# Event Contract API Overview
Event Contracts are prediction contracts on future events (e.g. elections, economic data, sports), traded in YES/NO (binary) directions. Full flow: Category → Competition filter → Series → Event → Contract → Snapshot / Subscribe OrderBook·Kline·Ticker.
| Module | Interface | Description | |
|---|---|---|---|
| Subscription | subscribe_event_contract | Subscribe to event contract real-time data by specifying code and data type | |
| unsubscribe_event_contract | Unsubscribe precisely by code, type and K-line source | ||
| unsubscribe_all_event_contract | Unsubscribe all event contracts on the current connection | ||
| Real-Time | get_event_contract_snapshot | Batch get event contract real-time snapshot (last price, cumulative volume, YES/NO best bid/ask, etc.) | |
| get_event_contract_order_book | Get event contract real-time order book (multi-level YES/NO); ORDER_BOOK subscription required | ||
| EventContractOrderBookHandlerBase | Event contract order book push callback | ||
| get_event_contract_kline | Get event contract real-time K-line; corresponding K-line subscription required | ||
| EventContractKlineHandlerBase | Event contract K-line push callback | ||
| get_event_contract_ticker | Get event contract real-time ticker; TICKER subscription required | ||
| EventContractTickerHandlerBase | Event contract ticker push callback | ||
| request_history_event_contract_kline | Fetch event contract historical K-line | ||
| Discovery | filter_competition | Competition filter; get competitions and markets | |
| get_event_contract_category | Get event contract category list | ||
| get_event_contract_series_list | Get Series list by category | ||
| get_event_contract_event_list | Get Event list by Series | ||
| get_event_contract | Get Contract list by Event, including recommended contracts | ||
| get_event_contract_milestone_list | Get milestone list | ||
| get_valid_combo_list | Get combo-eligible event list | ||
| request_combo_quotes | Combo quote request (RFQ) | ||