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Arbitrum One RPC Endpoint & API

Scaling Ethereum

Connect to Arbitrum One through OnFinality's managed JSON-RPC API over HTTPS and WebSocket. Query contracts and logs, submit transactions, access historical state, and use Arbitrum Trace and Debug APIs without operating your own Nitro node.

Chain ID42161

CurrencyETH

Sign up for a Free Plan to unlock up to 40 req/sec and API Usage and Performance Insights. Get Started

Public endpoint rate limit: 5 req/sec

Quick Start

Mainnet Sepolia

curl -H 'Content-Type: application/json' -d '{"id":1,"jsonrpc":"2.0","method":"eth_blockNumber"}' 'https://arbitrum.api.onfinality.io/public'

curl -H 'Content-Type: application/json' -d '{"id":1,"jsonrpc":"2.0","method":"eth_blockNumber"}' 'https://arbitrum.api.onfinality.io/public'

HTTPs

https://arbitrum.api.onfinality.io/public

https://arbitrum.api.onfinality.io/public

Websocket

wss://arbitrum.api.onfinality.io/public-ws

wss://arbitrum.api.onfinality.io/public-ws

Deploy Dedicated Node

Go to Growth Plan

High Performance
Powerful RPC Analytics
Up to 500 rps
No daily response limit
Priority Support
Decentralized Servers

Get Started

Arbitrum RPC Service Details

Item

Value

Network

Arbitrum One

Chain ID

42161

Native token

ETH

Stack

Arbitrum Nitro

API

Ethereum-compatible JSON-RPC

HTTPS

Supported

WebSocket

Supported

Archive access

Supported

Trace / Debug

Supported on paid plans

Public rate limit

5 RPS

Free authenticated

Up to 40 RPS

Growth

Up to 500 RPS

Regions

Hong Kong / France / N. Virginia

Testnet

Arbitrum Sepolia

Service status

Check details

Independent benchmark

CompareNodes

Arbitrum Trace & Debug API

OnFinality supports standard Ethereum trace/debug methods alongside Arbitrum-specific arbtrace_* methods for transaction analysis, smart-contract debugging, explorers and DeFi analytics.

Trace example

curl -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc":"2.0",
    "method":"debug_traceTransaction",
    "params":["0xTRANSACTION_HASH"],
    "id":1
  }' \
  https://arbitrum.api.onfinality.io/<API_KEY>

Standard Trace

trace_block
trace_call
trace_callMany
trace_filter
trace_replayTransaction
trace_replayBlockTransactions

Debug

debug_traceTransaction
debug_traceCall
debug_traceBlockByHash
debug_traceBlockByNumber

Arbitrum-specific Trace

arbtrace_block
arbtrace_call
arbtrace_callMany
arbtrace_filter
arbtrace_get
arbtrace_replayTransaction
arbtrace_replayBlockTransactions
arbtrace_transaction

Arbitrum Public RPC vs OnFinality

Arbitrum Public RPC

OnFinality

Development reads

✓

Production workloads

No guarantees

✓

HTTPS

✓

WebSocket

✓

Authenticated API

✓

Archive access

Not positioned as managed archive

✓

Trace / Debug

Limited/public endpoint dependent

✓

Analytics

✓

Dedicated infrastructure

✓

Arbitrum's public RPC is useful for development and low-volume reads. Production applications that require WebSockets, archive data, tracing, higher throughput, analytics, or infrastructure isolation can use a managed Arbitrum provider such as OnFinality.

Arbitrum RPC vs Sequencer Endpoint

RPC Provider

Direct Sequencer

Read chain state

✓

eth_call

✓

eth_getLogs

✓

Archive data

✓ provider dependent

Trace / Debug

✓ provider dependent

Submit raw transaction

✓

Main purpose

General app infrastructure

Direct transaction submission

OnFinality's Arbitrum endpoint is a general-purpose RPC endpoint, not a direct Sequencer endpoint.

Resources

Additional Info

Build faster with Arbitrum RPC endpoints

Use OnFinality's Arbitrum RPC APIs to connect wallets, dApps, dashboards, bots, and backend services without operating your own node from day one.

Public endpoint testing

Start with the Arbitrum public RPC endpoint for lightweight checks, prototypes, and quick integration tests.

Authenticated API access

Move production traffic to authenticated endpoints when you need clearer limits, analytics, and operational visibility.

Standard RPC methods

Query Arbitrum blocks, transactions, balances, events, and chain state through HTTP and WebSocket workflows.

Operate Arbitrum infrastructure with more control

Production teams need more than an endpoint URL. They need observability, predictable capacity, and a path from shared RPC access to isolated infrastructure.

Request visibility

Track usage patterns and response activity so your team can understand traffic growth before it becomes an incident.

Dedicated node path

Use dedicated Arbitrum nodes when your workload needs isolated resources, custom operations, or stronger capacity planning.

Archive and historical data

Plan for archive access when analytics, audits, indexers, or advanced app features need older Arbitrum state.

Choose the right Arbitrum RPC setup

Different Arbitrum products need different infrastructure. OnFinality gives teams a practical path from public RPC testing to production-grade API and node operations.