# debug_traceCall > For the complete documentation index, see [llms.txt](/docs/llms.txt). POST https://eth-mainnet.g.alchemy.com/v2/{apiKey} Runs an eth_call within the context of the given block execution using the final state of parent block as the base. Reference: https://www.alchemy.com/docs/node/debug-api/debug-api-endpoints/debug-trace-call ## Parameters | Name | Type | Required | Description | |------|------|----------|-------------| | Transaction Object | object | Yes | The transaction call object. | | Block identifier | string or enum | Yes | Block hash, block number (in hex), or block tag. | | Options | object | No | Options for the call including tracer and state overrides. | ## Result **Call traces** (object[]): Array of call traces. ## Example ### Request ```json { "jsonrpc": "2.0", "method": "debug_traceCall", "params": [ { "type": "0x02", "from": "0xcdd37ada79f589c15bd4f8fd2083dc88e34a2af2", "to": "0xdac17f958d2ee523a2206206994597c13d831ec7", "gas": "0xb59b", "value": "0x0", "data": "0xa9059cbb000000000000000000000000b29d1cef6da3262df35fdee71a176c62687e747d000000000000000000000000000000000000000000000000000000001e3f0ccc", "nonce": "0x8eaee", "accessList": [], "maxPriorityFeePerGas": "0xb2d05e00", "maxFeePerGas": "0x1ceb1eec4" }, "0x154bd82", { "tracer": "callTracer", "stateOverrides": { "0xdac17f958d2ee523a2206206994597c13d831ec7": { "stateDiff": { "0x0000000000000000000000000000000000000000000000000000000000000007": "0x000000000000000000000000000000000000000000000000000000746a528800" } } } } ], "id": 1 } ``` ### Response ```json { "jsonrpc": "2.0", "result": { "type": "CALL", "from": "0xe088776deabb472ffd2843e330e79c880a5f979e", "to": "0x70526cc7a6d6320b44122ea9d2d07670accc85a1", "value": "0x0", "gas": "0x7fffffffffffadf7", "gasUsed": "0x0", "input": "0x", "output": "0x" }, "id": 1 } ``` ## Code Examples ### cURL ```bash curl --request POST \ --url https://eth-mainnet.g.alchemy.com/v2/docs-demo \ --header 'Content-Type: application/json' \ --data '{ "jsonrpc": "2.0", "id": 1, "method": "debug_traceCall", "params": [ { "type": "0x02", "from": "0xcdd37ada79f589c15bd4f8fd2083dc88e34a2af2", "to": "0xdac17f958d2ee523a2206206994597c13d831ec7", "gas": "0xb59b", "value": "0x0", "data": "0xa9059cbb000000000000000000000000b29d1cef6da3262df35fdee71a176c62687e747d000000000000000000000000000000000000000000000000000000001e3f0ccc", "nonce": "0x8eaee", "accessList": [], "maxPriorityFeePerGas": "0xb2d05e00", "maxFeePerGas": "0x1ceb1eec4" }, "string", { "tracer": { "tracer": "callTracer", "tracerConfig": { "onlyTopCall": false } }, "stateOverrides": { "property1": { "stateDiff": { "balance": "string" } } } } ] }' ``` ### JavaScript ```javascript const options = { method: 'POST', headers: {'Content-Type': 'application/json'}, body: JSON.stringify({ jsonrpc: '2.0', id: 1, method: 'debug_traceCall', params: [ { type: '0x02', from: '0xcdd37ada79f589c15bd4f8fd2083dc88e34a2af2', to: '0xdac17f958d2ee523a2206206994597c13d831ec7', gas: '0xb59b', value: '0x0', data: '0xa9059cbb000000000000000000000000b29d1cef6da3262df35fdee71a176c62687e747d000000000000000000000000000000000000000000000000000000001e3f0ccc', nonce: '0x8eaee', accessList: [], maxPriorityFeePerGas: '0xb2d05e00', maxFeePerGas: '0x1ceb1eec4' }, 'string', { tracer: {tracer: 'callTracer', tracerConfig: {onlyTopCall: false}}, stateOverrides: {property1: {stateDiff: {balance: 'string'}}} } ] }) }; fetch('https://eth-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://eth-mainnet.g.alchemy.com/v2/docs-demo" payload = { "jsonrpc": "2.0", "id": 1, "method": "debug_traceCall", "params": [ { "type": "0x02", "from": "0xcdd37ada79f589c15bd4f8fd2083dc88e34a2af2", "to": "0xdac17f958d2ee523a2206206994597c13d831ec7", "gas": "0xb59b", "value": "0x0", "data": "0xa9059cbb000000000000000000000000b29d1cef6da3262df35fdee71a176c62687e747d000000000000000000000000000000000000000000000000000000001e3f0ccc", "nonce": "0x8eaee", "accessList": [], "maxPriorityFeePerGas": "0xb2d05e00", "maxFeePerGas": "0x1ceb1eec4" }, "string", { "tracer": { "tracer": "callTracer", "tracerConfig": { "onlyTopCall": False } }, "stateOverrides": { "property1": { "stateDiff": { "balance": "string" } } } } ] } 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://eth-mainnet.g.alchemy.com/v2/docs-demo" payload := strings.NewReader("{\n \"jsonrpc\": \"2.0\",\n \"id\": 1,\n \"method\": \"debug_traceCall\",\n \"params\": [\n {\n \"type\": \"0x02\",\n \"from\": \"0xcdd37ada79f589c15bd4f8fd2083dc88e34a2af2\",\n \"to\": \"0xdac17f958d2ee523a2206206994597c13d831ec7\",\n \"gas\": \"0xb59b\",\n \"value\": \"0x0\",\n \"data\": \"0xa9059cbb000000000000000000000000b29d1cef6da3262df35fdee71a176c62687e747d000000000000000000000000000000000000000000000000000000001e3f0ccc\",\n \"nonce\": \"0x8eaee\",\n \"accessList\": [],\n \"maxPriorityFeePerGas\": \"0xb2d05e00\",\n \"maxFeePerGas\": \"0x1ceb1eec4\"\n },\n \"string\",\n {\n \"tracer\": {\n \"tracer\": \"callTracer\",\n \"tracerConfig\": {\n \"onlyTopCall\": false\n }\n },\n \"stateOverrides\": {\n \"property1\": {\n \"stateDiff\": {\n \"balance\": \"string\"\n }\n }\n }\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://eth-mainnet.g.alchemy.com/v2/docs-demo") .header("Content-Type", "application/json") .body("{\n \"jsonrpc\": \"2.0\",\n \"id\": 1,\n \"method\": \"debug_traceCall\",\n \"params\": [\n {\n \"type\": \"0x02\",\n \"from\": \"0xcdd37ada79f589c15bd4f8fd2083dc88e34a2af2\",\n \"to\": \"0xdac17f958d2ee523a2206206994597c13d831ec7\",\n \"gas\": \"0xb59b\",\n \"value\": \"0x0\",\n \"data\": \"0xa9059cbb000000000000000000000000b29d1cef6da3262df35fdee71a176c62687e747d000000000000000000000000000000000000000000000000000000001e3f0ccc\",\n \"nonce\": \"0x8eaee\",\n \"accessList\": [],\n \"maxPriorityFeePerGas\": \"0xb2d05e00\",\n \"maxFeePerGas\": \"0x1ceb1eec4\"\n },\n \"string\",\n {\n \"tracer\": {\n \"tracer\": \"callTracer\",\n \"tracerConfig\": {\n \"onlyTopCall\": false\n }\n },\n \"stateOverrides\": {\n \"property1\": {\n \"stateDiff\": {\n \"balance\": \"string\"\n }\n }\n }\n }\n ]\n}") .asString(); ``` ### C# ```csharp using RestSharp; var options = new RestClientOptions("https://eth-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\": \"debug_traceCall\",\n \"params\": [\n {\n \"type\": \"0x02\",\n \"from\": \"0xcdd37ada79f589c15bd4f8fd2083dc88e34a2af2\",\n \"to\": \"0xdac17f958d2ee523a2206206994597c13d831ec7\",\n \"gas\": \"0xb59b\",\n \"value\": \"0x0\",\n \"data\": \"0xa9059cbb000000000000000000000000b29d1cef6da3262df35fdee71a176c62687e747d000000000000000000000000000000000000000000000000000000001e3f0ccc\",\n \"nonce\": \"0x8eaee\",\n \"accessList\": [],\n \"maxPriorityFeePerGas\": \"0xb2d05e00\",\n \"maxFeePerGas\": \"0x1ceb1eec4\"\n },\n \"string\",\n {\n \"tracer\": {\n \"tracer\": \"callTracer\",\n \"tracerConfig\": {\n \"onlyTopCall\": false\n }\n },\n \"stateOverrides\": {\n \"property1\": {\n \"stateDiff\": {\n \"balance\": \"string\"\n }\n }\n }\n }\n ]\n}", false); var response = await client.PostAsync(request); Console.WriteLine("{0}", response.Content); ``` ## OpenRPC Method Specification ```yaml name: debug_traceCall description: Runs an eth_call within the context of the given block execution using the final state of parent block as the base. params: - name: Transaction Object required: true description: The transaction call object. schema: title: Transaction Object type: object properties: from: type: string pattern: ^0[xX][0-9a-fA-F]{40}$ to: type: string pattern: ^0[xX][0-9a-fA-F]{40}$ gas: type: string pattern: ^0[xX]([1-9a-fA-F][0-9a-fA-F]*|0)$ gasPrice: type: string pattern: ^0[xX]([1-9a-fA-F][0-9a-fA-F]*|0)$ value: type: string pattern: ^0[xX]([1-9a-fA-F][0-9a-fA-F]*|0)$ data: type: string pattern: ^0[xX][0-9a-fA-F]*$ - name: Block identifier required: true description: Block hash, block number (in hex), or block tag. schema: oneOf: - title: 32 byte hex value type: string pattern: ^0x[0-9a-f]{64}$ - title: hex encoded bytes type: string pattern: ^0x[0-9a-f]*$ - title: block tag type: string enum: - latest - earliest - pending - name: Options required: false description: Options for the call including tracer and state overrides. schema: type: object properties: tracer: title: Tracer type: object properties: tracer: type: string enum: - callTracer - prestateTracer tracerConfig: type: object properties: onlyTopCall: type: boolean stateOverrides: type: object description: Address-to-state mapping that allows overriding account state additionalProperties: type: object properties: stateDiff: type: object description: Storage slot overrides for the account additionalProperties: type: string properties: balance: type: string description: The balance to override for the account result: name: Call traces description: Array of call traces. schema: type: array description: Array of block traces. items: type: object description: Array of block traces. properties: type: type: string description: CALL or CREATE from: type: string description: 20-byte address of the caller to: type: string description: 20-byte address of the recipient. Null when its a contract creation transaction. value: type: string description: Amount of value included in the transfer (in hex) gas: type: string description: Amount of gas provided for the call (in hex) gasUsed: type: string description: Amount of gas used during the call (in hex) input: type: string description: Call data output: type: string description: Return data error: type: string description: Error message, if any. revertReason: type: string description: Solidity revert reason, if any. calls: type: array description: Array of sub-calls made within the transaction. items: type: object description: Array of block traces. properties: type: type: string description: CALL or CREATE from: type: string description: 20-byte address of the caller to: type: string description: 20-byte address of the recipient. Null when its a contract creation transaction. value: type: string description: Amount of value included in the transfer (in hex) gas: type: string description: Amount of gas provided for the call (in hex) gasUsed: type: string description: Amount of gas used during the call (in hex) input: type: string description: Call data output: type: string description: Return data error: type: string description: Error message, if any. revertReason: type: string description: Solidity revert reason, if any. examples: - name: debug_traceCall example params: - name: Transaction Object value: type: '0x02' from: '0xcdd37ada79f589c15bd4f8fd2083dc88e34a2af2' to: '0xdac17f958d2ee523a2206206994597c13d831ec7' gas: '0xb59b' value: '0x0' data: '0xa9059cbb000000000000000000000000b29d1cef6da3262df35fdee71a176c62687e747d000000000000000000000000000000000000000000000000000000001e3f0ccc' nonce: '0x8eaee' accessList: [] maxPriorityFeePerGas: '0xb2d05e00' maxFeePerGas: '0x1ceb1eec4' - name: Block identifier value: '0x154bd82' - name: Options value: tracer: callTracer stateOverrides: '0xdac17f958d2ee523a2206206994597c13d831ec7': stateDiff: '0x0000000000000000000000000000000000000000000000000000000000000007': '0x000000000000000000000000000000000000000000000000000000746a528800' result: name: debug_traceCall response value: type: CALL from: '0xe088776deabb472ffd2843e330e79c880a5f979e' to: '0x70526cc7a6d6320b44122ea9d2d07670accc85a1' value: '0x0' gas: '0x7fffffffffffadf7' gasUsed: '0x0' input: 0x output: 0x ```