agentmods.dev

rails-engineering

rails-engineering is a cursor rule for Cursor from igmarin/rails-ai-bridge. It costs 352 tokens per session, scanned A, original, MIT.

A set of Rails engineering rules covering verification, request security, database queries, authentication, controller changes, and tests. Rails is a Ruby framework for building web applications.

In plain words
What is it for?
Use it when editing Rails models, controllers, routes, database queries, authentication-related code, or HTTP tests.
Why use it?
It helps prevent guessed project details, unsafe input handling, inefficient database access, and changes that bypass the application's existing conventions.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/. Also seen: mentions AGENTS.md.

not rated 16repo yesterday A scan 352 tokens original MIT

Good fit Use it when editing Rails models, controllers, routes, database queries, authentication-related code, or HTTP tests.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/igmarin/rails-ai-bridge/rails-engineering
View source ↗ igmarin/rails-ai-bridge
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/igmarin/rails-ai-bridge

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-engineering

README.md
[![agentmods](https://agentmods.dev/badge/rules/igmarin/rails-ai-bridge/rails-engineering/github.svg)](https://agentmods.dev/rules/igmarin/rails-ai-bridge/rails-engineering)
Your own site
<a href="https://agentmods.dev/rules/igmarin/rails-ai-bridge/rails-engineering"><img src="https://agentmods.dev/badge/rules/igmarin/rails-ai-bridge/rails-engineering/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-engineering

Your own site · 80×15
<a href="https://agentmods.dev/rules/igmarin/rails-ai-bridge/rails-engineering"><img src="https://agentmods.dev/badge/rules/igmarin/rails-ai-bridge/rails-engineering.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 352 This file is loaded in full into every session.
When invoked 352 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 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 5.1 $0.00352 $0.00352
Opus 5.5 $0.00141 $0.00141
Sonnet 5.5 $0.00070 $0.00070
Haiku 4.5 $0.00035 $0.00035

Measured 1mo ago against content hash 8a51c2b76171, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

rails-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 1mo 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.

examples/demo_app/.cursor/rules/rails-engineering.mdc · 29 lines

What it actually says

Engineering essentials

Anti-hallucination rules

  • Verify before you write (column, association, route, helper, gem).

  • Mark assumptions with [ASSUMPTION]. Silent guesses are forbidden.

  • This app is not average Rails. Query conventions and gems before scaffolding.

  • Check the inheritance chain (filters, concerns, STI) before editing a controller or model.

  • Empty tool output is information, not permission to invent.

  • Re-query after writes. Stale tool output lies.

  • Strong params: permit explicitly; never mass-assign raw params.

  • Auth: protect mutations and sensitive reads; public route ≠ public data.

  • N+1: includes / preload / eager_load for associations in views and serializers.

  • Bounds: paginate HTTP lists; find_each / in_batches in jobs; no Model.all in requests.

  • Large tables: narrow queries; check indexes before new filters/sorts; use rails_get_schema.

  • Security: no constantize/send/eval on user input; no SQL string interpolation; allow-list redirects.

  • Tests: request/system specs for HTTP; confirm runner with rails_get_test_info.

Generated files are snapshots — prefer rails_* MCP tools for current structure. Full engineering rules: .github/copilot-instructions.md or AGENTS.md. MCP tool reference: rails-mcp-tools.mdc.

  • Run bundle exec rspec after changes
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. 1mo ago First seen · 29 lines · 352 tokens per session scan A 8a51c2b76171

Subscribe to this mod's changes

rails-engineering is a cursor rule published in the GitHub repository igmarin/rails-ai-bridge (16 stars, last pushed yesterday), licensed MIT. It adds 352 tokens to every session, about $0.0014 per session on Opus 5.5. 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 2026-09-15.

Backend and APIsSecurityrails-airails-ai-assisted-development
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