The LlmGetTokenUsage function returns token usage statistics for
the specified client session. This information includes token counts
reported by the provider, as well as values maintained by the library for
the current conversation history.
The lpUsage parameter must point to an LLM_TOKEN_USAGE structure
initialized by the caller. The dwSize member must be set to the size of the
structure. This enables the function to validate the structure version
before returning usage information.
Token usage values are intended to help applications monitor request
size, response size and context usage. The exact values reported may vary
by provider and model, and should be treated as informational rather than
as a guarantee of billing or model behavior.
This function returns the usage information currently associated with the
client session. The values are updated as messages are sent and responses
are received.