GradeThread Condition Check & Lister does not read your marketplace accounts and has no "cookies" permission. When you request a condition read, the extension sends the public listing's image URLs and basic details (title, brand, price) to GradeThread's grading service to produce a score; results are not stored on our servers. Your recent reads and settings are stored only on your device. If you sign in, a short-lived access token is stored locally to apply your account's quota and unlock seller tools. Cross-listing runs entirely in your browser; your marketplace passwords and cookies are never sent to GradeThread. Full policy: https://gradethread.com/privacy