Mistral: Invalid Request Parameters (422)

The Mistral API does not support all OpenAI-compatible parameters and strictly rejects any extra fields in the request body. When tools configured as OpenAI-compatible providers — LiteLLM, LobeChat, Chatbox — send OpenAI-specific parameters like frequency_penalty, presence_penalty, or message-level id fields, Mistral returns HTTP 422 with an extra_forbidden Pydantic validation error. This is one of the most common errors for developers migrating from OpenAI to Mistral.