finding-dev-server-url

finding-dev-server-url is a skill for Claude Code from spencerpauly/awesome-cursor-skills. It costs 31 tokens per session (826 once invoked), scanned A, original, CC0-1.0.

A procedure for finding the local web addresses of running development servers, such as localhost ports, from terminal output. It can also open the detected app in Cursor's built-in browser.

In plain words
What is it for?
Use it to find the URL and port for a running Next.js, Vite, Create React App, Express, or similar development server, and optionally open that page.
Why use it?
It saves you from searching through terminals to discover which project is running and where. It filters out commands that are not likely to be servers.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter.

Not installable: its command points at a path on the author’s own machine, so it runs nowhere else. The line is /Users/me/app).

Good fit Use it to find the URL and port for a running Next.js, Vite, Create React App, Express, or similar development server, and optionally open that page.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

There is no command for this one: it runs only inside a plugin, and the catalogue could not identify which plugin ships it. The source is linked below.

Made for: Claude Code.

Wrote 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.

agentmods badge for finding-dev-server-url

README.md
[![agentmods](https://agentmods.dev/badge/skills/spencerpauly/awesome-cursor-skills/finding-dev-server-url/github.svg)](https://agentmods.dev/skills/spencerpauly/awesome-cursor-skills/finding-dev-server-url)
Your own site
<a href="https://agentmods.dev/skills/spencerpauly/awesome-cursor-skills/finding-dev-server-url"><img src="https://agentmods.dev/badge/skills/spencerpauly/awesome-cursor-skills/finding-dev-server-url/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.

agentmods 80×15 button for finding-dev-server-url

Your own site · 80×15
<a href="https://agentmods.dev/skills/spencerpauly/awesome-cursor-skills/finding-dev-server-url"><img src="https://agentmods.dev/badge/skills/spencerpauly/awesome-cursor-skills/finding-dev-server-url.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 31 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 826 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00031 $0.00826
Opus 5 $0.00015 $0.00413
Sonnet 5 $0.00006 $0.00165
Haiku 4.5 $0.00003 $0.00083

Measured 9d ago against content hash ee1b5d6b0cfe, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

finding-dev-server-url 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 9d 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

resources/finding-dev-server-url/SKILL.md · 101 lines

How it starts

The opening of the file, as written. The whole thing — 101 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Finding Dev Server URL

Detect which dev servers are running, what ports they're on, and open them.

How It Works

Cursor stores live terminal output in text files. Each terminal has a file at:

<terminals_folder>/<id>.txt

The terminals folder path is provided in your system context. Each file contains metadata (pid, cwd, last command) followed by the full terminal output.

Workflow

1. List All Terminals

ls <terminals_folder>/*.txt

2. Read Each Terminal's Metadata

Read the first ~10 lines of each terminal file to see:

  • pid — process ID
  • cwd — working directory
  • last_command — what's running (e.g. npm run dev, pnpm dev, python manage.py runserver)

Skip terminals where the last command is clearly not a server (e.g. git status, ls, cd).

3. Scan for Server URLs

Read the full content of terminals that look like they're running a server. Search for these patterns:

Framework Pattern
Next.js Local: http://localhost:XXXX or ▲ Ready
Vite Local: http://localhost:XXXX/
Create React App Local: http://localhost:XXXX
Express listening on port XXXX or listening at http://...
Django Starting development server at http://127.0.0.1:XXXX/
Rails Listening on http://127.0.0.1:XXXX
Flask Running on http://127.0.0.1:XXXX
Go Listening on :XXXX or http server started on :XXXX
PHP Development Server (http://localhost:XXXX) started
Remix http://localhost:XXXX
Astro http://localhost:XXXX
Nuxt http://localhost:XXXX

Regex to match most server output:

https?://(localhost|127\.0\.0\.1|0\.0\.0\.0)(:\d+)

Also check for standalone port patterns:

(listening|started|running|ready|serving).*(port\s*|:)\s*(\d{4,5})

4. Report

Print a summary:

Dev servers found:
  Terminal 1 (pid 12345) — npm run dev → http://localhost:3000 (cwd: /Users/me/app)
  Terminal 3 (pid 67890) — python manage.py runserver → http://127.0.0.1:8000 (cwd: /Users/me/api)

Read the full file on GitHub · 101 lines

Changes

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.

  1. 9d ago First seen · 101 lines · 31 tokens per session scan A ee1b5d6b0cfe

Subscribe to this mod's changes

finding-dev-server-url is a skill published in the GitHub repository spencerpauly/awesome-cursor-skills (765 stars, last pushed 1mo ago), licensed CC0-1.0. It adds 31 tokens to every session and 826 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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