devprobe

Instant diagnostics for your local dev environment. One command — see every listening port, which process owns it, and whether it responds.

$ npx devprobe

 PORT  | PID   | PROCESS          | STATUS | LATENCY | PROTO
-------|-------|------------------|--------|---------|--------
 3000  | 12841 | node             | UP     | 2ms     | HTTP 200
 5432  | 1023  | postgres         | UP     | 1ms     | TCP
 5500  | 9912  | node             | UP     | 1ms     | HTTP 200
 6379  | 1087  | redis-server     | UP     | <1ms    | TCP
 8080  | 5523  | java             | UP     | 12ms    | HTTP 200
 24282 | 3301  | python           | UP     | 3ms     | HTTP 404

No config. No port lists to maintain. It asks the OS directly what's listening.

Why

• EADDRINUSE — what's using port 3000? Now you know instantly
• AI agents (Claude Code, Cursor, etc.) waste tokens running lsof, parsing output, retrying — devprobe --json gives them structured data in one call
• Zero guesswork — shows ALL listening ports, not just a predefined list

Install

npx devprobe            # run without installing
npm i -g devprobe       # or install globally

Usage

devprobe                # show all listening ports
devprobe 3000           # check specific port
devprobe --range 3000-9000   # scan a range
devprobe --json         # JSON output (for scripts & AI agents)
devprobe --timeout 2000 # custom timeout in ms

Flags

| Flag | Description | Default | |---|---|---| | [port] | Check a single port | — | | --json | Output as JSON | false | | --range <from-to> | Scan a port range | — | | --timeout <ms> | Connection timeout in ms | 1000 | | --version | Show version | — | | --help | Show help | — |

For AI Agents

devprobe --json returns structured data that any AI coding agent can parse:

{
  "ports": [
    {
      "port": 3000,
      "status": "up",
      "pid": 12841,
      "process": "node",
      "latency": 2,
      "protocol": "HTTP 200"
    }
  ]
}

Add to your project's CLAUDE.md or agent config:

Use `devprobe --json` to diagnose port conflicts instead of lsof/netstat.

Platforms

• macOS — full support (lsof)
• Linux — full support (lsof)
• Windows — best-effort (netstat)

Roadmap

• [ ] --watch — realtime monitoring
• [ ] --wait <port> — wait until port is available
• [ ] --diagnose — problem analysis + recommendations
• [ ] Auto-detect service type (PostgreSQL, Redis, MySQL, etc.)
• [ ] Docker container awareness

Support the project

If devprobe saved you time, consider:

• Star this repo — it helps others find it
• Sponsor on GitHub — support development directly
• Share with your team — the more users, the better it gets

License

MIT