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POST
simulateTransaction
curl --request POST \
  --url 'https://mainnet.helius-rpc.com/?api-key=' \
  --header 'Content-Type: application/json' \
  --data '
{
  "jsonrpc": "2.0",
  "id": "1",
  "method": "simulateTransaction",
  "params": [
    "AQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABAAEDArczbMia1tLmq7zz4DinMNN0pJ1JtLdqIJPUw3YrGCzYAMHBsgN27lcgB6H2WQvFgyZuJYHa46puOQo9yQ8CVQbd9uHXZaGT2cvhRs7reawctIXtX1s3kTqM9YV+/wCp20C7Wj2aiuk5TReAXo+VTVg8QTHjs0UjNMMKCvpzZ+ABAgEBARU=",
    {
      "encoding": "base64"
    }
  ]
}
'
{
  "jsonrpc": "2.0",
  "id": 1,
  "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
    }
  }
}

Documentation Index

Fetch the complete documentation index at: https://www.helius.dev/docs/llms.txt

Use this file to discover all available pages before exploring further.

​
Request Parameters

​
transaction
string
required
The signed transaction, as an encoded string (base58 or base64).
​
encoding
string
Encoding used for the transaction data.
  • base58
  • base64
​
skipPreflight
boolean
Skip the preflight transaction checks.
​
preflightCommitment
string
Commitment level to use for preflight.
  • confirmed
  • finalized
  • processed
​
sigVerify
boolean
If true, verify the transaction signatures.
​
replaceRecentBlockhash
boolean
If true, replace the transaction recent blockhash with the most recent one.
​
minContextSlot
number
Minimum slot at which to perform preflight transaction checks.
​
innerInstructions
boolean
If true, include inner instructions in the response.
​
accounts
object
​
accounts.addresses
array
Array of accounts to return, as base-58 encoded strings.
​
accounts.encoding
string
Encoding format for returned account data.
  • base64
  • base58
  • base64+zstd
  • jsonParsed

Authorizations

​
api-key
string
query
required

Your Helius API key. You can get one for free in the dashboard.

Body

application/json
​
jsonrpc
enum<string>
default:2.0

The JSON-RPC protocol version.

Available options:
2.0
Example:

"2.0"

​
id
string
default:1

A unique identifier for the request.

Example:

"1"

​
method
enum<string>
default:simulateTransaction

The name of the RPC method to invoke.

Available options:
simulateTransaction
Example:

"simulateTransaction"

​
params
(string | object)[]

Parameters for simulating a transaction.

The signed transaction, as an encoded string (base58 or base64).

Example:

"AQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABAAEDArczbMia1tLmq7zz4DinMNN0pJ1JtLdqIJPUw3YrGCzYAMHBsgN27lcgB6H2WQvFgyZuJYHa46puOQo9yQ8CVQbd9uHXZaGT2cvhRs7reawctIXtX1s3kTqM9YV+/wCp20C7Wj2aiuk5TReAXo+VTVg8QTHjs0UjNMMKCvpzZ+ABAgEBARU="

Response

Successfully simulated the transaction.

​
jsonrpc
enum<string>

The JSON-RPC protocol version.

Available options:
2.0
Example:

"2.0"

​
id
string

Identifier matching the request.

Example:

"1"

​
result
object

Result of the simulated transaction.