The ccxt for prediction markets. Hosted unified API for prediction markets — trade Polymarket, Kalshi, Opinion, and more from one API key. Open-source SDK and self-host option included.
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Polymarket
Polymarket US 🇺🇸
Kalshi
Myriad
Metaculus
Smarkets
Different prediction market platforms have different APIs, data formats, and conventions. pmxt provides a single, consistent interface to work with all of them.
- Hosted API. Get a key at pmxt.dev/dashboard, construct a client, trade. PMXT handles custody, signing infrastructure, and on-chain settlement.
- Open source (MIT). Self-host the local server for full control — your keys, your machine, no PMXT in the loop. See Self-hosted.
- Language-agnostic. Python and TypeScript SDKs today, with HTTP access for any other language. No lock-in to a single ecosystem.
- Drop-in Dome API replacement. Automatic codemod (
dome-to-pmxt) for teams migrating after the Polymarket acquisition. - Unified trading, not just data. Place orders across Polymarket, Kalshi, and Limitless with a single interface.
- MCP-native. Use pmxt directly from Claude, Cursor, and other AI agents.
Ensure that Node.js (>= 18) is installed and the node command is available on your PATH. The Python SDK requires Python >= 3.8.
pip install pmxtnpm install pmxtjsnpm install -g @pmxt/cli
pmxt polymarket markets --query Trump --limit 5
pmxt polymarket fetchMarkets --query Trump --limit 5
pmxt auth statusgit clone https://github.com/pmxt-dev/pmxt.git
cd pmxt
npm install
npm run devnpx -y @pmxt/mcpSee @pmxt/mcp for setup with Claude, Cursor, and other MCP-compatible clients.
If you're currently using Dome API, pmxt is a drop-in replacement with a unified interface for Polymarket and Kalshi.
Check out pmxt as a Dome API alternative for a detailed migration guide, API comparison, and automatic codemod tool (dome-to-pmxt) to help you transition your code.
# Automatically migrate your codebase
npx dome-to-pmxt ./srcGet your API key at pmxt.dev/dashboard. For reads, only pmxt_api_key and wallet_address are required. For trading, also pass private_key — the SDK auto-wraps it into an EIP-712 signer.
import pmxt
# Reads — pmxt_api_key + wallet_address only
client = pmxt.Polymarket(
pmxt_api_key="pmxt_live_...",
wallet_address="0xYourWalletAddress",
)
positions = client.fetch_positions()
balance = client.fetch_balance()
markets = client.fetch_markets(query="nba")
# Trading — also pass private_key
trader = pmxt.Polymarket(
pmxt_api_key="pmxt_live_...",
wallet_address="0xYourWalletAddress",
private_key="0xYourPrivateKey",
)
order = trader.create_order(
market_id="market-uuid",
outcome_id="outcome-uuid",
side="buy",
order_type="market",
amount=5.0,
denom="usdc",
slippage_pct=30.0,
)Note: Named imports do not work in ESM. Use
import pmxt from 'pmxtjs'(default import) for the namespaced form, or importPolymarketfrompmxtjsonly via the CJS build.
import { Polymarket } from "pmxtjs";
// Reads — pmxtApiKey + walletAddress only
const client = new Polymarket({
pmxtApiKey: "pmxt_live_...",
walletAddress: "0xYourWalletAddress",
});
const positions = await client.fetchPositions();
const balance = await client.fetchBalance();
// Trading — also pass privateKey
const trader = new Polymarket({
pmxtApiKey: "pmxt_live_...",
walletAddress: "0xYourWalletAddress",
privateKey: "0xYourPrivateKey",
});
const order = await trader.createOrder({
marketId: "market-uuid",
outcomeId: "outcome-uuid",
side: "buy",
type: "market",
amount: 5.0,
denom: "usdc",
slippage_pct: 30.0,
} as any);Prediction markets are structured in a hierarchy to group related information.
- Event: The broad topic (e.g., "Who will Trump nominate as Fed Chair?")
- Market: A specific tradeable question (e.g., "Will Trump nominate Kevin Warsh as the next Fed Chair?")
- Outcome: The actual share you buy (e.g., "Yes" or "No")
pmxt supports unified trading across exchanges. The hosted API is the default — see Quickstart above for the basic flow.
With a PMXT API key, you only need your wallet address and a private key to sign orders. PMXT handles custody, signer infrastructure, and on-chain settlement.
import pmxt
trader = pmxt.Polymarket(
pmxt_api_key="pmxt_live_...",
wallet_address="0xYourWalletAddress",
private_key="0xYourPrivateKey",
)
# 1. Check balance
balance = trader.fetch_balance()
print(f"Available balance: {balance[0].available}")
# 2. Fetch markets
markets = trader.fetch_markets(query='Trump')
# 3. Place an order
order = trader.create_order(
market_id=markets[0].market_id,
outcome_id=markets[0].yes.outcome_id,
side='buy',
order_type='market',
amount=5.0,
denom='usdc',
slippage_pct=30.0,
)
print(f"Order status: {order.status}")Use this when you self-host the local server. See Self-hosted for setup. You provide venue credentials directly — no pmxt_api_key required. For detailed credential setup instructions, see the exchange-specific guides: Polymarket, Kalshi, Limitless.
exchange = pmxt.Polymarket(
private_key=os.getenv('POLYMARKET_PRIVATE_KEY'),
proxy_address=os.getenv('POLYMARKET_PROXY_ADDRESS'), # Optional: For proxy trading
signature_type='gnosis-safe' # Default
) exchange = pmxt.Kalshi(
api_key=os.getenv('KALSHI_API_KEY'),
private_key=os.getenv('KALSHI_PRIVATE_KEY') # RSA Private Key
)exchange = pmxt.Limitless(
api_key=os.getenv('LIMITLESS_API_KEY'),
private_key=os.getenv('LIMITLESS_PRIVATE_KEY') # For order signing (EIP-712)
)To self-host pmxt-core on your own machine: pip install pmxt-core (Python) or npm install pmxt-core (Node.js), then construct any venue client without pmxt_api_key. The SDK spawns a local PMXT service; you supply venue credentials directly. See the self-hosted guide for details.
See the API Reference for detailed documentation and more examples.
Check out the directory for more use cases:
OnDB.ai