What is the Arbitrum RPC URL?

The Arbitrum One RPC URL with BoltRPC is https://endpoints.boltrpc.io/rpc/YOUR_API_KEY/arbitrum. Replace YOUR_API_KEY with your API key from dashboard.boltrpc.io. The chain ID is 42161.

How do I add Arbitrum to MetaMask?

Open MetaMask, go to Settings, then Networks, then Add Network, and enter: Network Name: BoltRPC Arbitrum, RPC URL: https://endpoints.boltrpc.io/rpc/YOUR_API_KEY/arbitrum, Chain ID: 42161, Currency Symbol: ETH, Block Explorer: https://arbiscan.io.

What is the difference between Arbitrum One and Arbitrum Nova?

Arbitrum One is an Optimistic Rollup settling to Ethereum, used by most DeFi protocols. Arbitrum Nova is an AnyTrust chain optimized for gaming and social apps. BoltRPC supports Arbitrum One (Chain ID 42161).

Is Arbitrum good for MEV bots and trading infrastructure?

Yes. Arbitrum One is one of the most active chains for on-chain trading. MEV bots and trading scripts require a reliable RPC provider - public endpoints cannot handle production trading volume.

What is the Arbitrum Nitro upgrade?

Arbitrum Nitro is the current Arbitrum stack, introduced in 2022. It replaced Arbitrum Classic and brought higher throughput, lower fees, and better EVM compatibility. All current Arbitrum One applications run on Nitro.

Does BoltRPC support WebSocket for Arbitrum?

Yes. BoltRPC provides WebSocket endpoints for Arbitrum at wss://endpoints.boltrpc.io/ws/YOUR_API_KEY/arbitrum. WebSocket is used for subscribing to new blocks and monitoring pending transactions.

How does Arbitrum Optimistic Rollup finality work?

Arbitrum One uses Optimistic Rollup, posting transactions to Ethereum in batches with a 7-day challenge period. After the period expires, the batch achieves Ethereum L1 finality. For most applications, sequencer confirmation is sufficient. Bridge withdrawals must wait for the full challenge period.

Arbitrum RPC Endpoint

Trading bots, perps and DeFi protocols hammer Arbitrum One. Get a dedicated endpoint with WebSocket streams and predictable request-unit billing.

chain id · 42161JSON-RPC 2.0WebSocketPartial archiveDebug

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LIVE LATENCY

13ms

LIVE

gateway round-trip · sampled every second

IN PRODUCTION AT Chainlink

Your endpoint, ready in one line.

Drop this URL into your RPC client, HTTP library or wallet config. No SDK install required.

HTTPS

https://endpoints.boltrpc.io/rpc/YOUR_API_KEY/arbitrum

WEBSOCKET

wss://endpoints.boltrpc.io/ws/YOUR_API_KEY/arbitrum

Replace YOUR_API_KEY with your API key. Get a free key →

Pick your stack.

Copy-paste examples for the libraries you already use. Swap the API key, hit run.

import { ethers } from "ethers";

const provider = new ethers.JsonRpcProvider(
  "https://endpoints.boltrpc.io/rpc/YOUR_API_KEY/arbitrum"
);
const block = await provider.getBlockNumber();

import { createPublicClient, http } from "viem";
import { arbitrum } from "viem/chains";

const client = createPublicClient({
  chain: arbitrum,
  transport: http("https://endpoints.boltrpc.io/rpc/YOUR_API_KEY/arbitrum"),
});

curl https://endpoints.boltrpc.io/rpc/YOUR_API_KEY/arbitrum \
  -X POST \
  -H "Content-Type: application/json" \
  --data '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'

Connect your dApp, bot, or protocol to Arbitrum One with BoltRPC. Transparent, published request-unit pricing means predictable costs as your trading infrastructure scales.

Chain at a Glance


Chain ID	42161
Protocol	Optimistic Rollup (Nitro) on ETH
Block time	~0.25 s
Native token	ETH
Finality	Ethereum L1 finality ~7 days (challenge period)
EVM compatible	Yes

What Arbitrum is Built For

Arbitrum One is Ethereum’s largest L2 by total value locked. It exists to run DeFi at Ethereum security without Ethereum mainnet fees. GMX, Uniswap V3, Aave, Camelot and hundreds of high-frequency trading protocols operate here. Arbitrum Nitro’s sub-second block production means the chain processes blocks faster than most public RPC providers can keep up. MEV bots, arbitrage systems and liquidation bots are among the heaviest Arbitrum RPC consumers, all of them running concurrent requests at sustained volume.

Built for teams that ship on Arbitrum.

Predictable request-unit pricing

BoltRPC offers fixed monthly plans starting at $49. Visit boltrpc.io/pricing for full plan details. DEX event monitoring, liquidation log scanning, and batch receipt fetching all run on predictable, published per-method request-unit pricing, with no hidden multipliers.

Arbitrum's 250ms blocks demand a provider that keeps up

At Nitro's block speed, your application can receive new blocks faster than a congested or rate-limited public endpoint can serve them. BoltRPC's infrastructure is built for high-frequency polling and concurrent request patterns that Arbitrum DeFi requires.

Built for MEV and arbitrage workloads

Arbitrum One is one of the most active MEV environments in Web3. Searchers, arbitrage bots, and sandwich traders all run sustained concurrent request loads against their RPC. Public Arbitrum endpoints cannot handle this volume.

WebSocket for L2 batch timing

Arbitrum posts transaction batches to Ethereum at intervals. Trading systems that need to track L1 batch inclusion can subscribe via WebSocket to monitor sequencer output in real time.

Full Nitro JSON-RPC surface

BoltRPC supports the complete Arbitrum Nitro JSON-RPC specification including all eth_* methods and Arbitrum-specific methods.

One provider for Arbitrum and ApeChain

ApeChain is also built on Arbitrum AnyTrust. If you are building across the Arbitrum ecosystem, BoltRPC supports both Arbitrum One and ApeChain from one API key.

Full JSON-RPC coverage.

Every standard Arbitrum method you would expect. Archive-only methods are available on request for qualifying plans.

STANDARD6

eth_calleth_estimateGaseth_sendRawTransactioneth_getBlockByNumbereth_getLogseth_getTransactionReceipt

Arbitrum, explained.

Common questions about connecting to Arbitrum over BoltRPC.

Ask a question →Read the docs

: The Arbitrum One RPC URL with BoltRPC is https://endpoints.boltrpc.io/rpc/YOUR_API_KEY/arbitrum. Replace YOUR_API_KEY with your API key from dashboard.boltrpc.io. The chain ID is 42161.
: Open MetaMask, go to Settings, then Networks, then Add Network, and enter: Network Name: BoltRPC Arbitrum, RPC URL: https://endpoints.boltrpc.io/rpc/YOUR_API_KEY/arbitrum, Chain ID: 42161, Currency Symbol: ETH, Block Explorer: https://arbiscan.io.
: Arbitrum One is an Optimistic Rollup that settles to Ethereum. It is the main Arbitrum chain used by most DeFi protocols, with all transaction data posted to Ethereum for full decentralized security. Arbitrum Nova is an AnyTrust chain optimized for high-throughput, low-cost use cases like gaming and social apps. AnyTrust uses a Data Availability Committee to store transaction data off-chain, reducing costs while accepting a lower trust assumption than full Ethereum data availability. ApeChain is also built on Arbitrum AnyTrust. BoltRPC supports Arbitrum One (Chain ID 42161) and ApeChain.
: Yes. Arbitrum One is one of the most active chains for on-chain trading. MEV bots, arbitrage infrastructure, and high-frequency trading scripts all run on Arbitrum. These workloads require a reliable RPC provider, as public Arbitrum endpoints cannot handle the request volume from production trading systems. A single MEV searcher may run hundreds of concurrent eth_call simulations per second to evaluate potential trades before the next block is produced. At Arbitrum's 250ms block speed, the window for each decision is very short, making RPC reliability a direct competitive factor for searchers.
: Arbitrum Nitro is the current version of the Arbitrum stack, introduced in 2022. It replaced the original Arbitrum Classic architecture and brought major improvements: higher throughput, lower fees, and better EVM compatibility. All current Arbitrum One applications run on Nitro. The Nitro architecture compiles EVM bytecode to WASM for execution, which is what enables Arbitrum's high throughput and low fees while maintaining full EVM compatibility. BoltRPC supports the full Nitro JSON-RPC surface including Arbitrum-specific extensions for sequencer interaction and batch tracking.
: Yes. BoltRPC provides WebSocket endpoints for Arbitrum at wss://endpoints.boltrpc.io/ws/YOUR_API_KEY/arbitrum. WebSocket is commonly used on Arbitrum for subscribing to new blocks and monitoring pending transactions in trading systems.
: Arbitrum One uses Optimistic Rollup, which means transactions are considered valid by default and posted to Ethereum in batches. There is a 7-day challenge period during which fraud proofs can be submitted to contest invalid transactions. After the challenge period expires, the transaction batch achieves Ethereum L1 finality. For most applications, sequencer confirmation is sufficient, but bridge withdrawals must wait for the full challenge period.

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