node-inspect-debugger

Run node inspect path/to/script.js to launch the built-in debugger paused on the first line. Use sb() to set breakpoints, c to continue, n to step over, and repl to evaluate expressions in the current scope.

Send SIGUSR1 to the process with kill -SIGUSR1 <pid> to enable the inspector, then attach with node inspect -p <pid> or connect to the printed WebSocket URL on port 9229.

--inspect starts the inspector but keeps the script running, so early breakpoints may be missed. --inspect-brk pauses on the first line, letting you set breakpoints before any code executes.

Yes, launch with node --inspect-brk --import tsx script.ts. Note that breakpoints hit the emitted JavaScript lines, not the .ts source, unless you enable sourcemaps with a CDP client that follows them.

Common causes are attaching after execution finished, missing --inspect-brk, or setting breakpoints on TypeScript source lines that do not match the emitted JavaScript. Verify targets with curl http://127.0.0.1:9229/json/list.

Use chrome-remote-interface to enable the HeapProfiler or Profiler domains over CDP, then call takeHeapSnapshot or start/stop profiling and write the output to a file for Chrome DevTools analysis.