From 64a3e5a6049fa0489ec3e303e48012fd4bd7317a Mon Sep 17 00:00:00 2001
From: Robert McMahon <rjmcmahon@rjmcmahon.com>
Date: Fri, 3 Apr 2026 13:39:55 -0700
Subject: [PATCH] cli: emit fiwi: start only when stderr is a TTY.

Avoids interleaving the banner with captured stdout (e.g. SSH
port-metrics-json and check_concentrator table output).

Made-with: Cursor
---
 fiwi/cli.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fiwi/cli.py b/fiwi/cli.py
index 47f2a80..618a986 100644
--- a/fiwi/cli.py
+++ b/fiwi/cli.py
@@ -206,7 +206,9 @@ def main() -> int:
     if rc_ssh_map is not None:
         return rc_ssh_map
 
-    os.write(2, b"fiwi: start\n")
+    # Skip when stderr is a pipe (SSH capture, subprocess): avoids interleaving with stdout consumers.
+    if sys.stderr.isatty():
+        os.write(2, b"fiwi: start\n")
     try:
         load_brainstem()
     except Exception as exc: