> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lunary.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Manual Usage

If your application requires more flexibility and you can't use the decorators, you can use the `track_event` method directly.

Here's a brief overview of how to use it:

```py theme={null}
import lunary

lunary.track_event(
    run_type,
    event_name,
    run_id,
    parent_run_id=None,
    name=None,
    input=None,
    output=None,
    error=None,
    token_usage=None,
    user_id=None,
    user_props=None,
    tags=None,
    params=None,
    metadata=None,
)
```

The parameters are as follows:

* run\_type: The type of the run. It can be "llm", "agent", "tool", "chain" or "embed".
* event\_name: The event. It can be "start", "end", or "error".
* run\_id: A unique identifier for the run.
* parent\_run\_id: (Optional) The unique identifier of the parent run in case of nested run.
* name: (Optional) The name of the model, agent or chain.
* input: (Optional) The input data for the event. Can be any JSON-safe value.
* output: (Optional) The output data for the event. Can be any JSON-safe value.
* error: (Optional) Any error information.
* token\_usage: (Optional) The number of tokens used.
* user\_id: (Optional) The user ID.
* user\_props: (Optional) Any user properties.
* tags: (Optional) Any tags associated with the event.
* params: (Optional) The params passed to entity you're tracking (for example, the `temperature` for an LLM call).
* metadata: (Optional) Any metadata.

Here's an example of how to use it:

```py theme={null}
import uuid
import lunary

run_id = uuid.uuid4()

def my_tool(input):

  lunary.track_event(
      run_type="tool",
      event_name="start",
      run_id=run_id,
      name="my_tool",
      input=input,
      user_id="123",
      tags=["tag1", "tag2"],
  )

  # ...
  # do something
  # ...

  lunary.track_event(
      run_type="tool",
      event_name="end",
      run_id=run_id,
      output={"result": "success"},
  )
```