io.github.mobymedia/polymarket-news-mcp

polymarket-news-mcp

Give an AI agent a headline — get the Polymarket markets it moves.

An MCP (Model Context Protocol) server that connects real-world news to prediction markets. Plenty of MCP servers can look up Polymarket prices; this one answers a different question: "this just happened — where can the world's belief about it be read?" Matching is deterministic and explainable — every match reports the exact terms that fired and a confidence score, so your agent can judge the match itself.

Read-only by default — no API keys, no wallet, no custody: live odds and links only. Optional trading tools exist (v0.2.0+) but stay absent unless you install the [trading] extra and set your own signing key — see Trading.

Tools

Example

match_news("Federal Reserve signals rate hike as inflation stays hot")

[
  {"question": "Fed rate hike in 2026?", "match_score": 17.2,
   "outcomes": {"Yes": 0.47, "No": 0.53}, "volume_24h_usd": 812440,
   "matched_terms": ["fed", "hike", "rate", "rate hike"],
   "url": "https://polymarket.com/event/fed-rate-hike-in-2026"},
  {"question": "Fed Rate Hike by July 2026 Meeting?", "match_score": 17.0,
   "outcomes": {"Yes": 0.08, "No": 0.92}, ...}
]

Install

Requires Python ≥3.10. With uv (no install needed):

uvx polymarket-news-mcp

Claude Code

claude mcp add polymarket-news -- uvx polymarket-news-mcp

Claude Desktop / any MCP client (claude_desktop_config.json):

{
  "mcpServers": {
    "polymarket-news": {
      "command": "uvx",
      "args": ["polymarket-news-mcp"]
    }
  }
}

Or classic pip: pip install polymarket-news-mcp then command polymarket-news-mcp.

Trading (opt-in, v0.2.0+)

By default this server is read-only. Trading tools appear only when you provide your own signing key and install the extra:

pip install "polymarket-news-mcp[trading]"
export POLYMARKET_PRIVATE_KEY=0x...     # YOUR key. Stays local, signs locally.
export POLYMARKET_FUNDER=0x...          # your Polymarket proxy/funds address (browser-wallet accounts)
# optional: POLYMARKET_SIGNATURE_TYPE (0 EOA / 1 proxy / 2 Safe / 3 deposit wallet)
# optional: POLYMARKET_MAX_ORDER_USD (spend cap per order, default 100)

Tools: trading_status, place_limit_order, place_market_buy, my_open_orders, cancel_order, my_positions. Every order is bounded by the spend cap.

Transparency — builder attribution. Orders placed through this server carry the newsbet builder code (0 bps maker/taker — you pay no extra fees); Polymarket's Builders program attributes routed volume to the project. Forks can override via POLYMARKET_BUILDER_CODE.

Security. Your key never leaves your machine and is never logged. Use a dedicated trading wallet with limited funds. Market SELL is deliberately not offered (ambiguous upstream semantics) — sell via limit orders.

Known upstream caveat (July 2026). Polymarket's py-clob-client-v2 currently cannot sign for NEW "deposit wallet" accounts (#52, #70, #76). Accounts created via the Polymarket website with a browser wallet (signature types 0/1/2) work — set POLYMARKET_FUNDER to your Polymarket profile address.

Jurisdiction. Polymarket's CLOB rejects orders from restricted regions (incl. the US) server-side; using these tools where prohibited is on you. Nothing here is financial advice.

How matching works

IDF-weighted term overlap between your text and market questions/event titles, plus: phrase (bigram) agreement, numeric normalization ($120,000 ≡ 120k), accent folding, a salience gate (every match needs a rare informative anchor — "openai", never "the"), one-best-market-per-event dedupe, and a relative cutoff. Market data comes from Polymarket's public Gamma API (top ~2,000 markets by liquidity, cached 15 minutes at ~/.cache/polymarket-news-mcp/). First call after a cold start takes ~10–15s to build the index; subsequent calls are instant.

Notes & limits

• Informational only — not financial advice. Polymarket availability depends on your jurisdiction; this server never places orders.
• News feed sources: CoinDesk, Cointelegraph, Decrypt, The Block, SEC, BBC World & Politics, ESPN (RSS). PRs welcome for more.
• Match scores ≥15 are high-confidence; 10–15 are related-entity matches.

License

MIT