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 skills add ag0os/rails-dev-plugin --skill rails-api-patternsgit clone --depth 1 https://github.com/ag0os/rails-dev-pluginWrote 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/ag0os/rails-dev-plugin/rails-api-patterns)<a href="https://agentmods.dev/skills/ag0os/rails-dev-plugin/rails-api-patterns"><img src="https://agentmods.dev/badge/skills/ag0os/rails-dev-plugin/rails-api-patterns/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/skills/ag0os/rails-dev-plugin/rails-api-patterns"><img src="https://agentmods.dev/badge/skills/ag0os/rails-dev-plugin/rails-api-patterns.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 | $0.00073 | $0.00833 |
| Opus 5.5 | $0.00029 | $0.00333 |
| Sonnet 5.5 | $0.00015 | $0.00167 |
| Haiku 4.5 | $0.00007 | $0.00083 |
Grade A, and why
rails-api-patterns 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 — 61 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Rails API Patterns
Analyze and recommend best practices for Rails API design including controllers, serialization, authentication, versioning, and error handling.
Applies on the api delivery axis (Axis B, rails-stack-profiles) — including an /api namespace inside an otherwise html app. For server-rendered HTML use rails-views-patterns and hotwire-patterns.
Follow standard Rails API controller conventions (ActionController::API, strong parameters, rescue_from). See patterns.md for opinionated decisions and configuration.
Quick Reference
| Area | Decision | Key File |
|---|---|---|
| Base controller | ActionController::API + shared concerns |
app/controllers/api/base_controller.rb |
| Versioning | URL namespace (/api/v1/) -- NOT header-based |
config/routes.rb |
| Auth | JWT bearer token via JwtService |
app/controllers/concerns/authenticatable.rb |
| Serialization | Blueprinter preferred (views for complexity) | app/blueprints/ |
| Response format | { data:, meta:, errors: } envelope always |
All API responses |
| Pagination | Pagy or Kaminari + max_per_page: 100 cap |
app/controllers/concerns/paginatable.rb |
| Rate limiting | Rack::Attack: 100/min per token, 20/min per IP | config/initializers/rack_attack.rb |
| CORS | rack-cors gem, env-driven origins |
config/initializers/cors.rb |
Core Decisions
- Response envelope always -- every response wraps in
{ data:, meta:, errors: }, never bare objects/arrays - URL versioning from day one --
/api/v1/namespace even for first version; header-based versioning adds complexity without benefit for most apps - Blueprinter over AMS -- ActiveModel::Serializer is unmaintained; prefer Blueprinter for views-based serialization, or Jbuilder for complex one-offs
- Cap per_page at 100 -- enforce
[params[:per_page].to_i, 100].minto prevent clients from requesting unbounded results - Authenticate in base, skip explicitly --
before_action :authenticateinApi::BaseController, useskip_before_actionfor public endpoints - Dual rate limits -- per-token (100/min) for authenticated, per-IP (20/min) for unauthenticated; return
Retry-Afterheader
What ships with it
1 file 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.
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 · 61 lines · 73 tokens per session scan A 73c3074f55a7
rails-api-patterns is a skill published in the GitHub repository ag0os/rails-dev-plugin (5 stars, last pushed 4mo ago), licensed MIT. It adds 73 tokens to every session and 833 once invoked, about $0.0003 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 2026-08-31.
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