BREAKING
Prompt ports Fable 5 style to Opus 4.8
The five-gate reasoning habit
1
Scoping
↓
2
Evidence
↓
3
Attacking
↓
4
Verifying
↓
5
Reporting
Fable 5 API costs more than double
Fable 5 in
10
Opus in
5
Fable 5 out
50
Opus out
25
Native Fable 5 vs Opus 4.8 plus prompt
Fable 5
Native
●
Thinking always on
●
Better long-horizon autonomy
●
Heavy safety routing
Opus 4.8 + .md
Prompted
●
Run at High or Max effort
●
Same tokenizer, stable counts
●
Close but not identical
Hybrid split: planner and executor
A cheaper stand-in gains traction
AI NEWS BLITZ
A single prompt file is letting developers mimic Claude Fable 5 on the cheaper Opus 4.8.