# Vote by smart contract

All published polls would have a clarity smart contract to capture the votes and more details on the chain.

### Public function parameters

All deployed smart contracts will have a "cast-my-vote" public function, which accepts the following parameters.

#### Vote

It is a required field. The data type is a "list of string ASCII" with a limit of 36 characters.

```
(vote (list 2 (string-ascii 36)))
```

All selected option ids should be passed here. Option ids are available in poll JSON. The Poll JSON link is attached under the information section on the published Poll screen.

#### Volume

It is a required field. The data type is a "list of unsigned integers".

```
(volume (list 2 uint))
```

A number of votes for each selected option. It should be in the same order as the above option ids.

#### BNS

It is an optional field. The data type is a "list of string ASCII" with a limit of 256 characters".

```
(bns (string-ascii 256))
```

BNS name of the voter. It is required to be passed when the poll strategy is BTC Name holders. Else you can pass an empty string ASCII.

#### Domain

It is an optional field. The data type is a "Buffer" with a limit of 20 characters".

```
(domain (buff 20))
```

The domain of the BTC name. It is required to be passed when the poll strategy is BTC Name holders. Else you can pass an empty buffer.

#### Namespace

It is an optional field. The data type is a "Buffer" with a limit of 48 characters".

```
(domain (buff 48))
```

The namespace of the BTC name. It is required to be passed when the poll strategy is BTC Name holders. Else you can pass an empty buffer.

#### Token-ids

It is an optional field. The data type is a "list of unsigned integers".

```
(token-ids (list 60000 uint))
```

All NFT token holding ids need to be passed here. It is required to be passed when the strategy token type is a Non-fungible token. Else you can pass an empty list.

#### Definition of the public function

```
;; Cast your vote
(define-public 
    (cast-my-vote 
        (vote (list 2 (string-ascii 36))) 
        (volume (list 2 uint)) 
        (bns (string-ascii 256)) 
        (domain (buff 20)) 
        (namespace (buff 48)) 
        (token-ids (list 60000 uint))
    )
    ;; Body of the function
)
```

### Call smart contract function to vote

You can use the @stacks/transaction npm package to call clarity smart contract functions. The below-attached link has more information about the smart contract function call.

<https://www.npmjs.com/package/@stacks/transactions>