# tracer

The tracer object with the following fields:

* `tracer` - string - The type of tracer. It could be `callTracer` or `prestateTracer`. 
  * `callTracer` - The calltracer keeps track of all call frames, including depth 0 calls, that are made during a transaction
  * `prestateTracer` - The prestateTracer replays the transaction and tracks every part of state that occured during the transaction
  * If not set, generate an execution trace for every evm step.
* `tracerConfig` - object - The object to specify the configurations of the tracer
  * `onlyTopCall` - boolean - When set to true, this will only trace the primary (top-level) call and not any sub-calls. It eliminates the additional processing for each call frame

## Example

```Text JSON
{
	"tracer": "callTracer",
	"tracerConfig": {
		"onlyTopCall": false
	}
}
```