Traffic Context

Traffic context is the backbone of personalization. It captures where a visitor came from and uses that to personalize everything — page layout (SDUI), pricing, offers, and content.

What's Captured

Field	Source	Example
bev	Cookie (auto-set)	1712345_abcdef
partner_id	Query param or header	VISA
utm_source	Query param	google
utm_medium	Query param	cpc
utm_campaign	Query param	summer_2026
traffic_source	Auto-classified	PARTNER, PAID, ORGANIC
referrer_url	Referer header	https://facebook.com/post
device_type	User-Agent	MOBILE, DESKTOP
ip_address	X-Forwarded-For	203.0.113.42
loyalty_tier	From user account	2 (Gold)

How It's Used

Traffic Context
  │
  ├─ SDUI → Visibility rules filter sections/blocks
  ├─ Pricing → PricingContextService matches rules → PricingAdjustment
  ├─ Offers → Filtered by PricingAdjustment (disable/whitelist)
  └─ Analytics → visitor_session table for attribution

The Key Insight

Frontend does nothing. The backend:

1. Reads the bev cookie (set automatically)
2. Resolves stored traffic context from the last visit
3. Applies it to every API response

Traffic params (partner_id, utm_source) are only needed on the initial landing URL.