Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add spencerpauly/awesome-cursor-skills --skill detecting-port-conflictsgit clone --depth 1 https://github.com/spencerpauly/awesome-cursor-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/spencerpauly/awesome-cursor-skills/detecting-port-conflicts)<a href="https://agentmods.dev/skills/spencerpauly/awesome-cursor-skills/detecting-port-conflicts"><img src="https://agentmods.dev/badge/skills/spencerpauly/awesome-cursor-skills/detecting-port-conflicts/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/spencerpauly/awesome-cursor-skills/detecting-port-conflicts"><img src="https://agentmods.dev/badge/skills/spencerpauly/awesome-cursor-skills/detecting-port-conflicts.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00034 | $0.00450 |
| Opus 5 | $0.00017 | $0.00225 |
| Sonnet 5 | $0.00007 | $0.00090 |
| Haiku 4.5 | $0.00003 | $0.00045 |
Grade A, and why
detecting-port-conflicts scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
Copies of this mod
1 near-identical copy found in the catalogue:
- detecting-port-conflicts — 91% identical, 2 lines differ
What it actually says
Detecting Port Conflicts
When a dev server fails to start because a port is already in use, diagnose and resolve it.
Detection
Scan terminal output for these patterns:
EADDRINUSEaddress already in usePort XXXX is already in usebind: address already in useOSError: [Errno 98] Address already in use
Extract the port number from the error message.
Diagnosis
Find what's using the port:
lsof -i :<PORT> -P -n
This shows the PID, process name, and user. Common culprits:
- A previous dev server that didn't shut down cleanly
- Another project's dev server
- A Docker container
- A system service
Resolution Options
Option 1: Kill the blocking process
kill <PID>
# If it doesn't stop:
kill -9 <PID>
Then restart the original server.
Option 2: Use a different port
Suggest the next available port:
# Check if port+1 is free
lsof -i :<PORT+1> -P -n
Update the dev server config or start command:
- Next.js:
next dev -p <PORT> - Vite:
vite --port <PORT> - Express: set
PORTenv var - Django:
python manage.py runserver <PORT>
Option 3: Kill all node processes (nuclear option)
killall node
Only suggest this if the user confirms — it kills everything.
Tips
- On macOS, ports below 1024 require root
- Docker containers bind ports that persist even if the container is stopped — check
docker ps - If
lsofshows nothing, the port may be in TIME_WAIT state — just wait 30 seconds or use a different port
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 12d ago First seen · 76 lines · 34 tokens per session scan A 34a1104759ce
detecting-port-conflicts is a skill published in the GitHub repository spencerpauly/awesome-cursor-skills (770 stars, last pushed 1mo ago), licensed CC0-1.0. It adds 34 tokens to every session and 450 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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