Paymaster addresses and events

This page contains information on the addresses of the Circle Paymaster contracts, and the events the contracts emit during operation.

Paymaster addresses

You can access the permissionless paymaster contracts at the following addresses on supported blockchains:

Paymaster v0.7
Paymaster v0.8

Mainnet

Blockchain	Symbol	Paymaster contract address
Arbitrum	`ARB`	`0x6C973eBe80dCD8660841D4356bf15c32460271C9`
Base	`BASE`	`0x6C973eBe80dCD8660841D4356bf15c32460271C9`

Testnet

Blockchain	Symbol	Paymaster contract address
Arbitrum Sepolia	`ARB-SEPOLIA`	`0x31BE08D380A21fc740883c0BC434FcFc88740b58`
Arc Testnet	`ARC-TESTNET`	`0x31BE08D380A21fc740883c0BC434FcFc88740b58`
Base Sepolia	`BASE-SEPOLIA`	`0x31BE08D380A21fc740883c0BC434FcFc88740b58`

Mainnet

Blockchain	Symbol	Paymaster contract address
Arbitrum	`ARB`	`0x0578cFB241215b77442a541325d6A4E6dFE700Ec`
Avalanche	`AVAX`	`0x0578cFB241215b77442a541325d6A4E6dFE700Ec`
Base	`BASE`	`0x0578cFB241215b77442a541325d6A4E6dFE700Ec`
Ethereum	`ETH`	`0x0578cFB241215b77442a541325d6A4E6dFE700Ec`
Optimism	`OP`	`0x0578cFB241215b77442a541325d6A4E6dFE700Ec`
Polygon	`MATIC`	`0x0578cFB241215b77442a541325d6A4E6dFE700Ec`
Unichain	`UNI`	`0x0578cFB241215b77442a541325d6A4E6dFE700Ec`

Testnet

Blockchain	Symbol	Paymaster contract address
Arbitrum Sepolia	`ARB-SEPOLIA`	`0x3BA9A96eE3eFf3A69E2B18886AcF52027EFF8966`
Arc Testnet	`ARC-TESTNET`	`0x3BA9A96eE3eFf3A69E2B18886AcF52027EFF8966`
Avalanche Fuji	`AVAX-FUJI`	`0x3BA9A96eE3eFf3A69E2B18886AcF52027EFF8966`
Base Sepolia	`BASE-SEPOLIA`	`0x3BA9A96eE3eFf3A69E2B18886AcF52027EFF8966`
Ethereum Sepolia	`ETH-SEPOLIA`	`0x3BA9A96eE3eFf3A69E2B18886AcF52027EFF8966`
Optimism Sepolia	`OP-SEPOLIA`	`0x3BA9A96eE3eFf3A69E2B18886AcF52027EFF8966`
Polygon Amoy	`MATIC-AMOY`	`0x3BA9A96eE3eFf3A69E2B18886AcF52027EFF8966`
Unichain Sepolia	`UNI-SEPOLIA`	`0x3BA9A96eE3eFf3A69E2B18886AcF52027EFF8966`

Paymaster events

This section explains the events from the Circle Paymaster and when they are emitted. You can use these events to debug or track the state after submitting a user operation (user op) to a bundler.

TokenPaymasterV07.sol and TokenPaymasterV08.sol

These files are the main contract of the Circle Paymaster that support EntryPoint v0.7 and v0.8. The primary functions they integrate are:

_validatePaymasterUserOp: validates the user op and charges the prefund token from the sender before execution.
_postOp: refunds the token back to the sender when the actual amount of tokens needed is known after execution.

UserOperationSponsored

The contract emits this event after the _postOp is executed and the prefund token (if any) is refunded. Attributes

Name	Type	Description
`token`	`IERC20`	The ERC-20 token paid by the sender
`sender`	`address`	The sender address
`userOpHash`	`bytes32`	The hash of the user op
`nativeTokenPrice`	`uint256`	The price of 1 ether = 1e18 wei, denominated in token
`actualTokenNeeded`	`uint256`	The final transaction cost to the smart contract account (SCA), denominated in token
`feeTokenAmount`	`uint256`	The fee spread used to cover the slippage from exchanging USDC for ETH, denominated in token

Example Using this transaction as an example, the userOperationSponsored event contains the following data:

Name	Type	Value
`token`	`IERC20`	`0x0000000000000000000000001c7d4b196cb0c7b01d743fbc6116a902379c7238`
`sender`	`address`	`0x000000000000000000000000148cab4b1a7e8c23ae62967cfc8df6292ecf27a8`
`userOpHash`	`bytes32`	`cc6f71a0ba8d9b72e75c45fae7b830c403b46964eb1d3f8daa0b73d14e6c5b0d`
`nativeTokenPrice`	`uint256`	`3000000000`
`actualTokenNeeded`	`uint256`	`4551712`
`feeTokenAmount`	`uint256`	`0`

Wallets

Gas fees

Compliance

Contracts

Paymaster addresses and events