> For the complete documentation index, see [llms.txt](https://slice-ledger.gitbook.io/sliceledger/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://slice-ledger.gitbook.io/sliceledger/developer-guide/token-standards/slice-20-tokens.md).

# SLICE-20 Tokens

SLICE-20 Tokens on SliceLedger Chain

This token standard is equivalent of ERC20 built on top of the SliceLedger Chain network. Users would have to need SLICE in order to cover the transaction fees for sending SLICE-20 tokens. These tokens can be easily integrated into other dapps and get listed on cryptocurrency exchanges. 

There is a separate smart contract for creating and issuing SLICE -20 tokens for interested parties or developers where all they have to do is enter name, ticker, details and quantity of tokens to mint it within 10 minutes. 

SLICE-20 smart contract ABI: [**SRC20abi.json**](https://github.com/sliceledger-blockchain/slicetoken-abi/blob/main/SRC20abi.json)

### SLICE20 Contract Interface

```
function totalSupply() public view returns (uint);
function balanceOf(address tokenOwner) public view returns (uint balance);
function allowance(address tokenOwner, address spender) public view returns (uint remaining);
function transfer(address to, uint tokens) public returns (bool success);
function approve(address spender, uint tokens) public returns (bool success);
function transferFrom(address from, address to, uint tokens) public returns (bool success);

event Transfer(address indexed from, address indexed to, uint tokens);
event Approval(address indexed tokenOwner, address indexed spender, uint tokens);
```

**SliceLedger** Chain provides *RPC APIs* to developers for using Web3 library to call functions directly in a smart contract. Follow the steps below to interact with the smart contract by using ***Web3 Library*** and ***NodeJS***.

### Init Web3 Provider

Firstly, init Web3 provider by connecting **SliceLedger** Chain Fullnode RPC endpoint.

Check **SliceLedger *****Chain Network*** page to find details about Testnet or Mainnet network information

```
const Web3 = require('web3')
const web3 = new Web3('https://mainnet-slice-rpc.com')
const chainId = 2020
```

### Unlock Wallet

Refer ***Create new wallet*** page for creating/unlocking a new wallet.

**Example:**

```
// Unlock wallet by private key
const account = web3.eth.accounts.privateKeyToAccount(pkey)
const holder = account.address
web3.eth.accounts.wallet.add(account)
web.eth.defaultAccount = holder
```

### Init Web3 SLICE20 Contract

```
const slice20Abi = require('./SRC20abi.json')
const address = '[enter_your_contract_address]'
const slice20 = new web3.eth.Contract(slice20,
        address, {gasPrice: 250000000, gas: 2000000 })
```

### Check Balance

Use call function `balanceOf()` from SLICE20 contract to check token balance for any address.

**Example:**

```
slice20.methods.balanceOf(holder).call()
.then((result) => {
    console.log(result)
}).catch(e => console.log(e))
```

### Estimate TX Fee (gas)

To send tokens, SLICE is needed to cover the transaction fees. 

**Method:**

```
myContract.methods.myMethod([param1[, param2[, ...]]]).estimateGas(options[, callback])
```

**Example:**

```
slice20.methods.transfer(to, '500000000000000000000').estimateGas({
    from: holder
})
.then((result) => {
    console.log(result)
}).catch(e => console.log(e))
```

### Token Transfer

To transfer SLICE20 token, `transfer` function is used. 

**Example:**

```
// send 500000000000000000000 tokens to this address (e.g decimals 18)
const to = "0xdFfD678E4e06d0d56C74EBa4fef50C710c4b5291"
slice20.methods.transfer(to, '500000000000000000000').send({
    from: holder,
    gas: 2000000,
    gasPrice: 250000000,
    chainId: chainId
})
.then((result) => {
    console.log(result)
}).catch(e => console.log(e))
```