> For the complete documentation index, see [llms.txt](https://docs.libertyswap.finance/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.libertyswap.finance/zkx-wallet-web-app/gas-tank.md).

# Gas Tank

Gas Tank is a shared gas-fee reservoir built into ZKX Wallet: top it up once with a supported token, then spend that balance to pay transaction fees on other networks — even on a network where your wallet holds none of the native gas token.

Previously, sending a transaction on a given network required holding that network's native token (ETH on Ethereum, BNB on BNB Smart Chain, and so on). Gas Tank removes that requirement: top up once with a token you already hold — for example USDC on PulseChain — and the resulting balance is automatically available to cover fees on the networks Gas Tank supports.

#### **Where You See It**

* **Gas Tank page** — open it from the wallet sidebar, in the **Wallet** group, directly below **Receive**. It shows your Gas Tank balance and a breakdown of which tokens are available for gas (for example, "2 USDC available for gas", "100,000 WPLS available for gas").
* **Home screen** — your Gas Tank balance also appears as a small badge next to your total estimated balance (for example, "$3.06 on Gas Tank"), so you can check it without opening the Gas Tank page.

### How It Works

Each top-up goes through the same four-step lifecycle, and the wallet shows your progress at every step:

| Step                             | What happens                                                                                   |
| -------------------------------- | ---------------------------------------------------------------------------------------------- |
| **1. Choose a token to deposit** | Select any token currently in your wallet, on any network Gas Tank supports for deposits.      |
| **2. Confirm & submit**          | A confirmation popup shows the amount and fee before you send the top-up transaction.          |
| **3. Settling**                  | The wallet tracks the deposit while it confirms on-chain.                                      |
| **4. Ready to spend**            | The balance is added to Gas Tank and becomes available to pay fees on every supported network. |

### Where You Can Fund From vs. Where You Can Spend

This is the part that's easiest to get wrong: **the networks you can deposit from and the networks your balance can pay fees on are two different lists.** For example, depositing USDC on PulseChain does **not** make that balance spendable on PulseChain itself — it's spendable on the four destination networks below instead.

#### Deposit from (top-up networks)

Confirmed directly in the Gas Tank token picker:

| Network         | Tokens accepted for deposit |
| --------------- | --------------------------- |
| PulseChain      | PLS, WPLS, USDC, PCOCK      |
| Ethereum        | USDC, USDT, DAI, BUSD, WETH |
| BNB Smart Chain | USDT, BUSD, USDC, WBNB, BNB |
| Base            | USDC, USDbC, DAI, WETH, ETH |

#### Spend fees on

Stated directly in the in-app warning, "Gas Tank deposits cannot be withdrawn":

* Ethereum
* BNB Smart Chain
* Robinhood Chain
* Base

Your Gas Tank balance is converted to a shared USD value and doesn't track which network it was deposited from — it can be spent on any of the four networks above regardless of deposit source.

#### Quick reference by network

| Deposit network | Accepted deposit tokens     | Role in Gas Tank                                 |
| --------------- | --------------------------- | ------------------------------------------------ |
| PulseChain      | PLS, WPLS, USDC, PCOCK      | Deposit only — not in the fee-spend network list |
| Ethereum        | USDC, USDT, DAI, BUSD, WETH | Both deposit and spend                           |
| BNB Smart Chain | USDT, BUSD, USDC, WBNB, BNB | Both deposit and spend                           |
| Base            | USDC, USDbC, DAI, WETH, ETH | Both deposit and spend                           |
| Robinhood Chain | No deposit option           | Spend only — cannot deposit directly             |

### How to Top Up Gas Tank

1. **Open Gas Tank.** From the wallet sidebar, select **Gas Tank** (in the Wallet group, directly below **Receive**).
2. **Choose the token and network to deposit from.** Tap the token field — it defaults to the current network's native token — and pick from **Tokens in current account** or **Other tokens supported**.
3. **Enter the amount.** Type an amount or tap **Max** to deposit your full balance of that token. The app shows the equivalent USD value alongside as you type.
4. **Read the warning carefully.** A yellow warning block reminds you that the deposit **cannot be withdrawn**, and can only be used to pay fees on Ethereum, BNB Smart Chain, Robinhood Chain, and Base.
5. **Tap Top up and confirm.** The redesigned confirmation popup shows the amount and the gas fee for the deposit transaction itself, then tracks progress step by step until it completes.

### Spending Gas Tank When Sending

Per the release notes, the option to pay fees from Gas Tank is now built directly into the **Send** card. When you send a transaction on a network in the spend list (Ethereum, BNB Smart Chain, Robinhood Chain, Base), you can choose Gas Tank as the fee source instead of needing to hold that network's native token yourself.

Each transaction lets you choose which token in your Gas Tank balance pays the fee for that specific send — the choice is yours every time, not an automatic deduction from a fixed token.

### Compatibility: Smart Accounts, EIP-7702 & Hardware Wallets

**Smart Accounts** Gas Tank works with Smart Accounts, and with regular EOA accounts that can be upgraded to a smart account under **EIP-7702**. Available network, swap, bridge, and CCTP options are shown per chain, matched to what that chain supports.

**Ledger Hardware Wallets** v0.0.184 extends Gas Tank to Smart Accounts secured by a **Ledger** hardware wallet — previously, a feature like this was typically limited to software-only wallets.