Alchemy blockchain connector

alchemy_poc.js

// index.js
process.loadEnvFile();
const { APP_ID, API_KEY, ALCHEMY_NETWORK = "eth-sepolia" } = process.env;

console.log(`Using APP_ID=${APP_ID}`);

class AlchemyConnector {
  constructor({ apiKey, network }) {
    this.httpUrl = `https://${network}.g.alchemy.com/v2/${apiKey}`;
    this.id = 0;
  }

  async rpc(method, params = []) {
    const body = { jsonrpc: "2.0", id: ++this.id, method, params };
    const res = await fetch(this.httpUrl, {
      method: "POST",
      headers: { "content-type": "application/json" },
      body: JSON.stringify(body),
    });

    let text;
    try {
      text = await res.text();
      const data = JSON.parse(text);
      if (data.error) throw new Error(data.error.message);
      return data.result;
    } catch (err) {
      throw new Error(
        `RPC error (${res.status}): ${err.message}\nBody: ${text?.slice(0, 200)}`
      );
    }
  }

  getBlockNumber() {
    return this.rpc("eth_blockNumber");
  }

  getBalance(address, block = "latest") {
    return this.rpc("eth_getBalance", [address, block]);
  }
}

const alch = new AlchemyConnector({ apiKey: API_KEY, network: ALCHEMY_NETWORK });

(async () => {
  try {
    const blockHex = await alch.getBlockNumber();
    console.log("Current block:", parseInt(blockHex, 16));
  } catch (e) {
    console.error(e.message);
  }
})();