# eth_newFilter > For the complete documentation index, see [llms.txt](/docs/llms.txt). POST https://pharos-mainnet.g.alchemy.com/v2/{apiKey} Creates a filter object based on filter options to notify when state changes (logs). Reference: https://www.alchemy.com/docs/chains/pharos/pharos-api-endpoints/eth-new-filter ## Parameters | Name | Type | Required | Description | |------|------|----------|-------------| | Filter | object | Yes | The filter options object to specify the filter criteria for logs. | ## Result **Filter identifier** (string): A hexadecimal string representing the ID of the created filter. ## Example ### Request ```json { "jsonrpc": "2.0", "method": "eth_newFilter", "params": [ { "fromBlock": "0x137d3c2", "toBlock": "0x137d3c3", "address": "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2", "topics": [] } ], "id": 1 } ``` ### Response ```json { "jsonrpc": "2.0", "result": "0x01", "id": 1 } ``` ## Code Examples ### cURL ```bash curl --request POST \ --url https://pharos-mainnet.g.alchemy.com/v2/docs-demo \ --header 'Content-Type: application/json' \ --data '{ "jsonrpc": "2.0", "id": 1, "method": "eth_newFilter", "params": [ { "fromBlock": "0x137d3c2", "toBlock": "0x137d3c3", "address": "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2", "topics": [] } ] }' ``` ### JavaScript ```javascript const options = { method: 'POST', headers: {'Content-Type': 'application/json'}, body: JSON.stringify({ jsonrpc: '2.0', id: 1, method: 'eth_newFilter', params: [ { fromBlock: '0x137d3c2', toBlock: '0x137d3c3', address: '0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2', topics: [] } ] }) }; fetch('https://pharos-mainnet.g.alchemy.com/v2/docs-demo', options) .then(res => res.json()) .then(res => console.log(res)) .catch(err => console.error(err)); ``` ### Python ```python import requests url = "https://pharos-mainnet.g.alchemy.com/v2/docs-demo" payload = { "jsonrpc": "2.0", "id": 1, "method": "eth_newFilter", "params": [ { "fromBlock": "0x137d3c2", "toBlock": "0x137d3c3", "address": "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2", "topics": [] } ] } headers = {"Content-Type": "application/json"} response = requests.post(url, json=payload, headers=headers) print(response.text) ``` ### Go ```go package main import ( "fmt" "strings" "net/http" "io" ) func main() { url := "https://pharos-mainnet.g.alchemy.com/v2/docs-demo" payload := strings.NewReader("{\n \"jsonrpc\": \"2.0\",\n \"id\": 1,\n \"method\": \"eth_newFilter\",\n \"params\": [\n {\n \"fromBlock\": \"0x137d3c2\",\n \"toBlock\": \"0x137d3c3\",\n \"address\": \"0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2\",\n \"topics\": []\n }\n ]\n}") req, _ := http.NewRequest("POST", url, payload) req.Header.Add("Content-Type", "application/json") res, _ := http.DefaultClient.Do(req) defer res.Body.Close() body, _ := io.ReadAll(res.Body) fmt.Println(string(body)) } ``` ### Java ```java HttpResponse response = Unirest.post("https://pharos-mainnet.g.alchemy.com/v2/docs-demo") .header("Content-Type", "application/json") .body("{\n \"jsonrpc\": \"2.0\",\n \"id\": 1,\n \"method\": \"eth_newFilter\",\n \"params\": [\n {\n \"fromBlock\": \"0x137d3c2\",\n \"toBlock\": \"0x137d3c3\",\n \"address\": \"0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2\",\n \"topics\": []\n }\n ]\n}") .asString(); ``` ### C# ```csharp using RestSharp; var options = new RestClientOptions("https://pharos-mainnet.g.alchemy.com/v2/docs-demo"); var client = new RestClient(options); var request = new RestRequest(""); request.AddJsonBody("{\n \"jsonrpc\": \"2.0\",\n \"id\": 1,\n \"method\": \"eth_newFilter\",\n \"params\": [\n {\n \"fromBlock\": \"0x137d3c2\",\n \"toBlock\": \"0x137d3c3\",\n \"address\": \"0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2\",\n \"topics\": []\n }\n ]\n}", false); var response = await client.PostAsync(request); Console.WriteLine("{0}", response.Content); ``` ## OpenRPC Method Specification ```yaml name: eth_newFilter description: Creates a filter object based on filter options to notify when state changes (logs). params: - name: Filter required: true description: The filter options object to specify the filter criteria for logs. schema: title: filter type: object additionalProperties: false properties: fromBlock: title: from block oneOf: - title: Block number type: string pattern: ^0x([1-9a-f]+[0-9a-f]*|0)$ - title: Block tag type: string enum: - earliest - finalized - safe - latest - pending description: '`earliest`: The lowest numbered block the client has available; `finalized`: The most recent crypto-economically secure block, cannot be re-orged outside of manual intervention driven by community coordination; `safe`: The most recent block that is safe from re-orgs under honest majority and certain synchronicity assumptions; `latest`: The most recent block in the canonical chain observed by the client, this block may be re-orged out of the canonical chain even under healthy/normal conditions; `pending`: A sample next block built by the client on top of `latest` and containing the set of transactions usually taken from local mempool. Before the merge transition is finalized, any call querying for `finalized` or `safe` block MUST be responded to with `-39001: Unknown block` error' description: Block number or tag to start searching from. Defaults to `latest`. toBlock: title: to block oneOf: - title: Block number type: string pattern: ^0x([1-9a-f]+[0-9a-f]*|0)$ - title: Block tag type: string enum: - earliest - finalized - safe - latest - pending description: '`earliest`: The lowest numbered block the client has available; `finalized`: The most recent crypto-economically secure block, cannot be re-orged outside of manual intervention driven by community coordination; `safe`: The most recent block that is safe from re-orgs under honest majority and certain synchronicity assumptions; `latest`: The most recent block in the canonical chain observed by the client, this block may be re-orged out of the canonical chain even under healthy/normal conditions; `pending`: A sample next block built by the client on top of `latest` and containing the set of transactions usually taken from local mempool. Before the merge transition is finalized, any call querying for `finalized` or `safe` block MUST be responded to with `-39001: Unknown block` error' description: Block number or tag to end searching at. Defaults to `latest`. address: title: Address(es) oneOf: - title: Any Address type: 'null' - title: Address type: string pattern: ^0x[0-9a-fA-F]{40}$ - title: Addresses type: array items: title: hex encoded address type: string pattern: ^0x[0-9a-fA-F]{40}$ topics: title: Topics oneOf: - title: Any Topic Match type: 'null' - title: Specified Filter Topics type: array items: title: Filter Topic List Entry oneOf: - title: Single Topic Match type: string pattern: ^0x[0-9a-f]{64}$ - title: Multiple Topic Match type: array items: title: 32 hex encoded bytes type: string pattern: ^0x[0-9a-f]{64}$ result: name: Filter identifier description: A hexadecimal string representing the ID of the created filter. schema: title: hex encoded unsigned integer type: string pattern: ^0x([1-9a-f]+[0-9a-f]*|0)$ examples: - name: eth_newFilter example params: - name: Filter value: fromBlock: '0x137d3c2' toBlock: '0x137d3c3' address: '0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2' topics: [] result: name: Filter identifier value: '0x01' ```