LI.FI Widget provides a useWidgetEvents hook that lets you subscribe to a series of widget events and helps you retrieve helpful information about executing routes, track bridge and swap progress, track selection of chains and tokens, interactions with specific UI elements, and more. We continue working on extending available events and If you are interested in a specific event, reach out via our support. To minimize unnecessary re-renders and prevent potential glitches in the main Widget component, please integrate the useWidgetEvents hook outside of the component where the main LiFiWidget is integrated. Example of how to subscribe to widget events: 
import type { Route } from '@lifi/sdk';
import type { RouteExecutionUpdate } from '@lifi/widget';
import { useWidgetEvents, WidgetEvent } from '@lifi/widget';
import { useEffect } from 'react';

export const WidgetEventsExample = () => {
  const widgetEvents = useWidgetEvents();

  // ...

  useEffect(() => {
    const onRouteExecutionStarted = (route: Route) => {
      // console.log('onRouteExecutionStarted fired.');
    };
    const onRouteExecutionUpdated = (update: RouteExecutionUpdate) => {
      // console.log('onRouteExecutionUpdated fired.');
    };
    const onRouteExecutionCompleted = (route: Route) => {
      // console.log('onRouteExecutionCompleted fired.');
    };
    const onRouteExecutionFailed = (update: RouteExecutionUpdate) => {
      // console.log('onRouteExecutionFailed fired.');
    };
    const onRouteHighValueLoss = (update: RouteHighValueLossUpdate) => {
      // console.log('onRouteHighValueLoss continued.');
    };
    
    widgetEvents.on(WidgetEvent.RouteExecutionStarted, onRouteExecutionStarted);
    widgetEvents.on(WidgetEvent.RouteExecutionUpdated, onRouteExecutionUpdated);
    widgetEvents.on(WidgetEvent.RouteExecutionCompleted, onRouteExecutionCompleted);
    widgetEvents.on(WidgetEvent.RouteExecutionFailed, onRouteExecutionFailed);
    widgetEvents.on(WidgetEvent.RouteHighValueLoss, onRouteHighValueLoss);
    
    return () => widgetEvents.all.clear();
  }, [widgetEvents]);

  // ...
  
  // Return null because it's an example
  return null;
};

​
List of events

Here is the list of all available events:
  • Name: RouteExecutionStarted
    • Arguments Type: Route
    • Description: The event fires when the user clicks on the Start swapping or Start bridging button.
  • Name: RouteExecutionUpdated
    • Arguments Type: RouteExecutionUpdate
    • Description: The event fires when there is an update to the Route object during execution.
  • Name: RouteExecutionCompleted
    • Arguments Type: Route
    • Description: The event fires when the execution is completed successfully.
  • Name: RouteExecutionFailed
    • Arguments Type: RouteExecutionUpdate
    • Description: The event fires when the execution has failed.
  • Name: RouteHighValueLoss
    • Arguments Type: RouteHighValueLossUpdate
    • Description: The event fires when the High Value Loss bottom sheet appears on the screen.
  • Name: ContactSupport
    • Arguments Type: ContactSupport
    • Description: The event fires when the user clicks on the Contact support button on the Transaction Details page.
  • Name: SourceChainTokenSelected
    • Arguments Type: ChainTokenSelected
    • Description: The event fires when the user selects the source chain and token.
  • Name: DestinationChainTokenSelected
    • Arguments Type: ChainTokenSelected
    • Description: The event fires when the user selects the destination chain and token.
  • Name: SendToWalletToggled
    • Arguments Type: boolean
    • Description: The event fires when the user clicks on the wallet icon next to the action button on the main page to show/hide the destination wallet selection UI.
  • Name: ReviewTransactionPageEntered
    • Arguments Type: Route
    • Description: The event fires when the user enters the Review Transaction page by clicking on a route.
  • Name: WalletConnected
    • Arguments Type: WalletConnected
    • Description: The event fires when the user connects the wallet via the internal wallet management UI.
  • Name: WidgetExpanded
    • Arguments Type: boolean
    • Description: The event fires when the side panel with routes is shown to the user. Only available in wide widget variant.
  • Name: PageEntered
    • Arguments Type: NavigationRouteType
    • Description: The event fires when the user navigates to a page in the widget.
  • Name: FormFieldChanged
    • Arguments Type: FormFieldChanged
    • Description: The event fires whenever a form value is changed in the widget.
  • Name: SettingUpdated
    • Arguments Type: SettingUpdated
    • Description: The event fires whenever a setting is updated in the widget.
Routes: Some of the events here present information about routes. A route is the LI.FI way of presenting a quote on an exchange/transfer. A route is a collection of steps, transactions and costs associated with that transfer. In the Widget we present a set of routes that the user can select from. Once selected the execution of that route can begin and the user will be guided through the steps required to complete that route. The route events above can help track a route status.

​
Widget Events types

Properties and types of the useWidgetEvents hook. 
enum WidgetEvent {
  RouteExecutionStarted = 'routeExecutionStarted',
  RouteExecutionUpdated = 'routeExecutionUpdated',
  RouteExecutionCompleted = 'routeExecutionCompleted',
  RouteExecutionFailed = 'routeExecutionFailed',
  RouteHighValueLoss = 'routeHighValueLoss',
  ContactSupport = 'contactSupport',
  SourceChainTokenSelected = 'sourceChainTokenSelected',
  DestinationChainTokenSelected = 'destinationChainTokenSelected',
  SendToWalletToggled = 'sendToWalletToggled',
  ReviewTransactionPageEntered = 'reviewTransactionPageEntered',
  WalletConnected = 'walletConnected',
  WidgetExpanded = 'widgetExpanded',
  PageEntered = 'pageEntered',
  FormFieldChanged = 'formFieldChanged',
  SettingUpdated = 'settingUpdated',
}

type WidgetEvents = {
  routeExecutionStarted: Route;
  routeExecutionUpdated: RouteExecutionUpdate;
  routeExecutionCompleted: Route;
  routeExecutionFailed: RouteExecutionUpdate;
  routeHighValueLoss: RouteHighValueLossUpdate;
  contactSupport: ContactSupport;
  sourceChainTokenSelected: ChainTokenSelected;
  destinationChainTokenSelected: ChainTokenSelected;
  sendToWalletToggled: boolean;
  formFieldChanged: FormFieldChanged;
  reviewTransactionPageEntered?: Route;
  walletConnected: WalletConnected;
  widgetExpanded: boolean;
  pageEntered: NavigationRouteType;
  settingUpdated: SettingUpdated;
};

interface ContactSupport {
  supportId?: string;
}

interface RouteHighValueLossUpdate {
  fromAmountUSD: number;
  toAmountUSD: number;
  gasCostUSD?: number;
  feeCostUSD?: number;
  valueLoss: number;
}

interface RouteExecutionUpdate {
  route: Route;
  process: Process;
}

interface ChainTokenSelected {
  chainId: ChainId;
  tokenAddress: string;
}

interface WalletConnected {
  address?: string;
  chainId?: number;
  chainType?: ChainType;
}

export type FormFieldChanged = {
  [K in keyof DefaultValues]: {
    fieldName: K;
    newValue: DefaultValues[K];
    oldValue: DefaultValues[K];
  };
}[keyof DefaultValues];

export type SettingUpdated<
  K extends keyof SettingsProps = keyof SettingsProps,
> = {
  setting: K;
  newValue: SettingsProps[K];
  oldValue: SettingsProps[K];
  newSettings: SettingsProps;
  oldSettings: SettingsProps;
};