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invokefunction Method

Invokes a smart contract with its scripthash based on the specified operation and parameters and returns the result.

  • This method is used to test your VM script as if they ran on the blockchain at that point in time. This RPC call does not affect the blockchain in any way.

  • You must install the plugin RpcServer before you can invoke the method.

Parameter Description

  • scripthash: Smart contract scripthash. You need to use the proper byte order of the address passed according to its data type. If the data type is Hash160, use the big endian scripthash; if the data type is ByteArray, use the little endian scripthash.

  • operation: The operation name (string)

  • params: Optional. The parameters to be passed into the smart contract operation

  • signers: Optional. List of contract signature accounts.

    • account: signature account

    • scopes: signature's valid scopes, allowed values are:

    • None: Only transactions are signed and no contracts are allowed to use this signature.

    • CalledByEntry: It only applies to the chain call entry. That is, if the user invokes contract A, and then contract A calls contract B, only contract A can use the signature. It is recommended as the default value for the wallet.

    • CustomContracts: Custom contract. The signature can be used in the specified contract. It can be used in conjunction with CalledByEntry.

    • CustomGroups: Custom contract groups that can be used in a specified contract group. It can be used in conjunction with CalledByEntry.

    • Global: Global. Global. The risk is extremely high because the contract may transfer all assets in the address. Only choose it when the contract is extremely trusted.

    • allowedcontracts: contracts of the signature can take effect, if scopes is CustomContracts

    • allowedgroups: pubkeys of the signature can take effect, if scopes is CustomGroups

    You need to use the proper byte order of the address passed according to its data type. If the data type is Hash160, use the big endian script hash; if the data type is ByteArray, use the little endian scripthash.

    For example:

    { 
      "type": "String", 
      "value": "Hello" 
    }
    
    { 
      "type": "Hash160", 
      "value": "0xf621168b1fce3a89c33a5f6bcf7e774b4657031c" 
    }
    
    { 
      "type": "ByteArray", 
      "value": "7472616e73666572" 
    } 
    

Example

Request body:

{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "invokefunction",
    "params": [
        "0xf61eebf573ea36593fd43aa150c055ad7906ab83",
        "transfer",
        [
            {
                "type": "Hash160",
                "value": "0x86df72a6b4ab5335d506294f9ce993722253b6e2"
            },
            {
                "type": "Hash160",
                "value": "0xebae4ab3f21765e5f604dfdd590fdf142cfb89fa"
            },
            {
                "type": "Integer",
                "value": "10000"
            },
            {
                "type": "String",
                "value": ""
            }
        ],
        [
            {
                "account": "0x86df72a6b4ab5335d506294f9ce993722253b6e2",
                "scopes": "CalledByEntry",
                "allowedcontracts": [],
                "allowedgroups": []
            }
        ]
    ]
}

Response body:

{
    "jsonrpc": "2.0",
    "id": 1,
    "result": {
        "script": "DAABECcMFPqJ+ywU3w9Z3d8E9uVlF/KzSq7rDBTitlMicpPpnE8pBtU1U6u0pnLfhhTAHwwIdHJhbnNmZXIMFIOrBnmtVcBQoTrUP1k26nP16x72QWJ9W1I=",
        "state": "HALT",
        "gasconsumed": "999972",
        "exception": null,
        "stack": [
            {
                "type": "Boolean",
                "value": true
            }
        ],
        "tx": "AI3PBQRolZgAAAAAAMrSEgAAAAAAtRcAAAHitlMicpPpnE8pBtU1U6u0pnLfhgEAWQwAARAnDBT6ifssFN8PWd3fBPblZRfys0qu6wwU4rZTInKT6ZxPKQbVNVOrtKZy34YUwB8MCHRyYW5zZmVyDBSDqwZ5rVXAUKE61D9ZNupz9ese9kFifVtSAUIMQB87UjubTE7Kb/fOe8Yu2QDUQJ6c5pL9LjcoFaNkEiJzLY5yd72jrsvVbVFNZ6ObWloAmLkjCgDXw9enkVtwVBMrEQwhAs7UMjl93ETtugMcC8O5M/KP3ZZ3eS17IObANt2qrPHiEQtBE43vrw=="
    }
}

Response description:

  • script: the invocation script of the contract. You can analysis from https://neo.org/converter:

    SYSCALL System.Contract.Call 
    PUSHDATA1 0xf61eebf573ea36593fd43aa150c055ad7906ab83 
    PUSHDATA1 transfer 
    PUSHDATA1 0x86df72a6b4ab5335d506294f9ce993722253b6e2 
    PUSHDATA1 0xebae4ab3f21765e5f604dfdd590fdf142cfb89fa 
    PUSHINT16 10000 
    PUSHDATA1 
    
  • state: HALT means the vm executed successfully, and FAULT means the vm exited due to an exception.

  • gasconsumed: the system fee consumed for invocation.

  • stack: the contract execution result. If the value is String or ByteArray, it is encoded by Base64.

  • tx: the transaction's hex string of this invocation, need open wallet and added signers correctly.