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Changes being requested

It appears that the role attribute of ChatCompletionMessage is incorrectly using the type Literal["assistant"] instead of ChatCompletionRole. Messages sent to, and received from, the Chat Completions API can indeed accept all values defined in ChatCompletionRole, and not just "assistant".

Additional context & links

Chat Completions API documentation showing an example with messages of various roles (i.e. assistant, user, system).