You can turn Opus 4.8 into Fable 5 for Free
And you have 2 days before the window closes.
July 7 is the last day Fable 5 is included in paid plans.
Fom july 8 it's usage credits: $10/$50 per m/tok, 2x Opus, the most expensive model on Anthropic's price list.
What to do?
Make Fable 5 write a skill for Opus 4.8: its reasoning patterns, verification habits, task decomposition, extracted into one SKILL.md your daily model inherits.
The prompt is one line:
"write a SKILL.md for Opus 4.8 capturing how you decompose hard tasks, verify your own work, and decide what to do next".
While the window's still open, 6 more ways to squeeze it:
1/ Give it your hardest problems. it's built for work that takes humans days - easy tasks waste the window.
2/ One big brief instead of 20 messages: full context, constraints, edge cases in message one - it decomposes the rest.
3/ Effort on high by default: xhigh only for genuinely brutal runs - high on Fable often beats xhigh on older models.
4/ One .md memory file that accumulates learnings across sessions.
5/ Make it verify its own work before reporting - kills the fake "done".
6/ delete your opus-era prompts - over-detailed instructions actively hurt Fable 5.
Access to Fable expires on the 7th, but the files it wrote don't.
Everyone else will figure this out on July 8, but you have until the 7th.
Once you've done that, be sure to read the article about Loop engineering, because you'll be working with it extensively after July 7:
It forces the hot smoke and gases into an S-shaped path instead of letting them escape straight up the chimney. This simple obstacle dramatically increases efficiency and keeps your space warm for longer!