simulateTransaction

Simulate sending a transaction.

This method will use 30 Compute Units.

---

Parameters

• transaction string The transaction as an encoded string. The transaction must have a valid blockhash, but is not required to be signed.

• object optional. Configuration object containing the following fields:

  • commitment string. The level of commitment required for the query. The options include:

    • finalized string. The node will query the most recent block confirmed by the supermajority of the cluster as having reached maximum lockout, meaning the cluster has recognized this block as finalized.

    • confirmed string. The node will query the most recent block that has been voted on by the supermajority of the cluster.

    • processed string. The node will query its most recent block. Note that the block may not be complete.

  • sigVerify boolean (default: false) If true, the transaction signatures will be verified (conflicts with replaceRecentBlockhash).

  • replaceRecentBlockhash boolean (default: false) If true, the transaction recent blockhash will be replaced with the most recent blockhash (conflicts with sigVerify).

  • encoding string (default: base58) The encoding format for account data. It can be either base58 (slow, DEPRECATED) or base64.

  • minContextSlot integer. The minimum slot at which the request can be evaluated.

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

  • accounts object The accounts configuration object containing the following fields:

    • addresses string An array of accounts to return, as base-58 encoded strings

    • encoding string The encoding format for account data. It can be one of base58 (slow), base64, base64+zstd or jsonParsed.

Returns

result Null if the account doesn't exist otherwise RpcResponse JSON object with the following fields:

• context An object that contains metadata about the current state of the Solana network at the time the request was processed.

  • apiVersion The version number.

  • slot The current slot in the Solana cluster during which the transactions are processed and new blocks are added to the blockchain.

• err Error code if the transaction failed or null if the transaction succeeds.

• logs An array of log messages the transaction instructions output during execution, null if simulation failed before the transaction was able to execute (for example due to an invalid blockhash or signature verification failure).

• accounts An array of accounts with the same length as the accounts.addresses array in the request

  • null If the account doesn't exist or if err is not null.

  • object otherwise, a JSON object containing:

    • lamports The number of lamports assigned to this account as u64 (64-bit unsigned integer).

    • owner The base-58 encoded Pubkey of the program this account has been assigned to.

    • data The data associated with the account, either as encoded binary data or JSON format {'program': 'state'}, depending on encoding parameter.

    • executable A boolean indicating if the account contains a program (and is strictly read-only).

    • rentEpoch The epoch at which this account will next owe rent, as u64 (64-bit unsigned integer).

• unitsConsumed The number of compute budget units consumed during the processing of this transaction.

• returnData The most-recent return data generated by an instruction in the transaction, with the following fields:

  • programId string The program that generated the return data, as base-58 encoded Pubkey.

  • data The return data itself, as base-64 encoded binary data.

• innerInstructions The value is a list of inner instructions.

// Result
{
  "jsonrpc": "2.0",
  "result": {
    "context": {
      "slot": 218
    },
    "value": {
      "err": null,
      "accounts": null,
      "logs": [
        "Program 83astBRguLMdt2h5U1Tpdq5tjFoJ6noeGwaY3mDLVcri invoke [1]",
        "Program 83astBRguLMdt2h5U1Tpdq5tjFoJ6noeGwaY3mDLVcri consumed 2366 of 1400000 compute units",
        "Program return: 83astBRguLMdt2h5U1Tpdq5tjFoJ6noeGwaY3mDLVcri KgAAAAAAAAA=",
        "Program 83astBRguLMdt2h5U1Tpdq5tjFoJ6noeGwaY3mDLVcri success"
      ],
      "returnData": {
        "data": ["Kg==", "base64"],
        "programId": "83astBRguLMdt2h5U1Tpdq5tjFoJ6noeGwaY3mDLVcri"
      },
      "unitsConsumed": 2366
    }
  },
  "id": 1
}

mainnet

curl https://mainnet.solana.validationcloud.io/v1/<YOUR_API_KEY_HERE> \
    -X POST \
    -H "Content-Type: application/json" \
    -d '{"method":"simulateTransaction","params":["ENTER_ENCODED_TRANSACTION_ID"],"id":1,"jsonrpc":"2.0"}'
    

devnet

curl https://devnet.solana.validationcloud.io/v1/<YOUR_API_KEY_HERE> \
    -X POST \
    -H "Content-Type: application/json" \
    -d '{"method":"simulateTransaction","params":["ENTER_ENCODED_TRANSACTION_ID"],"id":1,"jsonrpc":"2.0"}'