# OKB X Layer

Source: https://developers.bitgo.com/docs/okbxlayer

## Overview

OKB X Layer is a Layer 2 scaling solution built on top of the Ethereum blockchain. The Polygon CDK (Chain Development Kit) powers it, and it uses ZK-rollup technology to deliver fast, low-cost transactions while inheriting Ethereum's security. OKB X Layer uses OKB as its native gas token. The X Layer Sepolia testnet uses chain ID `195`. It utilizes:

- Account model
- EcDSA signature algorithm

OKB X Layer supports both legacy and TSS (Threshold Signature Scheme) transfers.

## Explorer

<a href="https://www.oklink.com/xlayer" target="_blank" rel="noreferrer">https://www.oklink.com/xlayer</a>

## Wallets Types

BitGo enables holding OKB X Layer in the following wallet types:

|                  | Multisig Cold | Multisig Hot | MPC Cold | MPC Hot |
| ---------------- | ------------- | ------------ | -------- | ------- |
| **Custody**      | ❌            | ❌           | ✅       | ✅      |
| **Self-Custody** | ❌            | ❌           | ✅       | ✅      |

## Ticker Symbols

| Mainnet    | Testnet     |
| ---------- | ----------- |
| okbxlayer  | tokbxlayer  |

## Faucet

You can use a faucet to obtain free testnet OKB X Layer for development and testing purposes.

**Faucet:** <a href="https://www.okx.com/xlayer/faucet" target="_blank" rel="noreferrer">https://www.okx.com/xlayer/faucet</a>

## Units

Each OKB X Layer consists of `1,000,000,000,000,000,000` (<code>10<sup>18</sup></code>) wei, so not even a single OKB X Layer can be stored numerically without exceeding the range of JavaScript numbers. Gas fees use gwei.

- 1 OKB X Layer = <code>10<sup>18</sup></code> wei
- 1 wei = <code>10<sup>-18</sup></code> OKB X Layer
- 1 gwei = <code>10<sup>-9</sup></code> OKB X Layer

For that reason, only string balance properties are available, which are `balanceString`, `confirmedBalanceString`, and
`spendableBalanceString`.

## Tokens

The OKB X Layer blockchain natively supports tokens. To view all BitGo supported tokens on the OKB X Layer Mainnet, see the [OKB X Layer - ERC20 Tokens](/docs/okbxlayer-erc20-tokens).

## Fees

OKB X Layer supports both legacy (`eth_gasPrice`) and `EIP-1559` (`eth_feeHistory`) gas estimation. OKB X Layer uses OKB as the gas token for transaction fees.

OKB X Layer gas costs are typically very low. The base fee is the minimum price per unit of gas that a transaction must pay to be included in a block. Transactions must specify a maximum base fee higher than the block base fee to be included. The actual fee charged is the block base fee, even if the transaction specifies a higher maximum base fee.

The sequencer prioritizes transactions on a first-come first-served basis. Because priority fees do not make sense in this model, the sequencer ignores them. OKB X Layer users always just pay the base fee regardless of the tip they choose.

## Create Wallet

```shell cURL
export BITGO_EXPRESS_HOST="<YOUR_LOCALHOST>"
export COIN="tokbxlayer"
export ACCESS_TOKEN="<YOUR_ACCESS_TOKEN>"
export LABEL="<DESIRED_WALLET_NAME>"
export PASSPHRASE="<YOUR_BITGO_LOGIN_PASSPHRASE>"
export ENTERPRISE_ID="<YOUR_ENTERPRISE_ID>"

curl -X POST \
 http://$BITGO_EXPRESS_HOST/api/v2/$COIN/wallet/generate \
 -H 'Content-Type: application/json' \
 -H "Authorization: Bearer $ACCESS_TOKEN" \
  -d '{
    "label": "'"$LABEL"'",
    "passphrase": "'"$PASSPHRASE"'",
    "enterprise": "'"$ENTERPRISE_ID"'",
    "walletVersion": 4
}'
```
```js JavaScript
bitgo
  .coin('tokbxlayer')
  .wallets()
  .generateWallet({
    label: '<DESIRED_WALLET_NAME>',
    passphrase: '<YOUR_BITGO_LOGIN_PASSWORD>',
    enterprise: '<YOUR_ENTERPRISE_ID>',
    walletVersion: 4,
  })
  .then(function (wallet) {
    // print the new wallet
    console.dir(wallet);
  });
```

## Create Address

```shell cURL
export WALLET="585c51a5df8380e0e3082e46"
export ACCESS_TOKEN="<YOUR_ACCESS_TOKEN>"

curl -X POST \
-H "Authorization: Bearer $ACCESS_TOKEN" \
https://app.bitgo-test.com/api/v2/tokbxlayer/wallet/$WALLET/address

```
```js JavaScript
bitgo
  .coin('tokbxlayer')
  .wallets()
  .getWallet({ id: '585c51a5df8380e0e3082e46' })
  .then(function (wallet) {
    return wallet.createAddress();
  })
  .then(function (newAddress) {
    // print new address details
    console.dir(newAddress);
  });
```

## Consolidate Balance

Consolidation Fee Source: OKB X Layer Gas Tank

OKB X Layer uses forwarders, so it does not support manual consolidation.

## Estimate Fee

```shell cURL
export COIN="tokbxlayer"
export ACCESS_TOKEN="<YOUR_ACCESS_TOKEN>"

curl -X GET \
 https://app.bitgo-test.com/api/v2/$COIN/tx/fee \
 -H 'Content-Type: application/json' \
 -H "Authorization: Bearer $ACCESS_TOKEN"

```
```js JavaScript
const BitGoJS = require('../../../src/index.js');
const bitgo = new BitGoJS.BitGo({ env: 'test' });
const accessToken = '<YOUR_ACCESS_TOKEN>';
const coin = 'tokbxlayer';

async function getFeeEstimate() {
  try {
    await bitgo.authenticateWithAccessToken({ accessToken });
    const res = await bitgo.coin(coin).feeEstimate({ numBlocks: 2 });
    console.dir(res);
  } catch (err) {
    console.error('Error fetching fee estimate:', err);
  }
}

getFeeEstimate();

```

## Transact

Withdrawal Fee Source: Wallet Base Address

```shell cURL
export BITGO_EXPRESS_HOST="<YOUR_LOCALHOST>"
export COIN="tokbxlayer"
export WALLET_ID="<YOUR_WALLET_ID>"
export ACCESS_TOKEN="<YOUR_ACCESS_TOKEN>"
export ADDRESS="<DESTINATION_ADDRESS>"
export AMOUNT="<AMOUNT_IN_BASE_UNITS>"
export WALLET_PASSPHRASE="<YOUR_WALLET_PASSPHRASE>"

curl -X POST \
 http://$BITGO_EXPRESS_HOST/api/v2/$COIN/wallet/$WALLET_ID/sendcoins \
  -H 'Content-Type: application/json' \
  -H "Authorization: Bearer $ACCESS_TOKEN" \
  -d '{
    "address": "'"$ADDRESS"'",
    "amount": "'"$AMOUNT"'",
    "walletPassphrase": "'"$WALLET_PASSPHRASE"'"
}'
```
```shell cURL (send to many)
export BITGO_EXPRESS_HOST="<YOUR_LOCALHOST>"
export COIN="tokbxlayer"
export WALLET_ID="<YOUR_WALLET_ID>"
export ACCESS_TOKEN="<YOUR_ACCESS_TOKEN>"
export ADDRESS_1="<DESTINATION_ADDRESS_1>"
export AMOUNT_1="<AMOUNT_1_IN_BASE_UNITS>"
export WALLET_PASSPHRASE="<YOUR_WALLET_PASSPHRASE>"

curl -X POST \
  http://$BITGO_EXPRESS_HOST/api/v2/$COIN/wallet/$WALLET_ID/sendmany \
  -H 'Content-Type: application/json' \
  -H "Authorization: Bearer $ACCESS_TOKEN" \
  -d '{
    "recipients": [
    {
      "address": "'"$ADDRESS_1"'",
      "amount": "'"$AMOUNT_1"'"
    }
  ],
    "walletPassphrase": "'"$WALLET_PASSPHRASE"'"
}'
```
```js JavaScript
const tx = await fundedWallet.send({
    address: `<DESTINATION_ADDRESS>`,
    amount: `<AMOUNT>`,
    walletPassphrase: process.env.PASSWORD as string,
  });
```
```js JavaScript (send to many)
let params = {
  recipients: [
    {
      amount: "<AMOUNT_1>",
      address: "<DESTINATION_ADDRESS_1>",
    }
  ],
  walletPassphrase: "<YOUR_WALLET_PASSPHRASE>",
};
wallet.sendMany(params).then(function (transaction) {
  // Print transaction details
  console.dir(transaction);
});
```

## Stake

OKB X Layer isn't a stakeable asset.

## See Also

- [OKB X Layer - ERC20 Tokens](/docs/okbxlayer-erc20-tokens)