diff --git a/app/plugins/builtins/automation/plugin.py b/app/plugins/builtins/automation/plugin.py
index 14c935a..d9d6b09 100644
--- a/app/plugins/builtins/automation/plugin.py
+++ b/app/plugins/builtins/automation/plugin.py
@@ -187,16 +187,22 @@ class AutomationPlugin(BasePlugin):
         from app.plugins.builtins.automation.models import AutomationCronJob
         from sqlalchemy import select
 
+        # Get default tenant_id from the first tenant in the DB
+        from app.models.tenant import Tenant
+        tenant_result = await db.execute(select(Tenant).limit(1))
+        tenant = tenant_result.scalar_one_or_none()
+        default_tenant_id = tenant.id if tenant else None
+
         # Register agent definitions
         agent_names: list[str] = []
         for agent_def in manifest.agent_definitions:
             prefixed_name = f"{plugin_name}.{agent_def.name}"
             agent_names.append(prefixed_name)
             # Check if already exists (idempotent)
-            existing = await AgentService.get_by_name(db, agent_def.tenant_id, prefixed_name) if hasattr(AgentService, 'get_by_name') else None
+            existing = await AgentService.get_by_name(db, default_tenant_id, prefixed_name) if hasattr(AgentService, 'get_by_name') else None
             if existing is None:
                 try:
-                    await AgentService.create(db, agent_def.tenant_id, {
+                    await AgentService.create(db, default_tenant_id, {
                         "name": prefixed_name,
                         "description": agent_def.description,
                         "llm_model": agent_def.llm_model,
@@ -219,10 +225,10 @@ class AutomationPlugin(BasePlugin):
         for auto_def in manifest.automation_templates:
             prefixed_name = f"{plugin_name}.{auto_def.name}"
             automation_names.append(prefixed_name)
-            existing = await AutomationService.get_by_name(db, auto_def.tenant_id, prefixed_name) if hasattr(AutomationService, 'get_by_name') else None
+            existing = await AutomationService.get_by_name(db, default_tenant_id, prefixed_name) if hasattr(AutomationService, 'get_by_name') else None
             if existing is None:
                 try:
-                    await AutomationService.create(db, auto_def.tenant_id, {
+                    await AutomationService.create(db, default_tenant_id, {
                         "name": prefixed_name,
                         "description": auto_def.description,
                         "trigger_type": auto_def.trigger_type,
@@ -248,7 +254,7 @@ class AutomationPlugin(BasePlugin):
                 )
                 existing = result.scalar_one_or_none()
                 if existing is None:
-                    await CronJobService.create(db, cron_def.tenant_id, {
+                    await CronJobService.create(db, default_tenant_id, {
                         "name": prefixed_name,
                         "cron_expression": cron_def.cron_expression,
                         "job_type": cron_def.job_type,