Gasless Transactions

The ClawPaymaster enables gasless transactions for agent wallets on Abstract Chain. Agents can execute on-chain operations without needing to hold or manage ETH for gas fees — the paymaster covers it.

Overview

Property	Value
Contract	0x7BBBBbDaCE3EA19Fe317e620CbD89F1040F2ddAf
Default Mode	Free Tier
Default Daily Gas Limit	0.1 ETH
Sponsorship Modes	Free Tier, Revenue Funded, Token Paid

How Paymasters Work on Abstract

Abstract Chain is built on zkSync ERA, where paymasters are a native protocol feature. Unlike Ethereum L1 where account abstraction requires bundlers and entry points, zkSync ERA supports paymasters at the protocol level:

1. A transaction includes a paymaster address and paymaster input data
2. The sequencer calls the paymaster's validation hooks
3. If the paymaster approves, it pays the gas — the user pays nothing
4. After execution, the paymaster's post-transaction hook runs for accounting

ClawPaymaster manages the sponsorship logic and accounting — deciding which wallets get gas sponsorship and tracking usage.

Sponsorship Modes

enum SponsorshipMode {
    FREE_TIER,      // Fully sponsored up to rate limit
    TOKEN_PAID,     // User pays in ERC-20 token
    REVENUE_FUNDED  // Funded by protocol revenue
}

Free Tier (Default)

Wallets receive fully sponsored gas up to a configurable daily limit:

• Default daily limit: 0.1 ETH worth of gas
• Rate limiting: Resets at midnight UTC
• Condition: Paymaster must have sufficient ETH balance

This is ideal for onboarding new agents and low-volume operations.

Revenue Funded

For revenue-generating agents that contribute to the protocol, higher (or unlimited) gas limits:

• No daily gas cap enforcement
• Only requires paymaster to have sufficient balance
• Set per-wallet via setWalletConfig()

Token Paid

Agents pay for gas using ERC-20 tokens instead of ETH. The paymaster logic validates the token payment — the actual gas is still paid in ETH by the paymaster contract.

Sponsorship Validation Flow

Agent submits transaction
        │
        ▼
ClawPaymaster.validateSponsorship(wallet, gasAmount)
        │
        ├── Determine mode (wallet-specific or default)
        │
        ├── FREE_TIER:
        │   ├── Check daily limit: usedToday + gasAmount <= dailyLimit?
        │   ├── Check balance: paymaster.balance >= gasAmount?
        │   └── Return true/false
        │
        ├── REVENUE_FUNDED:
        │   ├── Check balance: paymaster.balance >= gasAmount?
        │   └── Return true
        │
        └── TOKEN_PAID:
            └── Return true (caller handles token payment)

After execution:

ClawPaymaster.recordSponsorship(wallet, gasUsed)
        │
        ├── Reset daily counter if new day
        ├── Add gasUsed to dailyGasUsed
        ├── Add gasUsed to totalSponsored
        └── Emit WalletSponsored event

Configuration

Per-Wallet Configuration

The paymaster owner can set custom configurations for individual wallets:

function setWalletConfig(
    address wallet,
    SponsorshipMode mode,
    uint256 dailyGasLimit
) external onlyOwner;

// Give a wallet revenue-funded mode with higher limits
await paymaster.setWalletConfig(
  walletAddress,
  1, // SponsorshipMode.REVENUE_FUNDED
  ethers.parseEther('1.0'), // 1 ETH daily limit
);

Wallet Config Structure

struct WalletConfig {
    SponsorshipMode mode;      // Sponsorship mode for this wallet
    uint256 dailyGasLimit;     // Custom daily gas limit
    uint256 dailyGasUsed;      // Gas used today
    uint256 lastResetDay;      // Day number of last reset
    bool approved;             // Whether custom config is active
}

Global Settings

// Set default mode for all wallets without custom config
function setDefaultMode(SponsorshipMode mode) external onlyOwner;

// Set default daily gas limit
function setDefaultDailyGasLimit(uint256 limit) external onlyOwner;

Funding the Paymaster

The paymaster needs ETH to sponsor gas. Anyone can fund it:

// Fund the paymaster
await paymaster.fund({ value: ethers.parseEther('1.0') });

// Or just send ETH directly
await wallet.sendTransaction({
  to: PAYMASTER_ADDRESS,
  value: ethers.parseEther('1.0'),
});

// Check balance
const balance = await paymaster.getBalance();
console.log('Paymaster balance:', ethers.formatEther(balance), 'ETH');

The owner can also withdraw funds:

function defund(address payable to, uint256 amount) external onlyOwner;

Checking Gas Availability

// Check if a specific wallet can be sponsored
const canSponsor = await paymaster.validateSponsorship(
  walletAddress,
  ethers.parseEther('0.001'), // estimated gas cost
);
console.log('Can sponsor:', canSponsor);

// Check remaining daily gas for a wallet
const remaining = await paymaster.getRemainingDailyGas(walletAddress);
console.log('Remaining daily gas:', ethers.formatEther(remaining), 'ETH');

// Check wallet config
const config = await paymaster.getWalletConfig(walletAddress);
console.log('Mode:', config.mode);
console.log('Daily limit:', ethers.formatEther(config.dailyGasLimit));
console.log('Used today:', ethers.formatEther(config.dailyGasUsed));

Staking PINCH for Gas

In the broader ClawWallet ecosystem, staking $PINCH tokens helps fund paymaster operations:

1. Stake PINCH in the PinchStaking contract
2. Staking rewards accrue from protocol fees
3. Protocol uses a portion of staking yield to fund the paymaster
4. This creates a sustainable gas sponsorship flywheel

See Staking for details on staking tiers and rewards.

Integration Example

Here's how a dApp integrates ClawPaymaster for gasless agent operations:

import { ethers } from 'ethers';

const PAYMASTER = '0x7BBBBbDaCE3EA19Fe317e620CbD89F1040F2ddAf';

const paymasterABI = [
  'function validateSponsorship(address wallet, uint256 gasAmount) external view returns (bool)',
  'function getRemainingDailyGas(address wallet) external view returns (uint256)',
  'function getBalance() external view returns (uint256)',
  'function getWalletConfig(address wallet) external view returns (tuple(uint8 mode, uint256 dailyGasLimit, uint256 dailyGasUsed, uint256 lastResetDay, bool approved))',
];

async function checkGasEligibility(walletAddress: string) {
  const provider = new ethers.JsonRpcProvider('https://api.mainnet.abs.xyz');
  const paymaster = new ethers.Contract(PAYMASTER, paymasterABI, provider);

  const remaining = await paymaster.getRemainingDailyGas(walletAddress);
  const balance = await paymaster.getBalance();

  return {
    remainingDailyGas: ethers.formatEther(remaining),
    paymasterBalance: ethers.formatEther(balance),
    canSponsor: remaining > 0n && balance > 0n,
  };
}

Events

Event	Description
WalletSponsored(wallet, gasUsed, mode)	Gas was sponsored for a wallet
PaymasterFunded(funder, amount)	ETH deposited into paymaster
PaymasterDefunded(to, amount)	ETH withdrawn from paymaster
WalletConfigUpdated(wallet, mode, limit)	Wallet config changed
DefaultModeUpdated(mode)	Default sponsorship mode changed

Statistics

// Total gas sponsored across all wallets (lifetime)
const totalSponsored = await paymaster.totalSponsored();
console.log('Total sponsored:', ethers.formatEther(totalSponsored), 'ETH');