> For the complete documentation index, see [llms.txt](https://hinkal-team.gitbook.io/hinkal/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hinkal-team.gitbook.io/hinkal/hinkal-wallet/getting-started/gas-tokens.md).

# Gas Tokens

Every transaction in Hinkal (Send, Swap, Shield, Unshield, or dApp interaction) is executed through a relayer that fronts the on-chain gas fee.\
\
The relayer:

* submits your transaction
* covers the blockchain fee upfront

You don’t need to keep a specific token just to pay for fees.

### Choosing a gas token

Before confirming a transaction:

* Tap **Gas token**
* Select the token you want to use
* The fee updates instantly

You’ll always see:

* exact amount
* in the selected token

## How gas works

Gas depends on:

* the network
* the type of transaction

### EVM chains (Ethereum, Arbitrum, Base, Optimism)

You can choose to pay fees in:

* ETH
* USDC
* USDT
* DAI

The relayer handles the rest.

### Polygon

Same as EVM, but:

* ETH is replaced with **MATIC**

So you can choose:

* MATIC
* USDC
* USDT
* DAI

### Solana

#### Public account

* Fees are paid in **SOL**

#### Private account

Fees depend on the transaction:

* **Sending**\
  → you pay in the token you are sending
* **Swapping**\
  → you pay in the token you receive

  Example:

  * Swap SOL → ETH\
    → fee is paid in **ETH**

### Key idea

* You don’t need to manage separate gas tokens
* You always see the fee before confirming
* The system handles everything in one step

### **How it works under the hood**

1. You choose a **gas token** on the transaction screen
2. The relayer broadcasts your signeexecutes the transaction and covers the network fee
3. The exact cost is deducted from your wallet in the token you selected

Everything happens in a single step - no separate payment required.

1. You choose a gas token on the transaction screen.
2. The relayer broadcasts your signed transaction and pays the gas in ETH.
3. Once the transaction is processed, the relayer **charges the dollar-value cost** from your wallet in the token you selected.

Because the settlement happens atomically with the call, you never owe the relayer a balance later, and you never have to keep ETH on hand

**Using the gas-token selector**

* Tap the **Gas token** dropdown
* Select a token (ETH / MATIC / USDC / USDT / DAI, depending on network)
* Your balance is shown so you know what you can use

The fee updates instantly, so you always see:

* exact amount
* in the selected token

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