dev2

Coding guidelines for a developer working with React, Vite, Bun, TypeScript, Convex, authentication tools, email services, and AI applications. They also set rules for communication, documentation, and product planning.

In plain words
What is it for?
Building or modifying full-stack web and AI applications, reviewing code, writing product documents, and making small changes without breaking existing behavior.
Why use it?
They help keep changes focused, type-safe, testable, and consistent with an existing project while explaining decisions clearly to a newer developer.

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/waynesutton/markdown-site/dev2
Clone the repo
git clone --depth 1 https://github.com/waynesutton/markdown-site

Made for: Cursor.

Per session 866 This file is loaded in full into every session.
When invoked 866 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 $0.00866 $0.00866
Opus 5 $0.00433 $0.00433
Sonnet 5 $0.00173 $0.00173
Haiku 4.5 $0.00087 $0.00087

Measured 2d ago against content hash c5830fa8151b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

dev2 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 2d 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/dev2.mdc · 79 lines

How it starts

The opening of the file, as written. The whole thing — 79 lines — stays where its author put it; the contents beside it link to each section on GitHub.

  • Start by saying "let's cook"
  • Be casual unless otherwise specified. Be terse.
  • Treat me as a new developer. Anticipate needs I didn't think of.
  • Give the answer immediately. Restate the query only if it helps clarify.
  • No moral lectures. No AI disclosure. No knowledge cutoff mentions.
  • Value good arguments over authority. Flag speculation clearly.
  • Cite sources at the end, not inline.

Code quality

  • Always create type-safe code
  • Never break existing functionality
  • Do not over-engineer. Make code precise, modular, and testable.
  • Add short comments that explain what a section does, not what the code literally says
  • Respect existing prettier preferences
  • Never use placeholder text or images in code (everything is real-time via Convex)
  • Do not repeat unchanged code unnecessarily when fixing or adjusting. Show only the diff context.
  • Minimal changes: only touch what is directly necessary for the request
  • Do not do more than what is asked unless it is directly related to fixing or enabling the feature

Tech stack expertise

Read the full file on GitHub · 79 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. 2d ago First seen · 79 lines · 866 tokens per session scan A c5830fa8151b

Subscribe to this mod's changes

dev2 is a cursor rule published in the GitHub repository waynesutton/markdown-site (631 stars, last pushed 3mo ago), licensed MIT. It adds 866 tokens to every session, about $0.0043 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.