Solana Documentation Solana RPC Methods HTTP Methods

simulateTransaction RPC Method

Simulates a signed transaction using the chain data available at the requested commitment, without broadcasting it.

Source

simulate_transaction

params

stringrequired

Transaction, as an encoded string.

The transaction must include a recent blockhash unless replaceRecentBlockhash is true, in which case Agave replaces it before simulation. The transaction is not required to be signed unless sigVerify is true.

objectoptional

Configuration object containing the following fields:

result

object

RpcResponse object containing:

$ curl https://api.devnet.solana.com -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
>       }
>     ]
>   }
> '

Response

{
  "jsonrpc": "2.0",
  "result": {
    "context": {
      "apiVersion": "3.1.8",
      "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,
      "fee": 5000,
      "preBalances": [],
      "postBalances": [],
      "preTokenBalances": [],
      "postTokenBalances": [],
      "loadedAddresses": {
        "readonly": [],
        "writable": []
      }
    }
  },
  "id": 1
}

$ curl https://api.devnet.solana.com -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
>       }
>     ]
>   }
> '

params

stringrequired

Transaction, as an encoded string.

The transaction must include a recent blockhash unless replaceRecentBlockhash is true, in which case Agave replaces it before simulation. The transaction is not required to be signed unless sigVerify is true.

objectoptional

Configuration object containing the following fields:

result

Response

{
  "jsonrpc": "2.0",
  "result": {
    "context": {
      "apiVersion": "3.1.8",
      "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,
      "fee": 5000,
      "preBalances": [],
      "postBalances": [],
      "preTokenBalances": [],
      "postTokenBalances": [],
      "loadedAddresses": {
        "readonly": [],
        "writable": []
      }
    }
  },
  "id": 1
}

object

RpcResponse object containing:

Example Result

The JsonParsed example shows the simulation result for a transaction that creates an associated token account.
The Json example shows the simulation result for a transaction with a CPI (innerInstructions) that can't be parsed.

{
  "jsonrpc": "2.0",
  "result": {
    "context": {
      "apiVersion": "3.1.8",
      "slot": 1282
    },
    "value": {
      "accounts": null,
      "err": null,
      "fee": 5000,
      "innerInstructions": [
        {
          "index": 0,
          "instructions": [
            {
              "parsed": {
                "info": {
                  "extensionTypes": [
                    "immutableOwner"
                  ],
                  "mint": "AH2uKiJxRXuQbUZQpCoyeujLLKNHvUATXxBVEBWMof92"
                },
                "type": "getAccountDataSize"
              },
              "program": "spl-token",
              "programId": "TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA",
              "stackHeight": 2
            },
            {
              "parsed": {
                "info": {
                  "lamports": 2039280,
                  "newAccount": "Bgig53phxYuoiB2mveeBYGs9WpQPoUCJfDBGwpgWnkP",
                  "owner": "TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA",
                  "source": "23g1K6sr2bevNwLYPoB79jzEQtErioYQ8mpUa76xA6yu",
                  "space": 165
                },
                "type": "createAccount"
              },
              "program": "system",
              "programId": "11111111111111111111111111111111",
              "stackHeight": 2
            },
            {
              "parsed": {
                "info": {
                  "account": "Bgig53phxYuoiB2mveeBYGs9WpQPoUCJfDBGwpgWnkP"
                },
                "type": "initializeImmutableOwner"
              },
              "program": "spl-token",
              "programId": "TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA",
              "stackHeight": 2
            },
            {
              "parsed": {
                "info": {
                  "account": "Bgig53phxYuoiB2mveeBYGs9WpQPoUCJfDBGwpgWnkP",
                  "mint": "AH2uKiJxRXuQbUZQpCoyeujLLKNHvUATXxBVEBWMof92",
                  "owner": "23g1K6sr2bevNwLYPoB79jzEQtErioYQ8mpUa76xA6yu"
                },
                "type": "initializeAccount3"
              },
              "program": "spl-token",
              "programId": "TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA",
              "stackHeight": 2
            }
          ]
        }
      ],
      "loadedAccountsDataSize": 238800,
      "loadedAddresses": {
        "readonly": [],
        "writable": []
      },
      "logs": [
        "Program ATokenGPvbdGVxr1b2hvZbsiqW5xWH25efTNsLJA8knL invoke [1]",
        "Program log: Create",
        "Program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA invoke [2]",
        "Program log: Instruction: GetAccountDataSize",
        "Program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA consumed 1595 of 193103 compute units",
        "Program return: TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA pQAAAAAAAAA=",
        "Program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA success",
        "Program 11111111111111111111111111111111 invoke [2]",
        "Program 11111111111111111111111111111111 success",
        "Program log: Initialize the associated token account",
        "Program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA invoke [2]",
        "Program log: Instruction: InitializeImmutableOwner",
        "Program log: Please upgrade to SPL Token 2022 for immutable owner support",
        "Program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA consumed 1405 of 186490 compute units",
        "Program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA success",
        "Program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA invoke [2]",
        "Program log: Instruction: InitializeAccount3",
        "Program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA consumed 4214 of 182608 compute units",
        "Program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA success",
        "Program ATokenGPvbdGVxr1b2hvZbsiqW5xWH25efTNsLJA8knL consumed 21889 of 200000 compute units",
        "Program ATokenGPvbdGVxr1b2hvZbsiqW5xWH25efTNsLJA8knL success"
      ],
      "postBalances": [
        996484120,
        2039280,
        1,
        1461600,
        731913600,
        929020800
      ],
      "postTokenBalances": [
        {
          "accountIndex": 1,
          "mint": "AH2uKiJxRXuQbUZQpCoyeujLLKNHvUATXxBVEBWMof92",
          "owner": "23g1K6sr2bevNwLYPoB79jzEQtErioYQ8mpUa76xA6yu",
          "programId": "TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA",
          "uiTokenAmount": {
            "amount": "0",
            "decimals": 2,
            "uiAmount": 0.0,
            "uiAmountString": "0"
          }
        }
      ],
      "preBalances": [
        998528400,
        0,
        1,
        1461600,
        731913600,
        929020800
      ],
      "preTokenBalances": [],
      "replacementBlockhash": {
        "blockhash": "3ojhhRUVJAfsFhaJ3ka7cmwmAHQizYWvDtykiSVVnnET",
        "lastValidBlockHeight": 1432
      },
      "returnData": null,
      "unitsConsumed": 21889
    }
  },
  "id": 1
}

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simulateTransaction RPC Method | Solana