hermes - 💡(How to fix) Fix TUI re-renders entire conversation history on terminal window resize [1 comments, 2 participants]

Bug Description

When the iTerm2 window is resized while running the Hermes CLI (via hermes command), the TUI re-renders the entire conversation history from the beginning, causing the terminal to scroll through all previous output. This makes window resizing disruptive and can require scrolling back to find the current position.

Steps to Reproduce

1. Open iTerm2 and run hermes to start a conversation
2. Have a few exchanges with the agent
3. Drag the iTerm2 window edge to resize it
4. Observe: the terminal scrolls through all previous messages from the start of the session

Expected Behavior

On terminal resize (SIGWINCH), the TUI should adjust the visible area cleanly without re-rendering the full conversation history. The current viewport position should be preserved.

Actual Behavior

The entire conversation history is re-rendered line by line from the beginning, causing a rapid scroll through all previous messages.

Environment

• OS: macOS (Apple Silicon)
• Terminal: iTerm2
• Shell: zsh
• Hermes version: latest

Notes

• Likely related to how prompt_toolkit handles SIGWINCH events in the Hermes TUI
• May affect other terminal emulators as well