hermes - 💡(How to fix) Fix [--tui] gateway exits mid-turn with stdin EOF (TUI closed the command pipe) — NOT byterover-related

Summary

In --tui mode on macOS, the Python gateway exits mid-turn with reason=stdin EOF (TUI closed the command pipe). This happens with built-in memory (memory.provider: ""), not byterover — so it may be a more general variant of #14036.

Environment

• OS: macOS 26.5 (darwin)
• Hermes: v0.14.0 (2026.5.16) @ a91a57fa5
• Python: 3.11.10
• Config: memory.provider: "" (built-in only), DeepSeek v4-pro via custom provider
• No byterover, no external memory plugins

What happens

Mid-conversation, the TUI shows "gateway exited" and the session is lost. The crash log shows clean exits, not crashes:

=== gateway exit · 2026-05-17 01:02:44 · reason=stdin EOF (TUI closed the command pipe) ===
=== gateway exit · 2026-05-17 12:52:16 · reason=stdin EOF (TUI closed the command pipe) ===
=== gateway exit · 2026-05-17 13:28:57 · reason=stdin EOF (TUI closed the command pipe) ===

Three exits within ~12 hours, all the same pattern. One SIGHUP (terminal closed) also recorded but that is expected.

Differences from #14036

#14036 is specifically triggered by memory.provider: byterover and shows SIGPIPE floods. This case:

• Uses built-in memory only
• Shows clean stdin EOF, no SIGPIPE flood
• Happens on macOS (darwin), not Linux

Same mechanism (Node TUI closes the pipe to Python gateway) but different trigger.

Workaround

hermes gateway install   # launchd service — decouples gateway from TUI lifecycle

After installing as launchd, TUI crashes no longer kill the gateway — re-launching hermes --tui reconnects.

Crash log excerpt

=== gateway exit · 2026-05-17 01:02:44 · reason=stdin EOF (TUI closed the command pipe) ===

=== SIGHUP received · 2026-05-17 12:18:28 ===
main-thread stack at signal delivery:
  File "tui_gateway/entry.py", line 227, in main
    for raw in sys.stdin:

=== gateway exit · 2026-05-17 12:52:16 · reason=stdin EOF (TUI closed the command pipe) ===

=== gateway exit · 2026-05-17 13:28:57 · reason=stdin EOF (TUI closed the command pipe) ===

Full crash log available if needed.