Back to the catalog

NegativeEV bet checker

Grade any MLB, WNBA, PGA or ATP bet against thousands of play-by-play sims. No key, no signup.

Open source Repository Open in the app JSON README (API)

About

Grade any MLB, WNBA, PGA or ATP bet against thousands of play-by-play sims. No key, no signup.

Details

Kind
MCP servers
Topic
No topic detected
Publisher
com.negativeev
Origin
official
Category
ferramentas
Transport
http
Version
1.4.5
Last push
2026-08-30T19:28:50Z
Repository state
ativo
License
MIT
Added
2026-08-29 03:01:16
Updated
2026-08-30 19:01:02
Origin id
com.negativeev/bet-checker

README

# NegativeEV MCP server

Grade any MLB, WNBA, PGA or ATP bet against thousands of play-by-play game simulations, from inside your AI client.

Whether a bet is worth taking depends on tonight's lineups, today's injuries, and the weather at first pitch. None of that is in a model's weights. Asked cold, a model answers fluently and wrongly. This server returns a probability counted from simulations of the actual game: each leg's simulated win probability, the probability the sportsbook's price implies, and the edge between them.

This is a hosted remote server. There is nothing to build or run from this repo. The repo is the server's public face and carries a mirror of its registry record ([server.json](./server.json)).

## Connect

No API key, no signup. Anonymous calls work immediately. The server speaks plain Streamable HTTP, so any MCP client can connect to `https://negativeev.com/mcp`.

**Claude Code**

```
claude mcp add --transport http negativeev https://negativeev.com/mcp
```

**Claude Desktop and claude.ai**

Settings → Connectors → Add custom connector, then paste `https://negativeev.com/mcp` as the URL.

**Cursor**

Add `{"negativeev": {"url": "https://negativeev.com/mcp"}}` under `mcpServers` in `~/.cursor/mcp.json`. Also listed on [cursor.directory](https://cursor.directory/plugins/negativeev-mcp-server).

**VS Code (Copilot)**

```
code --add-mcp '{"name":"negativeev","type":"http","url":"https://negativeev.com/mcp"}'
```

**ChatGPT**

Settings → Security and login → enable Developer mode, then add `https://negativeev.com/mcp` as a connector at `chatgpt.com/plugins`. Developer mode is required for custom MCP connectors and is available on Pro, Plus, Business, Enterprise and Education accounts on the web.

There is also a Claude Code plugin that wraps this server: [jessejohnsohn/negativeev-bet-checker](https://github.com/jessejohnsohn/negativeev-bet-checker). Install with `claude plugin install negativeev-bet-checker`.

Opening `https://negativeev.com/mcp` in a browser shows the same install steps.

## Tools

| Tool | What it does |
|---|---|
| `check_bet` | Grades a bet written as plain text, including a multi-leg parlay in one string. Returns each leg's simulated probability, the implied probability from the price, and the edge. It prices a bet you name. It does not search the board for value. |
| `get_slate` | Says whether there is a checkable slate right now. Free. Spends no check. |
| `get_usage` | Reports checks remaining and when the next frees up. Free. Spends no check. |

Call `get_slate` first to confirm there is a checkable slate. `check_bet` spends one of the caller's checks only when the bet fully grades, and every result says so outright in its `status` and `check_spent` fields. A bet that comes back `ungraded` was understood. It is simply not on the simulated slate, so re-sending it with different wording returns the same answer. Check `get_slate` instead.

## Limits and auth

Anonymous calls share a per-device quota of 100 checks a day, on its own counter. Signing in makes checks unlimited, with a pace cap of 1000 checks an hour. Send a signed-in user's access token as `Authorization: Bearer`. Details at negativeev.com/auth.md. An invalid or expired token is rejected with a 401 rather than silently downgraded, so re-authenticate rather than retrying anonymously.

## Details

| | |
|---|---|
| Endpoint | `https://negativeev.com/mcp` |
| Transport | Streamable HTTP (stateless) |
| Sports | MLB, WNBA, PGA, ATP |
| Registry name | `com.negativeev/bet-checker` |
| Auth | Optional bearer token, details at negativeev.com/auth.md |
| Server card | [`/.well-known/mcp/server-card.json`](https://negativeev.com/.well-known/mcp/server-card.json) |
| Cost | Free |

NegativeEV checks bets. It takes no bets and sells no picks.

More