---
title: "Arbitrum API"
description: "Arbitrum One Core RPC API with trace_block, debug_traceCall, archive, and all-history notes"
url: "https://blockreq.com/docs/build/api-reference/arbitrum/"
---

# Arbitrum API

Arbitrum One endpoints use EVM JSON-RPC, including trace and debug methods where available.

## Endpoint

| Item | Value |
| --- | --- |
| Network | Arbitrum One |
| Protocol | EVM JSON-RPC 2.0 |
| Chain ID | `42161` (`0xa4b1`) |
| Public HTTPS | `https://arbitrum-one-rpc.blockreq.com/v1/rpc/public` |
| Private HTTPS | `https://arbitrum-one-rpc.blockreq.com/v1/rpc/BRQ1P0000000000000000000000000000000000000000000000000000000` |
| WSS | `wss://arbitrum-one-rpc.blockreq.com/v1/rpc/BRQ1P0000000000000000000000000000000000000000000000000000000` when enabled |

## Core Methods

See [EVM JSON-RPC Methods](https://blockreq.com/docs/build/api-reference/evm-methods/index.md) for the complete method catalog.

| Capability | Methods |
| --- | --- |
| Latest state | `eth_chainId`, `eth_blockNumber`, `eth_call`, `eth_getBalance` |
| Archive/all history | `eth_getProof`, old-block `eth_call`, old-block `eth_getStorageAt` |
| Trace | `trace_block`, `trace_call`, `trace_filter`, `trace_get`, `trace_transaction`, `trace_replayTransaction` |
| Debug | `debug_traceCall`, `debug_traceTransaction`, `debug_traceBlockByNumber`, `debug_traceBlockByHash` |
| WSS | `eth_subscribe`, `eth_unsubscribe` |

## Trace and Debug Examples

`trace_block` and `debug_traceCall` require a trace/debug-capable provider lane. For `debug_traceCall`, include a tracer object.

```bash
curl -X POST https://arbitrum-one-rpc.blockreq.com/v1/rpc/BRQ1P0000000000000000000000000000000000000000000000000000000 \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"trace_block","params":["latest"],"id":1}'
```

```bash
curl -X POST https://arbitrum-one-rpc.blockreq.com/v1/rpc/BRQ1P0000000000000000000000000000000000000000000000000000000 \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"debug_traceCall","params":[{"to":"0x000000000000000000000000000000000000006e"},"latest",{"tracer":"callTracer"}],"id":1}'
```