Click on "Deploy Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type @ followed by the MCP server name and your instructions, e.g., "@Jackpot Calculator MCP estimate taxes and take-home on a $1 million lottery prize in Texas"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
Four read-only MCP tools for US lottery prize taxes, cash vs annuity comparisons, equal pool shares and jackpot probabilities. Calculations use a fixed 2026 data snapshot and the same engine as Jackpot Calculator.
Add this Streamable HTTP URL in a client that supports remote MCP servers:
https://jackpot-calculator-mcp.jiankn.workers.dev/mcpNo API key is required. The public endpoint allows up to 120 requests per minute per IP at the Cloudflare edge; rate limiting is approximate, not a global quota. Connection examples and output units: Jackpot Calculator MCP setup.
Related MCP server: OptionsAhoy: Stock Equity and Tax Optimizer
Tool | Required inputs | Output |
|
| Estimated final tax, withholding and cash take-home |
|
| Cash and 30-payment annuity, discounted present value and break-even rate |
|
| One equal owner's share with the whole-ticket withholding threshold |
|
| Distinct-combination jackpot probability; optional expected return with |
Money inputs are US dollars. Tax/payout results use integer cents.
The odds tool reports money in dollars. Rates and probabilities are fractions,
so 0.04 is 4%. Each result states its units, assumptions and related calculator.
Example tool call:
{
"name": "calculate_lottery_payout",
"arguments": { "prize": 1000000, "stateCode": "TX", "status": "single" }
}The bundled 2026 calculation returns an estimated $320,000 final federal tax and $680,000 take-home, separately from $240,000 federal withholding. See the interactive lottery tax calculator to explore other states and filing statuses.
For game-specific cash estimates, select game: "powerball" or
game: "megaMillions", provide the known cash prize and compare it with the
Powerball payout calculator
or Mega Millions tax calculator.
For annuities provide both the published cash option and advertised annuity total;
the package never guesses the cash option from a fixed percentage.
Node.js 22.12 or newer is required.
git clone https://github.com/jiankn/jackpot-calculator-mcp.git
cd jackpot-calculator-mcp
npm ci
npm test
node src/cli.mjsThe last command starts an MCP stdio server and waits for a client; it is not an
interactive CLI prompt. Configure a stdio client with command: "node" and
args: ["/absolute/path/to/jackpot-calculator-mcp/src/cli.mjs"].
Only protocol messages go to stdout.
Release archives can also be installed with npm install ./jackpot-calculator-mcp-0.1.0.tgz.
An npm registry listing is optional and is not needed for the hosted endpoint.
US resident taxpayers, same residence and ticket-purchase state; cross-state credits and nonresident alien withholding are not modeled.
Federal and state tax data is bundled, with original source URLs and dates. No live jackpot lookup, automatic tax update, ticket purchase or ticket check.
Standard deduction and incremental income tax. State head-of-household uses single-filer state brackets. California assumes a California Lottery prize.
NYC and Yonkers need an explicit locality with stateCode: "NY". Maryland
uses an average county rate; other local income taxes are excluded.
Annuities use 30 payments, first immediately and then annual payments growing 5%. Tax rules and other income stay constant. Future tax law and investment taxes are not modeled. Annuity methodology and calculator.
Pool outputs assume all members have the same tax profile. Different people need separate scenarios. Individually rounded fractional-cent shares can differ slightly from the whole prize.
Odds assume distinct combinations in one drawing. Expected value excludes taxes, Power Play, jackpot sharing and California pari-mutuel payout differences.
Estimates only, not tax or financial advice. Independent of Powerball, Mega Millions, the Multi-State Lottery Association and state lottery operators. Sources and methodology.
npm test checks known payouts, validation, pool withholding, annuity totals,
odds and real stdio/HTTP protocol calls. npm run verify:package packs the
allowlisted files, installs the archive into a clean directory and invokes the
installed server. CI runs both on Windows and Linux.
scripts/sync-engine.mjs is a maintainer-only snapshot step run within the
website checkout, before release. It records source hashes in PROVENANCE.md.
Standalone users already have the copied files and do not need to run it.
Code: MIT. Compiled data: CC BY 4.0; see LICENSE-DATA.md and the source URLs
inside data/. Issues: https://github.com/jiankn/jackpot-calculator-mcp/issues
Calculate jackpot coverage for distinct combinations in one drawing and optional before-tax expected ticket return.
Inputs: game (required), tickets, jackpotCash.
Estimate taxes and withholding on a known lottery cash prize. Input dollars; result integer cents. Bundled 2026 rules.
Inputs: prize (required), stateCode (required), game, status, +2 more.
Compare a published cash option with 30 growing annuity payments after taxes, including present value and break-even rate.
Inputs: jackpot (required), cashValue (required), stateCode (required), game, +6 more.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
Loading tool schema changelog…
Scored across 4 tools
Each tool targets a distinct lottery calculation: payout taxes, lump-sum vs annuity comparison, pool share, and odds/expected return. The main overlap is between calculate_lottery_payout and calculate_pool_share, since both estimate taxes and withholding on a prize amount; the pool context helps distinguish them but an agent could still hesitate between them.
Three tools use the clear calculate_<object> pattern, which makes their intent readable and predictable. compare_lump_sum_annuity is a minor deviation in verb style, but it remains descriptive and consistent with the snake_case convention.
Four tools is a well-scoped set for a focused jackpot calculator. Each tool covers a distinct calculation type without obvious filler or excessive surface area.
The surface covers the core lottery calculator lifecycle: prize payout taxes, annuity comparison, pool sharing, and odds/expected value. Minor gaps remain, such as explicit state-tax variation or reverse calculations, but the main workflows are represented.
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Price settlement or annuity payments, judge a buyout offer, look up any US state's transfer rules.
Verified US tax and money decision tools: verdict plus a pre-filled deep link to the full page.
