Spoiler MCP Server

by zerozaky Your server? Claim it

answering

Spoiler is answering right now. Last checked 13 min ago. It exposes 12 tools.

Sealed prediction-market verdicts, graded in public across Polymarket and Kalshi. No auth required.

Uptime history 91 days of history · worst day 0%

91 days agonow

100.0%

Uptime 24h

91 of 91 checks

Tools

read from the server

142 ms

Response time

average over 24h

authentication required

Access

streamable-http

Nothing serious here today

Today is the operative word: we check Spoiler every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 13 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add spoiler --transport http https://spoiler.bet/mcp

Settings → Connectors → Add custom connector, then paste this address

https://spoiler.bet/mcp

~/.codex/config.toml

[mcp_servers.spoiler]
url = "https://spoiler.bet/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "spoiler": {
      "url": "https://spoiler.bet/mcp"
    }
  }
}

.vscode/mcp.json

{
  "servers": {
    "spoiler": {
      "type": "http",
      "url": "https://spoiler.bet/mcp"
    }
  }
}

This endpoint answered with an authorization challenge. The server is running, but it did not say what kind of credentials it expects.

Available tools 12

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

paid

paid_board_snapshot

Get a board-wide snapshot of open calls and the public record, not one market. Price: 0.25 USDT per call, paid via x402 on X Layer.

paid_crypto_call_pack

Every open crypto call on the board, with public receipts. Price: 0.10 USDT per call, paid via x402 on X Layer.

paid_esports_call_pack

Every open esports call on the board, with public receipts. Price: 0.10 USDT per call, paid via x402 on X Layer.

paid_full_verdict

One called market in full depth: side, edge, probability, timeline, and on-chain proof. Price: 1.00 USDT per call, paid via x402 on X Layer.

paid_receipt_verify

Check one public receipt and its onchain proof. Price: 0.10 USDT per call, paid via x402 on X Layer.

paid_single_market_check

Ask about any market: our call and edge if we have one, or why it was screened out. Price: 0.05 USDT per call, paid via x402 on X Layer.

paid_spoiler_metrics

Board-wide win rate, Brier and the graded record, by category. Price: 0.05 USDT per call, paid via x402 on X Layer.

paid_top_edges_now

The five strongest open calls across the whole board right now. Price: 0.10 USDT per call, paid via x402 on X Layer.

paid_venue_gaps

Compare current Kalshi and Polymarket prices ranked by gap. Price: 0.50 USDT per call, paid via x402 on X Layer.

board

get_board

Read public Spoiler receipts, public meter counts, and public methodology summary.

lookup

lookup_market

Search public receipts by market text.

receipt

get_receipt

Read one public receipt by event id, slug, or commit hash prefix.

Endpoints

URL	Transport	State	Latency	Checked
https://spoiler.bet/mcp	streamable-http	needs auth	102 ms	13 min ago

Alternatives to Spoiler

same job, measured the same way

Kalshi

by pipeworx-io

Kalshi MCP — US-regulated prediction-market data (no auth on public reads).

321 installs/wk 63 tools answering

Polymarket Kalshi Trading

by oddsrail

Cross-venue prediction markets for AI agents: Polymarket + Kalshi, costed and attributed

answering

matchwire.win — Mapped Prediction Markets (Kalshi, Polymarket, Predict.fun)

by matchwire

One row per game, matched across Kalshi, Polymarket US/Intl and Predict.fun. Mapping only.

answering

pdata Prediction Markets

by pdata

Polymarket, Kalshi + 6 more prediction markets: live odds, volume, movers. Read-only, no auth.

14 tools answering

Predictit MCP

by mrfentmen

Prediction market contracts and prices from PredictIt. No key required.

806 installs/wk local only

Bellwether MCP

by bellwethermetrics

Live prediction market data from Polymarket and Kalshi with VWAP pricing and reportability.

53 installs/wk local only

Bellwether

by bellwether

Live Kalshi + Polymarket prediction-market data and cross-venue arbitrage spreads, one schema.

3 tools answering

Polymarket

by pipeworx-io

Polymarket MCP — prediction-market data via Gamma + CLOB + Data public APIs.

57 tools answering

Spoiler — questions

Answers built from our own checks of this server.

What can Spoiler do?

It exposes 12 tools, read directly from the server on our last check. Among them: get_board, get_receipt, lookup_market, paid_board_snapshot, paid_crypto_call_pack, paid_esports_call_pack and 6 more. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →

Is Spoiler working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 91 of 91 checks got a reply (100.0%), average response time 142 ms. The bar chart above shows every period we have measured.

How do I connect Spoiler?

Copy the ready config from this page. We generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each in the form that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address. You will need your own credentials: it refuses anonymous clients.

Does Spoiler need an API key?

Yes. Every time we knock, Spoiler answers with an authorization challenge instead of its tool list — that is how we know it is running and gated rather than broken. Bring your own credentials and it will talk.

How fast is Spoiler?

It answers our handshake in 142 ms on average, which is faster than 85% of all working MCP servers we measure. That puts it in the quick quarter of the ecosystem. The comparison comes from our own checks across the whole registry, every 15 minutes.