APIBundlerUserOp Simulation Endpoints

alchemy_simulateUserOperationAssetChanges

Simulates userOperations and returns a list of asset changes.

Changes in blockchain's state could lead to different outcomes

The results provided by this method are based on the blockchain’s state at the moment of simulation. Changes in the blockchain state, such as updates to contract variables or balances, can occur between the time of simulation and userOperation execution.

This could lead to different outcomes than predicted. For instance, if a userOperation’s effect is conditional on the current state of a contract, and this state is altered before the transaction is executed, the final result may not match the simulation.

Please conside this potential variance when using the API.

Path parameters

apiKeystringRequired

Request

This endpoint expects an object.
UserOperationobjectRequired

userOperation to simulate. The signature can be a dummy value; it doesn’t need to be valid.

entryPointstringRequiredformat: "^0x[0-9a-fA-F]{40}$"

EntryPoint to use for the simulation. This MUST be one of the EntryPoints returned by the supportedEntryPoints RPC call.

blockNumberstringOptionalformat: "^0x([1-9a-f]+[0-9a-f]*|0)$"
Optional block number in context of which the simulation should be executed. If not specified, the current block number is used.

Response

Object containing simulated asset changes and any potential errors.
changeslist of objects or null
errorobject or null