What problem does it solve? Interactive lag in the editor—slow typing, stuttering quick open, dropped frames when switching tabs, or sluggish scrolling in large files—is hard to diagnose without structured attribution. This Skill collects interaction performance reports (Event Timing + Long Animation Frame attribution) from real or seeded workspaces and classifies each slowdown as a genuine JavaScript bottleneck, rendering pipeline cost, or environmental noise before any code is changed. ## Core Features & Use Cases - Baseline and real-folder collection: Run seeded e2e tours for deterministic regression comparison, or point the collector at any real workspace folder via UNIVERSE_PERF_WORKSPACE to reproduce lag under real watcher, indexing, and search load. - Three-way diagnosis: Read slow-interaction reports with inputDelay/processing/presentation breakdowns plus LoAF script attribution to distinguish JS bottlenecks from rendering pipeline time and environment noise. - CDP Profiler verification: Confirm suspected JavaScript hotspots with Chrome DevTools Protocol sampling when LoAF attribution is insufficient. - Use Case: A user reports quick open feels laggy in a million-file workspace. Set UNIVERSE_PERF_WORKSPACE to that folder, run the collection spec with a lowered threshold, then read the report to find synchronous full-list scanning in the filter provider and verify the fix by rerunning the spec. ## Quick Start Ask the agent to collect an interaction performance report on a specific folder and diagnose whether the lag is a JavaScript bottleneck or rendering overhead.
