# Events

All Vault Events are detailed in IVaultEventsopen in new window

For event based systems the following Vault events can be useful to construct/track pool state:

• Swap(address indexed pool, IERC20 indexed tokenIn, IERC20 indexed tokenOut, uint256 amountIn, uint256 amountOut, uint256 swapFeePercentage, uint256 swapFeeAmount);

  • A swap has occurred.

• LiquidityAdded(address indexed pool, address indexed liquidityProvider, AddLiquidityKind indexed kind, uint256 totalSupply, uint256[] amountsAddedRaw, uint256[] swapFeeAmountsRaw);

  • Liquidity has been added to a pool (including initialization).

• LiquidityRemoved( address indexed pool, address indexed liquidityProvider, RemoveLiquidityKind indexed kind, uint256 totalSupply, uint256[] amountsRemovedRaw, uint256[] swapFeeAmountsRaw );

  • Liquidity has been removed from a pool.

• AggregateSwapFeePercentageChanged(address indexed pool, uint256 aggregateSwapFeePercentage)

  • A protocol or pool creator fee has changed, causing an update to the aggregate swap fee.

• SwapFeePercentageChanged(address indexed pool, uint256 swapFeePercentage);

  • Emitted when the swap fee percentage of a pool is updated.

• PoolPausedStateChanged(address indexed pool, bool paused)

  • A Pool's pause status has changed.