What is rails-load-defaults?

A guided upgrade process for a Ruby on Rails app’s default settings. It moves the app from older framework defaults to the defaults for its Rails version, one setting at a time.

Checking the current `config.load_defaults` version, preparing the next framework-defaults file, reviewing each setting, and moving the accepted settings into the main application configuration.

Rails changes default behavior between versions, and changing everything at once can make failures hard to trace. This breaks the upgrade into changes that can be tested separately.

rails-load-defaults — Skill for Claude Code by ombulabs

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.

Any agent

npx skills add ombulabs/claude-code_rails-load-defaults-skill --skill rails-load-defaults

Clone the repo

git clone --depth 1 https://github.com/ombulabs/claude-code_rails-load-defaults-skill

Made for: Claude Code.

Or install rails-load-defaults, the plugin that ships this one along with the rest of its 1 skill.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/ombulabs/claude-code_rails-load-defaults-skill/rails-load-defaults.svg)](https://agentmods.dev/skills/ombulabs/claude-code_rails-load-defaults-skill/rails-load-defaults)

Your own site

<a href="https://agentmods.dev/skills/ombulabs/claude-code_rails-load-defaults-skill/rails-load-defaults"><img src="https://agentmods.dev/badge/skills/ombulabs/claude-code_rails-load-defaults-skill/rails-load-defaults.svg" alt="Measured on agentmods" height="20"></a>

Per session 120 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,103 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits

NVIDIA SkillSpector warn 7 Sept 2026

SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

medium Prompt Injection · line 82
Subtle instructions detected that may alter agent decision-making or introduce hidden biases.

Fix: Review content for implicit steering or bias. Ensure instructions are explicit and align with the skill's stated purpose.

How audits are shown

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.

Model	Per session	Once invoked
Fable 5.1	$0.00120	$0.02103
Opus 5	$0.00060	$0.01052
Sonnet 5	$0.00024	$0.00421
Haiku 4.5	$0.00012	$0.00210

Measured 8d ago against content hash 6ec1d57f7669, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

rails-load-defaults 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 8d ago.

The scan reads SKILL.md. This mod also ships 11 executable files (templates/cookie_rotator.rb, templates/new_framework_defaults_5_0.rb, templates/new_framework_defaults_5_1.rb, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

rails-load-defaults/SKILL.md · 213 lines

How it starts

The opening of the file, as written. The whole thing — 213 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Rails load_defaults Upgrade Skill

This skill guides the incremental upgrade of config.load_defaults in a Rails application. The process walks through each config introduced in a new Rails version, one at a time, so the user can test each change in isolation.

Overview

When a Rails app has a load_defaults version lower than its Rails version, there are framework default configs that need to be adopted. This skill:

Detects the current load_defaults version
Determines the next target version
Generates the new_framework_defaults_X_Y.rb initializer with all configs commented
Walks through each config one by one, analyzing the codebase to recommend values
Waits for the user to test/commit each change before moving to the next
Consolidates into config/application.rb when all configs are done

Step 1: Detect Current State

Read config/application.rb and look for:

config.load_defaults X.Y

Also check if a config/initializers/new_framework_defaults_*.rb file already exists (the user may be mid-upgrade).

Report to the user:

Current load_defaults version
Current Rails version (from Gemfile.lock)
Which version transitions are needed (e.g., 6.1 → 7.0 → 7.1 → 7.2)

Step 2: Load Version Config Reference

Read the appropriate config reference file for the target version:

5.0: configs/5_0.yml
5.1: configs/5_1.yml
5.2: configs/5_2.yml
6.0: configs/6_0.yml
6.1: configs/6_1.yml
7.0: configs/7_0.yml
7.1: configs/7_1.yml
7.2: configs/7_2.yml
8.0: configs/8_0.yml
8.1: configs/8_1.yml

Each config file contains entries organized into tiers with lookup patterns and decision trees for each config.

Step 3: Create the Initializer File

If no new_framework_defaults_X_Y.rb exists yet, copy the template from the templates/ directory into the app's config/initializers/:

5.0: Copy templates/new_framework_defaults_5_0.rb → config/initializers/new_framework_defaults_5_0.rb
5.1: Copy templates/new_framework_defaults_5_1.rb → config/initializers/new_framework_defaults_5_1.rb
5.2: Copy templates/new_framework_defaults_5_2.rb → config/initializers/new_framework_defaults_5_2.rb
6.0: Copy templates/new_framework_defaults_6_0.rb → config/initializers/new_framework_defaults_6_0.rb
6.1: Copy templates/new_framework_defaults_6_1.rb → config/initializers/new_framework_defaults_6_1.rb
7.0: Copy templates/new_framework_defaults_7_0.rb → config/initializers/new_framework_defaults_7_0.rb
7.1: Copy templates/new_framework_defaults_7_1.rb → config/initializers/new_framework_defaults_7_1.rb
7.2: Copy templates/new_framework_defaults_7_2.rb → config/initializers/new_framework_defaults_7_2.rb
8.0: Copy templates/new_framework_defaults_8_0.rb → config/initializers/new_framework_defaults_8_0.rb
8.1: Copy templates/new_framework_defaults_8_1.rb → config/initializers/new_framework_defaults_8_1.rb

Read the full file on GitHub · 213 lines

Files

What ships with it

21 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.

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.

8d ago First seen · 213 lines · 120 tokens per session scan A 6ec1d57f7669

Subscribe to this mod's changes

rails-load-defaults is a skill published in the GitHub repository ombulabs/claude-code_rails-load-defaults-skill (17 stars, last pushed 18d ago), licensed MIT. It adds 120 tokens to every session and 2,103 once invoked, about $0.0006 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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