yagni

yagni is a cursor rule for Cursor from hutchic/.cursor. It costs 917 tokens per session, scanned A, original, no licence file.

A design rule based on “You Aren’t Gonna Need It,” which says to avoid building abstractions or shared infrastructure before real examples require them.

In plain words
What is it for?
Use it when designing or reviewing plans and code to check whether a proposed abstraction, schema, or generic system has at least two concrete uses.
Why use it?
It reduces unnecessary code and prevents plans from becoming more complex than the current needs justify.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

Good fit Use it when designing or reviewing plans and code to check whether a proposed abstraction, schema, or generic system has at least two concrete uses.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/hutchic/.cursor/yagni
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.

Clone the repo
git clone --depth 1 https://github.com/hutchic/.cursor

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 yagni

README.md
[![agentmods](https://agentmods.dev/badge/rules/hutchic/.cursor/yagni/github.svg)](https://agentmods.dev/rules/hutchic/.cursor/yagni)
Your own site
<a href="https://agentmods.dev/rules/hutchic/.cursor/yagni"><img src="https://agentmods.dev/badge/rules/hutchic/.cursor/yagni/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 yagni

Your own site · 80×15
<a href="https://agentmods.dev/rules/hutchic/.cursor/yagni"><img src="https://agentmods.dev/badge/rules/hutchic/.cursor/yagni.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 917 This file is loaded in full into every session.
When invoked 917 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown 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 $0.00917 $0.00917
Opus 5 $0.00458 $0.00458
Sonnet 5 $0.00183 $0.00183
Haiku 4.5 $0.00092 $0.00092

Measured 8d ago against content hash f8257b9b78b3, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

yagni 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 8d 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/meta/yagni.mdc · 67 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 8d ago First seen · 67 lines · 917 tokens per session scan A f8257b9b78b3

Subscribe to this mod's changes

yagni is a cursor rule published in the GitHub repository hutchic/.cursor (10 stars, last pushed 4mo ago), with no licence file. It adds 917 tokens to every session, about $0.0046 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.