Bug Description

Shift+Enter stopped inserting a newline in the classic Hermes CLI chat input. Instead, Enter behavior changed in a way that broke multiline composition in normal local terminal usage on macOS.

This appears to have regressed after the LF-submit fix for thin PTYs. In my case, Shift+Enter used to be a practical multiline shortcut and then stopped working.

Steps to Reproduce

1. Start classic Hermes CLI with hermes (not hermes --tui).
2. Type part of a message.
3. Press Shift+Enter.
4. Observe that no newline is inserted / multiline composition is broken.

Expected Behavior

In the classic CLI, Shift+Enter should insert a newline so multiline prompts can be composed normally.

Actual Behavior

Shift+Enter no longer inserts a newline. The CLI treats LF / c-j as submit, which breaks terminals that deliver Shift+Enter as LF / c-j.

Affected Component

CLI (interactive chat)

Messaging Platform (if gateway-related)

N/A (CLI only)

Debug Report

Report       https://paste.rs/1Lg8U
agent.log    https://paste.rs/U0uXO
gateway.log  https://paste.rs/iJqBj

Operating System

MacOS Sequoia

Python Version

3.14.4

Hermes Version

Hermes Agent v0.13.0 (2026.5.7)

Additional Logs / Traceback (optional)

None captured for this bug.

Root Cause Analysis (optional)

The relevant upstream change appears to be:

• fix(cli): submit LF enter in thin PTYs (commit 5044e1cbf)

In cli.py, _bind_prompt_submit_keys() was changed to bind both enter and c-j to submit. On terminals where Shift+Enter is delivered as LF / c-j, this makes Shift+Enter submit instead of inserting a newline.

Proposed Fix (optional)

For normal local CLI use, bind only enter to submit by default.
Handle c-j separately so it inserts \n by default, and gate LF-submit behind an opt-in environment variable for thin PTYs, e.g. HERMES_CLI_SUBMIT_ON_LF=1.
A working local pattern was:

• _bind_prompt_submit_keys() binds only enter
• @kb.add('c-j') inserts newline by default
• when HERMES_CLI_SUBMIT_ON_LF=1 is set, the c-j handler calls handle_enter(event) instead

Are you willing to submit a PR for this?

• I'd like to fix this myself and submit a PR