The overhead gas cost is the extra amount of gas required to process the relay call requested by the user. Let's call **X** the gas consumed by the destination contract method call, and **Y** the total gas consumed by the relay call, then the relay call cost (i.e. overhead gas cost) is: **Z = Y - X**.

## SmartWallet templates

RIF Relay V0.1 only has one SmartWallet [template](https://github.com/rsksmart/rif-relay/blob/main/docs/smart-wallets.md), which can be used as-is, or be injected with extra logic during the SmartWallet instance creation.

V0.2 introduces a cheaper template ([SmartWallet](https://github.com/rsksmart/rif-relay/blob/main/docs/smart-wallets.md)), to be used when there's no need for extra custom-logic in the smart wallets. The behaviour is the same as the CustomSmartWallet [template](https://github.com/rsksmart/rif-relay/blob/main/docs/smart-wallets.md) of V0.2, but without this capability.

### Gas cost from the deployment of each template. 

| RIF Version | SW Template       | Avg. overhead gas |
|-------------|-------------------|-------------------|
| 0.1         | SmartWallet       | 172400            |
| 0.2         | CustomSmartWallet | 98070             |
| 0.2         | SmartWallet       | 97695             |
| 1           | CustomSmartWallet | TBD               |
| 1           | SmartWallet       | TBD               |


:::tip[Note]
The instance of CustomSmartWallet used didn't point to any extra custom logic.
:::