> For the complete documentation index, see [llms.txt](https://change-chain-1.gitbook.io/change-chain/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://change-chain-1.gitbook.io/change-chain/developer-resources/sdks.md).

# SDKs

SDKs available in languages such as JavaScript

#### **Using the JavaScript SDK (ChangeJS)**

**Example: Interacting with a Smart Contract**

```javascript
// const { ChangeChainProvider, Contract, Wallet } = require('changejs');
const provider = new ChangeChainProvider('https://node.changechain.org');

// ABI and Contract Address
const abi = [
  // ABI array of the contract
];
const contractAddress = '0xCONTRACT_ADDRESS';

// Initialize wallet and contract
const privateKey = '0xYOUR_PRIVATE_KEY';
const wallet = new Wallet(privateKey, provider);
const contract = new Contract(contractAddress, abi, wallet);

// Call a contract function
async function getValue() {
  const value = await contract.functions.getValue();
  console.log('Contract Value:', value);
}

// Send a transaction to the contract
async function setValue(newValue) {
  const tx = await contract.functions.setValue(newValue);
  await tx.wait(); // Wait for transaction confirmation
  console.log('Value Set Successfully');
}

getValue();
setValue(42);
```