Creates a filter object, based on filter options, to notify when the state changes (logs). Unlike eth_newBlockFilter which notifies you of all new blocks, you can pass in filter options to track new logs matching the topics specified.

To check if the state has changed, call eth_getFilterChanges.

A note on specifying topic filters: Topics are order-dependent. A transaction with a log with topics [A, B] will be matched by the following topic filters:

[] “anything”

[A] “A in first position (and anything after)”

[null, B] “anything in first position AND B in second position (and anything after)”

[A, B] “A in first position AND B in second position (and anything after)”

[[A, B], [A, B]] “(A OR B) in first position AND (A OR B) in second position (and anything after)”

PARAMETERS

Filter Options - (required) An object with the following fields:

fromBlock - (optional, default: "latest") An integer block number, or "latest" for the last mined block or "pending", "earliest" for not yet mined transactions.
toBlock - (optional, default: "latest") An integer block number, or "latest" for the last mined block or "pending", "earliest" for not yet mined transactions.
address - (optional) A contract address or a list of addresses from which logs should originate.
topics - (optional) An array of 32-byte DATA topics. Topics are order-dependent. Each topic can also be an array of DATA with “or” options.

REQUEST

{
    "jsonrpc": "2.0",
    "method": "eth_newFilter",
    "params": [
        {
            "fromBlock": "0x1",
            "toBlock": "0x2",
            "address": "0x8888f1f195afa192cfee860698584c030f4c9db1",
            "topics": [
                "0x000000000000000000000000a94f5374fce5edbc8e2a8697c15331677e6ebf0b",
                null,
                [
                    "0x000000000000000000000000a94f5374fce5edbc8e2a8697c15331677e6ebf0b",
                    "0x0000000000000000000000000aff3454fce5edbc8cca8697c15331677e6ebccc"
                ]
            ]
        }
    ],
    "id": 0
}

RESPONSE

Result - A filter ID.

{
    "jsonrpc": "2.0",
    "id": 0,
    "result": "0x433f460405cc3301fc07314056de481e"
}