# invoke

Invoke allows for the generic execution of smart contracts on behalf of the user. It is reccommended to have a general understanding of the NEO blockchain, and to be able successfully use all other commands listed previously in this document before attempting a generic contract execution.

## **Input Arguments**

<table><thead><tr><th width="366">Parameter</th><th>Description</th></tr></thead><tbody><tr><td><code>scriptHash: string</code></td><td>Script hash of the smart contract to invoke</td></tr><tr><td><code>operation: string</code></td><td>Operation on the smart contract to call</td></tr><tr><td><code>args:</code> <a href="#argument"><img src="http://localhost:8080/assets/images/info.svg" alt="i"></a><code>Argument[]</code></td><td>Any input arguments for the operation</td></tr><tr><td><code>fee?: string</code></td><td>The parsed amount of network fee (in GAS) to include with transaction</td></tr><tr><td><code>network?: string</code></td><td>Network to submit this request to. If omitted, will default to network the wallet is currently set to</td></tr><tr><td><code>attachedAssets?:</code> <a href="#attachedassets"><img src="http://localhost:8080/assets/images/info.svg" alt="i"></a><code>AttachedAssets</code></td><td>Describes the assets to attach with the smart contract, e.g. attaching assets to mint tokens during a token sale</td></tr><tr><td><code>assetIntentOverrides?:</code> <a href="#assetintentoverrides"><img src="http://localhost:8080/assets/images/info.svg" alt="i"></a><code>AssetIntentOverrides</code></td><td><p>A hard override of all transaction utxo inputs and outputs.</p><p>IMPORTANT: If provided, fee and attachedAssets will be ignored.</p></td></tr><tr><td><code>triggerContractVerification?: boolean</code></td><td>Adds the instruction to invoke the contract verification trigger</td></tr><tr><td><code>broadcastOverride?: boolean</code></td><td>In the case that the dApp would like to be responsible for broadcasting the signed transaction rather than the wallet provider</td></tr><tr><td><code>txHashAttributes?:</code> <a href="#txhashattribute"><img src="http://localhost:8080/assets/images/info.svg" alt="i"></a><code>TxHashAttribute[]</code></td><td>Adds transaction attributes for the "Hash" usage block</td></tr></tbody></table>

### Argument

<table><thead><tr><th width="390">Parameter</th><th>Description</th></tr></thead><tbody><tr><td><code>type: 'String' | 'Boolean' | 'Hash160' | 'Hash256' | 'Integer' | 'ByteArray' | 'Array' | 'Address'</code></td><td>The type of the argument with you are using</td></tr><tr><td><code>value: any</code></td><td>String representation of the argument which you are using</td></tr></tbody></table>

### TxHashAttribute

| Parameter                                                                                                                                                                              | Description                                               |
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------- |
| `type: 'String' \| 'Boolean' \| 'Hash160' \| 'Hash256' \| 'Integer' \| 'ByteArray' \| 'Array' \| 'Address'`                                                                            | The type of the argument with you are using               |
| `value: any`                                                                                                                                                                           | String representation of the argument which you are using |
| `txAttrUsage: 'Hash1' \| 'Hash2' \| 'Hash3' \| 'Hash4' \| 'Hash5' \| 'Hash6' \| 'Hash7' \| 'Hash8' \| 'Hash9' \| 'Hash10' \| 'Hash11' \| 'Hash12' \| 'Hash13' \| 'Hash14' \| 'Hash15'` | Attribute usage value                                     |

### AttachedAssets

<table><thead><tr><th width="267">Parameter</th><th>Description</th></tr></thead><tbody><tr><td><code>NEO?: string</code></td><td>The amount of NEO to attach to the contract invocation</td></tr><tr><td><code>GAS?: string</code></td><td>The amount of GAS to attach to the contract invocation</td></tr></tbody></table>

### AssetIntentOverrides

<table><thead><tr><th width="328">Parameter</th><th>Description</th></tr></thead><tbody><tr><td><code>inputs:</code> <a href="#assetinput"><img src="http://localhost:8080/assets/images/info.svg" alt="i"></a><code>AssetInput[]</code></td><td>A list of UTXO inputs to use for this transaction</td></tr><tr><td><code>outputs:</code> <a href="#assetoutput"><img src="http://localhost:8080/assets/images/info.svg" alt="i"></a><code>AssetOutput[]</code></td><td>A list of UTXO outputs to use for this transaction</td></tr></tbody></table>

### AssetInput

<table><thead><tr><th width="230">Parameter</th><th>Description</th></tr></thead><tbody><tr><td><code>txid: string</code></td><td>Transaction id to be used as input</td></tr><tr><td><code>index: number</code></td><td>Index of the UTXO, can be found from transaction details</td></tr></tbody></table>

### AssetOutput

<table><thead><tr><th width="258">Parameter</th><th>Description</th></tr></thead><tbody><tr><td><code>asset: string</code></td><td>Asset of the UTXO</td></tr><tr><td><code>address: string</code></td><td>Address to receive the UTXO</td></tr><tr><td><code>value: string</code></td><td>String representation of double or integer value to be used as output</td></tr></tbody></table>

## **Success Response**

In the case where the "broadcastOverride" input argument is not set, or set to false.

<table><thead><tr><th width="275">Parameter</th><th>Description</th></tr></thead><tbody><tr><td><code>txid: string</code></td><td>The transaction ID of the invocation</td></tr><tr><td><code>nodeURL: string</code></td><td>The node which the transaction was broadcast to. Returned if transaction is broadcast by wallet provider</td></tr></tbody></table>

In the case where the "broadcastOverride" input argument is set to True.

<table><thead><tr><th width="256">Parameter</th><th>Description</th></tr></thead><tbody><tr><td><code>txid: string</code></td><td>The transaction ID of the invocation</td></tr><tr><td><code>signedTx: string</code></td><td>The serialized signed transaction. Only returned if the broadcastOverride input argument was set to True</td></tr></tbody></table>

## **Error Response**

<table><thead><tr><th width="289">Parameter</th><th>Description</th></tr></thead><tbody><tr><td><code>type: string</code></td><td>The type of error which has occured</td></tr><tr><td><code>description: string</code></td><td>A description of the error which has occured</td></tr><tr><td><code>data: string</code></td><td>Any raw data associated with the error</td></tr></tbody></table>

## Example

### Request

```js
neoline.invoke({
  scriptHash: 'af7c7328eee5a275a3bcaee2bf0cf662b5e739be',
  operation: 'balanceOf',
  args: [
    {
      type: 'Hash160',
      value: '91b83e96f2a7c4fdf0c1688441ec61986c7cae26'
    }
  ],
  attachedAssets: {
    NEO: '1',
    GAS: '0.0001'
  },
  fee: '0.001',
  network: 'TestNet',
  broadcastOverride: false,
  txHashAttributes: [
    {
      type: 'Boolean',
      value: true,
      txAttrUsage: 'Hash1'
    }
  ]
})
.then(result => {
  console.log('Invoke transaction success!');
  console.log('Transaction ID: ' + result.txid);
  console.log('RPC node URL: ' + result.nodeURL);
})
.catch((error) => {
  const {type, description, data} = error;
  switch(type) {
    case 'NO_PROVIDER':
        console.log('No provider available.');
        break;
    case 'RPC_ERROR':
        console.log('There was an error when broadcasting this transaction to the network.');
        break;
    case 'CANCELED':
        console.log('The user has canceled this transaction.');
        break;
    default:
        // Not an expected error object.  Just write the error to the console.
        console.error(error);
        break;
  }
});
```

### Response

```js
{
  txid: 'd08c5f58675376832480f2959732caa2a0e024ad0304ed77c62146a9621124d6',
  nodeUrl: 'https://testnet.api.neoline.io'
};
```