## Gas Top-Up

Gas top-up automatically includes a small amount of the destination chain’s native gas token (e.g., ETH) with the bridged tokens. This ensures recipients have gas to interact with their received tokens immediately.

## Enabling Gas Top-Up

To enable gas top-up in your quote request:

- Set `topupGas` to `true`
- Optionally specify the gas amount using `topupGasAmount`

## Checking Gas Top-Up Support

A chain supports gas top-up when **all** of the following are true:

1. **EVM chain only** - The chain’s `vmType` must be `"evm"
2. **Non-native currency** - You cannot top up gas when bridging the chain’s native token (e.g., ETH on Ethereum)
3. **Bridging enabled** - Either:
   - `tokenSupport` is `"All"`, OR
   - `currency.supportsBridging` is `true`

You can verify support by checking the **Gas Top Up Supported** column in [Supported Tokens & Routes](https://docs.relay.link/references/api/api_resources/supported-routes) or by querying the [Chains API](https://api.relay.link/chains).