# Jackpot Calculator (remote · jackpot-calculator-mcp.jiankn.workers.dev)

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

- Trust score: 74/100 (medium)
- Change this week: +4
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- remote · `jackpot-calculator-mcp.jiankn.workers.dev`: 74/100 (this document), [markdown](https://verifymcp.io/servers/jiankn-jackpot-calculator/jackpot-calculator-mcp.md), [page](https://verifymcp.io/servers/jiankn-jackpot-calculator/jackpot-calculator-mcp)

## Channel facts

- Endpoint: `https://jackpot-calculator-mcp.jiankn.workers.dev/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.1.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-11-05.

- **Endpoint Security**: 63/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one.
  - HTTPS enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 58/100
  - AI-judged instruction clarity (fair).
  - Context-footprint check failed: tool/resource definitions use about 584 tokens (~146/item across 4 items; 4 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 77/100
  - Stability observed for 23 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 91/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 73% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 4 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a current MCP spec version (2026-07-28).

## Install

### How do I install the Jackpot Calculator MCP server?

Jackpot Calculator is a hosted endpoint at https://jackpot-calculator-mcp.jiankn.workers.dev/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http jiankn-jackpot-calculator 'https://jackpot-calculator-mcp.jiankn.workers.dev/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "jiankn-jackpot-calculator": {
      "url": "https://jackpot-calculator-mcp.jiankn.workers.dev/mcp"
    }
  }
}
```

### VS Code

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

### Codex

```toml
[mcp_servers.jiankn-jackpot-calculator]
url = "https://jackpot-calculator-mcp.jiankn.workers.dev/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "jiankn-jackpot-calculator": {
      "type": "remote",
      "url": "https://jackpot-calculator-mcp.jiankn.workers.dev/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add jiankn-jackpot-calculator --url 'https://jackpot-calculator-mcp.jiankn.workers.dev/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  jiankn-jackpot-calculator:
    url: "https://jackpot-calculator-mcp.jiankn.workers.dev/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "jiankn-jackpot-calculator": {
      "Transport": "http",
      "Url": "https://jackpot-calculator-mcp.jiankn.workers.dev/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add jiankn-jackpot-calculator -t streamable-http -u 'https://jackpot-calculator-mcp.jiankn.workers.dev/mcp'
```

### Other

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

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-11-05 (score 74, +1)

No change was recorded against any check on this day. Stability & Change Management went from 73 to 77. That category is still filling its 30-day observation window: 22 days of observed history at the previous scan, 23 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-11-03 (score 73, +1)

No change was recorded against any check on this day. Stability & Change Management went from 67 to 70. That category is still filling its 30-day observation window: 20 days of observed history at the previous scan, 21 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-11-01 (score 72, +1)

No change was recorded against any check on this day. Stability & Change Management went from 60 to 63. That category is still filling its 30-day observation window: 18 days of observed history at the previous scan, 19 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-30 (score 71, +1)

No change was recorded against any check on this day. Stability & Change Management went from 53 to 57. That category is still filling its 30-day observation window: 16 days of observed history at the previous scan, 17 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-27 (score 70, +1)

No change was recorded against any check on this day. Stability & Change Management went from 43 to 47. That category is still filling its 30-day observation window: 13 days of observed history at the previous scan, 14 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-25 (score 69, +1)

No change was recorded against any check on this day. Stability & Change Management went from 37 to 40. That category is still filling its 30-day observation window: 11 days of observed history at the previous scan, 12 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-23 (score 68, +1)

No change was recorded against any check on this day. Stability & Change Management went from 30 to 33. That category is still filling its 30-day observation window: 9 days of observed history at the previous scan, 10 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-21 (score 67, +1)

No change was recorded against any check on this day. Stability & Change Management went from 23 to 27. That category is still filling its 30-day observation window: 7 days of observed history at the previous scan, 8 at this one. The score rises as the window fills, whether or not the server changes.

## MCP tools (4)

### `calculate_lottery_payout` (~124 tokens)

Lottery cash prize after taxes

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

Input parameters:

- `game` (string)
- `locality` (string): Only valid with stateCode NY.
- `otherIncome` (number): Other annual income in US dollars before the standard deduction.
- `prize` (number, required): US dollars, not cents. Maximum $1 trillion.
- `stateCode` (string, required): US residence and ticket-purchase state, two-letter code. Cross-state claims are not modeled.
- `status` (string)

### `compare_lump_sum_annuity` (~198 tokens)

Compare cash and annuity

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

Input parameters:

- `cashValue` (number, required): Published cash option in US dollars; do not infer it from a fixed ratio.
- `discountRate` (number): Annual discount rate as a fraction, e.g. 0.04 for 4%.
- `game` (string)
- `jackpot` (number, required): Advertised annuity total in US dollars.
- `locality` (string): Only valid with stateCode NY.
- `otherIncome` (number): Other annual income in US dollars before the standard deduction.
- `sharePercent` (number): Your percentage of one winning ticket.
- `stateCode` (string, required): US residence and ticket-purchase state, two-letter code. Cross-state claims are not modeled.
- `status` (string)
- `winners` (integer): Number of jackpot-winning tickets sharing the prize.

### `calculate_pool_share` (~139 tokens)

Equal lottery pool shares

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

Input parameters:

- `game` (string)
- `locality` (string): Only valid with stateCode NY.
- `members` (integer, required): Equal owners of one ticket. Result assumes every member has the specified tax profile.
- `otherIncome` (number): Other annual income in US dollars before the standard deduction.
- `prize` (number, required): Whole ticket cash prize in US dollars.
- `stateCode` (string, required): US residence and ticket-purchase state, two-letter code. Cross-state claims are not modeled.
- `status` (string)

### `calculate_lottery_odds` (~78 tokens)

Jackpot probability and expected return

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

Input parameters:

- `game` (string, required)
- `jackpotCash` (number): Optional jackpot cash option in US dollars, required to compute expected ticket return.
- `tickets` (integer): Different number combinations in the SAME drawing; repeated combinations do not add coverage.

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/jiankn-jackpot-calculator/jackpot-calculator-mcp#diagnostics

## Score history

- 2026-11-05: 74
- 2026-11-04: 73
- 2026-11-03: 73
- 2026-11-02: 72
- 2026-11-01: 72
- 2026-10-31: 71
- 2026-10-30: 71
- 2026-10-29: 70
- 2026-10-28: 70
- 2026-10-27: 70
- 2026-10-26: 69
- 2026-10-25: 69
- 2026-10-24: 68
- 2026-10-23: 68
- 2026-10-22: 67
- 2026-10-21: 67
- 2026-10-20: 66
- 2026-10-19: 66
- 2026-10-18: 65
- 2026-10-17: 65
- 2026-10-16: 64
- 2026-10-15: 64
- 2026-10-14: 63
- 2026-10-13: 63

## Common questions

### What is the Jackpot Calculator MCP server?

Jackpot Calculator is an MCP server listed in the public MCP registry as io.github.jiankn/jackpot-calculator. Estimate US lottery taxes, compare cash and annuity, split pool prizes and calculate jackpot odds. This page covers its hosted endpoint (https://jackpot-calculator-mcp.jiankn.workers.dev/mcp).

### Is the Jackpot Calculator MCP server safe to use?

Jackpot Calculator scores 74 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the Jackpot Calculator MCP server expose?

Jackpot Calculator exposes 4 tools: calculate_lottery_payout, compare_lump_sum_annuity, calculate_pool_share, calculate_lottery_odds. Their descriptions and schemas cost roughly 539 tokens of context every time the server is loaded.

### Does the Jackpot Calculator MCP server require authentication?

No. We connected to Jackpot Calculator without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the Jackpot Calculator MCP server still maintained?

Jackpot Calculator is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://jackpot-calculator-mcp.jiankn.workers.dev/mcp
- Repository: https://github.com/jiankn/jackpot-calculator-mcp
- Website: https://jackpotcalculator.com/mcp/
- Changelog RSS feed: https://verifymcp.io/servers/jiankn-jackpot-calculator/jackpot-calculator-mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/jiankn-jackpot-calculator/jackpot-calculator-mcp.json
- HTML version of this page: https://verifymcp.io/servers/jiankn-jackpot-calculator/jackpot-calculator-mcp