openpx 0.3.1

Python SDK for OpenPX prediction markets

openpx

Python SDK for OpenPX — a unified interface for prediction markets.

Installation

pip install openpx

Quick Start

from openpx import Exchange

# Connect to Kalshi (public API)
exchange = Exchange("kalshi")
markets = exchange.fetch_markets()

for market in markets[:5]:
    print(f"{market['question']}: {market['prices']}")

Supported Exchanges

• Kalshi — US-regulated event contracts
• Polymarket — Crypto-native prediction markets

Authentication

Kalshi

exchange = Exchange("kalshi", {
    "api_key_id": os.environ["KALSHI_API_KEY_ID"],
    "private_key_path": "./kalshi-private-key.pem",  # or "private_key_pem": "<inline PEM>"
})

Public market-data calls work without credentials.

Polymarket

Pick the credential path that matches your wallet:

Wallet model	Required keys
MetaMask EOA + Polymarket Safe	private_key (EOA) + funder (Safe)
Plain EOA (no Safe)	private_key only
Pre-derived API keys (most reliable)	api_key + api_secret + api_passphrase (+ private_key for order signing)

exchange = Exchange("polymarket", {
    "private_key": os.environ["POLYMARKET_PRIVATE_KEY"],
    "funder":      os.environ.get("POLYMARKET_FUNDER"),  # omit for plain EOA
})

signature_type is auto-detected from funder and almost never needs to be set explicitly. If you set it to "eoa" while a funder is configured, the SDK overrides it to "gnosis_safe" with a warning — that combo is rejected by Polymarket and is a common MetaMask misconfiguration.

If derive-api-key returns a Cloudflare WAF block (datacenter IPs are often blocked), generate keys once via the Polymarket web app and pass them as api_key / api_secret / api_passphrase to skip the derive flow entirely.

Full credential matrix: docs.openpx.io/setup/polymarket-credentials.

Requirements

• Python >= 3.9
• pydantic >= 2.0