diff --git a/plugins/platforms/zulip/adapter.py b/plugins/platforms/zulip/adapter.py
index 1e25176..f78074f 100644
--- a/plugins/platforms/zulip/adapter.py
+++ b/plugins/platforms/zulip/adapter.py
@@ -64,7 +64,11 @@ logger = logging.getLogger(__name__)
 
 # Constants
 DEFAULT_STREAM = "agent-hub"
-DEFAULT_ALL_BOTS_USER_ID = 1
+# SyslogGH realm: the @all-bots user has user_id=20 (verified via
+# /api/v1/users and CONTRACT_VERIFICATION_2026-06-29). Dynamic resolution
+# on connect overrides this; this value is the fallback when that fails —
+# user_id=1 was never valid in this realm and silently dropped @all-bots.
+DEFAULT_ALL_BOTS_USER_ID = 20
 DEFAULT_POLL_INTERVAL = 3.0
 MAX_ZULIP_MESSAGE = 10000
 TRUNCATION_NOTICE = "\n\n[...truncated at Zulip limit]"