The Ethereum API allows applications to connect to an Ethereum node that is part of the Ethereum blockchain. Developers can interact with on-chain data and send different types of transactions to the network by utilizing the endpoints provided by the API.

Send Your First Request on Alchemy

Let’s use the viem package to create an Ethereum client connected to Alchemy and fetch the latest block number!

npm install --save viem

Create Client Connected to Alchemy

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import { createPublicClient, http } from "viem"; 
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import { mainnet } from "viem/chains";
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const client = createPublicClient({
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  chain: mainnet,
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  transport: http("https://eth-mainnet.g.alchemy.com/v2/YOUR_ALCHEMY_API_KEY"),
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});

Now that you’ve created a client connected to Alchemy, you can continue with some basics:

Get Latest Block Number

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const blockNumber = await client.getBlockNumber();
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console.log("Current block number:", blockNumber);

Get an Address Balance

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const balance = await client.getBalance({ address: "0xab5801a7d398351b8be11c439e05c5b3259aec9b" });
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console.log("Balance (ETH):", Number(balance) / 1e18);

Read Block Data

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const block = await client.getBlock({
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  blockNumber: blockNumber, // from previous example
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});
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console.log(block);

Fetch a Transaction by Hash

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const tx = await client.getTransaction({ hash: "0xYOUR_TX_HASH" });
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console.log(tx);

Fetch Transaction Receipt

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const receipt = await client.getTransactionReceipt({
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  hash: "0xYOUR_TX_HASH"
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});
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console.log(receipt);

Ethereum Tutorials

Check out the following tutorials to learn how to build with Ethereum:

• Build a Web3 Dashboard
• Ethereum Developer Guide to the Merge
• How do I distinguish between a contract address and wallet address?

For full documentation on Web3 libraries, check out the official documentation:

• Viem Documentation - Modern TypeScript interface for Ethereum
• Ethers.js Documentation - Complete Ethereum wallet implementation