TriggerConstantContract

Invoke the readonly function (modified by the view or pure modifier) of a contract for contract data queries; or invoke the non-readonly function of a contract to predict whether the transaction can be successfully executed and estimate the energy consumption; or estimate the energy consumption for contract deployment.
Note:

TriggerConstantContract operation will not generate an on-chain transaction, nor will it change the status of the current node.

For estimating energy:

To estimate the energy consumption of contract deployment, simply pass the bytecode of the contract through the data field.

To estimate the energy consumption of contract calls, call non-read-only methods of contracts.

When using triggerconstantcontract to estimate energy consumption, the energy_used field in the returned value indicates the energy consumption. Therefore, the fee_limit of the transaction can be set to energy_used x energy unit price.

Parameter encoding and decoding example: Parameter and return value encoding and decoding.

Returns

Field	Type	Description
owner_address	string	Account address
contract_address	string	Contract address
call_value	int64	The amount of TRX passed into the contract
data	string	Operating parameters
call_token_value	int64	The amount of TRC-10 transferred into the contract
token_id	int64	TRC-10 token id

Conclusion:

The estimated energy consumption: energy_used

The penalty energy consumption: energy_penalty

The basic energy consumption: energy_used - energy_penalty

Request

Body Params application/json

object {0}

Example

{
  "owner_address": "PHqgRM8giN6Nr9DgA1FybUjKFwd79cxhyp",
  "contract_address": "PFHUpUNpmPVTYziBWCMk7kopiTzx9mX56r",
  "function_selector": "balanceOf(address)",
  "parameter": "000000000000000000000000a614f803b6fd780986a42c78ec9c7f77e6ded13c",
  "visible": true
}

Request samples

Shell

JavaScript

Java

Swift

PHP

Python

HTTP

Objective-C

Ruby

OCaml

Dart

Responses

🟢200Success

application/json

Body

object {0}

Examples

SuccessException

{
  "result": {
    "result": true
  },
  "energy_used": 541,
  "constant_result": [
    "00000000000000000000000000000000000000000000000000000001970c956f"
  ],
  "transaction": {
    "ret": [
      {}
    ],
    "visible": true,
    "txID": "d139a8df064439dbb4b918011660db25008bf925285c86bd877ea5e51ff4d047",
    "raw_data": {
      "contract": [
        {
          "parameter": {
            "value": {
              "data": "70a08231000000000000000000000000a614f803b6fd780986a42c78ec9c7f77e6ded13c",
              "owner_address": "PHqgRM8giN6Nr9DgA1FybUjKFwd79cxhyp",
              "contract_address": "PFHUpUNpmPVTYziBWCMk7kopiTzx9mX56r"
            },
            "type_url": "type.googleapis.com/protocol.TriggerSmartContract"
          },
          "type": "TriggerSmartContract"
        }
      ],
      "ref_block_bytes": "4715",
      "ref_block_hash": "a773bc452f75199a",
      "expiration": 1737542190000,
      "timestamp": 1737542131187
    },
    "raw_data_hex": "0a0247152208a773bc452f75199a40b087d7ecc8325a8e01081f1289010a31747970652e676f6f676c65617069732e636f6d2f70726f746f636f6c2e54726967676572536d617274436f6e747261637412540a1541fd49eda0f23ff7ec1d03b52c3a45991c24cd440e12154142a1e39aefa49290f2b3f9ed688d7cecf86cd6e0222470a08231000000000000000000000000a614f803b6fd780986a42c78ec9c7f77e6ded13c70f3bbd3ecc832"
  }
}