Null values passed in API

I think accepting null values would make the endpoint more robust. 
I’m not aware of a downside.

I was working on configuring Letta to work with Venice.ai and I found a problem is that when Letta doesn’t have a value, it sometimes sends ‘null’.
I had errors from max_tokens and tool_choice. I was able to set the tokens in Letta but the tool_choice field is continuing to give me problems.

example:
```
curl https://api.venice.ai/api/v1/chat/completions -H "Authorization: Bearer $VENICE_API_KEY" -H "Content-Type: application/json" -X POST -d '{

"model": "zai-org-glm-4.6",

"messages": [

{"role": "system", "content": "You are Letta, a concise assistant."},

{"role": "user", "content": "Quick connection test—just say hello."}

],

"temperature": 0.6,

"max_completion_tokens": null,

"tool_choice": null

}'
```