#​789 — February 26, 2026

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Ruby Weekly

Rage: The Modern, Real-Time Ruby Framework — We don’t mention Rage enough! 😅 It’s a high-performance fiber-based framework suited for concurrent workloads involving WebSockets, real-time communication, async jobs, etc. and it’s Rails compatible! This week’s v1.21.0 release makes it easier to adopt with an official set of agent skills to use. GitHub repo.

Roman Samoilov

💡 I think Rage's SKILL.md file is a good primer for humans too, really…

🚀 CTO-Ready Rails Upgrade Estimates. No AI Hallucinations — AI can’t replace hard-earned experience. The FastRuby.io® Rails Upgrade Roadmap is created by humans and backed by 60k+ dev hours, giving CTOs real timelines, risk visibility, and budgets that finance teams actually trust.

The Rails Upgrade Roadmap sponsor

How We Fixed YAML Comment Preservation in Ruby — Discourse sponsored Kevin Newton to stabilize Psych::Pure, a pure-Ruby alternative to the Psych YAML parser, in order to solve some of Discourse’s long standing requirements, such as needing to maintain comments in YAML files. This work is ultimately good news for all of us.

Jake Goldsborough (Discourse)

⚡️ IN BRIEF:

🤖 'Ruby is the Best Language for Building AI Apps' — Whether you agree with his thesis or not, there’s no denying that Carmine Paolino has been a powerhouse over the past year with his RubyLLM project. This post, backed up by his recent RubyConfTH keynote, paints a rosy picture of how Ruby and RubyLLM offer a smooth developer experience when working with LLMs.

Carmine Paolino

💡 The new RubyLLM 1.12 focuses on agents in particular, making it easy to create a basic agent using a class and DSL, much as you might make a model in Rails.

What Happened at 12:14? AppSignal Can Tell You in One Keystroke — Try Time Detective free for 30 days and get a snapshot of what's happening with your Ruby / Rails apps: errors, slow queries, log spikes, host metrics, and more.

AppSignal sponsor

📄 One Thread to Poll Them All: How a Single Pipe Made WaterDrop 50% Faster – Solid engineering read from the creator of Karafka. Maciej Mensfeld

📄 Git's Magic Files – Useful guide to the many files that influence git's behavior in areas like ignoring files, language detection, and pre-filling commit messages. Andrew Nesbitt

📄 Building LLM-Friendly MCP Tools in RubyMine: Pagination, Filtering, and Error Design Daniel Domjan (JetBrains)

🛠 Code & Tools

💎 Gem in a Box 3.0: Simple, Personal Gem Hosting — Fancy having your own, personal equivalent of rubygems.org or gem.coop? Gem in a Box will get you there, both for hosting and pushing your own gems, as well as proxying gems from elsewhere. It’s a Ruby app but you can deploy it with Docker, if you prefer. v3.0 adds Ruby 4.0 support and requires Ruby 3.0+.

Lea, Foy, et al.

Stop Guessing Which LLM Prompt Works Best — We built RubyLLM::Evals to bring systematic prompt development into Rails. Compare models, costs, and validate with production data.

SINAPTIA sponsor

SchnellMCP: A Ruby-Native MCP Server Experience — Annotate Ruby methods with a @mcp.tool YARD tag and they become MCP server tools callable by an LLM agent. This write-up digs into all the details. Inspired by Python's FastMCP.

Josef Šimánek

Checkset: Playwright-Powered Repeatable Verifications for Webapps — A ‘checkset’ is a bit like a more abstract, flexible version of a system test.

Andrea Fomera

📰 Classifieds

🧐 A cheaper Heroku? Our cost comparison calculator puts the PaaS alternatives head-to-head.

♦️ Build Ruby apps that never lose state, even when things fail. Learn by building an app from scratch in a free Temporal Ruby SDK course.

📢  Elsewhere in the ecosystem

  • Stringer (above) is a visually pleasing Rails-powered 'anti social' RSS feed reader that sticks to the basics, with no social features or ‘fancy machine learning’ at all. First featured over a year ago, it’s continued to see frequent updates.

  • WP2TXT is a Ruby-powered toolkit for extracting text content from Wikipedia dump files – it'll even download the dumps for you, and can extract specific articles without downloading the full dumps.

  • 🎨 Tailwind CSS v4.2 has added four new color palettes to the default theme: mauve, olive, mist, and taupe. Use them to look fresh now, before everyone else catches on.

  • Apropos of nothing, I enjoyed ▶️ this developer explaining how he created a Quake 2-esque FPS in just 64 kilobytes over the past ten years. If you'd rather play it, it's here (but Windows only).

  • Play with a full Windows 3.11 experience in your browser. There's a recreation of '90s search engine AltaVista, a version of mIRC that connects to an actual IRC server, and a variety of classic games.