Arbitrum
Arbitrum is an EVM rollup in the Gateway catalog. Its gas token is ETH, and any standard EVM client can talk to the Gateway Access Point without special configuration.
Networks and hosts
| Network | Chain ID | JSON-RPC Host |
|---|---|---|
| Mainnet | 42161 | arb-jsonrpc |
| Sepolia | 421614 | arb-sepolia-jsonrpc |
Chain ID 42161 is Arbitrum One and 421614 is Arbitrum Sepolia; other Arbitrum chains are outside the current supported networks table. Copy the complete Access Point from the dashboard.
Provider coverage
| Provider | Mainnet | Sepolia |
|---|---|---|
| Alchemy | Yes | Yes |
| QuickNode | Yes | Yes |
| Chainstack | Yes | Yes |
| dRPC | Yes | Yes |
| Tenderly | Yes | Yes |
All five integrations cover both Arbitrum networks, so a Route can mix upstreams from several vendors that answer the same reads.
Reads without an Endpoint
Arbitrum uses the EVM Endpoint-free set: eth_blockNumber, eth_getBlockByNumber with ["latest", false] or an explicit hexadecimal height and false, and debug_traceBlockByNumber with the callTracer configuration. Heights refer to Arbitrum block numbers, not L1 blocks. Other parameter variants require a Route; Endpoint-free RPC documents the exact forms and cache behavior.
Verify the network
curl '<arbitrum_access_point>' \
-H 'Authorization: Bearer <app_api_key>' \
-H 'Content-Type: application/json' \
--data '{"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]}'Mainnet returns 0xa4b1; Sepolia returns 0x66eee.
Coverage boundary
One JSON-RPC 2.0 object per HTTP POST. Arbitrum-specific namespaces, trace support, and historical state come from the upstream node; the Gateway routes them but adds no methods of its own.
See Routing and reliability for strategy details and Errors and recovery for Gateway error codes.