C-Chain Client

Overview

The C-Chain (Contract Chain) Client provides an interface for interacting with Avalanche's Contract Chain, which is an instance of the Ethereum Virtual Machine (EVM) with additional Avalanche-specific features like cross-chain atomic transactions.

When to use: Use the C-Chain Client for EVM operations and atomic transactions (cross-chain transfers).

Installation & Setup

For setup instructions, see the Getting Started guide.

import { createAvalancheClient } from "@avalanche-sdk/client";
import { avalanche } from "@avalanche-sdk/client/chains";

const client = createAvalancheClient({
  chain: avalanche,
  transport: { type: "http" },
});

const cChainClient = client.cChain;

Or create a standalone C-Chain client:

import { createCChainClient } from "@avalanche-sdk/client";

const cChainClient = createCChainClient({
  chain: avalanche,
  transport: { type: "http" },
});

Available Methods

The C-Chain Client provides methods for:

Atomic Transaction Operations: getAtomicTx, getAtomicTxStatus
UTXO Operations: getUTXOs
Transaction Operations: issueTx

Additionally, the C-Chain Client extends viem's Public Client, providing access to all standard EVM actions such as getBalance, getBlock, readContract, call, and more.

For complete method documentation with signatures, parameters, and examples, see the C-Chain Methods Reference.

Common Use Cases

Query Atomic Transactions

// Get atomic transaction details
const atomicTx = await client.cChain.getAtomicTx({
  txID: "2QouvMUbQ6oy7yQ9tLvL3L8tGQG2QK1wJ1q1wJ1q1wJ1q1wJ1q1wJ1q1wJ1",
});

console.log("Source chain:", atomicTx.sourceChain);
console.log("Destination chain:", atomicTx.destinationChain);
console.log("Transfers:", atomicTx.transfers);

// Get atomic transaction status
const status = await client.cChain.getAtomicTxStatus({
  txID: "2QouvMUbQ6oy7yQ9tLvL3L8tGQG2QK1wJ1q1wJ1q1wJ1q1wJ1q1wJ1q1wJ1",
});

console.log("Status:", status.status);

Query UTXOs

// Get UTXOs for C-Chain addresses
const utxos = await client.cChain.getUTXOs({
  addresses: ["0x742d35Cc6634C0532925a3b8D4C9db96C4b4d8b6"],
  limit: 100,
});

console.log("Number of UTXOs:", utxos.utxos.length);

Using viem Actions

The C-Chain Client extends viem's Public Client, so you have access to all standard EVM actions:

// Get EVM balance
const balance = await client.getBalance({
  address: "0x742d35Cc6634C0532925a3b8D4C9db96C4b4d8b6",
});

// Get transaction receipt
const receipt = await client.getTransactionReceipt({
  hash: "0x...",
});

// Get block number
const blockNumber = await client.getBlockNumber();

// Read smart contract
const result = await client.readContract({
  address: "0x...",
  abi: contractABI,
  functionName: "balanceOf",
  args: ["0x..."],
});

// Get block information
const block = await client.getBlock({
  blockNumber: blockNumber,
});

See the viem documentation for all available EVM actions.

Wallet Operations

For transaction operations (sending transactions, writing contracts), use the wallet client:

import { createAvalancheWalletClient } from "@avalanche-sdk/client";
import { privateKeyToAvalancheAccount } from "@avalanche-sdk/client/accounts";
import { parseEther } from "@avalanche-sdk/client/utils";

const account = privateKeyToAvalancheAccount("0x...");
const walletClient = createAvalancheWalletClient({
  account,
  chain: avalanche,
  transport: { type: "http" },
});

// Send AVAX
const txHash = await walletClient.send({
  to: "0x742d35Cc6634C0532925a3b8D4C9db96C4b4d8b6",
  value: parseEther("0.001"),
});

console.log("Transaction hash:", txHash);

Cross-Chain Operations

// Export from C-Chain to P-Chain
const exportTx = await walletClient.cChain.prepareExportTxn({
  destinationChain: "P",
  to: account.getXPAddress("P"),
  amount: "0.001",
});

const exportTxHash = await walletClient.sendXPTransaction(exportTx);
console.log("Export transaction:", exportTxHash);

// Import to C-Chain from P-Chain
const importTx = await walletClient.cChain.prepareImportTxn({
  to: account.getEVMAddress(),
  amount: "0.001",
  sourceChain: "P",
});

const importTxHash = await walletClient.sendXPTransaction(importTx);
console.log("Import transaction:", importTxHash);

For complete wallet operations documentation, see C-Chain Wallet Methods.

Next Steps

C-Chain Methods Reference - Complete method documentation
C-Chain Wallet Methods - Transaction preparation and sending
Wallet Client - Complete wallet operations
P-Chain Client - Validator operations
X-Chain Client - Asset operations

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