Request for End-User Usage Tracking for Claude Code on Vertex AI

Hi,

I’d like to monitor the usage and cost of Claude Code for each team member. We are currently using Claude Code through Vertex AI.

Initially, we considered using LiteLLM for this purpose, but after discussions with their team, we learned that end-user tracking is not yet supported.

Could you please suggest how we can enable end-user-level usage tracking in GCP for Claude Code?