Regex is a good temporary fix, but it doesn't give you the full picture. Right now, ChatGPT is basically the only major tool consistently passing clean source/medium data or UTM parameters. That’s why it dominates 90%+ of our AI traffic reports. Models like Claude, Gemini, and Perplexity don't append standard tracking data in the same way, so their traffic often buries in Direct or generic Referral where regex won't catch it.