eth_getFilterChanges

eth_getFilterChanges returns only what is new on OP Mainnet since you last polled a given filter — log objects for a log filter, block hashes for a block filter, or pending transaction hashes for a pending-tx filter. It pairs with a filter you created earlier (eth_newFilter, eth_newBlockFilter, or eth_newPendingTransactionFilter), so you never re-send the criteria. OP Mainnet is an OP Stack optimistic rollup that settles to Ethereum L1 and charges gas in ETH; with ~2s blocks you get fresh deltas quickly. Send polls to https://optimism.therpc.io/YOUR_API_KEY (chain ID 10, 0xa).

Use cases

• Poll on a short interval for new Velodrome or Synthetix log events without re-specifying the address/topic criteria each time; OP Mainnet's ~2s blocks reward tight polling cadences.
• Drive a block-tick loop on OP Mainnet: call eth_newBlockFilter once, then poll eth_getFilterChanges repeatedly to receive each new block hash as the sequencer produces it.

Parameters

Response

Example request

1curl https://optimism.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 Optimism playground.

Errors & troubleshooting

Common pitfalls

• Filters are dropped after about five minutes of inactivity; catch the filter-not-found error, recreate the filter, and resume polling.
• On log filters, inspect the removed field on each entry — even on an L2 sequencer, unsafe (pre-finalized) blocks can be reorganized and a log may be revoked.
• Tune your cadence: polling every few hundred milliseconds burns CUs needlessly on OP Mainnet's ~2s blocks, while polling slower than the five-minute window risks the filter expiring out from under you.

Supported networks

• Mainnet — Chain ID: 10
• Sepolia — Chain ID: 11155420

See also

• eth_newFilter
• eth_newBlockFilter
• eth_newPendingTransactionFilter
• eth_uninstallFilter

1curl https://optimism.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"]}'