we validate](https://www.meridary.com/how-we-validate): worked checks and sources for all seven calculators, plus the planning engine's independent federal-tax oracle.

## Free calculators

Each computes entirely in-browser (no account) and shows its assumptions and source:

- [Coast FIRE Calculator](https://www.meridary.com/calculators/coast-fire): The portfolio you need today to let compounding carry you to retirement.
- [Social Security Break-Even Calculator](https://www.meridary.com/calculators/social-security-break-even): The age when a larger later benefit catches up with claiming earlier.
- [RMD Calculator](https://www.meridary.com/calculators/rmd): Your required minimum distribution, on the current IRS tables.
- [Roth Conversion Tax Calculator](https://www.meridary.com/calculators/roth-conversion): What a conversion actually costs, the correct blended rate, not marginal × amount.
- [72(t) SEPP Calculator](https://www.meridary.com/calculators/72t): Penalty-free early withdrawals under substantially-equal-periodic-payments.
- [IRMAA Calculator](https://www.meridary.com/calculators/irmaa): Whether your income triggers a Medicare Part B & D surcharge, and by how much.
- [ACA Subsidy Calculator](https://www.meridary.com/calculators/aca-subsidy): Your premium tax credit and the 400%-of-poverty subsidy cliff.

## Guides

- [Guides](https://www.meridary.com/guides): answer-content on whether your money will last, how much you need to retire, and the Roth-conversion ladder.

## Comparisons

- [Compare](https://www.meridary.com/compare): how Meridary compares with other retirement planners.

## AI agent access

- [Meridary for Agents](https://www.meridary.com/developers/agents): standalone agent-only product, OAuth/MCP connection instructions, prepaid terms, and privacy boundary.
- [OpenAPI specification](https://www.meridary.com/openapi.json): machine-readable free and authenticated REST operations.
- MCP protected resource: https://www.meridary.com/mcp
- Free API: POST https://www.meridary.com/api/v1/calculators/rmd (2026 law, IRS Publication 590-B methodology, 0 units).
- Free OAuth tool: assess_retirement_readiness runs a stateless deterministic projection plus exactly 250 seeded trials. It stores no financial input or result, charges 0 units, reports its fixed assumptions and a 95% sampling interval, and returns summary facts rather than annual ledgers.
- The assessment uses 2026 rules, a 6% nominal investment return, 3% cash yield, 2% dividend yield, 2.5% inflation, and taxable cost basis equal to the stated taxable balance. Its output is educational planning output, not a recommendation or individualized financial advice.
- Agent subscription: $29/month; every paid invoice grants 50 units; up to 50 unused units roll one paid cycle; maximum balance 100; no overages. Projection costs 1 unit, comparison 2, retirement-age solve 5.
- Agent identity, plans, subscription, and units are separate from web planner data and access. Payment uses a human-completed Stripe Checkout browser handoff.
- Claude is the supported purchase host. OpenAI and unknown clients expose no Meridary offer or checkout tools; they can connect only for free operations or an existing paid Agent account.
- Agent tools can delete individual plans, all Agent Current Finances data and plans, or the complete Agent account and billing relationship. Complete Agent deletion revokes old Agent authorizations and requires fresh consent to reconnect, while leaving the shared web identity, sessions, web plans, and web purchases unchanged. A failed billing cleanup leaves Agent data available for a deletion retry. Connection-only revocation and deletion support are available at https://www.meridary.com/contact.
- [Agent privacy and retention](https://www.meridary.com/legal/privacy): financial-data handling, deletion behavior, Stripe processor records, and backup-retention status.

## Get Meridary

- [Pricing](https://www.meridary.com/pricing): buy a founding lifetime license ($149–$199) — one-time, with a 30-day money-back guarantee — or a $12/month cancel-anytime plan.
- [Try the demo](https://www.meridary.com/demo): run the real engine on a sample household, no signup.