Dev Tools · 14h ago
Chrome extension developer reveals MV3 cookie trap for AI usage trackers
A developer built AI Karma Tracker to monitor usage limits across six AI tools from one Chrome extension. Manifest V3 service workers cannot carry SameSite cookies, causing authentication failures on cross-origin fetches. The fix required moving API calls to content scripts running on the provider's domain.
Meridian48 take
The post is a useful technical deep-dive into MV3's cookie limitations, but the core problem—service workers lacking first-party cookies—is well-documented; the real value is the specific workaround for AI tool APIs.
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I built a Chrome extension that reads AI usage limits, and MV3 cookies nearly broke me →
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