When transactions are lingering in the mempool users can “Cancel” them. We’ll confirm their decision with an onscreen modal.
When a Dapp user confirms a transaction in their wallet, it is sent to the mempool to be processed. Sometimes, depending no how busy the network is, the transaction may stall while it waits to be processed.
While a user has a Pending transaction, MetaMask will show options to Speed Up (i.e. add Gas) or Cancel. If either of these options are selected, Assist.js will automatically update the transaction status in their browser to reflect these changes. Note: SpeedUp and Cancel attempts are not guaranteed on Mainnet.