# debug\_traceTransaction

### Parameters

1. `Transaction Hash`.
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_traceTransaction",
  "params": [
    "0x00389d11639c3d1b48019208565b4f12e1656762dcd3b91e5865e2c04c4191bf",
    {
      "tracer": "callTracer"
    }
  ],
  "id": 1,
  "jsonrpc": "2.0"
}'
```

{% endcode %}

#### Sample Response

{% code overflow="wrap" %}

```
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "from": "0x9534da06b535910967e52e4dd1b67898d1f112b1",
    "gas": "0x8cbc",
    "gasUsed": "0xa15d",
    "to": "0xdac17f958d2ee523a2206206994597c13d831ec7",
    "input": "0xa9059cbb0000000000000000000000005e85a36599e122204123200fca30d7f6942769a900000000000000000000000000000000000000000000000000000000059a5380",
    "value": "0x0",
    "type": "CALL"
  }
}
```

{% endcode %}