UTM builder
Motif reads utm_source and utm_medium on the first pageview before it looks at ad-click ids or referrers. Source and medium are lowercased. Tags after # never arrive. This builder lowercases for you.
What Motif stores
utm_source, utm_medium, utm_campaign, utm_term, and utm_content from the landing href. First non-empty source/medium pair wins. Later visits do not overwrite first touch.
Assistant presets
If you tag a link that you control, use source chatgpt, claude, perplexity, gemini, or copilot with medium ai_assistant. Examples: a newsletter that mentions an assistant, or a landing that you paste into a custom GPT. Then the UTM matches the names that Motif classifies. A natural click from chatgpt.com already sets that source from the referrer. Do not add a second tag that disagrees with it.