# Default Parameters (/docs/configuration/librechat_yaml/object_structure/default_params)

**Note** 
- The purpose of this part of the documentation is to help understand what `addParams` and `dropParams` do. You **CANNOT** globally configure the parameters and their values that LibeChat sends by default, it can only be configured within a single endpoint.

Custom endpoints share logic with the OpenAI endpoint, and thus have default parameters tailored to the OpenAI API.

```yaml filename="Default Parameters"
{
  "model": "your-selected-model",
  "user": "LibreChat_User_ID",
  "stream": true,
  "messages": [
    {
      "role": "user",
      "content": "hi how are you",
    },
  ],
}
```

### Breakdown
- `model`: The selected model from list of models.
- `user`: A unique identifier representing your end-user, which can help OpenAI to [monitor and detect abuse](https://platform.openai.com/docs/api-reference/chat/create#chat-create-user).
- `stream`: If set, partial message deltas will be sent, like in ChatGPT. Otherwise, generation will only be available when completed.
- `messages`: [OpenAI format for messages](https://platform.openai.com/docs/api-reference/chat/create#chat-create-messages); the `name` field is added to messages with `system` and `assistant` roles when a custom name is specified via preset.

**Note:** The `max_tokens` field is not sent to use the maximum amount of tokens available, which is default OpenAI API behavior. Some alternate APIs require this field, or it may default to a very low value and your responses may appear cut off; in this case, you should add it to `addParams` field as shown in the [Custom Endpoint Object Structure](/docs/configuration/librechat_yaml/object_structure/custom_endpoint).