NEAR Chain Abstraction Layer (NEAR-CA)

NEAR-CA is a TypeScript library designed to provide an abstraction layer for interacting with the NEAR blockchain, simplifying the process of performing transactions and managing accounts on both NEAR and Ethereum chains. This library is intended for use in server-side applications only.

Features

• EVM Account Derivation from NEAR blockchain.
• Transaction signing and sending on the Ethereum blockchain.
• Key derivation functions for cryptographic operations.
• Support for EIP-1559 transactions on Ethereum.
• Wallet Connect intergration tools.

Usage

CLI

For Ethereum, you can derive addresses, create payloads for transactions, and send signed transactions.

For more detailed usage examples, see the Examples README.

Integrations

near-safe extends this tool kit by using the EOA as an owner of an ERC-4337 Safe account.

Frontend/UI

Install near-ca, run the following command:

yarn add near-ca

Example: Setup NearEthAdapter and Send ETH

Here's an example of how to set up the NearEthAdapter and send ETH:

import dotenv from "dotenv";
import {
  broadcastSignedTransaction,
  convertToAction,
  isRlpHex,
  setupAdapter,
  signatureFromOutcome,
} from "near-ca";

dotenv.config();
const { NEAR_ACCOUNT_ID, NEAR_ACCOUNT_PRIVATE_KEY } = process.env;

const adapter = await setupAdapter({
  accountId: NEAR_ACCOUNT_ID!,
  mpcContractId: MPC_CONTRACT_ID!,
  // privateKey: NEAR_ACCOUNT_PRIVATE_KEY!, // Optional depending on setup
});

const {
  evmMessage,
  nearPayload: { receiverId, actions },
} = await evm.encodeSignRequest({
  method: "eth_sendTransaction",
  chainId: 11_155_111, // Sepolia
  params: [
    {
      from: evm.address,
      to: "0xdeADBeeF0000000000000000000000000b00B1e5",
      value: "0x01", // 1 WEI
      // data: "0x", // Optional
    },
  ],
});
console.log(`Requesting Signature for ${evmMessage}`);
// Using your near Account, send the nearPaylod as signature request:
const nearAccount = adapter.nearAccount();
//
const outtcome = await nearAccount.signAndSendTransaction({
  receiverId,
  actions: actions.map((a) => convertToAction(a)),
});
const signature = signatureFromOutcome(outtcome);
console.log("Signature aquired!");
if (isRlpHex(evmMessage)) {
  // This will be true for what we built above.
  broadcastSignedTransaction({ transaction: evmMessage, signature });
} else {
  // Use Signature for whatever else.
}

Other Examples (CLI)

These examples require Private Key to be supplied:

Each of the following scripts can be run with

npx tsx examples/*.ts

1. (Basic) Send ETH
2. WETH
   • Deposit (aka wrap-ETH)
   • Withdraw (aka unwrap-ETH)
3. Transfer ERC721
4. (Advanced) Buy NFT On Opensea

Configuration

Before using NEAR-CA, ensure you have the following environment variables set in your .env file:

• NEAR_ACCOUNT_ID: Your NEAR account identifier.
• NEAR_ACCOUNT_PRIVATE_KEY: Your NEAR account private key.
• MPC_CONTRACT_ID: The NEAR contract that handles multichain operations.
• NETWORK: Either near or testnet.

Copy the .env.example file and add these values to the .env file.

Steps to get your NEAR_ACCOUNT_ID and NEAR_ACCOUNT_PRIVATE_KEY:

1. Create a Near wallet address, super easy, here: https://wallet.bitte.ai/
2. Your XYZ.near is your NEAR_ACCOUNT_ID.
3. Visit Settings Page
4. Go to "Security & Recovery" -> "Export Account".
5. After the exporting is complete click on "Private Key" and copy it.
6. Paste it to NEAR_ACCOUNT_PRIVATE_KEY in your .env file.