Guide
Cookies & sessions
Most “fingerprint failed” panics on ads desks are cookie stories: you pasted yesterday’s BM jar into today’s profile, or three buyers shared one Chromium storage and then acted surprised.
Rules that keep money lanes alive
- One Multilogin profile ≈ one login you care about. Not “the agency Chrome.”
- Never merge cookies across unrelated Business Managers or MCC lanes.
- Export/import only when you understand what you overwrite — Multilogin’s Postman collection has Browser Profile Data / cookie folders; paths move — official API.
- After proxy changes, expect some sessions to invalidate. That is normal.
Warmth vs stolen jars
Warm cookies you earned inside a coherent geo/proxy story. Buying mystery cookie packs and dumping them into Multilogin is how you discover platform abuse systems the expensive way. We don’t facilitate that.
Next
Warmup · Proxy · Ads multi-account · API tokens
Playwright / API ops
When you attach over CDP, you inherit that profile’s jar — do not context.clearCookies() for “clean tests” on money lanes. Sacrificial QA profiles exist for a reason. Token problems are separate: token desk.
Quick failures
- Imported cookies from another geo → sudden logouts and 2FA storms.
- Shared team profile for “just checking Ads Manager” → BM soup.
- Cloud Phone vs browser jars are not interchangeable.
Affiliate disclosure applies.