Where visitors came from (sources, UTM tags, AI assistants, AI agents)
Every identified person and company shows a first and latest source, including traffic from ChatGPT, Perplexity, and Claude.
WhoLayer records where each visit started, so you can see which channels bring the people you identify.
What the tag records
On a landing (the start of a visit, or any page view with UTM tags, an ad click, or a link from another site) the tag sends:
- UTM tags:
utm_source,utm_medium,utm_campaign,utm_term,utm_content. - Whether an ad click id was present (
gclid,fbclid,li_fat_id,msclkid): yes or no only. The id itself is never sent or stored. - The referring site, without its query string.
Sources and categories
Each landing becomes one source, like Google Ads, LinkedIn, ChatGPT, Organic search, Direct, or Referral: example.com, in one of these categories: AI assistant, Paid search, Paid social, Organic search, Social, Email, Campaign, Referral, Direct.
Links from ChatGPT, Perplexity, Claude, Gemini, Copilot, and other AI assistants are AI assistant. ChatGPT adds utm_source=chatgpt.com to its links, so those count even when the browser hides the referrer.
Where you see it
- People: a Source column and a Source filter (for example, only people who came from an AI assistant).
- Companies: the latest source, and how many visitors came from AI assistants.
- Each person's page: first and latest source, which visit each came from, and a one-line summary of their journey, like "Compared pricing twice, read the security page, came from LinkedIn". The summary is built by fixed rules, not AI.
- Slack and Teams alerts, CRM notes, webhooks (
data.attribution),GET /visitors, CSV export, and the email digest.
The first source is the first landing we saw from that browser, including before the person was identified. The latest source moves forward with each new landing.
AI agents
AI agents that fetch your pages for a person (ChatGPT-User, Claude-User, Perplexity-User, and agents that sign their requests) are not people. They're never stored as visits, identified, or charged. The Overview coverage table counts them as AI agents. Automated browsers count as bots. Agentic browsers that look exactly like a normal browser can't be told apart from a person.