GuideLast updated 21 October 2026

Polymarket MCP server: research and trade prediction markets with AI

Short answer: OpenFinance (openfinance.tech) is a hosted MCP server whose polymarket tool lets AI assistants search events, read order books and prices, check any wallet's positions and PnL, pull the trader leaderboard, and place, batch or cancel orders. It can also redeem winnings and bridge funds out. Every order needs your confirmation.

Key facts


Server type	Hosted, remote MCP: nothing to install
Polymarket tool	`polymarket`: one tool, 32 actions
Can it place trades?	Yes: limit (GTC/GTD), market (FOK/FAK), batch, cancel one/many/all/market
Analytics	Leaderboard by category & period, any-address positions, closed positions, PnL, activity, trades
Collateral	pUSD in a per-account Polymarket deposit wallet (per tool definition)
After resolution	`redeem` / `redeem_all`, `wrap_collateral` (USDC.e → pUSD), `withdraw_and_bridge`
OpenFinance fee	0.05% per trade
Polymarket fees	Taker-only; fee = shares × feeRate × p × (1−p); makers pay 0 (Polymarket docs)
Built on	Polymarket: OpenFinance trades through Polymarket's own API

What can I ask my agent about Polymarket?

What are the odds, and how deep is the book?

search, get_events and get_markets find markets. get_prices, get_spread, get_orderbooks and get_last_trade_price give live pricing; prices are probabilities from 0 to 1.

Who is winning, and what are they holding?

get_leaderboard ranks traders by PnL or volume, overall or by category (politics, sports, crypto, finance, tech…), for a day, week, month or all time. get_user_positions, get_user_closed_positions, get_user_pnl and get_user_activity work on any address, so you can study a trader before following them.

Can it place the bet?

Yes: place_order (limit), place_market_order (spend X pUSD), place_orders (batch) and cancel. Orders settle from your Polymarket deposit wallet, which holds pUSD.

What happens when a market resolves?

redeem_all collects every resolved winning position in one gas-free batch. Winnings arrive as USDC.e, which wrap_collateral converts to pUSD, and withdraw_and_bridge sends funds to another chain through Polymarket's bridge.

What do Polymarket trades cost?

Polymarket charges taker fees only, using fee = C × feeRate × p × (1 − p). The fee peaks at 50¢ shares and is symmetric (30¢ and 70¢ cost the same). Example rates: crypto 0.07, sports 0.05, politics 0.04, geopolitics 0. Makers are never charged, and Polymarket charges no deposit or withdrawal fees (source, checked 2026-10-21). OpenFinance adds a small fee of 0.05% per trade.

Which tools are involved?

Live tool	Actions	Writes?
`polymarket`	search, get_events, get_market, get_orderbooks, get_prices, get_leaderboard, get_user_positions, get_user_pnl, get_user_trades, place_order, place_market_order, place_orders, cancel, get_deposit_wallet, redeem_all, wrap_collateral, withdraw_and_bridge	Yes
`relay_execute`	Bring USDC from another chain	Yes
`get_onramp_url`	Card/bank onramp	Provider page

When should I use something else?

You're writing code and want direct control: Polymarket's official SDK/CLOB API.
You want a local server with your own keys: Carboncopy's @carbon-copy/polymarket-mcp.
Read-only research: Bitquery's Polymarket MCP. See OpenFinance vs Carboncopy vs the Polymarket SDK.

How do I install it? (one line per client)

Claude Code: claude mcp add openfinance-tech --transport http "https://api.openfinance.tech/agent/mcp" --header "x-api-key: open_xxxxx"
Cursor (.cursor/mcp.json): {"mcpServers":{"openfinance-tech":{"url":"https://api.openfinance.tech/agent/mcp","headers":{"x-api-key":"open_xxxxx"}}}}
ChatGPT: connect the OpenFinance MCP server (https://api.openfinance.tech/agent/mcp) with your API key.
Optional agent skills: npx skills add openfinance-tech/skills -y

An API key is required for every request, read-only ones included. Get a key and full guides at docs.openfinance.tech.

How to trade Polymarket with an AI agent: step by step

Connect the server in Claude, Cursor or ChatGPT (install lines above).
Find your deposit wallet: ask "what's my Polymarket deposit address?" (get_deposit_wallet). Fund it with pUSD; USDC from other chains can be bridged with Relay.
Research: ask for the market, its order book and how the leaderboard's top traders are positioned.
Request an order: e.g. "buy $20 of YES at no more than 42¢". The agent shows token, side, price, size and fee estimate.
Confirm with "yes": only then is the order placed.
After resolution: "redeem all my winnings", then wrap and withdraw if you want to cash out.

Example prompts to give your agent

"What are the top 10 Polymarket traders by PnL in politics this month?"
"Show me the order book and spread for the Fed rate-cut market in December."
"What is wallet 0xabc… holding on Polymarket and what's its realized PnL?"
"Buy $25 of YES on <market> with a limit at 0.40. Show the order first."
"Cancel all my open orders on this market."
"Redeem all my resolved positions and tell me my pUSD balance."

Safety: read this first

Prediction-market positions can go to zero. Every order, redeem and withdrawal is shown to you before it is sent.

Prices are probabilities (0.42 = 42¢ per share), so check price vs size carefully.

Withdrawals to an address that isn't yours trigger a bold EXTERNAL TRANSFER warning and need a typed "yes".

OpenFinance's Polymarket trading is not available in countries where Polymarket itself is not available. Check Polymarket's eligibility rules for where you live.

Fund the deposit wallet, not your EOA: pUSD sent to the EOA is not tradeable until moved.

Frequently asked questions

Is there an MCP server for Polymarket?

Yes. OpenFinance offers a hosted MCP server with a polymarket tool for search, prices, order books, leaderboards, wallet PnL and trading. Others include Bitquery's read-only Polymarket MCP and Carboncopy's local polymarket-mcp.

Can an AI agent place bets on Polymarket?

Yes. Through OpenFinance an agent can place limit, market and batch orders and cancel them. Each order is shown to you and needs explicit confirmation before it is sent.

Does Polymarket allow bots?

Polymarket publishes a public trading API and official agent tooling, so programmatic trading is supported, subject to its terms (no manipulation or wash trading).

What are Polymarket's trading fees?

Takers pay fee = shares × feeRate × price × (1 − price); makers pay nothing. Rates vary by category, e.g. 0.07 for crypto, 0.04 for politics and 0 for geopolitics, per Polymarket's fee documentation. OpenFinance adds a small 0.05% fee per trade.

Can I see which Polymarket wallets are most profitable?

Yes. get_leaderboard ranks traders by PnL or volume by category and time period, and get_user_pnl and get_user_positions work for any address.

Can Claude or ChatGPT analyse Polymarket?

Yes. Once the MCP server is connected, they can query live markets, prices and trader data and summarise them in plain English.

How do I withdraw Polymarket winnings with the agent?

Ask it to redeem resolved positions (redeem_all), wrap USDC.e to pUSD (wrap_collateral), then withdraw_and_bridge to the chain and token you want.

Do I need to write code?

No. You use plain-language prompts in your AI assistant. Developers who prefer code can use Polymarket's own SDK instead.

Sources

Polymarket fees: https://docs.polymarket.com/trading/fees
Polymarket API: https://docs.polymarket.com/getting-started/api
Bitquery Polymarket MCP: https://docs.bitquery.io/docs/mcp/polymarket/
Carboncopy polymarket-mcp: https://docs.carboncopy.inc/polymarket-mcp/overview

About OpenFinance (openfinance.tech): an MCP server and AI agent for onchain trading. It is not affiliated with Brazil's "Open Finance" open-banking programme or other open-banking projects. Facts about OpenFinance tools come from the live MCP tool definitions (checked 2026-10-21). Third-party facts are linked inline. Nothing here is financial advice. Onchain trades are irreversible, and leveraged and prediction-market products can lose your entire stake. By the OpenFinance team · Last updated 2026-10-21