I spent a week with Fable 5 and let it build a native macOS app that edits my videos for me. 102 commits, most of it overnight. Here’s the exact workflow.
The headline finding: Fable 5 is the best executor I’ve worked with, better than Opus 4.8, my daily driver. But I never let it write the plan. The plan came from GPT 5.5 Pro extended thinking, running in a browser through the Oracle tool, and Fable’s job was to attack that plan and find the weak spots. That split — strongest planner up front, strongest executor behind it — is the whole recipe.
The project is The Gray Cut: a local tool that takes my raw takes plus the script I read, treats the script as ground truth, and cuts the bad takes for me. A Python engine listens with Whisper and maps every word onto the script; a SwiftUI app previews the proposed cut instantly with AVFoundation and exports an XML that imports straight into Premiere. Getting from the overnight prototype to something usable took four more days of iteration — and the trick that moved the needle was feeding it my own hand-edited XMLs as reference.
I also cover the orchestrator-and-worker setup (Fable supervising, Opus 4.8 doing the cheap implementation), why that split is purely about token economics, and where the model still needs a human to verify its work.
⏱️ TIMESTAMPS
0:00 The Best Executor I’ve Used
0:52 Why I Built This
2:42 The Plan (and Who Wrote It)
4:45 The Overnight Run
6:40 The Iteration Loop
8:44 The Result: The Gray Cut
10:47 The Recipe and the Caveats
🔗 LINKS & RESOURCES
Oracle (open-source, browser models with full context)
https://github.com/steipete/oracle
Superpowers plugin (the brainstorming skill)
https://github.com/obra/superpowers
My cmux orchestrator-and-worker video
https://www.youtube.com/watch?v=gqTxHnAMF-Q
Join the Discord Community
https://discord.gg/PKgAUuGnGG
Follow on X/Twitter
https://x.com/thegraytcat
Buy Me a Coffee
https://buymeacoffee.com/thegraycat
🐱 THE GRAY CAT
AI meets code. Building next-generation software with modern AI tooling.
Covering AI IDEs, Claude Code, MCP integrations, and TypeScript/Node.js development.
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