Description

Simulates the asset changes resulting from a single transaction.

Returns list of asset changes that occurred during the transaction simulation. Note that this method does not run the transaction on the blockchain.

Parameters

transaction object parameters

Response

SimulateExecutionResponse object parameters

calls array property parameters

logs array property parameters

Example Request and Response

Prerequisite: You will need to install the Alchemy SDK before making requests with it.

The commands for installing it using npm or yarn are given below:

$
npm install alchemy-sdk

Request

1
// Imports the Alchemy SDK
2
const { Alchemy, Network } = require("alchemy-sdk");
3
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// Configures the Alchemy SDK
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const config = {
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    apiKey: "alchemy-replit", // Replace with your API key
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    network: Network.ETH_MAINNET, // Replace with your network
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};
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// Creates an Alchemy object instance with the config to use for making requests
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const alchemy = new Alchemy(config);
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const main = async () => {
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    // define the transaction hash
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    const trnx = "0x88df016429689c079f3b2f6ad39fa052532c56795b733da78a91ebe6a713944b";
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    //Call the method to display the transaction based on the transaction hash
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    const response = await alchemy.transact.simulateExecution(trnx)
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    //Logging the response to the console
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    console.log(response)
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}
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main();

Response

$
{
>
  calls: [
>
    {
>
      type: 'CALL',
>
      from: '0xa7d9ddbe1f17865597fbd27ec712455208b6b76d',
>
      to: '0xf02c1c8e6114b1dbe8937a39260b5b0a374432bb',
>
      value: '0xf3dbb76162000',
>
      gas: '0x6fb0',
>
      gasUsed: '0x53a0',
>
      input: '0x68656c6c6f21',
>
      output: '0x'
>
    }
>
  ],
>
  logs: []
>
}

Use Cases

Here are some potential use cases for the simulateExecution method:

• Testing: You can use simulateExecution to test the logic of your smart contract without incurring the cost of actually executing the transaction on the blockchain.

• Gas estimation: The method can also be used to estimate the amount of gas required to execute a transaction. This can be useful in determining the appropriate gas limit to set for a transaction to ensure it is processed efficiently.

• Debugging: When you encounter errors while interacting with a smart contract, simulateExecution can help you debug the issue. By simulating the execution of the transaction, you can identify the specific line of code that is causing the error.

Related Methods

Here are the methods related to simulateExecution:

• simulateExecutionBundle: Simulates a list of transactions in sequence and returns list of decoded traces and logs that occurred for each transaction during simulation.