~rubyweekly | Bookmarks (186)

Fast MCP: A Ruby Implementation of the Model Context Protocol — MCP (Model Context Protocol) servers enable certain LLM-based agents (such as Claude, Claude Code, and Cursor) to perform actions/call tools outside of their usual restricted environment. This library lets you build tools in Ruby which such agents can then reach out to and use.

Ruby 3.2.8 and 3.1.7 Released — These minor releases fix the vulnerabilities in CGI and URI described here. Ruby 3.1.7 is also considered the final release of the 3.1 series with users encouraged to upgrade to 3.3 or 3.4.

NEW: Get Real-Time Alerts from Your Logs in Honeybadger — We just shipped a new feature for log management. Alarms allow you to combine a query (“count all slow requests in the past five minutes”) with a threshold (”when count is > 2”) and trigger alerts when the result exceeds the threshold. Read the blog post →

Exploring Ruby Ractors — Inspired by some recent posts about Ractors, John set out to see if he could use them to peg his CPU usage (“I paid for 10 cores, I’m gonna use 10 cores”). A fun exploration, including a look at just how much YJIT contributes to the modern Ruby performance story.

New Policies to Support the Growth of RubyGems — In response to a potential legal issue that arose around taking down a gem with a possibly trademarked name, Ruby Central is tightening up its official policies which can be read in full here – the policies will take final effect in late May, after a review period.

A Practical Guide to Taming Postgres Isolation Anomalies — A practical, Ruby-themed (though SQL heavy) walkthrough of Postgres’ concurrency control, detailing real-world issues like lost updates, write skew, and other isolation anomalies. Even if you rarely run into conflicts, you’ll come away with valuable insights on managing transactions.

Examples of Value Objects with Ruby's Data Class — We linked to Lucian’s article on value objects last week. He follows up with some useful examples of using them to remove boilerplate code and handle API responses.

🚀 FastRuby.io Makes Your Rails Upgrade Delightfully Boring with Bonsai — The team behind RailsBump.org offers gradual, 0-downtime upgrades — transform your engineering culture with our experts.

PicoRuby: A Tiny Ruby Implementation for Microcontrollers — An interesting alternative mruby implementation designed to get its footprint down even smaller to run on small one-chip microcontrollers. Just 256KB of ROM and 128KB of RAM is needed.

RuboCop v1.75.0: The Static Code Analyzer and Formatter — RuboCop gains improved support for Ruby 3.4. As creator Bozhidar Batsov noted on X: “You won’t be able to tell it from the outside, but this release required a ton of work to get to the point where Ruby 3.4 functionality was exposed via Prism’s Parser translation layer.”

Terrapin 1.1: Run Shell Commands Safely — A little extra abstraction for running shell commands that provides safer interpolation, particularly if using user-supplied values.

Psyllium: A Gem Making It Easier to Use Fibers — Adds convenience methods to the Fiber class to make it easier to use in the same way that threads might be used.

Ruby Debugging Tips and Recommendations in 2025 — A brief piece but packed with advice from Stan (who knows a thing or two from all his work on debug.rb and modernizing IRB). Did you know you can use the Ruby LSP extension with debug.rb?

iri: Simple Immutable Ruby URI Builder — Offers an interesting chain-able fluent API for adding various elements to URLs.

Ruby, Ractors, and Lock-Free Data Structures — An extensive, multi-chapter article that goes into serious depth about Ractors, lock-free data structures and shared mutable global state in multi-threaded Ruby apps. There’s also code if you want to play along or experiment.

▶  Building an 'Always-On' Production Profiler — A talk from Ruby Kaigi 2024 on Datadog’s production profiler. There’s a lot of detail here on how and what (CPU profiles, GC, allocations, heap live objects) to profile, various challenges of profiling in production, and using Rust in a gem.

Installing the sassc Gem on a Mac: A Debugging Story — Native extensions are often the source of a failed bundle install and never particularly fun to figure out (at least for me). Luckily, Richard takes us on a tour of the issues here, advice that could be useful beyond just sassc.

Creating Value Objects the Idiomatic Way — If you’ve got a value more elaborate than a number, string or simple list or hash, you might choose to use a class to create objects that represent those values: value objects. The modern way to do this in Ruby is with the Data class and Lucian shows it off here.

Simple Declarative Presence for Hotwire Apps with AnyCable — How to implement user presence tracking in a Hotwire application with minimal effort by using AnyCable and its new primitives.

Finding the Opposite of What You Have with Rails invert_where — Rails has so many helpful methods that many simply skip my radar as someone who’s been using Rails for so long. invert_where is certainly new to me and does something quite interesting..

🚀 Need to Upgrade Ruby? Here is a Free Step by Step Guide by FastRuby — The team behind Bonsai and the next_rails gem shares their best practices for upgrading to any Ruby version.

Just the Docs: A Jekyll Theme for Documentation Sites — Only tangentially Ruby related (but it is for Jekyll) but I love the look of docs/project sites using this. It’s clean, simple, and makes a lot of right design decisions for you out of the box.

TruffleRuby 24.2: The High Performance Ruby Implementation — Now supporting Ruby 3.3.5 features, TruffleRuby is an interesting Ruby implementation based upon GraalVM (a variant of the JDK with ahead-of-time native compilation well suited for dynamic languages).

Confused About Request Queue Time? — Check out our illustrated guide, with diagrams galore and just a tiny bit of math.