simulateTransaction

All the specifications for simulateTransaction RPC Method on Solana

Simulate sending a transaction.

Parameters required for this RPC call

• Transaction, as an encoded string.

• The amount of lamports to airdrop

• configuration object: This contains the following parameters. All optional.

  • encoding: Encoding used for the transaction data. Values: base58 (slow, DEPRECATED), or base64.

  • commitment: Commitment level to simulate the transaction at. See Configuring State Commitment. Default finalized.

  • replaceRecentBlockhash: If true the transaction recent blockhash will be replaced with the most recent blockhash (conflicts with sigVerify)

  • sigVerify: If true the transaction signatures will be verified (conflicts with replaceRecentBlockhash)

  • innerInstructions: If true the response will include inner instructions. These inner instructions will be jsonParsed where possible, otherwise json.

  • accounts: If true the response will include inner instructions. These inner instructions will be jsonParsed where possible, otherwise json.

  • minContextSlot: Set the minimum slot at which to perform preflight transaction checks.

cURL

curl https://rpc.shyft.to?api_key=YOUR-API-KEY -s -X \
  POST -H "Content-Type: application/json" -d ' 
   {
     "jsonrpc": "2.0",
     "id": 1,
     "method": "simulateTransaction",
     "params": [
       "AQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABAAEEjNmKiZGiOtSZ+g0//wH5kEQo3+UzictY+KlLV8hjXcs44M/Xnr+1SlZsqS6cFMQc46yj9PIsxqkycxJmXT+veJjIvefX4nhY9rY+B5qreeqTHu4mG6Xtxr5udn4MN8PnBt324e51j94YQl285GzN2rYa/E2DuQ0n/r35KNihi/zamQ6EeyeeVDvPVgUO2W3Lgt9hT+CfyqHvIa11egFPCgEDAwIBAAkDZAAAAAAAAAA=",
       {
         "commitment": "confirmed",
         "encoding": "base64",
         "replaceRecentBlockhash": true
       }
     ]
   }
 '

Web3.js

import {
  Connection,
  VersionedTransaction,
  clusterApiUrl,
  type SimulateTransactionConfig,
} from "@solana/web3.js";

const connection = new Connection("https://rpc.shyft.to?api_key=YOUR-API-KEY", "confirmed");

const base64Tx =
  "AQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABAAEEjNmKiZGiOtSZ+g0//wH5kEQo3+UzictY+KlLV8hjXcs44M/Xnr+1SlZsqS6cFMQc46yj9PIsxqkycxJmXT+veJjIvefX4nhY9rY+B5qreeqTHu4mG6Xtxr5udn4MN8PnBt324e51j94YQl285GzN2rYa/E2DuQ0n/r35KNihi/zamQ6EeyeeVDvPVgUO2W3Lgt9hT+CfyqHvIa11egFPCgEDAwIBAAkDZAAAAAAAAAA=";

let tx = VersionedTransaction.deserialize(Buffer.from(base64Tx, "base64"));

let simulateTxConfig: SimulateTransactionConfig = {
  commitment: "finalized",
  replaceRecentBlockhash: true,
  sigVerify: false,
  minContextSlot: undefined,
  innerInstructions: undefined,
  accounts: undefined,
};

let simulateResult = await connection.simulateTransaction(tx, simulateTxConfig);

console.log(simulateResult);

Response

{
  "jsonrpc": "2.0",
  "result": {
    "context": {
      "apiVersion": "2.3.3",
      "slot": 393226680
    },
    "value": {
      "accounts": null,
      "err": null,
      "innerInstructions": null,
      "loadedAccountsDataSize": 413,
      "logs": [
        "Program TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb invoke [1]",
        "Program log: Instruction: Transfer",
        "Program TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb consumed 1714 of 200000 compute units",
        "Program TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb success"
      ],
      "replacementBlockhash": {
        "blockhash": "6oFLsE7kmgJx9PjR4R63VRNtpAVJ648gCTr3nq5Hihit",
        "lastValidBlockHeight": 381186895
      },
      "returnData": null,
      "unitsConsumed": 1714
    }
  },
  "id": 1
}