Borrowing it
Nothing to install: this file belongs to levifig/rails-instructions. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/levifig/rails-instructions/main/.github/instructions/rails-importmaps.instructions.mdgit clone --depth 1 https://github.com/levifig/rails-instructionsWrote 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.
[](https://agentmods.dev/instructions/levifig/rails-instructions/rails-importmaps)<a href="https://agentmods.dev/instructions/levifig/rails-instructions/rails-importmaps"><img src="https://agentmods.dev/badge/instructions/levifig/rails-instructions/rails-importmaps/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.
<a href="https://agentmods.dev/instructions/levifig/rails-instructions/rails-importmaps"><img src="https://agentmods.dev/badge/instructions/levifig/rails-instructions/rails-importmaps.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00799 | $0.00799 |
| Opus 5.5 | $0.00320 | $0.00320 |
| Sonnet 5.5 | $0.00160 | $0.00160 |
| Haiku 4.5 | $0.00080 | $0.00080 |
Grade A, and why
rails-instructions rails-importmaps.instructions.md 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.
How it starts
The opening of the file, as written. The whole thing — 119 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Rails Import Maps Guide
Core Philosophy
- Eliminate JavaScript build steps while maintaining modern development practices
- Send JavaScript modules directly to the browser without bundling or transpiling
- Reference external modules using standardized module specifiers
- Embrace simplicity and developer happiness - this is the Rails Way™
Configuration Principles
- Define all JavaScript dependencies in
config/importmap.rb - Pin external libraries to specific versions for production stability
- Use semantic versioning when pinning dependencies
- Prefer CDN URLs for popular libraries to leverage browser caching
- Vendor critical dependencies that cannot tolerate CDN failures
- Always specify
preload: truefor essential modules
File Organization
- Keep all JavaScript files in the
app/javascriptdirectory - Use
controllers/subdirectory exclusively for Stimulus controllers - Create
components/for reusable UI JavaScript modules - Create
utilities/for shared helper functions - Follow Rails naming conventions consistently
Naming Conventions for AI Agents
- Name Stimulus controllers with
*_controller.jssuffix - Use descriptive nouns for component files (
modal.js,dropdown.js) - Use action-based names for utilities (
debounce.js,format_currency.js) - Maintain consistent naming patterns across the codebase
- Document module purpose at the top of each file
Module Management
- Import modules using standard ESM syntax
- Avoid polluting the global namespace
- Use named exports for better code discoverability
- Keep modules focused on a single responsibility
- Export only what needs to be public
Dependency Management
- Pin to exact versions in production for stability
- Use version ranges only in development
- Regularly audit and update dependencies
- Remove unused dependencies promptly
- Document why each dependency is needed
Performance Optimization
- Use
preload: trueonly for critical dependencies - Implement lazy loading for features not needed on initial load
- Leverage browser caching by using CDN URLs
- Evaluate module size before adding dependencies
- Consider vendoring large libraries that change infrequently
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.
- 1mo ago First seen · 119 lines · 799 tokens per session scan A 2f77520a9b7a
rails-instructions rails-importmaps.instructions.md is an instructions file published in the GitHub repository levifig/rails-instructions (56 stars, last pushed 1y ago), licensed MIT. It adds 799 tokens to every session, about $0.0032 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 2026-08-30.
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