8 listed, each with a source and last-checked date. For the full comparison table, FAQ and picks, see Prediction market APIs and agents.
Prediction market APIs & agentsofficial prediction markets
Trading: live; separate demo environment with mock funds (demo.kalshi.co)
Pricing: API access free; exchange trading fees apply per contract
✓ Checked 2026-10-17
Prediction market APIs & agentsofficial prediction markets
Trading: live only (no testnet); CLOB V2 since Apr 28 2026
Pricing: API access free; trading fees vary by market
✓ Checked 2026-10-17
PPrediction market APIs & agentsofficial
prediction markets
Trading: live (trades via the Polymarket API)
Pricing: free, open source
✓ Checked 2026-10-17
PPrediction market APIs & agentsofficial
prediction markets (US)
Trading: live
Pricing: API access free; trading fees per Polymarket US schedule
✓ Checked 2026-10-17
LPrediction market APIs & agentsofficial
prediction markets (crypto, on Base)
Trading: live only; no sandbox or testnet (docs say rehearse with minimum-size live orders)
Pricing: API access free; trading fees per market
✓ Checked 2026-10-17
MPrediction market APIs & agentsofficial
play-money prediction markets
Trading: play money (mana); no real-money risk
Pricing: free
✓ Checked 2026-10-17
KPrediction market APIs & agentscommunity
prediction markets
Trading: demo and live; trading off by default
Pricing: free, open source
✓ Checked 2026-10-17
PPrediction market APIs & agentscommunity
prediction markets (Kalshi, Polymarket, Limitless)
Trading: data only (no execution)
Pricing: free during beta (1,000 req/day); paid tiers announced
✓ Checked 2026-10-17