/bun:debug

Launch a script with Bun’s debugger enabled for interactive debugging.

Parameters

• file (required): Script file to debug
• --brk: Break at first line (for fast-exiting scripts)
• --wait: Wait for debugger to attach before running
• --port=<port>: Use specific port (default: auto-assigned)

Execution

Standard debug (opens debug URL):

bun --inspect $FILE

Break at first line:

bun --inspect-brk $FILE

Wait for debugger attachment:

bun --inspect-wait $FILE

Custom port:

bun --inspect=$PORT $FILE

Debug tests:

bun --inspect-brk test $PATTERN

Output

The command outputs a debug URL:

------------------- Bun Inspector -------------------
Listening: ws://localhost:6499/
Open: debug.bun.sh/#localhost:6499
-----------------------------------------------------

Post-launch

1. Report the debug URL to user
2. Explain how to connect:
   • Open debug.bun.sh/#localhost:<port> in browser
   • Or use VSCode with Bun extension attached to the WebSocket URL
3. Remind about breakpoint controls (F8 continue, F10 step over, F11 step into)

VSCode Integration

For VSCode debugging, suggest adding to .vscode/launch.json:

{
  "type": "bun",
  "request": "launch",
  "name": "Debug",
  "program": "${file}",
  "stopOnEntry": true
}