eth_getLogs

Returns an array of all logs matching a filter object. The primary tool for indexing on-chain events.

Caution

Queries that span large block ranges or high-activity contracts can time out or be rejected. Keep fromBlock-to-toBlock ranges under 2,000 blocks for reliable results. Node providers may enforce their own limits.

Tip

Flashblocks: set "fromBlock": "pending" and "toBlock": "pending" against https://mainnet-preconf.base.org to query logs from pre-confirmed transactions, refreshed every ~200ms. For a real-time stream, consider the pendingLogs WebSocket subscription instead.

Parameters

filter (object, required)

Filter options. At least one criterion should be provided.

Field	Type	Description
fromBlock	string	Start of the block range. Block number in hex or a block tag. Pass "pending" on a Flashblocks endpoint to include pre-confirmed logs. Defaults to "latest".
toBlock	string	End of the block range. Block number in hex or a block tag. Defaults to "latest".
address	string | array	A contract address or array of addresses to filter by. Optional.
topics	array	Array of 32-byte topic filters. Each position can be null (match any), a single topic hex string, or an array of hex strings (match any in the array). Position 0 is typically the keccak256 hash of the event signature. Optional.
blockHash	string	Restricts logs to the block with this hash. When supplied, fromBlock and toBlock are ignored. Optional.

Returns

result (array of log objects):

Field	Type	Description
address	string	20-byte address of the contract that emitted the log.
topics	array	Array of 0–4 indexed 32-byte topics. Topic 0 is typically the event signature hash.
data	string	ABI-encoded non-indexed event parameters.
blockNumber	string	Block number in which this log was emitted (hex).
transactionHash	string	32-byte hash of the transaction that emitted this log.
transactionIndex	string	Index of the transaction in the block (hex).
blockHash	string	32-byte hash of the block.
logIndex	string	The log’s index position within the block (hex).
removed	boolean	true if the log was removed due to a chain reorganization.

Example

Request

Standard (block range)

curl https://mainnet.base.org \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getLogs",
    "params": [{
      "fromBlock": "0x12ced00",
      "toBlock": "0x12ced28",
      "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "topics": ["0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"]
    }],
    "id": 1
  }'

Flashblocks (pending, ~200ms)

curl https://mainnet-preconf.base.org \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getLogs",
    "params": [{
      "fromBlock": "pending",
      "toBlock": "pending",
      "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "topics": ["0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"]
    }],
    "id": 1
  }'

Response

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": [
    {
      "address": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
      "topics": [
        "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
        "0x000000000000000000000000d3cda913deb6f4967b2ef66ae97de114a83bcc01",
        "0x0000000000000000000000004200000000000000000000000000000000000006"
      ],
      "data": "0x0000000000000000000000000000000000000000000000000000000005f5e100",
      "blockNumber": "0x12ced28",
      "transactionHash": "0xb903239f8543d04b5dc1ba6579132b143087c68db1b2168786408fcbce568238",
      "transactionIndex": "0x0",
      "blockHash": "0x3a4e8c5d7f2b1a6e9d0c4f8b3e7a2d5c8f1b4e7a0d3c6f9b2e5a8d1c4f7b0e3",
      "logIndex": "0x0",
      "removed": false
    }
  ]
}