# How can i make a new app with flow ,where is my start point
**URL:** https://forum.flow.com/t/how-can-i-make-a-new-app-with-flow-where-is-my-start-point/1825
**Category:** Flow Go SDK
**Tags:** flow-sdk-go
**Created:** [April 28, 2021, 2:35am UTC](https://forum.flow.com/t/how-can-i-make-a-new-app-with-flow-where-is-my-start-point/1825 "2021-04-28T02:35:14Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@darede](https://forum.flow.com/u/darede)
#### Post date: [April 28, 2021, 2:35am UTC](https://forum.flow.com/t/how-can-i-make-a-new-app-with-flow-where-is-my-start-point/1825/1 "2021-04-28T02:35:14Z")
Messrs, i want make app just like NBA\_TOP where should i start ,i had read candence, Flow Emulator, go sdk ,as a Back end ,where could make test env
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### Author:  [@darede](https://forum.flow.com/u/darede)
#### Post date: [April 28, 2021, 3:27am UTC](https://forum.flow.com/t/how-can-i-make-a-new-app-with-flow-where-is-my-start-point/1825/2 "2021-04-28T03:27:24Z")
now ,i want make a go api /create\_acount
i follow the example create random seed an string len 32
then get the privateKey publicKey
then use templates.CreateAccount get a scrpit
c, err := client.New(“[access.devnet.nodes.onflow.org:9000](http://access.devnet.nodes.onflow.org:9000)”, grpc.WithInsecure())
err = tx.SignEnvelope(payer, payerKey.Index, payerSigner)
NewUserAddress = accountCreatedEvent.Address()
finally address is 0000000000000000
Why the address is 0000000000000000
and i don`t konw which step mistake ,there is no panic happen
next is my code
> func (this \*MarketController) Create\_uer() {
> o := orm.NewOrmUsingDB(“default”) // 创建一个 Ormer
> Name := this.GetString(“username”)
> if Name != “” {
>
> ```
> User := new(models.User)
> User.Name = Name
>
> ```
>
> // start make NFT relevant
> ///
> ctx := context.Background()
>
> ```
> random_seed := beegoutils.Random_string()
> // 为账户生成一个新的私钥
> // 注意: 这只是一个例子, 请使用安全的方式随机生成种子
> seed := []byte(random_seed)
> //fmt.Println("seed",seed)
> privateKey, _ := crypto.GeneratePrivateKey(crypto.ECDSA_secp256k1, seed)
> encPrivateKey := privateKey.Encode()
>
> // 得到公钥
> publicKey := privateKey.PublicKey()
>
> // 从公钥中构建一个用户密钥
> accountKey := flow.NewAccountKey().
> SetPublicKey(publicKey).
> SetHashAlgo(crypto.SHA3_256). // SHA3_256 哈希算法生成的密钥对
> SetWeight(flow.AccountKeyWeightThreshold) // 授予这个密钥签名权重
>
> //const rawPublicKey = "9cd98d436d111aab0718ab008a466d636a22ac3679d335b77e33ef7c52d9c8ce47cf5ad71ba38cedd336402aa62d5986dc224311383383c09125ec0636c0b042"
> //publicKey, err := crypto.DecodePublicKeyHex(crypto.ECDSA_P256, rawPublicKey)
>
> var address flow.Address
> // 生成一个帐户创建脚本
> // 这将创建一个帐户，该帐户只有一个公钥，没有代码
> script := templates.CreateAccount([]*flow.AccountKey{accountKey}, nil, address)
>
> // 连接到本地运行的模拟器
> c, err := client.New("access.devnet.nodes.onflow.org:9000", grpc.WithInsecure())
> if err != nil {
> panic(">>>> failed to connect to emulator")
> }
>
> signer := crypto.NewInMemorySigner(privateKey, accountKey.HashAlgo)
>
> payerSigner := signer
> payer := flow.HexToAddress("0xfc98bbf96a3ef8c1")
>
> acc, err := c.GetAccount(ctx, payer)
> println( " address >>> ",acc ,err )
> payerKey := acc.Keys[0]
>
> //(flow.Address, *flow.AccountKey, crypto.Signer)
>
> //payer, payerKey, payerSigner := examples.ServiceAccount(c)
> //fmt.Println("|",script,payer,payerKey,payerSigner)
>
> // 获取 上一个区块头
> //referenceBlockID := examples.GetReferenceBlockId(c)
> isSealed := true
>
> latestBlock, err := c.GetLatestBlock(ctx, isSealed)
> referenceBlockID := latestBlock.ID
> //script_value,_ := script.([]byte)
> tx := flow.NewTransaction().
> SetScript(script.Script).
> SetGasLimit(100).
> SetProposalKey(payer, payerKey.Index, payerKey.SequenceNumber).
> SetPayer(payer)
>
> // Sign the transaction with the service account, which already exists
> // All new accounts must be created by an existing account
>
> // 业务签名
> fmt.Println("payerKey",payerKey,payerKey.Index)
> fmt.Println("payerKey.Index",payerKey.Index)
> fmt.Println("payerSigner",payerSigner)
>
> err = tx.SignEnvelope(payer, payerKey.Index, payerSigner)
> if err != nil {
> panic("failed to sign transaction")
> }
> tx.SetReferenceBlockID(referenceBlockID)
>
> err = c.SendTransaction(ctx, *tx)
> if err != nil {
> fmt.Println("panic %v", err)
> panic("failed to send transaction ")
> }
>
> result, err := c.GetTransactionResult(ctx, tx.ID())
> if err != nil {
> panic("failed to get transaction result")
> }
> // 获取地址
> var myAddress flow.Address
> fmt.Println("result", result)
>
> for _, event := range result.Events {
> if event.Type == flow.EventAccountCreated {
> accountCreatedEvent := flow.AccountCreatedEvent(event)
> myAddress = accountCreatedEvent.Address()
> }
> }
>
> fmt.Println("Account created with address:", myAddress.Hex(), myAddress)
>
> // 准备新增用户所需数据
> User.Address = fmt.Sprintf("%v", myAddress)
> User.PrivateKey = fmt.Sprintf("%v", privateKey)
> User.PublicKey = fmt.Sprintf("%v", publicKey)
> User.AccountKey = fmt.Sprintf("%v", accountKey)
> User.EncprivateKey = fmt.Sprintf("%v", encPrivateKey)
> fmt.Println("PrivateKey", privateKey, "publicKey", publicKey,"seed",seed,"encPrivateKey",encPrivateKey,)
> // 先 创建钱包 再创建用户
>
> wallet := new(models.Wallet)
> wallet.Balance = 100
> w_id, w_err := o.Insert(wallet)
> User.Wallet = wallet
> id, err := o.Insert(User)
>
> //返回插入成功消息
> if err == nil && w_err == nil {
> this.Data["json"] = map[string]interface{}{
> "code": 200, "message": "ok", "id": id, "wallet_id": w_id,
> }
> this.ServeJSON()
> } else {
> this.Data["json"] = map[string]interface{}{
> "code": 200, "message": "fails", "id": id, "res": " inseart mysql fails %v, $v " + fmt.Sprintf("", err, ) + fmt.Sprintf("", w_err),
> }
> this.ServeJSON()
> }
>
> ```
>
> } else {
> this.Data[“json”] = map[string]interface{}{
> “code”: 200, “message”: “fails”, “resule”: “miss username parmas”,
> }
> this.ServeJSON()
> }
>
> }
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### Author:  [@flowjosh](https://forum.flow.com/u/flowjosh)
#### Post date: [April 29, 2021, 7:34pm UTC](https://forum.flow.com/t/how-can-i-make-a-new-app-with-flow-where-is-my-start-point/1825/3 "2021-04-29T19:34:17Z")
What error are you getting?