Arbitrum is a Layer 2 scaling solution for Ethereum that leverages optimistic rollups to provide fast and low-cost transactions. Designed to support the needs of decentralized applications (dApps), Arbitrum enhances the scalability and efficiency of Ethereum-based applications while maintaining full EVM compatibility.

The Arbitrum API facilitates interaction with the Arbitrum network through a collection of JSON-RPC methods. Given its compatibility with the Ethereum ecosystem, developers familiar with Ethereum’s JSON-RPC APIs will find working with Arbitrum both intuitive and straightforward.

Send Your First Request on Alchemy

Let’s use the viem package to create an Arbitrum 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 { arbitrum } from "viem/chains";
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const client = createPublicClient({
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  chain: arbitrum,
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  transport: http("https://arb-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);

Arbitrum APIs

For the full list of Arbitrum APIs, see the Arbitrum API Endpoints.