eth_getFilterChanges

eth_getFilterChanges pulls everything that has matched a previously installed filter on Arbitrum One since your last poll. Arbitrum One (chain ID 42161) is an Optimistic Rollup whose sequencer produces sub-second soft confirmations and settles to Ethereum L1 with gas paid in ETH, so a tight poll loop sees new events quickly. Call it against https://arbitrum.therpc.io/YOUR_API_KEY with a filter ID and it returns, depending on the filter type, an array of log objects, block hash strings, or pending transaction hash strings — and an empty array when nothing new has arrived.

Use cases

• Poll on a short interval for new log events — for example token Transfers on Arbitrum One — without resending the filter criteria each time.
• Drive a block-tick loop: call eth_newBlockFilter once, then poll eth_getFilterChanges repeatedly to react to each new sequencer block.

Parameters

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_getFilterChanges",
7    "params": ["0x1"],
8    "id": 1
9  }'

Try it live in the Arbitrum One playground.

Errors & troubleshooting

Common pitfalls

• Filters drop after roughly 5 minutes of inactivity; catch the filter not found error and recreate the filter rather than assuming it lives forever.
• For log filters, check each entry's removed field — Arbitrum's soft-confirmed blocks can be reorganised before they settle to L1, and removed: true marks a log that was rolled back.
• Polling too aggressively burns Compute Units for empty responses; polling too rarely risks the filter expiring between calls — keep the interval comfortably under 5 minutes.

Supported networks

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

See also

• eth_newFilter
• eth_newBlockFilter
• eth_newPendingTransactionFilter
• eth_uninstallFilter

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_getFilterChanges","params":["0x1"]}'