simulateTransaction

Simulate sending a transaction. This method uses 160 credits from your daily balance.

This method is useful for testing and debugging transactions before sending them to the network.

Parameters

• transaction: (string) [required] - The transaction as an encoded string. The transaction must have a valid block hash, but doesn't need to be signed.
• config: (object) [optional] - Configuration object with the following options:
  • commitment: (string) [optional] - The commitment level to use for the query. The default is finalized. Possible values are:
    • finalized - Queries the most recent block confirmed by a super majority of the cluster as having reached maximum lockout, meaning the cluster has recognized this block as finalized.
    • confirmed - Queries the most recent block that has been voted on by a super majority of the cluster.
    • processed - Queries its most recent block. The block may still be skipped by the cluster.
  • sigVerify: (boolean) [optional] - If true, verifies the signatures in the transaction. Conflicts with replaceRecentBlockhash. The default is false.
  • replaceRecentBlockhash: (boolean) [optional] - If true, replaces the recent block hash in the transaction with the latest block hash. Conflicts with sigVerify. The default is false.
  • encoding: (string) [optional] - The encoding format to use. Can be one of base58 (deprecated) or base64.
  • minContextSlot: [optional] - The minimum slot to use for the query.
  • innerInstructions: (boolean) [optional] - If true, returns the inner instructions of the transaction. The inner instructions will be jsonParsed where possible, otherwise json.
  • accounts: (object) [optional] - An object containing the following fields:
    • addresses: (array) [optional] - An array of addresses to include in the response.
    • encoding: (string) [optional] - The encoding format to use. Can be one of base58, base64, base64+zstd, or jsonParsed.

Returns

result - null if the account doesn't exist; otherwise an object with the following fields:

• context - An object containing the following keys:
  • slot - The slot number of the block that was queried.
  • apiVersion - The API version used for the query.
• value - An object with the following fields:
  • err - An error if transaction failed, null if transaction succeeded.
  • logs - An array of log messages generated by the transaction. Returns null if the simulation failed.
  • accounts -
    • data - The account data, encoded in the specified format.
    • executable - A boolean indicating whether the account is executable.
    • lamports - The number of lamports in the account.
    • owner - The public key of the program that owns the account.
    • rentEpoch - The epoch in which the account will next be due for rent.
    • space - The size of the account data in bytes.
  • unitsConsumed - The number of compute units consumed by the transaction.
  • returnData - An array of objects containing the following fields:
    • programId - The public key of the program that executed the transaction.
    • data - The account data, encoded as base64 binary data.
  • innerInstructions - An array of inner instructions.

Request

• curl

curl https://solana-testnet.infura.io/v3/<YOUR-API-KEY> \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc": "2.0", "id": 1, "method": "simulateTransaction", "params": ["AQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABAAEDArczbMia1tLmq7zz4DinMNN0pJ1JtLdqIJPUw3YrGCzYAMHBsgN27lcgB6H2WQvFgyZuJYHa46puOQo9yQ8CVQbd9uHXZaGT2cvhRs7reawctIXtX1s3kTqM9YV+/wCp20C7Wj2aiuk5TReAXo+VTVg8QTHjs0UjNMMKCvpzZ+ABAgEBARU=", {"encoding": "base64"}]}'

Response

• JSON

{
  "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
}