Gemini Prediction Markets API

Public endpoints for browsing prediction markets. Market Data: Use these REST endpoints to discover active events and each contract's instrumentSymbol (e.g., GEMI-FEDJAN26-DN25). For active trading and market making, prefer Prediction Markets WebSocket streams with that instrumentSymbol.

• List Events - Discover active events and instrument symbols
• Prediction Markets WebSocket Streams - Stream prices, depth, order events, and positions

Read, check, and accept the latest Prediction Markets terms for API key and OAuth trading flows.

Authenticated REST endpoints for placing and managing orders. Treat REST order placement as payload reference or a one-off server workflow; for active trading and market making, prefer WebSocket order.place.

Authenticated endpoints for viewing positions and order history. Use REST positions for recovery or audit snapshots after reconnects, missed WebSocket messages, and settlement windows.

Public endpoints for discovering and inspecting combo contracts. Combos are pre-packaged multi-leg contracts; order entry uses the same place/cancel endpoints as single contracts.

Endpoints for the Maker Rebate and Liquidity Rewards programs.

• Maker Rebate — per-fill rebates earned by resting limit orders that get filled. Rates and rebate multipliers are configured per category. Public rate schedule plus authenticated payout and summary endpoints.
• Liquidity Rewards — daily USD reward pools distributed across qualifying makers based on quote uptime, spread, and size. Public config + event listing, authenticated daily and lifetime summary endpoints.

When a program is not active, its endpoints return 503 Service Unavailable. Note on field naming. Response fields under the Rewards endpoints use snake_case (e.g. event_ticker, daily_pool_usd). This differs from the camelCase convention used by the rest of the Prediction Markets REST endpoints.