Content about #LLM

Developing Kobako has surfaced quite a few interesting cases. Continuing from the previous post, Building Kobako with AI: Will It Eventually Crash?, I ran into yet another new problem afterward—and this time it was the Segmentation Fault error I had always dreaded seeing during development. That signals a high chance something went wrong in the non-Ruby territory between Rust and WebAssembly.

Last week I published Kobako: Letting Agents Safely Operate Rails, introducing the goals of the Kobako gem. Since then I’ve kept pushing development forward with Claude Code—but I quickly ran into a situation that demanded major changes. Is this simply the fate of developing with AI?

This is a question worth discussing: when using AI to assist development, is the problem that AI isn’t capable enough, or that the design we humans handed it was too poor?

At RubyKaigi 2026 this year, while chatting with friends about Harness Engineering and the Sandbox aspect of it, I realized that Ruby still lacks a solid solution in this space. On the second night, I happened to be assigned to the druby (Ruby’s built-in distributed object system) group at the Code Party — and that’s how the idea for Kobako was born.

The Ralph Loop technique — a trick for making AI Coding Agents automatically repeat execution — was popular last year, but I didn’t trust whether it was safe enough or sufficiently stable.

A few months ago, Claude Code’s update introduced the /loop skill, which essentially uses Claude Code’s built-in Cron tool to repeat specific prompts at fixed intervals, achieving a similar effect. At least it’s safer and more controllable.

However, things are rarely that simple.

I previously wrote Should You Have Your Own Agent Skills? to explain why I believe everyone should maintain their own skills. But another phenomenon I’ve noticed is: are those “impressive skill collections” really as magical as they seem?

From my own experience, things work just as well without all that content — stuffing in too much might actually waste tokens and even hurt performance.

Recently, due to work requirements, I needed to evaluate AI Agents and also ended up comparing them with Agentic AI. If you’re also evaluating or adopting AI agent-related technologies, these two concepts may look similar but are quite different.