Tier S+: Exceptional, but not always available.
Fable 5
Best-in-class when available, but access is the problem.
Our take
The video treats Fable 5 as a level above the rest for hard coding and architecture work, especially after it solved a Pine Script task that other models could not finish cleanly.
Best for
- Hard first-pass builds
- Architecture-heavy work
- Difficult trading or scripting tasks
Watch out
- Availability is uncertain
- Repos should be handed to a stable model for continuation
- Expect access and behavior to change
Why it is ranked here
- It was the only tested model to produce a functioning Pine Script indicator without syntax errors and without visual clutter.
- The team treated it as the heavy-lift model, then handed the repository to Opus for continuation.
- Because access was paused, it is not a dependable day-to-day default even though the capability was exceptional.
Video evidence
NEW AI Model Tier List for Vibe Coding!
Takeaway: Fable 5 sits above the normal S tier when access is available.
The source video ranks it as the strongest tested model for difficult coding work, while warning that access is unstable.
Open source notes