tell-local-dev-server

tell-local-dev-server is a cursor rule for Cursor from ashishpatill/tell-proof. It costs 182 tokens per session, scanned A, original, MIT.

A project rule for running the Tell application's local development server. It requires stopping an existing instance of the same project before starting another.

In plain words
What is it for?
Starting Tell's web, fixture, or generic-app development servers while checking ports 3000 and 3001 and identifying which processes belong to this project.
Why use it?
It prevents multiple copies of the project from competing for ports and helps avoid accidentally stopping unrelated applications.

Cursor rule for Cursor

Install

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.

agentmods
npx agentmods add rules/ashishpatill/tell-proof/tell-local-dev-server
Clone the repo
git clone --depth 1 https://github.com/ashishpatill/tell-proof

Made for: Cursor.

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 tell-local-dev-server

README.md
[![agentmods](https://agentmods.dev/badge/rules/ashishpatill/tell-proof/tell-local-dev-server.svg)](https://agentmods.dev/rules/ashishpatill/tell-proof/tell-local-dev-server)
Your own site
<a href="https://agentmods.dev/rules/ashishpatill/tell-proof/tell-local-dev-server"><img src="https://agentmods.dev/badge/rules/ashishpatill/tell-proof/tell-local-dev-server.svg" alt="Measured on agentmods" height="20"></a>
Per session 182 This file is loaded in full into every session.
When invoked 182 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
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 $0.00182 $0.00182
Opus 5 $0.00091 $0.00091
Sonnet 5 $0.00036 $0.00036
Haiku 4.5 $0.00018 $0.00018

Measured 4d ago against content hash 0f28d9c27a3b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

tell-local-dev-server 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 4d 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.

.cursor/rules/tell-local-dev-server.mdc · 13 lines

What it actually says

Local Dev Server Runs

  • This rule applies only when starting a local dev server for this Tell project.
  • Before running pnpm dev, pnpm -F @tell/web dev, pnpm dev:fixture, pnpm -F @tell/generic-app dev, or an equivalent local server command, first stop any existing local instance of this project.
  • Check active terminals and listening processes for the expected project ports: web on 3000, fixture app on 3001.
  • Only kill processes that are clearly this project's dev servers, such as next dev processes with cwd under this repo. Do not kill unrelated apps that happen to use the same port; report the conflict instead.
  • After the old project instance is stopped and the port is free, start the requested local dev command.
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. 4d ago First seen · 13 lines · 182 tokens per session scan A 0f28d9c27a3b

Subscribe to this mod's changes

tell-local-dev-server is a cursor rule published in the GitHub repository ashishpatill/tell-proof (1 stars, last pushed 9d ago), licensed MIT. It adds 182 tokens to every session, about $0.0009 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 2026-08-31.