Paymaster Integration

builder.setPaymasterOptions({
  apikey: YOUR_API_KEY,
  rpc: PAYMASTER_URL
});

// Create a helper function to get supported tokens
async function getSupportedTokens(client, builder) {
  try {
    // Get the wallet address
    const sender = await builder.getSender();
    
    // Create a minimal UserOp for the request
    const minimalUserOp = {
      sender,
      nonce: "0x0",
      initCode: "0x",
      callData: "0x",
      callGasLimit: "0x0",
      verificationGasLimit: "0x0",
      preVerificationGas: "0x0",
      maxFeePerGas: "0x0",
      maxPriorityFeePerGas: "0x0",
      paymasterAndData: "0x",
      signature: "0x"
    };
    
    // Setup the provider for the paymaster RPC
    const provider = new ethers.providers.JsonRpcProvider(PAYMASTER_URL);
    
    // Call the pm_supported_tokens method
    const tokensResponse = await provider.send("pm_supported_tokens", [
      minimalUserOp,
      YOUR_API_KEY,
      ENTRYPOINT_ADDRESS
    ]);
    
    // Parse and return the token list
    if (tokensResponse && tokensResponse.tokens) {
      return tokensResponse.tokens.map(token => ({
        address: token.token || token.address,
        decimals: token.decimals,
        symbol: token.symbol,
        type: token.type
      }));
    }
    
    return [];
  } catch (error) {
    console.error("Error getting supported tokens:", error);
    return [];
  }
}
 
// Usage
const supportedTokens = await getSupportedTokens(client, builder);
console.log("Supported tokens:", supportedTokens);

// Handle different response formats
let tokens = [];
if (tokensResponse.tokens) {
  tokens = tokensResponse.tokens;
} else if (Array.isArray(tokensResponse)) {
  tokens = tokensResponse;
} else if (typeof tokensResponse === 'object') {
  // Try to find tokens in the response object
  const possibleTokensArray = Object.values(tokensResponse).find(val => Array.isArray(val));
  if (possibleTokensArray && Array.isArray(possibleTokensArray)) {
    tokens = possibleTokensArray;
  }
}

// Type 0: Free gas (developer sponsors)
builder.setPaymasterOptions({ 
  type: 0,
  apikey: YOUR_API_KEY,
  rpc: PAYMASTER_URL
});
 
// Type 1: Prepay with ERC20 tokens
builder.setPaymasterOptions({ 
  type: 1,
  token: TOKEN_ADDRESS, // The ERC20 token address
  apikey: YOUR_API_KEY,
  rpc: PAYMASTER_URL
});
 
// Type 2: Postpay with ERC20 tokens
builder.setPaymasterOptions({ 
  type: 2,
  token: TOKEN_ADDRESS, // The ERC20 token address
  apikey: YOUR_API_KEY,
  rpc: PAYMASTER_URL
});