# use the main branch

npm install starknet

# to use latest features (merges in develop branch)

npm install starknet@next

通过 Provider 对象，您可以定义要使用的网络。

import {Provider} from 'starknet';

const provider = new Provider({sequencer: { network: constants.NetworkName.SN_MAIN } })

const provider = new Provider({
  sequencer: {
    baseUrl: 'https://mynetwork.mycompany.io',
    feederGatewayUrl: 'feeder_gateway',
    gatewayUrl: 'gateway',
  }
})} 

import { RpcProvider } from "starknet";
const providerRPC = new RpcProvider({ nodeUrl: "http://192.168.1.99:9545" }); // for a pathfinder node located in a PC in the local network
const pendingTx = await providerRPC.getPendingTransactions();} 

一旦您的提供商初始化，您就可以连接现有帐户。

你需要2条数据：

• 账户地址

• 该账户的私钥

// initialize provider
const provider = new Provider({ sequencer: { baseUrl:"http://127.0.0.1:5050"  } });
// initialize existing pre-deployed account 0 of Devnet
const privateKey = "0xe3e70682c2094cac629f6fbed82c07cd";
const accountAddress = "0x7e00d496e324876bbc8531f2d9a82bf154d1a04a50218ee74cdd372f75a551a";

const account = new Account(provider, accountAddress, privateKey);} 

import fs from "fs";
const compressedContract = await provider.getClassAt(addrContract);
fs.writeFileSync('./myAbi.json', json.stringify( compressedContract.abi, undefined, 2));

// initialize provider
const provider = new Provider({ sequencer: { network: constants.NetworkName.SN_GOERLI } });

// initialize deployed contract
const testAddress = "0x7667469b8e93faa642573078b6bf8c790d3a6184b2a1bb39c5c923a732862e1";
const compiledTest = json.parse(fs.readFileSync("./compiledContracts/test.json").toString("ascii"));

// connect the contract
const myTestContract = new Contract(compiledTest.abi, testAddress, provider);}

与合约交互

要读取余额，您需要连接提供商和合约。你必须使用元类方法来调用Starknet：（contract.function_name(params)这里params没有必要，因为该get_balance函数没有参数）。

import { Provider, Contract, Account, ec, json } from "starknet";
//initialize Provider
const provider = new Provider({ sequencer: { network: constants.NetworkName.SN_GOERLI } });
// Connect the deployed Test contract in Tesnet
const testAddress = "0x5f7cd1fd465baff2ba9d2d1501ad0a2eb5337d9a885be319366b5205a414fdd";

// read abi of Test contract
const { abi: testAbi } = await provider.getClassAt(testAddress);
if (testAbi === undefined) { throw new Error("no abi.") };
const myTestContract = new Contract(testAbi, testAddress, provider);

// Interaction with the contract with call
const bal1 = await myTestContract.get_balance();
console.log("Initial balance =", bal1.res.toString()); // .res because the return value is called 'res' in the Cairo 0 contract.
// With Cairo 1 contract, the result value is in bal1, as bigint.

使用元类

//initialize Provider
const provider = new Provider({ sequencer: { network: constants.NetworkName.SN_GOERLI } });
// connect your account. To adapt to your own account:
const privateKey0 = process.env.OZ_ACCOUNT_PRIVATE_KEY;
const account0Address = "0x123....789";

const account0 = new Account(provider, account0Address, privateKey0);
// add ,"1" after privateKey0 if this account is not a Cairo 0 contract

// Connect the deployed Test contract in Tesnet
const testAddress = "0x5f7cd1fd465baff2ba9d2d1501ad0a2eb5337d9a885be319366b5205a414fdd";

// read abi of Test contract
const { abi: testAbi } = await provider.getClassAt(testAddress);
if (testAbi === undefined) { throw new Error("no abi.") };
const myTestContract = new Contract(testAbi, testAddress, provider);

// Connect account with the contract
myTestContract.connect(account0);

// Interactions with the contract with meta-class
const bal1 = await myTestContract.get_balance();
console.log("Initial balance =", bal1.res.toString()); // Cairo 0 contract
// increase_balance needs 2 felts, to add them to the balance.
const myCall = myTestContract.populate("increase_balance", [10,30]);
const res = await myTestContract.increase_balance(myCall.calldata);
await provider.waitForTransaction(res.transaction_hash);

const bal2 = await myTestContract.get_balance();
console.log("Final balance =", bal2.res.toString());