hermes - 💡(How to fix) Fix [Docker] Shift+Enter / Alt+Enter newline does not work in TUI via docker exec [1 comments, 2 participants]

Problem

When running Hermes TUI via docker exec, the Shift+Enter and Alt+Enter key combinations do not insert a newline — they behave identically to Enter and submit the message immediately.

Example:

docker exec -it hermes-agent /opt/hermes/.venv/bin/hermes --tui

In the TUI:

• Pressing Shift+Enter → submits the message (same as Enter)
• Pressing Alt+Enter / Option+Enter (macOS iTerm2) → submits the message (same as Enter)
• Pressing Ctrl+J → submits the message (same as Enter)

According to the official documentation (ui-tui README), Shift+Enter / Alt+Enter should insert a newline for multi-line input.

Environment

• Host: macOS (iTerm2 terminal)
• Container: Docker running Hermes Agent
• Hermes version: v2026.4.23
• Access method: docker exec -it hermes-agent /opt/hermes/.venv/bin/hermes --tui

Root Cause

The Docker PTY layer normalizes Shift+Enter, Alt+Enter, and Ctrl+J to the same byte sequence as Enter (\n). This means the TUI application receives identical input regardless of which modifier key is used, making it impossible to distinguish "newline" from "submit".

Expected Behavior

• Enter → submit message
• Shift+Enter / Alt+Enter → insert newline (multi-line input)
• Ctrl+J → insert newline (alternative)

Request

1. Investigate whether a workaround is possible for Docker environments (e.g., alternative key binding for newline)
2. If not feasible, consider adding documentation note about this limitation for Docker users
3. Open to alternative multi-line input methods if the above cannot be resolved

Workaround

None currently available for Docker users who need multi-line input in TUI.