Repair Multi-Tab Session Synchronization & State Bugs

The problem

Users get logged out of one tab while remaining logged in on another, or concurrent token refreshes trigger race conditions that invalidate sessions. These synchronization bugs are notoriously difficult to reproduce and often lead to security vulnerabilities or broken user experiences.

What it does

• Identifies race conditions in concurrent token refresh logic across multiple browser tabs.
• Audits storage events and BroadcastChannel implementations for state propagation gaps.
• Maps session generation ownership to prevent stale tabs from overwriting newer authentication states.
• Diagnoses redirect loops caused by inconsistent local storage or cookie states.
• Proposes deterministic fixes using localized mocks and boundary checks instead of flaky timing sleeps.

Why this beats prompting it yourself

General LLMs often suggest "hacks" like setTimeout to fix race conditions, which fail in production. This skill enforces a canonical invariant for session convergence and systematically checks edge cases like offline tab resumption and storage event delivery that are easily overlooked in manual prompts.

Use cases

• Fixing "ghost" sessions where a logged-out user can still perform actions in an old tab.
• Resolving infinite redirect loops on login pages during multi-tab usage.
• Implementing robust cross-tab logout propagation in React or Vue applications.
• Debugging failed JWT refreshes when multiple tabs hit the refresh endpoint simultaneously.

Known limitations

Requires access to session management code or detailed traces of storage events. Cannot verify fixes on production environments without local reproduction steps.