# Agents on Rails: Claude Fable 5.1 and GLM 5.3 Flash (formerly known as ox-alpha)

DevFeed: [Agents on Rails: Claude Fable 5.1 and GLM 5.3 Flash (formerly known as ox-alpha)](<https://devfeed.tech/articles/agents-on-rails-claude-fable-5-1-and-glm-5-3-flash-formerly-known-as-ox-alpha-3565.md>)

Original publisher: [Read original article](<https://rubyonrails.org/2026/9/2/agents-on-rails-claude-fable-5-1-and-glm-5-3-flash>)

Author: Svyatoslav Kryukov, Artur Petrov

Published: 2026-09-02T00:00:00Z

Content type: news

Language: en

Sources: [Ruby on Rails: Compress the complexity of modern web apps](<https://devfeed.tech/sources/ruby-on-rails-compress-the-complexity-of-modern-web-apps.md>)

Topics: [Claude](<https://devfeed.tech/topics/claude.md>)

Tags: [agents](<https://devfeed.tech/tags/agents.md>), [apis](<https://devfeed.tech/tags/apis.md>), [benchmark](<https://devfeed.tech/tags/benchmark.md>), [claude](<https://devfeed.tech/tags/claude.md>), [cost](<https://devfeed.tech/tags/cost.md>), [flash](<https://devfeed.tech/tags/flash.md>), [leaderboard](<https://devfeed.tech/tags/leaderboard.md>), [model](<https://devfeed.tech/tags/model.md>), [security](<https://devfeed.tech/tags/security.md>)

## AI overview

A benchmark update compares Claude Fable 5.1 with Claude Opus 5, Fable 5, and GLM 5.3 Flash on Rails tasks, accuracy, cost, speed, security-task handling, and Rails API recall.

## Source excerpt

Claude Fable 5.1 dropped yesterday. See how it handles real Rails tasks, and where it landed on the leaderboard today. We also finally have a name for the stealth model from the last round.