Note
The Transaction Simulation feature provides estimates based on a simulation of the blockchain. Fireblocks makes no guarantees on the accuracy of any information provided.
Overview
When using decentralized applications (dApps) or directly interacting with smart contracts, you must sign a contract call. Such transactions can contain complex information that can be unclear to understand. The Transaction Simulation feature allows you to view the expected results of a contract call transaction before signing it. This can help you stay protected against phishing attempts, malicious and compromised dApps, and any unexpected results.
After initiating a contract call transaction on Fireblocks, the transaction is sent to your Fireblocks mobile app or via the Fireblocks API for approval and includes the expected events and balance changes should you choose to sign the transaction. You can tap on these estimates to view more details of the simulated transaction.
Simulated estimates appear for the following contract call operations:
- Approvals
- Wrap
- Unwrap
- Swap
- Stake
- NFT purchase
- Mint
- Burn
- Cancel order
- Borrow
Transaction simulation details
After receiving an approval request for a contract call transaction in your Fireblocks mobile app, the following transaction simulation information displays:
- The number of supported events simulated in the transaction
- The network on which the transaction will occur
- The estimated USD balance change as a result of the transaction
- Details for each event
Note
Simulated estimates display for any transaction that contains supported events. If a transaction contains unsupported events, simulated estimates will not appear for that transaction. Even if the Transaction Simulation feature is unable to provide estimates, you can still proceed with your transaction. The lack of simulated estimates, for any reason, will not affect the approval flow of your transactions.
Event types
The Transaction Simulation displays the following types of events:
- Outgoing
- Incoming
- Mint token
- Burn token
- Approval
When a single transaction includes multiple actions, such as more than one token being transferred, the actions are grouped based on whether they are outgoing or incoming.
Event details
The following information displays for any events included in the simulation:
- The event name and icon
- The asset name and asset amount
- The USD value
Event representation
Events are represented differently according to the following criteria:
- Events containing a positive amount are highlighted in green.
- Events containing a negative amount are highlighted in white.
- Approval events are highlighted in yellow.
Additional details
The Transaction Simulation feature is expandable. You can tap on the transaction simulation to see further details and all the estimates for the transaction.
The additional information is categorized into two tabs:
- Events: Shows all the actions that will take place during the transaction. The type of information shown on this tab can include:
- The type of action, such as outgoing transactions, incoming transactions, mint transactions, burn transactions, and token approvals.
- Amount of the token included in the action
- USD value of each token involved in the action
- Assets: Shows all of the assets and their amounts involved in the transaction. The type of information shown on this tab can include:
- Token name
- Token address
- Amount of the token
- USD amount of the token
Feature benefits
- Gain clarity on the output of a contract call including outgoing and incoming assets, allowances, and approvals
- Validate that your intended action is correctly reflected in the contract call
- Quickly detect unintended or malicious contract calls
Supported blockchains
Currently, the Transaction Simulation feature only estimates contract call transactions on Ethereum for ERC-20 and ERC-721 tokens.