Overview

To avoid nonce synchronization issues, we currently only process one transaction per wallet per blockchain at a given time. However, by opting in to the Parallel Transactions Wallet feature, you can perform up to 100 transactions simultaneously.

All transactions performed in parallel are assigned a “pending signature” instead of a “Queued” status.

Before Parallel Transactions Wallet a transaction looked like this, whereas now, the Parallel Transactions Wallet feature changes the transaction flow.

Failed transactions

If a single transaction fails within a sequence of submitted transactions, subsequent transactions remain pending in the mempool. For example, if 3 ETH transactions are successfully created with nonces [3, 4, 5], and transaction #4 fails, transaction #5 will remain stuck until a transaction with nonce 4 is mined. Transaction #3 will be mined independently of transaction #4.

Resolution

If a transaction fails in a sequence of chained transactions, the nonce manager detects the failure and reuses the failed transaction's nonce for the next transaction in the mempool. This requires no manual adjustments or specifying of a nonce. To resolve the stuck transaction queue, you must resubmit the failed transaction or initiate any other transaction from the relevant wallet.

Request for failing pending transactions

Transactions are selected for mining in a sequential manner. Those with a lower nonce are prioritized over those with a higher nonce. If a lower nonce transaction is stuck, all subsequent transactions become stuck as well. If the stuck transaction is replaced, its subsequent transactions can now be selected by the block producers.

If you want to cancel multiple transactions that have a higher nonce, you must issue an RBF request to all pending transactions in reverse order (higher nonce to lower nonce).

If multiple pending transactions exist in the mempool and one transaction is replaced, all subsequent transactions are then mined. When trying to cancel a transaction where all subsequent transactions are pending in the mempool, you can decide to fail the next transactions in line instead of creating a new transaction that would cause them to be executed.

You can cancel the stuck transactions using RBF. It is important to drop the stuck transactions before executing an additional transaction in order to release the entire queue.

Additional information

• The Parallel Transactions Wallet feature cannot be enabled if a wallet is using Raw Signing for transactions.
• Reach out to your CSM to enable this feature in your workspace.
• The feature entails no additional costs.
• The feature currently only supports EVM blockchains.
• The feature supports up to 100 simultaneous transactions.
• RBF behavior is not affected.