🔌 Connect a deployed contract

Once your provider is initialized, you can connect a contract already deployed in the network.

You need 2 data:

• the address of the contract
• the ABI file of the contract (or the compiled/compressed contract file, that includes the abi)

If you don't have the abi file, the provider.getClassAt() and provider.getClassByHash() commands will recover the compressed contract file. As these methods generate a significant workload to the sequencer/node, it's recommended to store the result in your computer, to be able to reuse it later without using the provider:

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

When possible, prefer to read the compiled contract from a local Json file, as it's much more faster, using the json.parse util provided by Starknet.js, as shown below.

Get the abi from a compiled/compressed file

import { Provider, Contract, json } from 'starknet';

If you have the compiled/compressed file of the contract, use this code to recover all data, including ABI:

const compiledContract = json.parse(
  fs.readFileSync('./compiledContracts/test.json').toString('ascii')
);

Note the json.parse util provided by Starknet.js

Connect the contract

// 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);