How to prevent Fable 5 from switching down to Opus 4.8 in Claude Code

How to Automatically Switch Fable 5 Back from Opus 4.8

Setting Up Tmux for Fable 5

• To prevent Fable 5 sessions from automatically switching down to Opus 4.8, the first step is to install tmux, a terminal multiplexer that allows multiple terminal sessions to be accessed simultaneously.

• Open a tmux window and initiate a Fable 5 Claude Code session within it. This setup will allow you to manage your Fable instances more effectively.

Monitoring and Switching Models

• Start another instance of Fable 5 Claude Code in a different terminal, ensuring it connects with the tmux session running on your computer. This connection enables the second instance to interact with the first one.

• In this second instance, configure it to monitor the tmux pane of the first instance for any warning messages indicating that it has switched down to Opus 4.8.

Automating Model Adjustments

• You can customize this second instance by selecting any model you prefer and setting up a loop prompt that checks at specified intervals for warnings from the first instance.

• Upon detecting a warning message, the script should read recent lines from the JSONL transcript of that session, cleanse any references related to security or cybersecurity, and then send commands back through tmux to revert the model back to Fable 5 while injecting an updated prompt without sensitive references.