  AccountSummaryTags | Class containing all existing values being reported by EClientSocket::reqAccountSummary |
| Bar | The historical data bar's description |
| CodeMsgPair | Associates error code and error message as a pair |
| ComboLeg | Class representing a leg within combo orders |
| CommissionReport | Class representing the commissions generated by an execution |
| Contract | Class describing an instrument's definition |
 ContractCondition | |
 PercentChangeCondition | Used with conditional orders to place or submit an order based on a percentage change of an instrument to the last close price |
| PriceCondition | Used with conditional orders to cancel or submit order based on price of an instrument |
 VolumeCondition | Used with conditional orders to submit or cancel an order based on a specified volume change in a security |
| ContractDetails | Extended contract details |
| DeltaNeutralContract | Delta-Neutral Contract |
| EClient | TWS/Gateway client class This client class contains all the available methods to communicate with IB. Up to thirty-two clients can be connected to a single instance of the TWS/Gateway simultaneously. From herein, the TWS/Gateway will be referred to as the Host |
| EClientSocket | TWS/Gateway client class This client class contains all the available methods to communicate with IB. Up to 32 clients can be connected to a single instance of the TWS/Gateway simultaneously. From herein, the TWS/Gateway will be referred to as the Host |
| EClientErrors | Contains all possible errors occurring on the client side. This errors are not sent by the TWS but rather generated as the result of malfunction within the TWS API client |
| EClientMsgSink | |
| EClientSocket | TWS/Gateway client class This client class contains all the available methods to communicate with IB. Up to 32 clients can be connected to a single instance of the TWS/Gateway simultaneously. From herein, the TWS/Gateway will be referred to as the Host |
| EReader | Captures incoming messages to the API client and places them into a queue |
| EReaderSignal | Notifies the thread reading information from the TWS whenever there are messages ready to be consumed. Not currently used in Python API |
| EWrapper | This interface's methods are used by the TWS/Gateway to communicate with the API client. Every API client application needs to implement this interface in order to handle all the events generated by the TWS/Gateway. Almost every EClientSocket method call will result in at least one event delivered here |
| Execution | Class describing an order's execution |
| ExecutionFilter | When requesting executions, a filter can be specified to receive only a subset of them |
| HistoricalTick | The historical tick's description. Used when requesting historical tick data with whatToShow = MIDPOINT |
| HistoricalTickBidAsk | The historical tick's description. Used when requesting historical tick data with whatToShow = BID_ASK |
| HistoricalTickLast | The historical last tick's description. Used when requesting historical tick data with whatToShow = TRADES |
| Liquidity | Class describing the liquidity type of an execution |
| OperatorCondition | |
| TimeCondition | Time condition used in conditional orders to submit or cancel orders at specified time |
| Order | The order's description |
| OrderComboLeg | Allows to specify a price on an order's leg |
| OrderCondition | |
| ExecutionCondition | This class represents a condition requiring a specific execution event to be fulfilled. Orders can be activated or canceled if a set of given conditions is met. An ExecutionCondition is met whenever a trade occurs on a certain product at the given exchange |
| OrderState | Provides an active order's current state |
| ScannerSubscription | Defines a market scanner request |
| SoftDollarTier | A container for storing Soft Dollar Tier information |
| TagValue | Convenience class to define key-value pairs |
| TickAttrib | Tick attributes that describes additional information for price ticks |
