eth_newBlockFilter

eth_newBlockFilter creates a server-side filter on Arbitrum One that tracks new block arrivals and returns a hex filter ID. You then poll that ID with eth_getFilterChanges to receive the hashes of blocks produced since your last poll. Arbitrum One — the ETH-fee Optimistic Rollup on Nitro/ArbOS — gives sub-second soft confirmations from its sequencer, so blocks arrive quickly and you should poll at a brisk cadence to keep up. The endpoint is https://arbitrum.therpc.io/YOUR_API_KEY (chain ID 42161, 0xa4b1).

Use cases

• Trigger block-level processing on every new Arbitrum One block — for example re-checking whether your pending transactions have been included by the sequencer.
• Keep cached on-chain state fresh by invalidating reads (token balances, GMX or Aave positions) each time a new block hash arrives.

Parameters

此方法不需要任何参数，传入空数组 [] 即可。

Response

Example request

1curl https://arbitrum.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H "Content-Type: application/json" \
4  -d '{
5    "jsonrpc": "2.0",
6    "method": "eth_newBlockFilter",
7    "params": [],
8    "id": 1
9  }'

Try it live in the Arbitrum One playground.

Errors & troubleshooting

Common pitfalls

• Polling yields only block hashes, not full blocks — call eth_getBlockByHash for each hash when you need the block's contents.
• Filters are dropped after roughly five minutes without polling; when eth_getFilterChanges returns a filter-not-found error, recreate the filter and resume.
• Arbitrum One's sub-second sequencer confirmations are soft: true finality follows the L1 challenge window, so validate finality before treating block data as irreversible.

Supported networks

• Mainnet — Chain ID: 42161
• Sepolia — Chain ID: 421614

See also

• eth_getFilterChanges
• eth_uninstallFilter
• eth_newFilter
• eth_subscribe

1curl https://arbitrum.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H 'Content-Type: application/json' \
4  -d '{"jsonrpc":"2.0","id":1,"method":"eth_newBlockFilter","params":[]}'