Simulate transaction

The output of the transaction will have the exact transaction outputs and events that running an actual signed transaction would have. However, it will not have the associated state hashes, as they are not updated in storage. This can be used to estimate the maximum gas units for a submitted transaction.

To use this, you must:

Create a SignedTransaction with a zero-padded signature.
Submit a SubmitTransactionRequest containing a UserTransactionRequest containing that signature.

To use this endpoint with BCS, you must submit a SignedTransaction encoded as BCS. See SignedTransaction in types/src/transaction/mod.rs.

POST

transactions

simulate

curl --request POST \
  --url https://aptos-mainnet.s.chainbase.online/{api-key}/v1/transactions/simulate \
  --header 'Content-Type: application/json' \
  --data '{
  "sender": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd",
  "sequence_number": "32425224034",
  "max_gas_amount": "32425224034",
  "gas_unit_price": "32425224034",
  "expiration_timestamp_secs": "32425224034",
  "payload": {
    "type": "entry_function_payload",
    "function": "0x1::aptos_coin::transfer",
    "type_arguments": [
      "<string>"
    ],
    "arguments": [
      "<any>"
    ]
  },
  "signature": {
    "type": "ed25519_signature",
    "public_key": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd",
    "signature": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd"
  }
}'

[
  {
    "version": "32425224034",
    "hash": "<string>",
    "state_change_hash": "<string>",
    "event_root_hash": "<string>",
    "state_checkpoint_hash": "<string>",
    "gas_used": "32425224034",
    "success": true,
    "vm_status": "<string>",
    "accumulator_root_hash": "<string>",
    "changes": [
      {
        "type": "delete_module",
        "address": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd",
        "state_key_hash": "<string>",
        "module": "0x1::aptos_coin"
      }
    ],
    "sender": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd",
    "sequence_number": "32425224034",
    "max_gas_amount": "32425224034",
    "gas_unit_price": "32425224034",
    "expiration_timestamp_secs": "32425224034",
    "payload": {
      "type": "entry_function_payload",
      "function": "0x1::aptos_coin::transfer",
      "type_arguments": [
        "<string>"
      ],
      "arguments": [
        "<any>"
      ]
    },
    "signature": {
      "type": "ed25519_signature",
      "public_key": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd",
      "signature": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd"
    },
    "events": [
      {
        "guid": {
          "creation_number": "32425224034",
          "account_address": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd"
        },
        "sequence_number": "32425224034",
        "type": "<string>",
        "data": "<any>"
      }
    ],
    "timestamp": "32425224034"
  }
]

Query Parameters

estimate_max_gas_amount

boolean

If set to true, the max gas value in the transaction will be ignored and the maximum possible gas will be used

estimate_gas_unit_price

boolean

If set to true, the gas unit price in the transaction will be ignored and the estimated value will be used

estimate_prioritized_gas_unit_price

boolean

If set to true, the transaction will use a higher price than the original estimate.

Body

A request to submit a transaction

This requires a transaction and a signature of it

sender

string

required

A hex encoded 32 byte Aptos account address.

This is represented in a string as a 64 character hex string, sometimes shortened by stripping leading 0s, and adding a 0x.

For example, address 0x0000000000000000000000000000000000000000000000000000000000000001 is represented as 0x1.

Example:

"0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd"

sequence_number

string

required

A string containing a 64-bit unsigned integer.

We represent u64 values as a string to ensure compatibility with languages such as JavaScript that do not parse u64s in JSON natively.

Example:

"32425224034"

max_gas_amount

string

required

A string containing a 64-bit unsigned integer.

We represent u64 values as a string to ensure compatibility with languages such as JavaScript that do not parse u64s in JSON natively.

Example:

"32425224034"

gas_unit_price

string

required

A string containing a 64-bit unsigned integer.

We represent u64 values as a string to ensure compatibility with languages such as JavaScript that do not parse u64s in JSON natively.

Example:

"32425224034"

expiration_timestamp_secs

string

required

A string containing a 64-bit unsigned integer.

We represent u64 values as a string to ensure compatibility with languages such as JavaScript that do not parse u64s in JSON natively.

Example:

"32425224034"

payload

object

required

An enum of the possible transaction payloads

payload.type

string

required

Example:

"entry_function_payload"

payload.function

string

required

Entry function id is string representation of a entry function defined on-chain.

Format: {address}::{module name}::{function name}

Both module name and function name are case-sensitive.

Example:

"0x1::aptos_coin::transfer"

payload.type_arguments

string[]

required

Type arguments of the function

String representation of an on-chain Move type tag that is exposed in transaction payload. Values: - bool - u8 - u16 - u32 - u64 - u128 - u256 - address - signer - vector: vector<{non-reference MoveTypeId}> - struct: {address}::{module_name}::{struct_name}::<{generic types}>

Vector type value examples:
  - `vector<u8>`
  - `vector<vector<u64>>`
  - `vector<0x1::coin::CoinStore<0x1::aptos_coin::AptosCoin>>`

Struct type value examples:
  - `0x1::coin::CoinStore<0x1::aptos_coin::AptosCoin>
  - `0x1::account::Account`

Note:
  1. Empty chars should be ignored when comparing 2 struct tag ids.
  2. When used in an URL path, should be encoded by url-encoding (AKA percent-encoding).

payload.arguments

any[]

required

Arguments of the function

signature

object

required

An enum representing the different transaction signatures available

Response

200

application/json

version

string

required

A string containing a 64-bit unsigned integer.

We represent u64 values as a string to ensure compatibility with languages such as JavaScript that do not parse u64s in JSON natively.

Example:

"32425224034"

hash

string

required

state_change_hash

string

required

event_root_hash

string

required

gas_used

string

required

A string containing a 64-bit unsigned integer.

We represent u64 values as a string to ensure compatibility with languages such as JavaScript that do not parse u64s in JSON natively.

Example:

"32425224034"

success

boolean

required

Whether the transaction was successful

vm_status

string

required

The VM status of the transaction, can tell useful information in a failure

accumulator_root_hash

string

required

changes

object[]

required

Final state of resources changed by the transaction

A final state change of a transaction on a resource or module

sender

string

required

A hex encoded 32 byte Aptos account address.

This is represented in a string as a 64 character hex string, sometimes shortened by stripping leading 0s, and adding a 0x.

For example, address 0x0000000000000000000000000000000000000000000000000000000000000001 is represented as 0x1.

Example:

"0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd"

sequence_number

string

required

A string containing a 64-bit unsigned integer.

We represent u64 values as a string to ensure compatibility with languages such as JavaScript that do not parse u64s in JSON natively.

Example:

"32425224034"

max_gas_amount

string

required

A string containing a 64-bit unsigned integer.

We represent u64 values as a string to ensure compatibility with languages such as JavaScript that do not parse u64s in JSON natively.

Example:

"32425224034"

gas_unit_price

string

required

A string containing a 64-bit unsigned integer.

We represent u64 values as a string to ensure compatibility with languages such as JavaScript that do not parse u64s in JSON natively.

Example:

"32425224034"

expiration_timestamp_secs

string

required

A string containing a 64-bit unsigned integer.

We represent u64 values as a string to ensure compatibility with languages such as JavaScript that do not parse u64s in JSON natively.

Example:

"32425224034"

payload

object

required

An enum of the possible transaction payloads

payload.type

string

required

Example:

"entry_function_payload"

payload.function

string

required

Entry function id is string representation of a entry function defined on-chain.

Format: {address}::{module name}::{function name}

Both module name and function name are case-sensitive.

Example:

"0x1::aptos_coin::transfer"

payload.type_arguments

string[]

required

Type arguments of the function

Vector type value examples:
  - `vector<u8>`
  - `vector<vector<u64>>`
  - `vector<0x1::coin::CoinStore<0x1::aptos_coin::AptosCoin>>`

Struct type value examples:
  - `0x1::coin::CoinStore<0x1::aptos_coin::AptosCoin>
  - `0x1::account::Account`

Note:
  1. Empty chars should be ignored when comparing 2 struct tag ids.
  2. When used in an URL path, should be encoded by url-encoding (AKA percent-encoding).

payload.arguments

any[]

required

Arguments of the function

events

object[]

required

Events generated by the transaction

An event from a transaction

events.guid

object

required

events.sequence_number

string

required

A string containing a 64-bit unsigned integer.

We represent u64 values as a string to ensure compatibility with languages such as JavaScript that do not parse u64s in JSON natively.

Example:

"32425224034"

events.type

string

required

Vector type value examples:
  - `vector<u8>`
  - `vector<vector<u64>>`
  - `vector<0x1::coin::CoinStore<0x1::aptos_coin::AptosCoin>>`

Struct type value examples:
  - `0x1::coin::CoinStore<0x1::aptos_coin::AptosCoin>
  - `0x1::account::Account`

Note:
  1. Empty chars should be ignored when comparing 2 struct tag ids.
  2. When used in an URL path, should be encoded by url-encoding (AKA percent-encoding).

events.data

any

required

The JSON representation of the event

timestamp

string

required

A string containing a 64-bit unsigned integer.

We represent u64 values as a string to ensure compatibility with languages such as JavaScript that do not parse u64s in JSON natively.

Example:

"32425224034"

state_checkpoint_hash

string

signature

object

An enum representing the different transaction signatures available

curl --request POST \
  --url https://aptos-mainnet.s.chainbase.online/{api-key}/v1/transactions/simulate \
  --header 'Content-Type: application/json' \
  --data '{
  "sender": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd",
  "sequence_number": "32425224034",
  "max_gas_amount": "32425224034",
  "gas_unit_price": "32425224034",
  "expiration_timestamp_secs": "32425224034",
  "payload": {
    "type": "entry_function_payload",
    "function": "0x1::aptos_coin::transfer",
    "type_arguments": [
      "<string>"
    ],
    "arguments": [
      "<any>"
    ]
  },
  "signature": {
    "type": "ed25519_signature",
    "public_key": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd",
    "signature": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd"
  }
}'

[
  {
    "version": "32425224034",
    "hash": "<string>",
    "state_change_hash": "<string>",
    "event_root_hash": "<string>",
    "state_checkpoint_hash": "<string>",
    "gas_used": "32425224034",
    "success": true,
    "vm_status": "<string>",
    "accumulator_root_hash": "<string>",
    "changes": [
      {
        "type": "delete_module",
        "address": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd",
        "state_key_hash": "<string>",
        "module": "0x1::aptos_coin"
      }
    ],
    "sender": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd",
    "sequence_number": "32425224034",
    "max_gas_amount": "32425224034",
    "gas_unit_price": "32425224034",
    "expiration_timestamp_secs": "32425224034",
    "payload": {
      "type": "entry_function_payload",
      "function": "0x1::aptos_coin::transfer",
      "type_arguments": [
        "<string>"
      ],
      "arguments": [
        "<any>"
      ]
    },
    "signature": {
      "type": "ed25519_signature",
      "public_key": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd",
      "signature": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd"
    },
    "events": [
      {
        "guid": {
          "creation_number": "32425224034",
          "account_address": "0xc739507214d0e1bf9795485299d709e00024e92f7c0d055a4c2c39717882bdfd"
        },
        "sequence_number": "32425224034",
        "type": "<string>",
        "data": "<any>"
      }
    ],
    "timestamp": "32425224034"
  }
]

API Reference

Web3 API

SQL API

Simulate transaction

Query Parameters

Body

Response