Ruby Users Forum - Monthly Update - September 2026

I Ran a Security Scanner Against Mastodon, Discourse, and Chatwoot's AWS Defaults. He

I used Stave, an open-source configuration safety tool, to answer those questions for three of the most popular open-source Rails applications: Mastodon (47K stars), Discourse (43K stars), and Chatwoot (22K stars). Read more

Building a Ractor-Native Ruby 4 Stack: RESP, Redis and Background Jobs

Building a Ractor-Native Ruby 4 Stack: RESP, Redis and Background Jobs Read more

Rocky Mountain Ruby 2026 Recap

A summary of my time at Rocky Mountain Ruby 2026. https://kevinjmurphy.com/posts/rocky-mountain-ruby-2026-recap/

Billing in Rails 8 — a practical guide to Pay + Stripe

I just released Billing in Rails 8, a 126-page implementation guide for building subscription billing into a Rails app with Pay and Stripe. It focuses less on getting the first Stripe Checkout session working and more on everything that comes after: keeping provider state separate from product behavior, stable application-level plans, entitlements and limits, trials, upgrades and downgrades, cancellation, failed payments, reconciliation, and testing the whole thing without making Stripe your application architecture. Read more

Tech Repost 2026-09-29: Programming Is Building a Mental Model

This applies to programming with any languages, including Ruby: Tech Repost 2026-09-29: Programming Is Building a Mental Model…

Rails World '26: The RubyGems Compact Index

Every time Bundler resolves your Gemfile, it’s talking to the compact index. In this post, the speaker walked us through what the compact index actually is, how RubyGems.org keeps it in sync at scale, and two features Jenny helped ship in the past year to make gem installs faster and more secure. Read more

Ruby Memes 2026-09-30: DHH's AI Vision

Ruby Memes 2026-09-30: DHH’s AI Vision

Rails World '26: Herb and ReActionView

ReActionView adds real reactivity to your existing .html.erb templates, no Hotwire, no Stimulus, no JavaScript you have to write yourself. That is the part that got me. Read more

Montreal.rb September 2026: Ruby Version Managers in 2026

The video and slides for the Montreal.rb September 2026 talk “Ruby Version Managers in 2026” have been published!

Why 37Signals Built a New WYSIWYG Editor (Lexxy) for Action Text

I was in the audience at Rails World 2026 for Jorge Manrubia’s talk on Lexxy, a new rich text editor for Action Text. Jorge explained why 37signals built a new editor, what Lexxy adds, and how the work opens Action Text to other editors beyond Trix, the editor that’s shipped with Action Text since day one. Read more

Dissecting DHH's RailsWorld 2026 Keynote Speech from a Software Engineering POV

Dissecting DHH’s RailsWorld 2026 Keynote Speech from a Software Engineering Point Of View

LlmCostTracker 0.14.2: OpenRouter billed cost, xAI and Mistral prices, and a reprice

LlmCostTracker tracks LLM spend and budgets in a Rails app by user, feature, or any tag, in your own database and with no proxy. Read more

Chat Modes: Configuring the LLM for Each Turn

RubyLLM::Modes is an extension for RubyLLM: before each chat turn, a router picks the instructions, tools, model, and thinking for that reply. The router uses Jev through the new RubyLLM.judge: about 350 ms and $0.04 per 1,000 turns. Read more

The Job Was Enqueued by Older Code

What happens to queued Active Job payloads after a job-class rename? A runnable Rails 8.1.3 exploration of class lookup, exception handling, compatible rolling deploys, and when the old class can be removed. Read more

I agree with DHH and here is why ...

I’ve seen this pattern many times in my 55 years as a computer programmer. p(bloom) has always been greater than p(doom) Read more

asgard v0.4.0 now supports scheduling periodic tasks

Creating tasks to support your development workflow has always been an easy thing to do with the Thor-based asgard ruby gem with its Loki files defining your tasks and their dependencies. asgard’s two big features are its ability to run dependencies to a task either serially or concurrently or a mix of both before running the target task. Now you can create a new category of tasks that run periodically using the new schedule keyword in your loki files. Read more

The USA geography in your Rails app

https://claudiob.github.io/usa/ Read more

llm_cost_tracker 0.14.1: RubyLLM 2.x, long streams, transaction-safe writes

llm_cost_tracker is self-hosted LLM cost tracking for Rails: every call through RubyLLM, the OpenAI and Anthropic SDKs, Gemini, or any OpenAI-compatible API is logged with tokens, cost, and tags, with no proxy. 0.14.1 is a bug-fix release: Read more

Smart avatar cropping in rails: face detection with YuNet, ONNX and ActiveStorage

Learn how to implement CPU-efficient, face-aware avatar cropping in Ruby on Rails without external APIs or Python sidecars. Read more

Ruby, Rails & AI Daily: DHH Goes "Pencils Down" at Rails World as Agents Keep Jumping

DHH opened Rails World 2026 by announcing that 37signals has stopped writing routine code by hand, with HEY being rebuilt as six native apps plus a Rust mail backend, and a call for every app to ship a CLI so users can bring their own agent. The roundup also covers Day 1 talks on Active Search, Lexxy and hardening Active Storage, the Agents on Rails max-effort report where DeepSeek 4.1 Flash found the harness API key and used it to pull Fizzy’s source from GitHub, the OpenAI agent that breached an Australian Medicare portal, and Ruby 3.4.11. It closes with three practical guardrails for Rails teams running coding agents: keep provider keys out of the sandbox, default-deny egress, and grade outcomes the agent cannot rewrite.

The Ruby Users Forum in the Ruby on Rails Podcast

Active Storage image optimization at scale: lessons from 1,916 conference photos

We replaced a hosted gallery with a Rails 8.1 app on one box for Friendly.rb, then open sourced it. Nine Active Storage derivatives per photo, AVIF measured 31.6% under WebP, and the things the guides do not warn you about past a few dozen images. Read the full article on:

[ANN] New bidi2pdf release: faster PDF generation + agent-friendly CLI

A new version of bidi2pdf is out. Read more

Rails Has .forty_two — But No .sixth

A short look at one of Rails’ weirdest little helpers and its history. Read more