# debug\_traceBlockByHash

### Parameters

1. `Blockhash` - the hash of the block to be traced.
2. `Tracer` - choose from one of these options:
   * `4byteTracer` - Solidity contract functions are [addressed](https://docs.soliditylang.org/en/develop/abi-spec.html#function-selector) using the first four byte of the Keccak-256 hash of their signature. This `tracer` monitors and analyzes the usage of specific function signatures within smart contracts by capturing their unique first four bytes.
   * `callTracer` - collects data about all call frames executed within a transaction, creating a hierarchical list of call frames structured mirroring the EVM's operations. This is useful for debugging and analytical purposes.
   * `prestateTracer` - captures and analyzes the state of the blockchain before the execution of a specific transaction. It helps in understanding the state changes and effects that a transaction will have on the blockchain's data and accounts before the transaction is actually executed.
   * `noopTracer` - returns empty results. This is used for testing purpose.
   * `opcountTracer` - count and track the number of operations (or opcodes) executed during a specific transaction.
   * `unigramTracer` - counts the frequency of occurrence of each opcode.
   * `bigramTracer` - a bigram refers to a sequence of two bytes or characters. This tracer is designed to observe and provide insights into the patterns and occurrences of these two-byte sequences as they appear within the data of executed transactions.
   * `trigramTracer` - a trigram refers to a sequence of three bytes or characters. This tracer is designed to observe and provide insights into the patterns and occurrences of these three-byte sequences as they appear within the data of executed transactions.
   * `evmdisTracer` - generates the bytecode disassembly of executed transactions, providing developers with insights into how smart contracts operate at a low-level bytecode level for debugging, security audits, and performance optimization purposes.

#### Sample Request

{% code overflow="wrap" %}

```
curl https://lb.nodies.app/v1/<INSERT URL> \
   -H "x-api-key: <API-KEY>" \
   -X POST \
   -H "Content-Type: application/json" \
   -d '{ 
  "method": "debug_traceBlockByHash",
  "params": [
    "0xe7b411f474a917139a34428450a1472d7516bc4f156647f5694d4cd376fdac8c",
    {
      "tracer": "prestateTracer"
    }
  ],
  "id": 1,
  "jsonrpc": "2.0"
}'
```

{% endcode %}

#### Sample Response

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": [
    {
      "result": {
        "0x2a65aca4d5fc5b5c859090a6c34d164135398226": {
          "balance": "0x10ba0751b58644a920",
          "nonce": 797
        },
        "0x6fcd2bc280cebdb8b56a36bcf2e91a499eefcacb": {
          "balance": "0x2710",
          "nonce": 1
        },
        "0x790b8a3ce86e707ed0ed32bf89b3269692a23cc1": {
          "balance": "0x16482bba30e7c601b",
          "nonce": 627
        }
      }
    }
  ]
}
```