eth_getLogs

eth_getLogs returns every event log that matches a filter object — you specify a block range (or a single blockHash), an optional contract address, and optional topics, and get back all matching logs in one shot. It is the primary method for backfilling an index and for one-off historical queries, the workhorse behind dashboards and subgraphs on Base. Base is Coinbase's OP Stack optimistic rollup that settles to Ethereum L1 and uses ETH for gas, with ~2s blocks; its dense event stream from DeFi venues like Aerodrome and Uniswap makes scoped filters important. Send queries to https://base.therpc.io/YOUR_API_KEY (chain ID 8453, hex 0x2105).

Use cases

• Backfill Transfer events for an ERC-20 token on Base across a historical block range to build a holder ledger.
• Index DeFi protocol events — Aerodrome gauge votes, Uniswap swaps — into an analytics dashboard by filtering on each contract's address and event topic.
• Reconstruct a contract's current state from its past events when no view function exposes the data directly.
• Verify a specific event was emitted in a given transaction by filtering on blockHash plus the contract address and topic.

Parameters

Response

Example request

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

Try it live in the Base playground.

Errors & troubleshooting

Common pitfalls

• Logs from blocks that are not yet finalized can vanish if Base reorgs them; check the removed field and re-query against finalized before treating an event as settled.
• A wide range with no address or topics filter can time out or hit the block-range and 10,000-result caps — paginate in chunks of roughly 1,000–5,000 blocks, which on Base's ~2s cadence is only minutes of chain time.
• Looping eth_getLogs with fromBlock: "latest" to watch live events wastes calls; install eth_newFilter + eth_getFilterChanges, or use eth_subscribe, for the live tail.

Supported networks

• Mainnet — Chain ID: 8453
• Sepolia — Chain ID: 84532

See also

• eth_newFilter
• eth_getFilterLogs
• eth_subscribe

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