MobX Spy

MobX Spy is a DevTools extension that lets you profile and inspect all MobX state changes in your application. It hooks into MobX's spy API to capture actions, reactions, observable updates, and more — then presents the results in a clean, grouped view for easy analysis.

How it works

MobX Spy uses a profiler-style workflow. Click Record, interact with your app, then click Stop to see the results. Events are captured silently in the background with zero rendering overhead, so your app's performance stays unaffected during profiling.

What you can see

- Actions, reactions, scheduled reactions, observable updates, additions, removals, splices, errors, and more

- Events grouped by name with count badges — instantly see which actions fire most often