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unclezorounclezoro
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update with cex doc
1 parent 2b491eb commit a5522ac

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lines changed

‎.gitignore‎

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./wallet-user/js-example/yarn-error.log
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./wallet-user/js-example/yarn-debug.log
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./wallet-user/js-example/.pnpm-debug.log
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./sponsor/payment-gateway/js-example/node_modules/
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./sponsor/payment-gateway/js-example/npm-debug.log
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./sponsor/payment-gateway/js-example/yarn-error.log
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./sponsor/payment-gateway/js-example/yarn-debug.log
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./sponsor/payment-gateway/js-example/.pnpm-debug.log
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./sponsor/cex/js-example/node_modules/
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./sponsor/cex/js-example/npm-debug.log
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./sponsor/cex/js-example/yarn-error.log
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./sponsor/cex/js-example/yarn-debug.log
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./sponsor/cex/js-example/.pnpm-debug.log
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./payment-gateway/js-example/node_modules/
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./payment-gateway/js-example/npm-debug.log
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./payment-gateway/js-example/yarn-error.log
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./payment-gateway/js-example/yarn-debug.log
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./payment-gateway/js-example/.pnpm-debug.log
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./cex/js-example/node_modules/
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./cex/js-example/npm-debug.log
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./cex/js-example/yarn-error.log
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./cex/js-example/yarn-debug.log
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./cex/js-example/.pnpm-debug.log
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.idea/

‎sponsor/payment-gateway/go-example/go.mod‎ renamed to ‎cex/go-example/go.mod‎

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‎sponsor/payment-gateway/go-example/go.sum‎ renamed to ‎cex/go-example/go.sum‎

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‎cex/go-example/main.go‎

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package main
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import (
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"context"
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"crypto/ecdsa"
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"encoding/json"
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"fmt"
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"log"
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"math/big"
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"github.com/ethereum/go-ethereum/common"
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"github.com/ethereum/go-ethereum/common/hexutil"
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"github.com/ethereum/go-ethereum/core/types"
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"github.com/ethereum/go-ethereum/crypto"
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"github.com/ethereum/go-ethereum/ethclient"
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)
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const TokenContractAddress = "0x.."
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const WithdrawRecipientAddress = "0x.."
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const SponsorPolicyId = ".."
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const SponsorAPIEndpoint = "https://open-platform.nodereal.io/{YOUR_API_KEY}/eoa-paymaster-testnet"
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const HotwalletPrivateKey = ".."
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func main() {
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sponsorSetUpPolicyRules()
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cexDoGaslessWithdrawl()
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}
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func sponsorSetUpPolicyRules() {
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sponsorClient, err := NewSponsorClient(SponsorAPIEndpoint)
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if err != nil {
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log.Fatal(err)
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}
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// sponsor the tx that interact with the stable coin ERC20 contract
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success, err := sponsorClient.AddToWhitelist(context.Background(), WhitelistParams{
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PolicyUUID: SponsorPolicyId,
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WhitelistType: ToAccountWhitelist,
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Values: []string{TokenContractAddress},
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})
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if err != nil || !success {
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log.Fatal("failed to add token contract whitelist", err)
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}
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// sponsor the tx that from hotwallets
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fromAddress := getAddressFromPrivateKey(HotwalletPrivateKey)
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success, err = sponsorClient.AddToWhitelist(context.Background(), WhitelistParams{
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PolicyUUID: SponsorPolicyId,
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WhitelistType: FromAccountWhitelist,
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Values: []string{fromAddress.String()},
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})
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if err != nil || !success {
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log.Fatal("failed to add contract method whitelist")
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}
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}
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func cexDoGaslessWithdrawl() {
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withdrawAmount := big.NewInt(1e17)
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// Connect to an Ethereum node (for transaction assembly)
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client, err := ethclient.Dial("https://bsc-testnet-dataseed.bnbchain.org")
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if err != nil {
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log.Fatalf("Failed to connect to the Ethereum network: %v", err)
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}
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// Create a PaymasterClient (for transaction sending)
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paymasterClient, err := NewPaymasterClient("https://bsc-paymaster-testnet.nodereal.io")
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if err != nil {
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log.Fatalf("Failed to create PaymasterClient: %v", err)
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}
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// Load your private key
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privateKey, err := crypto.HexToECDSA(HotwalletPrivateKey)
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if err != nil {
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log.Fatalf("Failed to load private key: %v", err)
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}
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fromAddress := getAddressFromPrivateKey(HotwalletPrivateKey)
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// Token contract address
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tokenAddress := common.HexToAddress(TokenContractAddress)
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// Create ERC20 transfer data
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data, err := createERC20TransferData(common.HexToAddress(WithdrawRecipientAddress), withdrawAmount)
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if err != nil {
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log.Fatalf("Failed to create ERC20 transfer data: %v", err)
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}
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// Get the latest nonce for the from address
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nonce, err := client.PendingNonceAt(context.Background(), fromAddress)
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if err != nil {
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log.Fatalf("Failed to get nonce: %v", err)
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}
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// Create the transaction
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gasPrice := big.NewInt(0)
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tx := types.NewTransaction(nonce, tokenAddress, big.NewInt(0), 300000, gasPrice, data)
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// Get the chain ID
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chainID, err := client.ChainID(context.Background())
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if err != nil {
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log.Fatalf("Failed to get chain ID: %v", err)
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}
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// Sign the transaction
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signedTx, err := types.SignTx(tx, types.NewEIP155Signer(chainID), privateKey)
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if err != nil {
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log.Fatalf("Failed to sign transaction: %v", err)
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}
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// Convert to Transaction struct for IsSponsorable check
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gasLimit := tx.Gas()
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sponsorableTx := Transaction{
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To: &tokenAddress,
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From: fromAddress,
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Value: (*hexutil.Big)(big.NewInt(0)),
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Gas: (*hexutil.Uint64)(&gasLimit),
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Data: (*hexutil.Bytes)(&data),
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}
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// Check if the transaction is sponsorable
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sponsorableInfo, err := paymasterClient.IsSponsorable(context.Background(), sponsorableTx)
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if err != nil {
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log.Fatalf("Error checking sponsorable status: %v", err)
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}
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jsonInfo, _ := json.MarshalIndent(sponsorableInfo, "", " ")
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fmt.Printf("Sponsorable Information:\n%s\n", string(jsonInfo))
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if sponsorableInfo.Sponsorable {
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// Send the transaction using PaymasterClient
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err := paymasterClient.SendTransaction(context.Background(), signedTx)
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if err != nil {
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log.Fatalf("Failed to send sponsorable transaction: %v", err)
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}
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fmt.Printf("Sponsorable transaction sent: %s\n", signedTx.Hash())
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} else {
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fmt.Println("Transaction is not sponsorable. You may need to send it as a regular transaction.")
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}
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}
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func getAddressFromPrivateKey(pk string) common.Address {
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// Load your private key
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privateKey, err := crypto.HexToECDSA(pk)
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if err != nil {
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log.Fatalf("Failed to load private key: %v", err)
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}
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publicKey := privateKey.Public()
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publicKeyECDSA, ok := publicKey.(*ecdsa.PublicKey)
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if !ok {
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log.Fatal("Error casting public key to ECDSA")
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}
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return crypto.PubkeyToAddress(*publicKeyECDSA)
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}

‎sponsor/payment-gateway/go-example/paymasterClient.go‎ renamed to ‎cex/go-example/paymasterClient.go‎

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‎cex/go-example/readme.md‎

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# GO Example
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This repository contains a Go application demonstrating:
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1. Sponsor manage the policy to sponsor any transaction sent by Cex hotwallets.
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2. Cex do token withdrawal without pay gas fee through paymaster.
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## Quick Start
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The example is performed on BSC testnet, please ensure you have some test ERC20 on BSC testnet. (You can get some
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from the official faucet)
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1. Install dependencies
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```shell
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$ go mod tidy
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```
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2. Configure the file
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Before running the application, you need to edit the `main.go` to set up the following:
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- Set "TokenContractAddress" to the ERC20 token contract address that users want to withdraw.
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- Set "WithdrawRecipientAddress" to the receiver address of user's withdrawal request.
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- Set "SponsorPolicyId" to the policy ID created by the sponsor on Meganode Paymaster, create one
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from [here](https://docs.nodereal.io/docs/meganode-paymaster-sponsor-guidelines) if you don't have it.
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- Set "SponsorAPIEndpoint" to the API key created by the sponsor in the Nodereal MegaNode Console.
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create one from [here](https://docs.nodereal.io/docs/meganode-paymaster-sponsor-guidelines) if you don't have it.
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- Set "HotwalletPrivateKey" to the Cex's hotwallet private key, ensuring this wallet contains the required ERC20 tokens.
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3. Run the example
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```
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$ go run main.go
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```
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‎sponsor/payment-gateway/go-example/sponsorClient.go‎ renamed to ‎cex/go-example/sponsorClient.go‎

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‎cex/js-example/index.js‎

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const ethers = require('ethers');
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// Replace with the cex hot wallet private key (be cautious with private keys!)
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const hotwalletPrivateKey = 'HOT_WALLET_PRIVATE_KEY';
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// replace with user ERC20 withdraw address
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const userWithdrawAddress = 'USER_WITHDRAW_ADDRESS';
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// ERC20 token contract address (replace with the address of the token you want to send)
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const erc20TokenAddress = 'TOKEN_CONTRACT_ADDRESS';
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const sponsorEndpoint = 'https://open-platform.nodereal.io/{SPONSOR_API_KEY}/eoa-paymaster-testnet';
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const policyID = 'SPONSOR_POLICY_ID'
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class SponsorProvider extends ethers.providers.JsonRpcProvider {
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constructor(url) {
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super(url);
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}
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async addToWhitelist(params) {
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return this.send('pm_addToWhitelist', [params]);
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}
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async removeFromWhitelist(params) {
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return this.send('pm_rmFromWhitelist', [params]);
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}
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async emptyWhitelist(params) {
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return this.send('pm_emptyWhitelist', [params]);
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}
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async getWhitelist(params) {
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return this.send('pm_getWhitelist', [params]);
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}
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}
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class PaymasterProvider extends ethers.providers.JsonRpcProvider {
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constructor(url) {
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super(url);
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}
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async isSponsorable(transaction) {
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const params = [{
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to: transaction.to,
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from: transaction.from,
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value: transaction.value != null ? ethers.utils.hexlify(transaction.value) : '0x0',
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gas: ethers.utils.hexlify(transaction.gasLimit || 0),
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data: transaction.data || '0x'
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}];
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const result = await this.send('pm_isSponsorable', params);
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return result;
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}
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}
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async function cexDoGaslessWithdrawTx() {
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// Provider for assembling the transaction (e.g., mainnet)
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const assemblyProvider = new ethers.providers.JsonRpcProvider('https://bsc-testnet-dataseed.bnbchain.org');
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// Provider for sending the transaction (e.g., could be a different network or provider)
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const paymasterProvider = new PaymasterProvider('https://bsc-paymaster-testnet.nodereal.io');
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const wallet = new ethers.Wallet(hotwalletPrivateKey, assemblyProvider);
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// ERC20 token ABI (only including the transfer function)
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const tokenAbi = [
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"function transfer(address to, uint256 amount) returns (bool)"
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];
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// Create contract instance
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const tokenContract = new ethers.Contract(erc20TokenAddress, tokenAbi, wallet);
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// Transaction details
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const tokenAmount = ethers.utils.parseUnits('1.0', 18); // Amount of tokens to send (adjust decimals as needed)
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try {
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// Get the current nonce for the sender's address
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const nonce = await assemblyProvider.getTransactionCount(wallet.address);
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// Create the transaction object
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const transaction = await tokenContract.populateTransaction.transfer(userWithdrawAddress, tokenAmount);
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// Add nonce and gas settings
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transaction.nonce = nonce;
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transaction.gasPrice = 0; // Set gas price to 0
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transaction.gasLimit = 100000; // Adjust gas limit as needed for token transfers
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try {
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const sponsorableInfo = await paymasterProvider.isSponsorable(transaction);
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console.log('Sponsorable Information:', sponsorableInfo);
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} catch (error) {
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console.error('Error checking sponsorable status:', error);
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}
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// Sign the transaction
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const signedTx = await wallet.signTransaction(transaction);
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// Send the raw transaction using the sending provider
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const tx = await paymasterProvider.send('eth_sendRawTransaction', [signedTx]);
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console.log('Transaction sent:', tx);
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} catch (error) {
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console.error('Error sending transaction:', error);
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}
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}
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async function sponsorSetUpPolicyRules() {
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const client = new SponsorProvider(sponsorEndpoint);
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const wallet = new ethers.Wallet(hotwalletPrivateKey)
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// sponsor the tx that interact with the stable coin ERC20 contract
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try {
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await client.emptyWhitelist({
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policyUuid: policyID,
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whitelistType: "FromAccountWhitelist",
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});
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await client.emptyWhitelist({
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policyUuid: policyID,
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whitelistType: "ToAccountWhitelist",
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});
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// sponsor the tx that interact with the stable coin ERC20 contract
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const res1 = await client.addToWhitelist({
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policyUuid: policyID,
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whitelistType: "ToAccountWhitelist",
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values: [erc20TokenAddress]
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});
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console.log("Added ERC20 contract address to whitelist ", res1);
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// sponsor the tx that sent by hotwallet
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const res2 = await client.addToWhitelist({
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policyUuid: policyID,
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whitelistType: "FromAccountWhitelist",
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values: [wallet.address]
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});
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console.log("Added hotwallet to whitelist ", res2);
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} catch (error){
134+
console.error("Error:", error)
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}
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}
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async function main() {
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try {
140+
await sponsorSetUpPolicyRules();
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await cexDoGaslessWithdrawTx();
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} catch (error) {
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console.error("Error:", error);
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}
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}
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main();

‎sponsor/payment-gateway/js-example/package-lock.json‎ renamed to ‎cex/js-example/package-lock.json‎

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‎sponsor/payment-gateway/js-example/package.json‎ renamed to ‎cex/js-example/package.json‎

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