Issue

If a transaction status is Confirming or Broadcasting for a long time, it likely means that you have not entered a high enough fee.

Ethereum and EVM-based blockchain transaction fees vary depending on network activity. Spikes in transaction fees (gas price) can cause transactions with low transaction fees to get stuck in the mempool with 0 confirmations. These are transactions that have yet to be incorporated into the blockchain.

Miners incorporate transactions based on the fee or gas price paid with the transaction. Transactions with higher fees are prioritized over transactions with lower fees. Ethereum and EVM-based networks require transactions originating from the same account to be confirmed in sequential order. Therefore, a stuck transaction will prevent later transactions from being processed.

Resolution

EVM blockchains support replacing a pending transaction in the mempool with a higher-fee transaction to confirm the initial transaction more quickly. The replacement transaction fee must meet specific requirements to be incorporated into the blockchain.

Replace-by-Fee (RBF) is a mechanism that allows users to boost or drop a transaction or contract call on Ethereum and other EVM-based networks.

Prerequisites

Who can initiate RBF transactions?

If your workspace policy requires that the transaction's initiator must be the signer, only users with signing permissions can initiate RBF transactions. Users without signing permissions (for example, Editors or Non-Signing Admins) cannot initiate RBF transactions. The replacement transaction follows your normal approval and signing workflow.

Boost transaction

Boost transaction uses RBF to raise the priority of the original transaction.

1. In the Fireblocks Console, open the Recent activity panel.
2. Find the stuck transaction, then select Boost . The Replace by Fee dialog opens with the transaction's details already entered and the fast fee pre-selected.
3. Confirm or enter a new fee to replace the previous fee. Note that the new fee must be at least 15% greater than the original fee.
4. Select Create transfer. The new transaction requires approval and signing in accordance with your workspace's policies.

Drop transaction

Drop transaction uses RBF to replace the original transaction with a new transaction of 0 value, and a destination identical to the source, effectively canceling the transfer.

1. In the Fireblocks Console, open the Recent activity panel.
2. Find the stuck transaction, then select Drop .
3. On the Drop Transaction dialog, confirm the higher fee and select Drop Transaction. The new transaction requires approval and signing in accordance with your workspace's policies.

All other queued transactions from the same source vault account will continue processing. Learn more about queued transactions.

After you drop the transaction, you can create a new transfer with the current gas price.

How does this work?

You can use the Replace by Fee (RBF) mechanism to boost and drop transactions due to a sequence nonce associated with every Ethereum account. The sequence nonce for an Ethereum account represents the number of transactions initiated by an Ethereum account. 

When you use RBF to boost or drop a stuck transaction, Fireblocks replaces the stuck transaction by submitting another transaction with the same nonce as the original transaction.

• Boost: Replaces a failed transaction by initiating another similar transaction with the same nonce, destination, and amount, but with a higher fee. After the new transaction is selected and mined, the original transaction becomes obsolete.
• Drop: Replace the original transaction with a new ETH transaction with “0” as the amount. It has the same nonce as the original transaction and invalidates the original transaction.

An EVM-based transaction completed on the blockchain, but is stuck or not displayed as complete in your Fireblocks Console

Check how many confirmations the transaction has on a blockchain explorer and compare it with your confirmation policy.

If you can not resolve this issue, contact Fireblocks Support.