Unlike eth_newBlockFilterwhich 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

Object - The filter options:
- fromBlock: QUANTITY|TAG - (optional, default: "latest") Integer block number, or "latest" for the last mined block or "pending", "earliest" for not yet mined transactions.
- toBlock: QUANTITY|TAG - (optional, default: "latest") Integer block number, or "latest" for the last mined block or "pending", "earliest" for not yet mined transactions.
- address: DATA|Array, 20 Bytes - (optional) Contract address or a list of addresses from which logs should originate.
- topics: Array of DATA, - (optional) Array of 32 Bytes DATA topics. Topics are order-dependent. Each topic can also be an array of DATA with “or” options.
```
params: [
	{
		fromBlock: "0x1",
		toBlock: "0x2",
		address: "0x8888f1f195afa192cfee860698584c030f4c9db1",
		topics: [
			"0x000000000000000000000000a94f5374fce5edbc8e2a8697c15331677e6ebf0b",
			null,
			[
				"0x000000000000000000000000a94f5374fce5edbc8e2a8697c15331677e6ebf0b",
				"0x0000000000000000000000000aff3454fce5edbc8cca8697c15331677e6ebccc",
			],
		],
	},
];
```

Returns

QUANTITY - A filter id.

Example

Request

curl https://opt-mainnet.unifra.io/v1/your-api-key \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"eth_newFilter","params":[{"fromBlock": "0x1","toBlock": "0x2","address": "0x8888f1f195afa192cfee860698584c030f4c9db1","topics": ["0x000000000000000000000000a94f5374fce5edbc8e2a8697c15331677e6ebf0b", null, ["0x000000000000000000000000a94f5374fce5edbc8e2a8697c15331677e6ebf0b", "0x0000000000000000000000000aff3454fce5edbc8cca8697c15331677e6ebccc"]]}],"id":0}'

URL: https://opt-mainnet.unifra.io/v1/your-api-key
RequestType: POST
Body:
{
    "jsonrpc":"2.0",
    "method":"eth_newFilter",
    "params":[{"fromBlock": "0x1","toBlock": "0x2","address": "0x8888f1f195afa192cfee860698584c030f4c9db1","topics": ["0x000000000000000000000000a94f5374fce5edbc8e2a8697c15331677e6ebf0b", null, ["0x000000000000000000000000a94f5374fce5edbc8e2a8697c15331677e6ebf0b", "0x0000000000000000000000000aff3454fce5edbc8cca8697c15331677e6ebccc"]]}],
    "id":0
}

Result

{
	"jsonrpc": "2.0",
	"id": 0,
	"result": "0xdcc9a819f80efa9e1d215a9d41b2d22e"
}

🚧
The below parameter inputs do not work, please reference the section above instead.

200200

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