# TriggerConstantContract

**Body params:** 

* `owner_address` - Owner address that triggers the contract. If visible=true, use base58check format, otherwise use hex format. For constant call you can use the all-zero address.
* `contract_address` - Smart contract address. If visible=true, use base58check format, otherwise use hex format.
* `function_selector` - Function call, must not be left blank.
* `parameter` - Parameter encoding needs to be in accordance with the ABI rules, the rules are more complicated, users can use the ethers library to encode,For details, please refer to the document-Guide-Smart Contract-Best Practice-Parameter Encoding and Decoding.
* `visible` - Optional.Whehter the address is in base58 format.

**Request**

```
curl --request POST \
     --url https://tron.api.watchdata.io/wallet/triggerconstantcontract \
     --header 'Accept: application/json' \
     --header 'Content-Type: application/json' \
     --data '
{
     "owner_address": "410000000000000000000000000000000000000000",
     "contract_address": "41a614f803b6fd780986a42c78ec9c7f77e6ded13c",
     "function_selector": "balanceOf(address)",
     "parameter": "000000000000000000000000a614f803b6fd780986a42c78ec9c7f77e6ded13c",
     "visible": true
}
'
```

**Response**

```
{
  "result": {
    "code": "OTHER_ERROR",
    "message": "class java.lang.IllegalArgumentException : Illegal character 0 at 2"
  }
}
```


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