use-vertex() {
  local project="${ANTHROPIC_VERTEX_PROJECT_ID:-sandbox-jason-7023}"
  local region="${CLOUD_ML_REGION:-us-east5}"

  # Probe/refresh ADC
  if ! gcloud auth application-default print-access-token >/dev/null 2>&1; then
    gcloud auth login --update-adc || return 1
  fi

  export CLAUDE_CODE_USE_VERTEX=1
  export ANTHROPIC_VERTEX_PROJECT_ID="$project"
  export CLOUD_ML_REGION="$region"
  export ANTHROPIC_DEFAULT_OPUS_MODEL="${VERTEX_OPUS_MODEL:-claude-opus-4-7}"
  export ANTHROPIC_DEFAULT_SONNET_MODEL="${VERTEX_SONNET_MODEL:-claude-sonnet-4-6}"
  export ANTHROPIC_DEFAULT_HAIKU_MODEL="${VERTEX_HAIKU_MODEL:-claude-haiku-4-5-20251001}"

  # pi google-vertex provider auto-activates with all three present
  export GOOGLE_CLOUD_PROJECT="$project"
  export GOOGLE_CLOUD_LOCATION="$region"

  unset CLAUDE_CODE_USE_BEDROCK CLAUDE_BEDROCK_AWS_REGION

  printf 'Vertex AI environment set.\n\tOpus:   %s\n\tSonnet: %s\n\tHaiku:  %s\n' \
    "$ANTHROPIC_DEFAULT_OPUS_MODEL" "$ANTHROPIC_DEFAULT_SONNET_MODEL" "$ANTHROPIC_DEFAULT_HAIKU_MODEL" >&2
}
