# arc_getCertificate > For the complete documentation index, see [llms.txt](/docs/llms.txt). POST https://arc-mainnet.g.alchemy.com/v2/{apiKey} Returns the Malachite BFT commit certificate for a finalized block on Arc. The certificate contains the consensus round, the finalized block hash, and the base64-encoded validator signatures that decided the block. It is produced by Arc's Malachite consensus layer and is only available for blocks that have already been finalized. Because Arc has deterministic finality on inclusion, once a certificate exists for a given height it is immutable and safe to cache indefinitely. See the [Arc node RPC reference](https://docs.arc.io/arc/tutorials/run-an-arc-node) for background on the `arc` namespace. Reference: https://www.alchemy.com/docs/chains/arc/arc-api-endpoints/arc-get-certificate ## Parameters | Name | Type | Required | Description | |------|------|----------|-------------| | Block height | integer or string | Yes | The block height to fetch the certificate for. Accepts either a decimal integer (for example `7`) or a hex-encoded quantity string (for example `"0x7"`). Must be greater than or equal to `1`. | ## Result **Commit certificate** (object): The commit certificate for the requested block height. ## Example ### Request ```json { "jsonrpc": "2.0", "method": "arc_getCertificate", "params": [ "0x7" ], "id": 1 } ``` ### Response ```json { "jsonrpc": "2.0", "result": { "height": 7, "round": 0, "block_hash": "0x751ccaee8df96f648c9ab00121a4ac1a1bcafc0c8e8cb0d205c67346edb37af2", "signatures": [ { "address": "0x602930d1ab44f1744f42e842b701c2b149c5da4f", "signature": "K3SKb2xKYGWLZ9eMIXtXYckACgU6AaOVwmymD4nIVT6GXvQ9UylllQpSWhTZfuV7oDjo75ynruLh4xHv++jQBA==" }, { "address": "0x6791e002c8419e8a2fa5266e2951ed1780bc2295", "signature": "uNmquXJkx+4NyNnkLUnnRY+1ZZygb5drQbh9ya50oW0z0H9HS21R7PyueayfHoADnJT9DqbDF+D8KECLmy3+Cw==" }, { "address": "0x2e78053671f707844a631bc907d4855894848fe3", "signature": "2/52ncq8uRzHMiBiVxTFk10BzEq9InHfHckBu/qK9fomDNmgOPSuwWURu49EGPDti7Q60If4n7/Qt3dLa2N7CQ==" } ] }, "id": 1 } ``` ## Code Examples ### cURL ```bash curl --request POST \ --url https://arc-mainnet.g.alchemy.com/v2/docs-demo \ --header 'Content-Type: application/json' \ --data '{ "jsonrpc": "2.0", "id": 1, "method": "arc_getCertificate", "params": [ "0x7" ] }' ``` ### JavaScript ```javascript const options = { method: 'POST', headers: {'Content-Type': 'application/json'}, body: JSON.stringify({jsonrpc: '2.0', id: 1, method: 'arc_getCertificate', params: ['0x7']}) }; fetch('https://arc-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://arc-mainnet.g.alchemy.com/v2/docs-demo" payload = { "jsonrpc": "2.0", "id": 1, "method": "arc_getCertificate", "params": ["0x7"] } 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://arc-mainnet.g.alchemy.com/v2/docs-demo" payload := strings.NewReader("{\n \"jsonrpc\": \"2.0\",\n \"id\": 1,\n \"method\": \"arc_getCertificate\",\n \"params\": [\n \"0x7\"\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://arc-mainnet.g.alchemy.com/v2/docs-demo") .header("Content-Type", "application/json") .body("{\n \"jsonrpc\": \"2.0\",\n \"id\": 1,\n \"method\": \"arc_getCertificate\",\n \"params\": [\n \"0x7\"\n ]\n}") .asString(); ``` ### C# ```csharp using RestSharp; var options = new RestClientOptions("https://arc-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\": \"arc_getCertificate\",\n \"params\": [\n \"0x7\"\n ]\n}", false); var response = await client.PostAsync(request); Console.WriteLine("{0}", response.Content); ``` ## OpenRPC Method Specification ```yaml name: arc_getCertificate summary: Returns the Malachite BFT commit certificate for a finalized Arc block at the given height. description: |- Returns the Malachite BFT commit certificate for a finalized block on Arc. The certificate contains the consensus round, the finalized block hash, and the base64-encoded validator signatures that decided the block. It is produced by Arc's Malachite consensus layer and is only available for blocks that have already been finalized. Because Arc has deterministic finality on inclusion, once a certificate exists for a given height it is immutable and safe to cache indefinitely. See the [Arc node RPC reference](https://docs.arc.io/arc/tutorials/run-an-arc-node) for background on the `arc` namespace. x-compute-units: 20 params: - name: Block height required: true description: The block height to fetch the certificate for. Accepts either a decimal integer (for example `7`) or a hex-encoded quantity string (for example `"0x7"`). Must be greater than or equal to `1`. schema: oneOf: - title: Block height (decimal) type: integer minimum: 1 - title: Block height (hex quantity) type: string pattern: ^0[xX][0-9a-fA-F]+$ result: name: Commit certificate description: The commit certificate for the requested block height. schema: title: Commit certificate type: object required: - height - round - block_hash - signatures properties: height: title: Block height description: The block height this certificate finalizes. type: integer minimum: 1 round: title: Consensus round description: The Malachite consensus round in which the block was decided. type: integer minimum: 0 block_hash: title: Block hash description: The 32-byte hash of the block finalized at this height. type: string pattern: ^0x[0-9a-fA-F]{64}$ signatures: title: Validator signatures description: One entry per validator that signed the commit certificate. type: array items: title: Validator signature type: object required: - address - signature properties: address: title: Validator address description: The 20-byte validator address. type: string pattern: ^0x[0-9a-fA-F]{40}$ signature: title: Signature description: Standard padded Base64 encoding of the 64-byte validator signature. type: string examples: - name: arc_getCertificate example params: - name: Block height value: '0x7' result: name: Commit certificate value: height: 7 round: 0 block_hash: '0x751ccaee8df96f648c9ab00121a4ac1a1bcafc0c8e8cb0d205c67346edb37af2' signatures: - address: '0x602930d1ab44f1744f42e842b701c2b149c5da4f' signature: K3SKb2xKYGWLZ9eMIXtXYckACgU6AaOVwmymD4nIVT6GXvQ9UylllQpSWhTZfuV7oDjo75ynruLh4xHv++jQBA== - address: '0x6791e002c8419e8a2fa5266e2951ed1780bc2295' signature: uNmquXJkx+4NyNnkLUnnRY+1ZZygb5drQbh9ya50oW0z0H9HS21R7PyueayfHoADnJT9DqbDF+D8KECLmy3+Cw== - address: '0x2e78053671f707844a631bc907d4855894848fe3' signature: 2/52ncq8uRzHMiBiVxTFk10BzEq9InHfHckBu/qK9fomDNmgOPSuwWURu49EGPDti7Q60If4n7/Qt3dLa2N7CQ== errors: - code: -32004 message: Certificate not found - code: -32602 message: Invalid params (height must be >= 1) ```