> ## Documentation Index
> Fetch the complete documentation index at: https://developers.circle.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Gas Station

Gas Station enables developers to build experiences that abstract gas - both for
end-users and developers. Developers can sponsor network fees for the end-user,
removing the need for end-users to hold native tokens in their wallets. The
sponsored gas fees are charged to the developer's credit card; hence, not having
them to hold native tokens across chains. This abstracts gas fees: one of the
biggest problems of building blockchain apps.

## Problem with gas fees

Blockchains require gas transaction fees to incentivize validators and protect
networks against denial of service attacks. The mechanics for these fees have
traditionally been built into the blockchain itself, often requiring gas fees to
be paid in native tokens and sourced by the address that initiated the
transaction.

The experience of sourcing native tokens by the originating wallet makes it hard
for users to interact onchain and limits the usability of blockchain
applications. Depending on the blockchain, there can be different ways to
abstract gas. For example:

1. On EVM chains: With the introduction of
   [ERC-4337](https://eips.ethereum.org/EIPS/eip-4337) (account abstraction),
   there is a way to pay network fees in non-native tokens via smart contracts
   called paymasters
2. On Solana: By using the concept of fee-payers, third party wallets can pay
   for gas on behalf of a user.

## Circle's Gas Station solution

Circle's Gas Station utilizes paymasters (on EVM) and fee-payers (on Solana) to
create a solution that completely abstracts gas. Circle has deployed paymaster
smart contracts and fee-payer wallets that developers can use with Circle
Wallets.

The solution has the following components:

1. **Gas Sponsor:** A third party smart contract or wallet that pays on-chain
   gas fees according to the sponsorship conditions.
   1. Paymaster (EVM): Smart contract (ERC-4337 standard)
   2. Fee-Payer (Solana): Wallets that pay gas fees
2. **Policy:** Let developers set up custom rules and limits on the blockchains
   they want to sponsor.
3. **Billing:** Let developers pay all the gas fees using their preferred
   payment modes (cards).

On EVM chains, the Programmable Wallet must be an ERC-4337-compliant smart
contract account. Developers can create these wallets by passing
`"accountType": "SCA"` in the create wallet API for Wallets.

To learn more on creating a SCA wallet follow one of the two guides:

1. [Create your first developer-controlled wallets](/wallets/dev-controlled/create-your-first-wallet).
2. [Create your first user-controlled wallet](/wallets/user-controlled/react-native-sdk-ui-customization-api).

On Solana, Gas Station can
[sponsor](/wallets/gas-station/solana-ata-sponsorship) the rent deposit for
ATAs, or you can
[create and fund an ATA yourself](/wallets/gas-station/create-solana-ata).

## Supported blockchains

Circle Gas Stations support the following blockchains:

| Blockchain Network       | PW User-Controlled | PW Developer Controlled |
| :----------------------- | :----------------- | :---------------------- |
| Aptos Mainnet            | ✅                  | ✅                       |
| Aptos Testnet            | ✅                  | ✅                       |
| Arbitrum Mainnet         | ✅                  | ✅                       |
| Arbitrum Sepolia Testnet | ✅                  | ✅                       |
| Arc Testnet              | ✅                  | ✅                       |
| Avalanche Mainnet        | ✅                  | ✅                       |
| Avalanche Fuji Testnet   | ✅                  | ✅                       |
| Base Mainnet             | ✅                  | ✅                       |
| Base Sepolia Testnet     | ✅                  | ✅                       |
| Ethereum Mainnet         | ✅                  | ✅                       |
| Ethereum Sepolia Testnet | ✅                  | ✅                       |
| Monad Mainnet            | ✅                  | ✅                       |
| Monad Testnet            | ✅                  | ✅                       |
| Optimism Mainnet         | ✅                  | ✅                       |
| Optimism Sepolia Testnet | ✅                  | ✅                       |
| Polygon Mainnet          | ✅                  | ✅                       |
| Polygon Amoy Testnet     | ✅                  | ✅                       |
| Solana Mainnet           | ✅                  | ✅                       |
| Solana Devnet            | ✅                  | ✅                       |
| Unichain Mainnet         | ✅                  | ✅                       |
| Unichain Sepolia Testnet | ✅                  | ✅                       |

## Related products

Gas Station allows you to sponsor network fees for your users. If you want to
allow users to pay their network fees with USDC themselves, see the
[Circle Paymaster](/paymaster).

### Comparison with Circle Paymaster

| Category               | Circle Paymaster                                                                                    | Gas Station                                                                      |
| ---------------------- | --------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------- |
| **Description**        | A permissionless smart contract that allows users to pay gas fees in USDC instead of native tokens. | A feature of Wallets that allows developers to sponsor gas fees for their users. |
| **Circle account**     | Not required                                                                                        | Required                                                                         |
| **Compatible wallets** | Any ERC-4337-compliant wallet                                                                       | Circle Wallets                                                                   |
| **Gas fees paid in**   | USDC                                                                                                | Fiat currency via credit card                                                    |
| **Pricing model**      | 10% of the gas fee                                                                                  | 5% of the gas fee                                                                |
| **Paid by**            | End user                                                                                            | Developer                                                                        |