Gas Station

Gas Station enables developers to build experiences that completely 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 will be charged to the developer's credit card on file; 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 blockbuilders and protect networks against DOS 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 on-chain and limits the usability of blockchain applications. Depending on the blockchain, there can be different ways to abstract gas. For exmaple:

1. On EVM chains: With the introduction of ERC-4337 (account abstraction), there is a way to simply abstract gas via smart contracts called Paymasters
2. On Solana: By using the concept of fee payers, Gas can be paid by 3P wallets.

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 programmable 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 & limits on the transactions, wallets, and contracts 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 programmable wallets.

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

1. Create your first developer-controlled wallets.
2. Create your first user-controlled wallet.

Supported blockchains

Circle Gas Stations support the following blockchains: