engineering

A set of general programming rules for keeping each function or interface component focused, naming exported code clearly, and handling effects and errors consistently.

In plain words
What is it for?
Use it when designing functions and components, managing calculated values, writing browser effects, handling failures, and extracting shared helpers.
Why use it?
It keeps code easier to read, test, and change by limiting mixed responsibilities and unclear data handling.

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/ddebixx/frontend-template/engineering
Clone the repo
git clone --depth 1 https://github.com/ddebixx/frontend-template

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 159 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00000 $0.00159
Opus 5 $0.00000 $0.00079
Sonnet 5 $0.00000 $0.00032
Haiku 4.5 $0.00000 $0.00016

Measured yesterday against content hash a6a8e6c7df0f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

engineering 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 yesterday.

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/engineering.mdc · 17 lines

What it actually says

Engineering practices

  • One responsibility per function/component; prefer ≤ ~20 lines / ≤ 2 indents
  • Named exports only — no default exports for app code; no React.FC
  • Prefer derived values over storing props/computed data in state
  • useEffect: extract a named inner function; keep deps complete
  • Separated try/catch; avoid returning null/undefined when a clearer type exists
  • Pure helpers in src/utils; comment why, not what

Details: docs/frontend/conventions/ENGINEERING.md

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. yesterday First seen · 17 lines · 0 tokens per session scan A a6a8e6c7df0f

Subscribe to this mod's changes

engineering is a cursor rule published in the GitHub repository ddebixx/frontend-template (3 stars, last pushed 24d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 159 tokens. 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.