​
Usage

const { approveAsync, approveData, isLoading, error } = useApprove();

​
Parameters

  • encryptKey (string): User’s decryption PIN
  • wallet (WalletData): Wallet public/private key pair
  • contractAddress (string): Token contract to approve
  • spender (string): Contract address to authorize
  • amount (string | number): Maximum spend allowance
  • decimals (number): Token decimals (default: 18)

​
Return Value

Returns an object containing:

  • approveAsync: Function to trigger token approval
  • approveData: Transaction hash of the approval
  • isLoading: Boolean indicating if the operation is in progress
  • error: Any error that occurred during the process

​
Example Implementation

'use client'

import { useApprove } from "@chipi-pay/chipi-sdk";
import { useState } from "react";

const VESU_CONTRACT = "0x037ae3f583c8d644b7556c93a04b83b52fa96159b2b0cbd83c14d3122aef80a2";

// Sample wallet data - replace with your wallet in production
const sampleWallet: { publicKey: string; encryptedPrivateKey: string } = {
  publicKey: "0x123...yourPublicKeyHere",
  encryptedPrivateKey: "encrypted:key:data" // This would be encrypted data in production
};

export function ApproveForm() {
  const { approveAsync, approveData, isLoading, error } = useApprove();
  const [wallet] = useState(sampleWallet);
  const [form, setForm] = useState({
    pin: '',
    amount: ''
  });

  const handleApprove = async (e: React.FormEvent) => {
    e.preventDefault();

    try {
      await approveAsync({
        encryptKey: form.pin,
        wallet: {
          publicKey: wallet.publicKey,
          encryptedPrivateKey: wallet.encryptedPrivateKey
        },
        contractAddress: VESU_CONTRACT,
        spender: VESU_CONTRACT, // Authorizing VESU contract
        amount: form.amount,
        decimals: 18
      });
    } catch (err) {
      console.error('Approval failed:', err);
    }
  };

  return (
    <div className="bg-white rounded-xl shadow-lg p-6">
      <h2 className="text-2xl font-bold mb-4">Approve Token Access</h2>
      
      <form onSubmit={handleApprove} className="space-y-4">
        <div>
          <label className="block text-sm font-medium mb-1">Security PIN</label>
          <input
            type="password"
            value={form.pin}
            onChange={(e) => setForm({...form, pin: e.target.value})}
            className="w-full p-2 border rounded-md"
            required
          />
        </div>

        <div>
          <label className="block text-sm font-medium mb-1">Amount to Approve</label>
          <input
            type="number"
            value={form.amount}
            onChange={(e) => setForm({...form, amount: e.target.value})}
            className="w-full p-2 border rounded-md"
            required
          />
        </div>

        <button 
          type="submit" 
          disabled={isLoading}
          className="w-full bg-blue-600 text-white py-2 px-4 rounded-md hover:bg-blue-700 disabled:bg-gray-400"
        >
          {isLoading ? 'Approving...' : 'Authorize Contract'}
        </button>
      </form>

      {approveData && (
        <div className="mt-4 p-3 bg-gray-50 rounded-md">
          <p className="text-sm font-mono break-all">
            Approval TX: {approveData}
          </p>
        </div>
      )}

      {error && (
        <div className="mt-4 p-3 bg-red-50 text-red-700 rounded-md">
          Error: {error.message}
        </div>
      )}
    </div>
  );
}

​
Security Considerations

  • Always use encrypted private keys
  • Never store or transmit raw private keys
  • Implement proper PIN validation
  • Use secure storage for wallet data
  • Consider implementing approval limits

​
Error Handling

  • Handle insufficient token balance
  • Validate contract addresses
  • Check for existing approvals
  • Monitor gas fees
  • Implement retry logic for failed transactions

Approvals are specific to each token-contract pair. You’ll need to re-approve when interacting with new contracts.

  • Stake - Requires prior approval
  • Transfer - For moving tokens after approval