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packages/atxp-client/src/baseAppAccount.ts

@@ -0,0 +1,187 @@
+import type { Account, PaymentMaker } from './types.js';
+import { ConsoleLogger, Logger } from '@atxp/common';
+import { requestSpendPermission } from "@base-org/account/spend-permission";
+import { createBaseAccountSDK, getCryptoKeyAccount } from "@base-org/account";
+import { base } from "viem/chains";
+import { generatePrivateKey, privateKeyToAccount } from 'viem/accounts';
+import {
+  Address,
+  createWalletClient,
+  http,
+  parseEther,
+  publicActions,
+  encodeFunctionData,
+} from "viem";
+
+const USDC_CONTRACT_ADDRESS = "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"; // USDC on Base mainnet
+const USDC_DECIMALS = 6;
+const ERC20_ABI = [
+  {
+    constant: false,
+    inputs: [
+      { name: "_to", type: "address" },
+      { name: "_value", type: "uint256" },
+    ],
+    name: "transfer",
+    outputs: [{ name: "", type: "bool" }],
+    type: "function",
+  },
+  {
+      "constant": true,
+      "inputs": [
+          {
+              "name": "_owner",
+              "type": "address"
+          }
+      ],
+      "name": "balanceOf",
+      "outputs": [
+          {
+              "name": "balance",
+              "type": "uint256"
+          }
+      ],
+      "payable": false,
+      "stateMutability": "view",
+      "type": "function"
+  }
+];
+
+type UserConsent = {
+  privateKey: `0x${string}`,
+  userAddress: `0x${string}`,
+  permission: any,
+  appName: string,
+  appLogoUrl: string
+}
+
+class BaseAppPaymentMaker implements PaymentMaker {
+  private userAddress: `0x${string}`;
+  private logger: Logger;
+
+  constructor(baseRPCUrl: string, userAddress: `0x${string}`, logger?: Logger) {
+    if (!baseRPCUrl) {
+      throw new Error('Base RPC URL is required');
+    }
+    if (!userAddress) {
+      throw new Error('User address is required');
+    }
+    this.userAddress = userAddress;
+    this.logger = logger ?? new ConsoleLogger();
+  }
+
+  private async ensureSpendPermission(appName: string): Promise<UserConsent> {
+    const sdk = createBaseAccountSDK({
+      appName: appName,
+      appChainIds: [base.id],
+    });
+    const provider = sdk.getProvider();
+
+    const privateKey = generatePrivateKey();
+    const spender = privateKeyToAccount(privateKey);
+
+    const permission = await requestSpendPermission({
+      account: account.account.address,
+      spender: spender.address,
+      token: USDC_CONTRACT_ADDRESS,
+      chainId: base.id,
+      allowance: 10n,
+      periodInDays: 7,
+      provider,
+    });
+
+    return {privateKey, userAddress: account.account.address, permission, appName, appLogoUrl};
+  }
+
+  generateJWT = async({paymentRequestId, codeChallenge}: {paymentRequestId: string, codeChallenge: string}): Promise<string> => {
+    const headerObj = { alg: 'ES256K' }; // this value is specific to Base
+    const payloadObj = {
+      sub: this.account.address,
+      iss: 'accounts.atxp.ai',
+      aud: 'https://auth.atxp.ai',
+      iat: Math.floor(Date.now() / 1000),
+      exp: Math.floor(Date.now() / 1000) + 60 * 60,
+      ...(codeChallenge ? { code_challenge: codeChallenge } : {}),
+      ...(paymentRequestId ? { payment_request_id: paymentRequestId } : {}),
+    } as Record<string, unknown>;
+
+    const header = Buffer.from(JSON.stringify(headerObj)).toString('base64url');
+    const payload = Buffer.from(JSON.stringify(payloadObj)).toString('base64url');
+    const message = `${header}.${payload}`;
+
+    // For Ethereum wallets, we need to use personal_sign format
+    const messageBytes = Buffer.from(message, 'utf8');
+    const signResult = await this.signingClient.signMessage({
+      account: this.account,
+      message: { raw: messageBytes },
+    });
+
+    // The paymcp server expects ES256K signatures as hex strings with 0x prefix
+    // The signResult from viem is already in hex format with 0x prefix (65 bytes)
+    // We encode the hex string itself (including 0x) as base64url
+    const signature = Buffer.from(signResult, 'utf8').toString('base64url');
+
+    return `${header}.${payload}.${signature}`;
+  }
+
+  makePayment = async (amount: BigNumber, currency: string, receiver: string): Promise<string> => {
+    currency = currency.toLowerCase();
+    if (currency !== 'usdc') {
+      throw new Error('Only usdc currency is supported; received ' + currency);
+    }
+
+    this.logger.info(`Making payment of ${amount} ${currency} to ${receiver} on Base`);
+
+    // Convert amount to USDC units (6 decimals) as BigInt
+    const amountInUSDCUnits = BigInt(amount.multipliedBy(10 ** USDC_DECIMALS).toFixed(0));
+
+    const data = encodeFunctionData({
+      abi: ERC20_ABI,
+      functionName: "transfer",
+      args: [receiver as Address, amountInUSDCUnits],
+    });
+    const hash = await this.signingClient.sendTransaction({
+      chain: base,
+      account: this.account,
+      to: USDC_CONTRACT_ADDRESS,
+      data: data,
+      value: parseEther('0'),
+    });
+
+    // Wait for transaction confirmation with more blocks to ensure propagation
+    this.logger.info(`Waiting for transaction confirmation: ${hash}`);
+    const receipt = await this.signingClient.waitForTransactionReceipt({ 
+      hash: hash as `0x${string}`,
+      confirmations: 3  // Wait for 3 confirmations to ensure better propagation
+    });
+
+    if (receipt.status === 'reverted') {
+      throw new Error(`Transaction reverted: ${hash}`);
+    }
+
+    this.logger.info(`Transaction confirmed: ${hash} in block ${receipt.blockNumber}`);
+
+    return hash;
+  }
+}
+
+export class BaseAppAccount implements Account {
+  accountId: string;
+  paymentMakers: { [key: string]: PaymentMaker };
+
+  static async create(baseRPCUrl: string) {
+    const account = await getCryptoKeyAccount();
+
+    if (!account.account?.address) {
+      throw new Error('No account address found—please ensure that wallet is connected');
+    }
+    return new BaseAppAccount(baseRPCUrl, account.account.address);
+  }
+
+  constructor(baseRPCUrl: string, userAddress: `0x${string}`) {
+    this.accountId = userAddress;
+    this.paymentMakers = {
+      'base': new BaseAppPaymentMaker(baseRPCUrl, userAddress),
+    };
+  }
+}

packages/atxp-client/tsconfig.cjs.json

@@ -2,7 +2,7 @@
   "extends": "./tsconfig.json",
   "compilerOptions": {
     "module": "CommonJS",
-    "moduleResolution": "node",
+    "moduleResolution": "node16",
     "outDir": "./dist-cjs"
   }
 }

packages/atxp-client/tsconfig.json

@@ -1,8 +1,8 @@
 {
   "compilerOptions": {
     "target": "ES2020",
-    "module": "ESNext",
-    "moduleResolution": "node",
+    "module": "NodeNext",
+    "moduleResolution": "nodenext",
     "lib": ["ES2020", "DOM"],
     "outDir": "./dist",
     "rootDir": "./src",