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Today
Omakase 0.2 — agents as plain Ruby objects
I released Omakase 0.2, a small agent framework on top of
RubyLLM about 800 lines. The idea is that an agent is an ordinary Ruby object: its fields are
state, its public methods are what the model can call (no tool registry, no JSON schemas to keep in
sync - describe above a method is the description the model reads), and the methods you declare
without a body are written by the model at runtime. The return type is the contract: a schema block
gives you validated data, a scalar unwraps to a value, and a Ruby class means the method hands back
the object your code built - under the default :code_act strategy the model answers by writing
Ruby that is evaluated on the agent itself and calling finish(value), so the answer is computed
rather than retyped as JSON. There’s also :predict for one-shot structured output, MCP servers and
SKILL.md directories that arrive as methods, per-method model selection, attachments, and a
FakeChat so agents can be tested without a network. The transcripts in the README are from a 30B
model on OpenRouter rather than a frontier one, on the theory that a strategy which only works on
the biggest model available is a demo and not a library. The docs
cover the Rails side - agents in app/agents, jobs, multi-turn built from your own tables - and are
blunt about the fact that generated code runs with instance_eval, so untrusted input belongs to
:predict unless you swap in your own executor. MIT, Ruby 3.2+. [more inside]
Updates to Testing Rails from Scratch book
Hi, I’ve pushed some updates to my work-in-progress book on using Rails defaults (mostly) for test-driven development, based on my approach and opinions from using RSpec for 15 years. The updates are now available on Leanpub, and I wrote a quick post on Left of the Dev to share what’s available now and what’s next. Thank you for your support! [more inside]
Aug 13, 2026 Reminder: Entitled/Incompetent/Mean Members of Ruby/Rails Community
In light of some Ruby community events that happened recently (you can lookup recent posts about discriminatory treatment against me), it never hurts to share a regular reminder about the Entitled/Incompetent/Mean Members of the Ruby community.
Chasing an Elusive Rails SSE Hang
Last month, we chased a rare Rails bug that could quietly stall production servers, traced it to a subtle race condition in the framework, and got the fix merged into Rails. Read how we found it [more inside]
Testing authentication in Rails with Minitest
Chapter 12 of the free Minitest Rails guide is live: [more inside]
Rails’ travel_to looks like a simple time-testing helper but it reveals a powerful pa
Temporarily change state → yield → guarantee restoration. [more inside]
Magic Presenter: A modern replacement for Draper
Magic Presenter is a presentation layer gem for Rails models designed to replace Draper. It retains the Decorator/Presenter pattern while addressing fundamental architectural flaws and design bottlenecks present in Draper. [more inside]
How we configured OpenTelemetry logs in Rails
We added OpenTelemetry logs to our Rails app without a Collector and fixed a few bugs in the Ruby SDK along the way. Here is how we did it:
XO Ruby joins RubyConf as Another Exclusive Discriminatory Unexcellent Conference
So, I got contacted by the organizer of the XO Ruby conference (aka Travelling Ruby), Pascal Laliberté, on meetup.com because I organize the Montreal.rb Ruby Meetup and am a Montreal-based Expert Ruby Software Engineer. He said XO Ruby is coming to Montreal and asked me for help with it. We end up meeting in a video conference call…
Fair by design: orchestrating background jobs in Ruby
Fair by design: orchestrating background jobs in Ruby [more inside]
sghtmltopdf: an HTML to PDF renderer in Rust, with a Ruby gem and Rails integration
wkhtmltopdf was archived in 2023, leaving Rails apps stuck between an unmaintained binary and spawning headless Chrome. I built sghtmltopdf, a new rendering engine written in Rust that implements CSS Fragmentation and @page directly, so page breaks, orphans and widows are first-class rather than approximated. It ships as a CLI, an HTTP server, and a Ruby gem (gem "sghtmltopdf"). [more inside]
What Active Record Transactions Actually Protect
An Active Record transaction traced across one database connection, retained model state, remote side effects, false returns, non-local exits, nested transactions, savepoints, and PostgreSQL statement failures. [more inside]
Solid Objects: Easiest reactive ERB there has ever been
I’ve been building Solid Objects, a gem that brings the Durable Objects programming model (addressable objects, durable state, serialized turns) to ordinary Rails applications. It runs on the MySQL, PostgreSQL, or SQLite database the app already has. No Redis, no Cloudflare account, no separate actor service. [more inside]
Ruby 2D v1.0 released
Years in the making, rebuilt from the ground up, tons of new features, full WebAssembly support, a new website with live examples. Check it out! https://github.com/ruby2d/ruby2d [more inside]
Turbo Drive, Frames and Streams: a reference verified against the source
Turbo’s documentation is complete but unconnected: Drive, Frames and Streams sit side by side with nothing saying what links them or how to choose. This is the reference I wanted when I started, written by reading the source of Turbo 8.0.23 and turbo-rails 2.0.23 rather than the docs, because that is where the gaps are. [more inside]
The Shopify Goldmine: How to Build Your First App in Rails
From Rails Dev to Shopify Partner: A Beginner’s Guide to Building Apps If you know Ruby on… [more inside]
From Conditionals to Polymorphism
A conditional that keeps growing is a design problem, not a style problem. How to turn each branch into an object, one green step at a time. [more inside]
Running a Ruby MCP Server in Production
In this article, Amanda goes through what a Ruby MCP server needs once it stops being a subprocess: Streamable HTTP instead of stdio, a choice between a standalone service and an endpoint inside an existing Rails app, statelessness so it survives more than one Puma worker, Host and Origin validation that a security advisory made mandatory, a shared token as the internal floor with OAuth as the answer beyond it, and read-only models and server_context deciding what any caller can actually reach. [more inside]
Install any Ruby version in seconds using rv
In this guide, you’ll learn how to use rv, a very fast version and package manager for Ruby to get started in minutes instead of hours:
wurk: Sidekiq Pro and Enterprise features, MIT licensed
wurk is a drop-in, 100% API-compatible replacement for Sidekiq that ships the Pro and Enterprise features Batches, unique jobs, rate limiting, periodic jobs, encrypted arguments under MIT. Swap the gem, keep your existing perform_async calls and your Redis. [more inside]
Wide Events: Token-efficient Rails telemetry for coding agents
I released Wide Events, a Rails gem that records each request or job execution as one dense, high-cardinality telemetry event. It gives coding agents queryable production context without making them reconstruct what happened from scattered logs, spans, and metrics. Agents can retrieve only the relevant rows and fields for a route, account, build SHA, feature flag, or error, keeping the context compact. [more inside]