Jackpot Calculator

io.github.jianknPublished by GitHub account jianknv0.1.0Updated Oct 24, 2026

Estimate US lottery taxes, compare cash and annuity, split pool prizes and calculate jackpot odds.

The publisher's own server: Calculator Tools MCP

VerifiedStreamable HTTPWeb executableFinanceData & Analytics

Overview

AI-generated overview

A hosted MCP server that lets an assistant estimate US lottery prize taxes, compare cash versus annuity payouts, split pool shares and compute jackpot odds.

What you can do
Estimate federal and state taxes, withholding and take-home on a known cash prize for a given state and filing status, with optional locality for New York areas and a bundled 2026 rule set. Compare a published cash option with 30 growing annuity payments after taxes, including present value and break-even rate. Estimate one equal pool member's share, taxes and withholding, assuming all members share the same tax profile. Calculate jackpot coverage for distinct combinations in one drawing, with an optional before-tax expected ticket return. Results state their units, assumptions and related calculator.
When to use it
Useful when someone wants quick, clearly labeled estimates of US lottery payouts, tax withholding, cash-versus-annuity trade-offs, pool splits or jackpot odds, without doing the arithmetic by hand. It is a calculator, not a source of live jackpot data or advice.
Requirements
Remote Streamable HTTP endpoint; no API key or account. The public endpoint allows roughly 120 requests per minute per IP at the Cloudflare edge. A local stdio option exists from source or a release archive and needs Node.js 22.12 or newer.
Before you install
Estimates only, not tax or financial advice. Tax data is a fixed 2026 snapshot with no live updates or jackpot lookup. It does not model cross-state credits, nonresident alien withholding, most local income taxes, future tax law or investment taxes, and pool results assume identical tax profiles. No ticket purchase or ticket checking.

Installation

In SourceWeft

  1. Open Jackpot Calculator in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/io.github.jiankn%2Fjackpot-calculator/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "jackpot-calculator": {
      "type": "http",
      "url": "https://jackpot-calculator-mcp.jiankn.workers.dev/mcp"
    }
  }
}

README

Jackpot Calculator MCP

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.

Connect to the hosted server

Add this Streamable HTTP URL in a client that supports remote MCP servers:

text
https://jackpot-calculator-mcp.jiankn.workers.dev/mcp

No 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.

Tools

ToolRequired inputsOutput
calculate_lottery_payoutprize, stateCodeEstimated final tax, withholding and cash take-home
compare_lump_sum_annuityjackpot, cashValue, stateCodeCash and 30-payment annuity, discounted present value and break-even rate
calculate_pool_shareprize, members, stateCodeOne equal owner's share with the whole-ticket withholding threshold
calculate_lottery_oddsgameDistinct-combination jackpot probability; optional expected return with jackpotCash

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:

json
{  "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.

Run locally from the source or release archive

Node.js 22.12 or newer is required.

sh
git clone https://github.com/jiankn/jackpot-calculator-mcp.gitcd jackpot-calculator-mcpnpm cinpm testnode src/cli.mjs

The 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.

Calculation boundaries

  • 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.

Development and releases

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

Source: README.md at commit 7b505db

Tools

4

calculate_lottery_payout

Lottery cash prize after taxes

Estimate taxes and withholding on a known lottery cash prize. Input dollars; result integer cents. Bundled 2026 rules.

ParametersgameprizerequiredstatuslocalitystateCoderequiredotherIncome

compare_lump_sum_annuity

Compare cash and annuity

Compare a published cash option with 30 growing annuity payments after taxes, including present value and break-even rate.

ParametersgamestatusjackpotrequiredwinnerslocalitycashValuerequiredstateCoderequiredotherIncomediscountRatesharePercent

calculate_pool_share

Equal lottery pool shares

Estimate one equal member’s cash prize, taxes and withholding. Each member is assumed to have the specified tax profile.

ParametersgameprizerequiredstatusmembersrequiredlocalitystateCoderequiredotherIncome

calculate_lottery_odds

Jackpot probability and expected return

Calculate jackpot coverage for distinct combinations in one drawing and optional before-tax expected ticket return.

ParametersgamerequiredticketsjackpotCash

Version history

1
  1. v0.1.0LatestOct 13, 2026

Score

100% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts

Other Calculator integrations

Calculator Tools MCP

tools.calculatorOfficial publisher

A remote MCP endpoint that lets an assistant publish a live calculator, tracker, tool, or game from Cursor, Claude, or ChatGPT.

Streamable HTTPWeb executable
Productivity & WorkflowNot indexed yetOct 25, 2026

Free IFTA Calculator

dev.pages.ifta-calculatorOfficial publisher

Read-only helper that answers US/Canadian IFTA fuel-tax questions and estimates quarterly tax from miles and gallons per jurisdiction.

Streamable HTTPWeb executable
Finance1 toolOct 29, 2026

Zovo Tip Pool Calculator

Published by GitHub account theluckystrike

Remote calculator that splits pooled tips among restaurant, bar, cafe or salon staff and computes server tip-outs to support staff.

Streamable HTTPWeb executable
Finance2 toolsNov 8, 2026

Zovo PTO Accrual Calculator

Published by GitHub account theluckystrike

A remote MCP server that calculates employee PTO, vacation and sick leave balances from an accrual policy, for one person or a whole team.

Streamable HTTPWeb executable
Business & Commerce2 toolsNov 8, 2026

Zovo Cap Table Calculator

Published by GitHub account theluckystrike

Remote MCP server that computes startup cap tables and SAFE ownership, letting an assistant model dilution across SAFEs, convertible notes and priced rounds.

Streamable HTTPWeb executable
Data & Analytics2 toolsNov 8, 2026