# Gasless Swaps

_Learn how to use the Get Gas feature to swap a small amount of MUSD or MEZO for BTC gas when your balance is low._

_Source: https://mezo.org/docs/users/getting-started/get-gas_

The **Get Gas** feature lets you acquire a small amount of BTC to cover transaction (gas) fees on Mezo — even if you have no BTC in your wallet. It works by performing a **gasless swap**, exchanging a small amount of MUSD or MEZO for exactly **0.0001 BTC**, enough to cover multiple transactions on the network.

Because the swap is gasless (powered by meta-transactions), you don't need any existing BTC to use it.

## When Does It Appear?

A **"Get Gas"** button automatically appears in the Mezo app when your wallet's BTC balance drops below **0.000001 BTC**. This ensures you always have a way to top up gas without needing to bridge in more BTC or use an external exchange.

## Supported Tokens

The supported tokens for Get Gas swaps are **MUSD** and **MEZO**. This means users arriving on the chain with just MEZO can get a free swap into BTC for gas without needing to bridge additional assets.

## How to Get Gas

1. **Open the Get Gas modal**

   When your BTC balance is low, click the **"Get Gas"** button that appears in the app.

2. **Select a token**

   Select MUSD or MEZO as your source token. The modal will display the estimated cost for the swap.

3. **Review the quote**

   The app quotes the amount of MUSD or MEZO needed to receive exactly **0.0001 BTC**. The output amount is fixed so you always get a predictable gas amount regardless of token price.

4. **Confirm the swap**

   Click **"Get Gas"** to initiate the swap. You will be prompted to sign two messages in your wallet:
   - A **permit signature** (token approval)
   - An **execute signature** (swap authorization)

   No gas fee is required for these signatures.

5. **Wait for confirmation**

   The app will submit your transaction and automatically poll for confirmation. Once confirmed, you'll see a success screen with the transaction hash.

## How It Works

The Get Gas feature uses **meta-transactions** to execute the swap without requiring gas from the user:

1. **Permit**: You sign an off-chain message granting the relay permission to spend the required amount of your chosen token.
2. **Relay**: A backend relay service submits the swap transaction on your behalf, covering the gas cost.
3. **Swap**: The transaction executes on-chain, swapping your token for **0.0001 BTC**, which is deposited directly into your wallet.

This design means you can always get gas as long as you hold MUSD or MEZO — no BTC needed to get started.

## Key Details

| Detail | Value |
|---|---|
| **Output amount** | 0.0001 BTC (fixed) |
| **Eligible tokens** | MUSD, MEZO |
| **Gas required** | None (gasless via meta-transactions) |
| **Trigger** | BTC balance below 0.000001 BTC |

> **Note:**
>
> The cost in MUSD or MEZO will vary based on current pool prices. The quote shown in the modal reflects the real-time rate at the time of the swap.