// the find
software-mansion/live-debugger
Tool for debugging LiveView applications
LiveDebugger is a dev-only browser UI for inspecting Phoenix LiveView applications. It attaches to your running app, shows the LiveComponent tree, lets you browse assigns, and traces callback executions in real time. It's from Software Mansion, the same shop behind React Native Reanimated, so the tooling quality shows.
The callback tracing with filtering is genuinely useful — you can watch handle_event, handle_info, and render calls stream in and filter by component or callback type without adding any instrumentation code. The browser DevTools extension (Chrome + Firefox) is a smart call; it means the debugger panel sits next to your app instead of on a separate port. The Igniter installation path is a nice touch for projects already using Ash. The e2e test suite with Playwright gives you confidence that the UI itself isn't broken across versions.
It's strictly dev-only and the README makes this very clear, but there's no production-safe trace export — if you want to understand a bug that only reproduces under load, you're out of luck. The assigns history is ETS-backed and in-process, so it evaporates on restart and doesn't survive node crashes. The tool only works with Phoenix LiveView; if you have any dead views or plain controllers contributing to the problem, you're looking at a different surface. Running on a fixed port (4007) without easy configuration could conflict in teams running multiple Phoenix apps locally.