cursor-rules

cursor-rules is a cursor rule for coding agents from trianglegrrl/promptonomicon. It costs 334 tokens per session, scanned A, original, MIT.

A project rule set for Promptonomicon, a documentation-led software development process. It defines stages for understanding, designing, planning, coding with test-driven development, documenting, and keeping records in sync.

In plain words
What is it for?
Use it to guide new features, bug fixes, and other major changes, including where to store design and implementation notes and which project tools to consult.
Why use it?
It gives coding agents a consistent process and quality expectations for substantial changes. It also helps prevent undocumented decisions, silent failures, and missing tests.

Cursor rule

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/trianglegrrl/promptonomicon/cursor-rules
Clone the repo
git clone --depth 1 https://github.com/trianglegrrl/promptonomicon

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 cursor-rules

README.md
[![agentmods](https://agentmods.dev/badge/rules/trianglegrrl/promptonomicon/cursor-rules.svg)](https://agentmods.dev/rules/trianglegrrl/promptonomicon/cursor-rules)
Your own site
<a href="https://agentmods.dev/rules/trianglegrrl/promptonomicon/cursor-rules"><img src="https://agentmods.dev/badge/rules/trianglegrrl/promptonomicon/cursor-rules.svg" alt="Measured on agentmods" height="20"></a>
Per session 334 This file is loaded in full into every session.
When invoked 334 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 $0.00334 $0.00334
Opus 5 $0.00167 $0.00167
Sonnet 5 $0.00067 $0.00067
Haiku 4.5 $0.00033 $0.00033

Measured 4d ago against content hash b56e60ebae1b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

cursor-rules 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.

.promptonomicon/ai-assistants/cursor-rules.mdc · 44 lines

What it actually says

Promptonomicon Framework

This project uses the Promptonomicon framework for structured, documentation-driven development.

Primary Rule

For ALL new features, bug fixes, or significant changes: Follow the Promptonomicon process defined in .promptonomicon/PROMPTONOMICON.md

Process Overview

  1. Understand - Investigate requirements thoroughly
  2. Design - Create design documentation in ai-docs/ai-design/
  3. Plan - Build implementation plan in ai-docs/ai-plans/
  4. Develop - Execute with test-driven development
  5. Document - Capture reality in ai-docs/ai-implementation/
  6. Update - Synchronize all documentation

Key Principles

  • Documentation-driven development
  • Fail-hard policy (no silent failures)
  • Test coverage requirements at each step
  • Clean code practices (SOLID, DRY, KISS)

MCP Servers Available

  • versionator: Use for checking latest package versions
  • context7: Use for fetching current library documentation (if API key configured)

File Naming

Use datestamps: date +%Y%m%d

  • Design: ai-docs/ai-design/YYYYMMDD_design_feature_name.md
  • Plan: ai-docs/ai-plans/YYYYMMDD_plan_feature_name.md
  • Implementation: ai-docs/ai-implementation/YYYYMMDD_implementation_feature_name.md

Scratch Directory

Use .scratch/ for temporary work and track progress in .scratch/todo.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. 4d ago First seen · 44 lines · 334 tokens per session scan A b56e60ebae1b

Subscribe to this mod's changes

cursor-rules is a cursor rule published in the GitHub repository trianglegrrl/promptonomicon (7 stars, last pushed 6mo ago), licensed MIT. It adds 334 tokens to every session, about $0.0017 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.