rails-cursorrules-prompt-file

rails-cursorrules-prompt-file is a cursor rule for Cursor from ItamarZand88/awesome-agent-conventions. It costs 190 tokens per session, scanned A, a copy of rails-cursorrules-prompt-file, MIT.

Basic Rails 8 development rules covering generators, local development, database setup, controllers, background jobs, caching, deployment, and tests. Rails is a Ruby web framework.

In plain words
What is it for?
Use them when building or changing Rails applications, including models, controllers, migrations, tests, Hotwire interactions, and deployment configuration.
Why use it?
They guide the agent toward the project’s expected Rails structure and reduce inconsistent boilerplate or unsafe database changes.

Cursor rule for Cursor

Written for Cursor: a Cursor rule (.mdc). Also seen: mentions Cursor.

Good fit Use them when building or changing Rails applications, including models, controllers, migrations, tests, Hotwire interactions, and deployment configuration.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/itamarzand88/awesome-agent-conventions/rails-cursorrules-prompt-file
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/ItamarZand88/awesome-agent-conventions

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 rails-cursorrules-prompt-file

README.md
[![agentmods](https://agentmods.dev/badge/rules/itamarzand88/awesome-agent-conventions/rails-cursorrules-prompt-file/github.svg)](https://agentmods.dev/rules/itamarzand88/awesome-agent-conventions/rails-cursorrules-prompt-file)
Your own site
<a href="https://agentmods.dev/rules/itamarzand88/awesome-agent-conventions/rails-cursorrules-prompt-file"><img src="https://agentmods.dev/badge/rules/itamarzand88/awesome-agent-conventions/rails-cursorrules-prompt-file/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 rails-cursorrules-prompt-file

Your own site · 80×15
<a href="https://agentmods.dev/rules/itamarzand88/awesome-agent-conventions/rails-cursorrules-prompt-file"><img src="https://agentmods.dev/badge/rules/itamarzand88/awesome-agent-conventions/rails-cursorrules-prompt-file.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 190 This file is loaded in full into every session.
When invoked 190 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 91% copy Near-identical to another mod 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 $0.00190 $0.00190
Opus 5 $0.00095 $0.00095
Sonnet 5 $0.00038 $0.00038
Haiku 4.5 $0.00019 $0.00019

Measured 11d ago against content hash 81e618729d7c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

rails-cursorrules-prompt-file 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 11d 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.

Origin

This is a copy

91% identical to rails-cursorrules-prompt-file — 1 line differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

conventions/agent-rules/examples/awesome-cursorrules-rails/rails-cursorrules-prompt-file.mdc · 16 lines

What it actually says


description: "Cursor rules for Rails development with basic setup." globs: */ alwaysApply: false

Rails 8 Development Guidelines

  • Prefer Rails command-line generators over hand-written boilerplate.
  • Use bin/dev for local development and check logs after significant changes.
  • Follow Rails 8 conventions for Solid Queue, Solid Cache, Solid Cable, Propshaft, and Kamal where appropriate.
  • Keep controllers RESTful and focused; use service objects for complex business logic.
  • Use PostgreSQL, proper indexes, connection pooling, and safe migrations.
  • Write Minitest coverage for models, controllers, and integration flows.
  • Use Hotwire for standard Rails interactivity and Vite only when npm-managed JavaScript is needed.
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. 11d ago First seen · 16 lines · 190 tokens per session scan A 81e618729d7c

Subscribe to this mod's changes

rails-cursorrules-prompt-file is a cursor rule published in the GitHub repository ItamarZand88/awesome-agent-conventions (31 stars, last pushed 1mo ago), licensed MIT. It adds 190 tokens to every session, about $0.0010 per session on Opus 5. A static security scan graded it A with 0 findings. It is 91% identical to rails-cursorrules-prompt-file, differing in 1 line, and is treated as a copy.