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.
npx agentmods add skills/el-feo/ai-context/railsnpx skills add el-feo/ai-context --skill railsgit clone --depth 1 https://github.com/el-feo/ai-contextWrote 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/skills/el-feo/ai-context/rails)<a href="https://agentmods.dev/skills/el-feo/ai-context/rails"><img src="https://agentmods.dev/badge/skills/el-feo/ai-context/rails.svg" alt="Measured on agentmods" 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 | $0.00072 | $0.00807 |
| Opus 5 | $0.00036 | $0.00404 |
| Sonnet 5 | $0.00014 | $0.00161 |
| Haiku 4.5 | $0.00007 | $0.00081 |
Grade A, and why
rails 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 5d 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 — 50 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Rails v8.1 Development Guide
Reference documentation based on the official Rails Guides v8.1.1, organized by topic. Each reference file has a table of contents. Consult the relevant file when working on specific Rails components.
Reference Navigation
Active Record
Split across 4 files by topic:
- active_record_basics.md (5,800 lines) — Models, CRUD, naming conventions, migrations, validations, callbacks
- active_record_queries.md (2,700 lines) — Query interface, conditions, ordering, joins, eager loading, scopes, calculations
- active_record_associations.md (3,400 lines) — Association types, configuration, STI, delegated types, reference
- active_record_advanced.md (4,100 lines) — Active Model, PostgreSQL features, multiple databases, composite primary keys, encryption
Controllers & Views
- controllers.md (1,900 lines) — Action Controller basics, strong params, cookies, sessions, callbacks, CSRF, HTTP auth, streaming, error handling
- views.md (4,800 lines) — Action View, templates, partials, layouts, view helpers, form helpers, rendering
Configuration & Internals
- configuration.md (4,750 lines) — Rails config options, versioned defaults, environment settings, initializers, load hooks, initialization process
- internals_autoloading.md (915 lines) — Zeitwerk autoloading, reloading, eager loading, threading, concurrency
- internals_engines_cli.md (3,920 lines) — Rack middleware, Rails engines, CLI tools, custom generators
Other References
- testing_debugging.md (3,700 lines) — Unit/integration/system tests, fixtures, debugging
- jobs_mailers_cable.md (3,650 lines) — Active Job, Action Mailer, Action Mailbox, Action Cable
- i18n_support.md (5,700 lines) — I18n, locale files, Active Support core extensions, instrumentation
- storage_caching.md (2,450 lines) — Active Storage file uploads, caching strategies
- security_performance.md (2,270 lines) — XSS, CSRF, SQL injection prevention, performance tuning
- assets_frontend.md (2,080 lines) — Asset pipeline, JavaScript bundling, CSS, Action Text
- routing.md (1,380 lines) — RESTful routing, nested routes, constraints, concerns
- api_development.md (585 lines) — API-only apps, serialization, authentication, versioning, CORS
What ships with it
17 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- references/active_record_advanced.md 124 KB
- references/active_record_associations.md 98 KB
- references/active_record_basics.md 173 KB
- references/active_record_queries.md 82 KB
- references/api_development.md 19 KB
- references/assets_frontend.md 74 KB
- references/configuration.md 191 KB
- references/controllers.md 65 KB
- references/i18n_support.md 174 KB
- references/internals_autoloading.md 38 KB
- references/internals_engines_cli.md 127 KB
- references/jobs_mailers_cable.md 112 KB
- references/routing.md 49 KB
- references/security_performance.md 117 KB
- references/storage_caching.md 82 KB
- references/testing_debugging.md 120 KB
- references/views.md 152 KB
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.
- 5d ago First seen · 50 lines · 72 tokens per session scan A 29c78db794d4
rails is a skill published in the GitHub repository el-feo/ai-context (12 stars, last pushed 1mo ago), licensed MIT. It adds 72 tokens to every session and 807 once invoked, about $0.0004 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 2026-08-30.
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