diff --git a/asf-doc b/asf-doc
index 174fc37..33d5d56 160000
--- a/asf-doc
+++ b/asf-doc
@@ -1 +1 @@
-Subproject commit 174fc379498e07dc39c301bc27b1533f9b83681c
+Subproject commit 33d5d5623a07e7ef8a6036d0ea0823151b36d071
diff --git a/backend/apps/agentic/runtime/base.py b/backend/apps/agentic/runtime/base.py
index 9a6ca2c..b4370e9 100644
--- a/backend/apps/agentic/runtime/base.py
+++ b/backend/apps/agentic/runtime/base.py
@@ -14,7 +14,6 @@ class BasePlaybook:
     DESC = ""
     TAGS = []
     PROMPT_SLUG = ""
-    REQUIRED_PROMPTS = []
     SCRIPT_PATH = None
 
     def __init__(self, *, playbook_run=None):
diff --git a/backend/apps/agentic/services/custom.py b/backend/apps/agentic/services/custom.py
index 1d3726b..2e9eec1 100644
--- a/backend/apps/agentic/services/custom.py
+++ b/backend/apps/agentic/services/custom.py
@@ -1,12 +1,14 @@
 from pathlib import Path
 
+import redis
 from django.conf import settings
 
-from apps.agentic.runtime.module import scan_module_definitions
+from apps.agentic.runtime.module import AGENTIC_MODULE_CONSUMER_GROUP, scan_module_definitions
 from apps.agentic.services.playbooks import scan_playbook_definitions
+from apps.common.redis_stream import RedisStreamClient
 from integrations.siem.registry import reload_registry, scan_registry_configs
 
-PROMPT_LANGUAGES = ("en", "zh")
+MAX_STREAM_MESSAGES = 20
 
 
 def _source_for_path(path):
@@ -22,10 +24,10 @@ def _source_for_path(path):
 def _module_record(definition):
     return {
         "name": definition.name,
+        "description": getattr(definition.module_class, "DESC", ""),
         "stream_name": definition.stream_name,
         "thread_num": definition.thread_num,
         "path": str(definition.path),
-        "source": _source_for_path(definition.path),
     }
 
 
@@ -42,74 +44,131 @@ def _playbook_record(definition):
 
 
 def _siem_record(item):
-    path = item["path"]
+    return item
+
+
+def _decode(value):
+    return value.decode() if isinstance(value, bytes) else value
+
+
+def _info_get(info, key, default=None):
+    return info.get(key, info.get(key.encode(), default))
+
+
+def _stream_group_record(group):
     return {
-        **item,
-        "source": _source_for_path(path),
+        "name": _decode(_info_get(group, "name", "")),
+        "consumers": _info_get(group, "consumers", 0),
+        "pending": _info_get(group, "pending", 0),
+        "last_delivered_id": _decode(_info_get(group, "last-delivered-id", "")),
     }
 
 
-def _prompt_record(definition, prompt_name, language, path):
+def _entry_id(entry):
+    if isinstance(entry, (list, tuple)) and entry:
+        return _decode(entry[0])
+    return ""
+
+
+def _stream_health(stream_name, *, redis_client=None):
+    try:
+        client = redis_client or RedisStreamClient()
+        info = client.stream_info(stream_name)
+        groups = client.stream_groups(stream_name)
+    except redis.ResponseError as exc:
+        if "no such key" in str(exc).lower():
+            return {
+                "available": False,
+                "length": 0,
+                "first_id": "",
+                "last_id": "",
+                "groups": [],
+                "warning": "Stream does not exist yet.",
+            }
+        raise
+
     return {
-        "playbook": definition.name,
-        "prompt": prompt_name,
-        "language": language,
-        "path": str(path),
-        "source": "custom",
+        "available": True,
+        "length": _info_get(info, "length", 0),
+        "first_id": _entry_id(_info_get(info, "first-entry")),
+        "last_id": _entry_id(_info_get(info, "last-entry")),
+        "groups": [_stream_group_record(group) for group in groups],
+        "warning": "",
     }
 
 
-def _scan_playbook_prompts(playbooks):
-    items = []
-    errors = []
-    for definition in playbooks:
-        if _source_for_path(definition.path) != "custom":
-            continue
-        required_prompts = getattr(definition.script_class, "REQUIRED_PROMPTS", []) or []
-        for prompt_name in required_prompts:
-            for language in PROMPT_LANGUAGES:
-                path = definition.script_class.prompt_path(prompt_name, language=language)
-                if path.exists():
-                    items.append(_prompt_record(definition, prompt_name, language, path))
-                else:
-                    errors.append({
-                        "path": str(path),
-                        "error": f"Missing custom playbook prompt: {definition.name} {prompt_name}_{language}",
-                    })
-    return items, errors
+def _module_record_with_stream_health(definition, *, redis_client=None):
+    record = _module_record(definition)
+    try:
+        record["stream_health"] = _stream_health(definition.stream_name, redis_client=redis_client)
+    except redis.RedisError as exc:
+        record["stream_health"] = {
+            "available": False,
+            "length": 0,
+            "first_id": "",
+            "last_id": "",
+            "groups": [],
+            "warning": f"{type(exc).__name__}: {exc}",
+        }
+    return record
 
 
-def refresh_custom_definitions():
-    reload_registry()
-    modules, module_errors = scan_module_definitions()
-    playbooks, playbook_errors = scan_playbook_definitions()
-    siem_indices, siem_errors = scan_registry_configs()
-    prompt_items, prompt_errors = _scan_playbook_prompts(playbooks)
-    sections = {
-        "modules": {
-            "items": [_module_record(item) for item in modules],
-            "errors": module_errors,
-        },
-        "playbooks": {
-            "items": [_playbook_record(item) for item in playbooks],
-            "errors": playbook_errors,
-        },
-        "siem": {
-            "items": [_siem_record(item) for item in siem_indices],
-            "errors": siem_errors,
-        },
-        "prompts": {
-            "items": prompt_items,
-            "errors": prompt_errors,
+def _section_result(section, items, errors):
+    return {
+        "section": section,
+        "success": not errors,
+        "counts": {
+            "items": len(items),
+            "errors": len(errors),
         },
+        "items": items,
+        "errors": errors,
     }
-    result = dict(sections)
-    result["success"] = not any(section["errors"] for section in sections.values())
-    result["counts"] = {
-        "modules": len(result["modules"]["items"]),
-        "playbooks": len(result["playbooks"]["items"]),
-        "siem": len(result["siem"]["items"]),
-        "prompts": len(result["prompts"]["items"]),
-        "errors": sum(len(section["errors"]) for section in sections.values()),
+
+
+def list_module_definitions_with_health():
+    modules, errors = scan_module_definitions()
+    items = [
+        _module_record_with_stream_health(definition)
+        for definition in modules
+    ]
+    return _section_result("modules", items, errors)
+
+
+def list_playbook_definition_records():
+    playbooks, errors = scan_playbook_definitions()
+    items = [_playbook_record(item) for item in playbooks]
+    return _section_result("playbooks", items, errors)
+
+
+def list_siem_definition_records(*, reload=False):
+    if reload:
+        reload_registry()
+    siem_indices, errors = scan_registry_configs()
+    items = [_siem_record(item) for item in siem_indices]
+    return _section_result("siem", items, errors)
+
+
+def known_module_streams():
+    modules, _errors = scan_module_definitions()
+    return {definition.stream_name for definition in modules}
+
+
+def read_module_stream_recent(stream_name, limit):
+    limit = max(1, min(int(limit or 5), MAX_STREAM_MESSAGES))
+    messages = RedisStreamClient().read_stream_recent(stream_name, limit)
+    return {
+        "stream_name": stream_name,
+        "consumer_group": AGENTIC_MODULE_CONSUMER_GROUP,
+        "limit": limit,
+        "messages": messages,
+    }
+
+
+def read_module_stream_message(stream_name, message_id):
+    message = RedisStreamClient().read_stream_message_by_id(stream_name, message_id)
+    return {
+        "stream_name": stream_name,
+        "message_id": message_id,
+        "message": message,
     }
-    return result
diff --git a/backend/apps/common/redis_stream.py b/backend/apps/common/redis_stream.py
index 0bb9c33..ca1b15e 100644
--- a/backend/apps/common/redis_stream.py
+++ b/backend/apps/common/redis_stream.py
@@ -80,6 +80,10 @@ class RedisStreamClient:
         messages = self.redis.xrange(stream, min="-", max="+", count=count)
         return [_decode_stream_message(message_id, fields, stream=stream) for message_id, fields in messages]
 
+    def read_stream_recent(self, stream, count):
+        messages = self.redis.xrevrange(stream, max="+", min="-", count=count)
+        return [_decode_stream_message(message_id, fields, stream=stream) for message_id, fields in messages]
+
     def read_stream_message_by_id(self, stream, message_id):
         messages = self.redis.xrange(stream, min=message_id, max=message_id, count=1)
         if not messages:
@@ -87,5 +91,11 @@ class RedisStreamClient:
         found_id, fields = messages[0]
         return _decode_stream_message(found_id, fields, stream=stream)
 
+    def stream_info(self, stream):
+        return self.redis.xinfo_stream(stream)
+
+    def stream_groups(self, stream):
+        return self.redis.xinfo_groups(stream)
+
     def delete_stream(self, stream):
         return bool(self.redis.delete(stream))
diff --git a/backend/apps/settings/custom_views.py b/backend/apps/settings/custom_views.py
new file mode 100644
index 0000000..3f9b4b5
--- /dev/null
+++ b/backend/apps/settings/custom_views.py
@@ -0,0 +1,119 @@
+import redis
+from django.contrib.contenttypes.models import ContentType
+from rest_framework import permissions, status, views
+from rest_framework.response import Response
+
+from apps.accounts.permissions import IsAdmin
+from apps.agentic.services.custom import (
+    MAX_STREAM_MESSAGES,
+    known_module_streams,
+    list_module_definitions_with_health,
+    list_playbook_definition_records,
+    list_siem_definition_records,
+    read_module_stream_message,
+    read_module_stream_recent,
+)
+from apps.audit.models import AuditLog
+from .models import RuntimeConfig
+
+
+def _audit_refresh(section, request, result):
+    instance = RuntimeConfig.get_current()
+    AuditLog.objects.create(
+        content_type=ContentType.objects.get_for_model(RuntimeConfig),
+        object_id=str(instance.pk),
+        action="refresh",
+        actor=request.user if getattr(request.user, "is_authenticated", False) else None,
+        metadata={
+            "section": section,
+            "success": result["success"],
+            "counts": result["counts"],
+        },
+    )
+
+
+class CustomDefinitionsModuleView(views.APIView):
+    permission_classes = [permissions.IsAuthenticated, IsAdmin]
+
+    def get(self, request):
+        return Response(list_module_definitions_with_health(), status=status.HTTP_200_OK)
+
+    def post(self, request):
+        result = list_module_definitions_with_health()
+        _audit_refresh("modules", request, result)
+        return Response(result, status=status.HTTP_200_OK)
+
+
+class CustomDefinitionsPlaybookView(views.APIView):
+    permission_classes = [permissions.IsAuthenticated, IsAdmin]
+
+    def get(self, request):
+        return Response(list_playbook_definition_records(), status=status.HTTP_200_OK)
+
+    def post(self, request):
+        result = list_playbook_definition_records()
+        _audit_refresh("playbooks", request, result)
+        return Response(result, status=status.HTTP_200_OK)
+
+
+class CustomDefinitionsSiemView(views.APIView):
+    permission_classes = [permissions.IsAuthenticated, IsAdmin]
+
+    def get(self, request):
+        return Response(list_siem_definition_records(), status=status.HTTP_200_OK)
+
+    def post(self, request):
+        result = list_siem_definition_records(reload=True)
+        _audit_refresh("siem", request, result)
+        return Response(result, status=status.HTTP_200_OK)
+
+
+def _stream_name(request):
+    stream_name = str(request.query_params.get("stream_name") or "").strip()
+    if not stream_name:
+        return None, Response({"stream_name": ["This query parameter is required."]}, status=status.HTTP_400_BAD_REQUEST)
+    if stream_name not in known_module_streams():
+        return None, Response({"detail": "Unknown module stream."}, status=status.HTTP_400_BAD_REQUEST)
+    return stream_name, None
+
+
+def _stream_limit(request):
+    raw_limit = request.query_params.get("limit", 5)
+    try:
+        return max(1, min(int(raw_limit), MAX_STREAM_MESSAGES)), None
+    except (TypeError, ValueError):
+        return None, Response({"limit": ["Limit must be an integer."]}, status=status.HTTP_400_BAD_REQUEST)
+
+
+class CustomModuleStreamMessagesView(views.APIView):
+    permission_classes = [permissions.IsAuthenticated, IsAdmin]
+
+    def get(self, request):
+        stream_name, error = _stream_name(request)
+        if error is not None:
+            return error
+        limit, error = _stream_limit(request)
+        if error is not None:
+            return error
+        try:
+            result = read_module_stream_recent(stream_name, limit)
+        except redis.RedisError as exc:
+            return Response({"detail": f"{type(exc).__name__}: {exc}"}, status=status.HTTP_503_SERVICE_UNAVAILABLE)
+        return Response(result, status=status.HTTP_200_OK)
+
+
+class CustomModuleStreamMessageView(views.APIView):
+    permission_classes = [permissions.IsAuthenticated, IsAdmin]
+
+    def get(self, request):
+        stream_name, error = _stream_name(request)
+        if error is not None:
+            return error
+        message_id = str(request.query_params.get("message_id") or "").strip()
+        if not message_id:
+            return Response({"message_id": ["This query parameter is required."]}, status=status.HTTP_400_BAD_REQUEST)
+        try:
+            result = read_module_stream_message(stream_name, message_id)
+        except redis.RedisError as exc:
+            return Response({"detail": f"{type(exc).__name__}: {exc}"}, status=status.HTTP_503_SERVICE_UNAVAILABLE)
+        return Response(result, status=status.HTTP_200_OK)
diff --git a/backend/apps/settings/urls.py b/backend/apps/settings/urls.py
index 25e3a91..487043d 100644
--- a/backend/apps/settings/urls.py
+++ b/backend/apps/settings/urls.py
@@ -1,12 +1,18 @@
 from django.urls import include, path
 from rest_framework.routers import DefaultRouter
 
+from .custom_views import (
+    CustomDefinitionsModuleView,
+    CustomDefinitionsPlaybookView,
+    CustomDefinitionsSiemView,
+    CustomModuleStreamMessageView,
+    CustomModuleStreamMessagesView,
+)
 from .views import (
     LLMProviderConfigViewSet,
     LdapConfigView,
     LdapTestView,
     RuntimeConfigView,
-    RuntimeCustomDefinitionsRefreshView,
     SiemElkConfigView,
     SiemElkTestView,
     SiemSplunkConfigView,
@@ -29,6 +35,10 @@ urlpatterns = [
     path("settings/ldap/", LdapConfigView.as_view(), name="ldap-config"),
     path("settings/ldap/test/", LdapTestView.as_view(), name="ldap-test"),
     path("settings/runtime/", RuntimeConfigView.as_view(), name="runtime-config"),
-    path("settings/runtime/custom-definitions/refresh/", RuntimeCustomDefinitionsRefreshView.as_view(), name="runtime-custom-definitions-refresh"),
+    path("custom/modules/", CustomDefinitionsModuleView.as_view(), name="custom-definitions-modules"),
+    path("custom/modules/stream/messages/", CustomModuleStreamMessagesView.as_view(), name="custom-module-stream-messages"),
+    path("custom/modules/stream/message/", CustomModuleStreamMessageView.as_view(), name="custom-module-stream-message"),
+    path("custom/playbooks/", CustomDefinitionsPlaybookView.as_view(), name="custom-definitions-playbooks"),
+    path("custom/siem/", CustomDefinitionsSiemView.as_view(), name="custom-definitions-siem"),
     path("settings/", include(router.urls)),
 ]
diff --git a/backend/apps/settings/views.py b/backend/apps/settings/views.py
index f589cd2..c7a1774 100644
--- a/backend/apps/settings/views.py
+++ b/backend/apps/settings/views.py
@@ -8,7 +8,6 @@ from rest_framework.filters import OrderingFilter, SearchFilter
 from rest_framework.response import Response
 
 from apps.accounts.permissions import IsAdmin
-from apps.agentic.services.custom import refresh_custom_definitions
 from apps.audit.models import AuditLog
 from apps.common.advanced_filters import AdvancedFilterBackend
 from .models import (
@@ -389,20 +388,3 @@ class RuntimeConfigView(views.APIView):
         transaction.on_commit(lambda: invalidate("runtime"))
         return Response(RuntimeConfigSerializer(instance).data)
 
-
-class RuntimeCustomDefinitionsRefreshView(views.APIView):
-    permission_classes = [permissions.IsAuthenticated, IsAdmin]
-
-    def post(self, request):
-        result = refresh_custom_definitions()
-        instance = RuntimeConfig.get_current()
-        _write_audit(
-            instance,
-            "refresh",
-            request.user,
-            metadata={
-                "success": result["success"],
-                "counts": result["counts"],
-            },
-        )
-        return Response(result, status=status.HTTP_200_OK)
diff --git a/backend/custom/playbooks/case_summary.py b/backend/custom/playbooks/case_summary.py
index 16ada43..bd8e55d 100644
--- a/backend/custom/playbooks/case_summary.py
+++ b/backend/custom/playbooks/case_summary.py
@@ -13,7 +13,6 @@ class Playbook(BasePlaybook):
     DESC = "Generate a concise analyst-facing summary for the linked Case."
     TAGS = ["Custom", "LLM", "Case"]
     PROMPT_SLUG = "case_summary"
-    REQUIRED_PROMPTS = ["System"]
 
     def run(self):
         if self.case is None:
diff --git a/backend/integrations/siem/registry.py b/backend/integrations/siem/registry.py
index 8582f9d..c928dea 100644
--- a/backend/integrations/siem/registry.py
+++ b/backend/integrations/siem/registry.py
@@ -57,7 +57,16 @@ def scan_registry_configs():
         except Exception as exc:
             errors.append({"path": str(yaml_file), "error": f"{type(exc).__name__}: {exc}"})
             continue
-        indices.append({"name": index_info.name, "backend": index_info.backend, "path": str(yaml_file)})
+        fields = [field.model_dump() for field in index_info.fields]
+        indices.append({
+            "name": index_info.name,
+            "backend": index_info.backend,
+            "description": index_info.description,
+            "path": str(yaml_file),
+            "field_count": len(fields),
+            "key_field_count": sum(1 for field in index_info.fields if field.is_key_field),
+            "fields": fields,
+        })
     return indices, errors
 
 
diff --git a/docs/superpowers/specs/2026-06-28-custom-definitions-design.md b/docs/superpowers/specs/2026-06-28-custom-definitions-design.md
index f8da612..99a6c44 100644
--- a/docs/superpowers/specs/2026-06-28-custom-definitions-design.md
+++ b/docs/superpowers/specs/2026-06-28-custom-definitions-design.md
@@ -25,7 +25,7 @@ Prompt 文件不再作为 Custom Definitions 的管理对象。Playbook 可以
 
 ## 目标
 
-- 让管理员可以从独立入口查看所有已加载 definition，并区分 `official` / `custom` 来源。
+- 让管理员可以从独立入口查看所有已加载 definition。Playbook 需要区分 `official` / `custom` 来源；Modules 和 SIEM YAML 没有 official 来源概念，不展示 source。
 - 将验证功能按 tab 拆分，避免一个聚合结果难以定位问题。
 - 让 Module 页面展示对应 Redis Stream 的基础运行信息，并支持只读查看最近消息或指定消息。
 - 让 Playbook 页面展示可运行定义，但不在 Custom 页面直接执行 playbook。
@@ -89,7 +89,6 @@ Module section 返回：
 
 - `name`
 - `description`
-- `source`
 - `path`
 - `stream_name`
 - `thread_num`
@@ -139,7 +138,6 @@ SIEM section 返回：
 - `name`
 - `backend`
 - `description`
-- `source`
 - `path`
 - `field_count`
 - `key_field_count`
@@ -163,13 +161,11 @@ Toolbar：
 
 - `Refresh / Validate`
 - `Reload`
-- source filter
 - search
 
 主表字段：
 
 - Module name
-- source
 - description
 - stream_name
 - thread_num
@@ -208,7 +204,6 @@ Toolbar：
 
 动作：
 
-- `Copy name`
 - Playbook 运行记录跳转留到后续单独设计，本次不实现 URL 过滤或 deep link。
 
 ### SIEM YAML tab
@@ -218,7 +213,6 @@ Toolbar：
 - `Refresh / Validate`
 - `Reload`
 - backend filter
-- source filter
 - search
 
 主表字段：
@@ -226,7 +220,6 @@ Toolbar：
 - index name
 - backend
 - description
-- source
 - field count
 - key field count
 - path
@@ -235,7 +228,7 @@ Toolbar：
 
 - name
 - type
-- key
+- key field
 - description
 - sample values
 
@@ -292,7 +285,7 @@ Toolbar：
 - Runtime 页不再显示 Custom Definitions。
 - 每个 tab 可单独 Refresh / Validate 并展示本 section errors。
 - Modules 详情抽屉可读取最近 stream 消息和指定 message id。
-- Playbooks tab 只展示和复制，不直接执行 playbook。
+- Playbooks tab 只展示，不直接执行 playbook。
 - SIEM YAML 详情抽屉展示 fields 表。
 
 文档：
diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index 5f8d654..24bfc67 100644
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -11,6 +11,7 @@ import PlaybookList from './pages/PlaybookList'
 import KnowledgeList from './pages/KnowledgeList'
 import Dashboard from './pages/Dashboard'
 import SystemSettings from './pages/SystemSettings'
+import CustomDefinitions from './pages/CustomDefinitions'
 import {useAuthStore} from './stores/auth'
 import {hasPermission, type PermissionKey} from './utils/permissions'
 import {getMe} from './api/auth'
@@ -56,6 +57,7 @@ export default function App() {
         <Route path="playbooks/:rowId" element={<ResourceDetailRoute resourceKey="playbooks" />} />
         <Route path="knowledge" element={<KnowledgeList />} />
         <Route path="knowledge/:rowId" element={<ResourceDetailRoute resourceKey="knowledge" />} />
+        <Route path="custom" element={<PermissionRoute permission="admin"><CustomDefinitions /></PermissionRoute>} />
         <Route path="system" element={<PermissionRoute permission="admin"><SystemSettings /></PermissionRoute>} />
         <Route path="system/users" element={<Navigate to="/system" replace />} />
       </Route>
diff --git a/frontend/src/components/MainLayout.tsx b/frontend/src/components/MainLayout.tsx
index 257e324..f0941b7 100644
--- a/frontend/src/components/MainLayout.tsx
+++ b/frontend/src/components/MainLayout.tsx
@@ -7,7 +7,7 @@ import {
     MenuUnfoldOutlined,
     UserOutlined,
 } from '@ant-design/icons'
-import {BookOpenText, BrainCircuit, BriefcaseBusiness, Fingerprint, LayoutDashboard, Settings, Siren, WandSparkles} from 'lucide-react'
+import {BookOpenText, BrainCircuit, BriefcaseBusiness, Fingerprint, LayoutDashboard, Puzzle, Settings, Siren, WandSparkles} from 'lucide-react'
 import {useAuthStore} from '../stores/auth'
 import {getResourceConfig} from '../config/resources'
 import type {ResourceConfig} from '../types/records'
@@ -28,6 +28,7 @@ const breadcrumbMap: Record<string, string> = {
   enrichments: 'Enrichments',
   playbooks: 'Playbooks',
   knowledge: 'Knowledge',
+  custom: 'Custom',
   dashboard: 'Dashboard',
   system: 'Setting',
 }
@@ -63,7 +64,7 @@ export default function MainLayout() {
   }, [location.pathname])
 
   const selectedKey = (() => {
-    const allKeys = ['/dashboard', '/cases', '/alerts', '/artifacts', '/enrichments', '/playbooks', '/knowledge', '/system']
+    const allKeys = ['/dashboard', '/cases', '/alerts', '/artifacts', '/enrichments', '/playbooks', '/knowledge', '/custom', '/system']
     if (allKeys.includes(location.pathname)) return location.pathname
     return '/' + (location.pathname.split('/').filter(Boolean)[0] || 'cases')
   })()
@@ -77,6 +78,7 @@ export default function MainLayout() {
     { key: '/enrichments', icon: <WandSparkles {...lucideIconProps} />, label: 'Enrichments' },
     { key: '/playbooks', icon: <BrainCircuit {...lucideIconProps} />, label: 'Playbooks' },
     { key: '/knowledge', icon: <BookOpenText {...lucideIconProps} />, label: 'Knowledge' },
+    hasPermission(user, 'admin') ? { key: '/custom', icon: <Puzzle {...lucideIconProps} />, label: 'Custom' } : null,
     hasPermission(user, 'admin') ? { key: '/system', icon: <Settings {...lucideIconProps} />, label: 'Setting' } : null,
   ].filter((item): item is NonNullable<typeof item> => Boolean(item))
 
diff --git a/frontend/src/pages/CustomDefinitions.tsx b/frontend/src/pages/CustomDefinitions.tsx
new file mode 100644
index 0000000..9482608
--- /dev/null
+++ b/frontend/src/pages/CustomDefinitions.tsx
@@ -0,0 +1,594 @@
+import {useCallback, useEffect, useMemo, useState} from 'react'
+import {Alert, Button, Descriptions, Drawer, Empty, Flex, Input, InputNumber, List, message, Select, Space, Table, Tabs, Tag, Typography} from 'antd'
+import {ReloadOutlined} from '@ant-design/icons'
+import type {ColumnsType} from 'antd/es/table'
+import {Boxes, BrainCircuit, DatabaseZap} from 'lucide-react'
+import client from '../api/client'
+import JsonViewer from '../components/JsonViewer'
+import IconTabLabel from '../components/IconTabLabel'
+import {comfortableTagProps} from '../utils/tagStyles'
+
+type SourceType = 'official' | 'custom'
+type SourceFilter = 'all' | SourceType
+
+interface DefinitionError {
+  path: string
+  error: string
+}
+
+interface SectionResult<T> {
+  section: string
+  success: boolean
+  counts: {
+    items: number
+    errors: number
+  }
+  items: T[]
+  errors: DefinitionError[]
+}
+
+interface StreamGroup {
+  name: string
+  consumers: number
+  pending: number
+  last_delivered_id: string
+}
+
+interface StreamHealth {
+  available: boolean
+  length: number
+  first_id: string
+  last_id: string
+  groups: StreamGroup[]
+  warning: string
+}
+
+interface ModuleDefinition {
+  name: string
+  description: string
+  path: string
+  stream_name: string
+  thread_num: number
+  stream_health: StreamHealth
+}
+
+interface PlaybookDefinition {
+  name: string
+  description: string
+  tags: string[]
+  source: SourceType
+  path: string
+}
+
+interface SiemField {
+  name: string
+  type: string
+  description: string
+  is_key_field: boolean
+  sample_values: unknown[]
+}
+
+interface SiemDefinition {
+  name: string
+  backend: 'ELK' | 'Splunk'
+  description: string
+  path: string
+  field_count: number
+  key_field_count: number
+  fields: SiemField[]
+}
+
+interface StreamMessage {
+  message_id: string
+  data: unknown
+}
+
+interface StreamMessagesResponse {
+  stream_name: string
+  consumer_group: string
+  limit: number
+  messages: StreamMessage[]
+}
+
+interface StreamMessageResponse {
+  stream_name: string
+  message_id: string
+  message: StreamMessage | Record<string, never>
+}
+
+function apiErrorMessage(error: unknown, fallback: string) {
+  const data = (error as { response?: { data?: unknown } }).response?.data
+  if (typeof data === 'string') return data
+  if (data && typeof data === 'object') {
+    const detail = (data as { detail?: unknown }).detail
+    if (typeof detail === 'string') return detail
+    return JSON.stringify(data)
+  }
+  return fallback
+}
+
+function sourceOptions(): Array<{ label: string; value: SourceFilter }> {
+  return [
+    { label: 'All sources', value: 'all' },
+    { label: 'Official', value: 'official' },
+    { label: 'Custom', value: 'custom' },
+  ]
+}
+
+function SourceTag({ source }: { source: SourceType }) {
+  return <Tag {...comfortableTagProps} color={source === 'custom' ? 'blue' : 'gold'}>{source}</Tag>
+}
+
+function PathText({ path }: { path: string }) {
+  return (
+    <Typography.Text type="secondary" style={{ fontSize: 12 }} ellipsis={{ tooltip: path }}>
+      {path}
+    </Typography.Text>
+  )
+}
+
+function filterBySource<T extends { source: SourceType }>(items: T[], source: SourceFilter) {
+  return source === 'all' ? items : items.filter((item) => item.source === source)
+}
+
+const PLAYBOOK_TAG_COLORS: Record<string, string> = {
+  System: 'gold',
+  LLM: 'purple',
+  Case: 'green',
+  Knowledge: 'magenta',
+  CMDB: 'geekblue',
+  'Threat Intel': 'volcano',
+  Enrichment: 'cyan',
+  Custom: 'blue',
+}
+
+const SIEM_BACKEND_COLORS: Record<string, string> = {
+  ELK: 'orange',
+  Splunk: 'green',
+}
+
+function includesSearch(values: unknown[], search: string) {
+  const keyword = search.trim().toLowerCase()
+  if (!keyword) return true
+  return values.some((value) => String(value || '').toLowerCase().includes(keyword))
+}
+
+function DefinitionErrors({ errors }: { errors: DefinitionError[] }) {
+  if (!errors.length) return null
+  return (
+    <Flex vertical gap={8} style={{ width: '100%', marginBottom: 12 }}>
+      {errors.map((error) => (
+        <Alert key={`${error.path}-${error.error}`} type="error" showIcon title={error.path} description={error.error} />
+      ))}
+    </Flex>
+  )
+}
+
+function useDefinitionSection<T>(endpoint: string, label: string) {
+  const [result, setResult] = useState<SectionResult<T> | null>(null)
+  const [loading, setLoading] = useState(false)
+  const [refreshing, setRefreshing] = useState(false)
+
+  const load = useCallback(async () => {
+    setLoading(true)
+    try {
+      const { data } = await client.get<SectionResult<T>>(endpoint)
+      setResult(data)
+    } catch (error) {
+      message.error(apiErrorMessage(error, `Failed to load ${label}`))
+      setResult(null)
+    } finally {
+      setLoading(false)
+    }
+  }, [endpoint, label])
+
+  const refresh = useCallback(async () => {
+    setRefreshing(true)
+    try {
+      const { data } = await client.post<SectionResult<T>>(endpoint)
+      setResult(data)
+      if (data.success) {
+        message.success(`${label} refreshed`)
+      } else {
+        message.warning(`${label} refreshed with ${data.counts.errors} error(s)`)
+      }
+    } catch (error) {
+      message.error(apiErrorMessage(error, `Failed to refresh ${label}`))
+    } finally {
+      setRefreshing(false)
+    }
+  }, [endpoint, label])
+
+  useEffect(() => {
+    // eslint-disable-next-line react-hooks/set-state-in-effect
+    load()
+  }, [load])
+
+  return { result, loading, refreshing, load, refresh }
+}
+
+function SectionToolbar({
+  search,
+  onSearchChange,
+  source,
+  onSourceChange,
+  onReload,
+  onRefresh,
+  loading,
+  refreshing,
+  extra,
+}: {
+  search: string
+  onSearchChange: (value: string) => void
+  source?: SourceFilter
+  onSourceChange?: (value: SourceFilter) => void
+  onReload: () => void
+  onRefresh: () => void
+  loading: boolean
+  refreshing: boolean
+  extra?: React.ReactNode
+}) {
+  return (
+    <Space wrap style={{ marginBottom: 12 }}>
+      <Button type="primary" onClick={onRefresh} loading={refreshing}>Refresh / Validate</Button>
+      <Button icon={<ReloadOutlined />} onClick={onReload} loading={loading}>Reload</Button>
+      {source && onSourceChange ? <Select<SourceFilter> value={source} options={sourceOptions()} onChange={onSourceChange} style={{ width: 140 }} /> : null}
+      {extra}
+      <Input.Search allowClear placeholder="Search" value={search} onChange={(event) => onSearchChange(event.target.value)} style={{ width: 280 }} />
+    </Space>
+  )
+}
+
+function ModuleDrawer({ module, open, onClose }: { module: ModuleDefinition | null; open: boolean; onClose: () => void }) {
+  const [messages, setMessages] = useState<StreamMessage[]>([])
+  const [messageLimit, setMessageLimit] = useState(5)
+  const [messageId, setMessageId] = useState('')
+  const [selectedMessage, setSelectedMessage] = useState<StreamMessage | Record<string, never> | null>(null)
+  const [loadingMessages, setLoadingMessages] = useState(false)
+  const [messageError, setMessageError] = useState('')
+  const streamName = module?.stream_name || ''
+
+  const loadRecent = useCallback(async () => {
+    if (!streamName) return
+    setLoadingMessages(true)
+    setMessageError('')
+    try {
+      const { data } = await client.get<StreamMessagesResponse>('/custom/modules/stream/messages/', {
+        params: { stream_name: streamName, limit: messageLimit },
+      })
+      setMessages(data.messages)
+    } catch (error) {
+      setMessages([])
+      setMessageError(apiErrorMessage(error, 'Failed to load stream messages'))
+    } finally {
+      setLoadingMessages(false)
+    }
+  }, [messageLimit, streamName])
+
+  useEffect(() => {
+    if (!open || !streamName) return
+    // eslint-disable-next-line react-hooks/set-state-in-effect
+    setMessages([])
+    setSelectedMessage(null)
+    setMessageId('')
+    loadRecent()
+  }, [loadRecent, open, streamName])
+
+  const loadById = async () => {
+    if (!module?.stream_name || !messageId.trim()) return
+    setLoadingMessages(true)
+    setMessageError('')
+    try {
+      const { data } = await client.get<StreamMessageResponse>('/custom/modules/stream/message/', {
+        params: { stream_name: module.stream_name, message_id: messageId.trim() },
+      })
+      setSelectedMessage(data.message)
+    } catch (error) {
+      setSelectedMessage(null)
+      setMessageError(apiErrorMessage(error, 'Failed to load stream message'))
+    } finally {
+      setLoadingMessages(false)
+    }
+  }
+
+  return (
+    <Drawer title={module?.name || 'Module'} open={open} onClose={onClose} size="min(920px, calc(100vw - 48px))">
+      {module ? (
+        <Flex vertical gap={16} style={{ width: '100%' }}>
+          <Descriptions size="small" column={1} bordered items={[
+            { key: 'description', label: 'Description', children: module.description || '—' },
+            { key: 'stream', label: 'Stream', children: <Typography.Text copyable>{module.stream_name}</Typography.Text> },
+            { key: 'threads', label: 'Threads', children: module.thread_num },
+            { key: 'path', label: 'Path', children: <PathText path={module.path} /> },
+          ]} />
+
+          <Descriptions size="small" title="Stream health" column={2} bordered items={[
+            { key: 'available', label: 'Available', children: module.stream_health.available ? 'Yes' : 'No' },
+            { key: 'length', label: 'Length', children: module.stream_health.length },
+            { key: 'first', label: 'First ID', children: module.stream_health.first_id || '—' },
+            { key: 'last', label: 'Last ID', children: module.stream_health.last_id || '—' },
+          ]} />
+          {module.stream_health.warning ? <Alert type="warning" showIcon title={module.stream_health.warning} /> : null}
+          {module.stream_health.groups.length ? (
+            <Table<StreamGroup>
+              size="small"
+              rowKey="name"
+              pagination={false}
+              dataSource={module.stream_health.groups}
+              columns={[
+                { title: 'Group', dataIndex: 'name' },
+                { title: 'Consumers', dataIndex: 'consumers', width: 120 },
+                { title: 'Pending', dataIndex: 'pending', width: 120 },
+                { title: 'Last delivered', dataIndex: 'last_delivered_id', width: 220 },
+              ]}
+            />
+          ) : null}
+
+          <div>
+            <Typography.Text strong>Recent messages</Typography.Text>
+            <Space style={{ marginLeft: 12 }}>
+              <InputNumber min={1} max={20} value={messageLimit} onChange={(value) => setMessageLimit(Number(value || 5))} />
+              <Button onClick={loadRecent} loading={loadingMessages}>Load recent</Button>
+            </Space>
+          </div>
+          {messageError ? <Alert type="error" showIcon title={messageError} /> : null}
+          <List
+            loading={loadingMessages}
+            dataSource={messages}
+            locale={{ emptyText: <Empty description="No messages" /> }}
+            renderItem={(item) => (
+              <List.Item>
+                <Flex vertical gap={4} style={{ width: '100%' }}>
+                  <Typography.Text code>{item.message_id}</Typography.Text>
+                  <JsonViewer value={item.data} maxHeight={260} />
+                </Flex>
+              </List.Item>
+            )}
+          />
+
+          <div>
+            <Typography.Text strong>Read by message ID</Typography.Text>
+            <Input.Search
+              allowClear
+              enterButton="Read"
+              value={messageId}
+              onChange={(event) => setMessageId(event.target.value)}
+              onSearch={loadById}
+              style={{ marginTop: 8 }}
+              placeholder="1700000000000-0"
+            />
+          </div>
+          {selectedMessage ? <JsonViewer value={selectedMessage} maxHeight={320} /> : null}
+        </Flex>
+      ) : null}
+    </Drawer>
+  )
+}
+
+function ModulesTab() {
+  const { result, loading, refreshing, load, refresh } = useDefinitionSection<ModuleDefinition>('/custom/modules/', 'Modules')
+  const [search, setSearch] = useState('')
+  const [selected, setSelected] = useState<ModuleDefinition | null>(null)
+  const rows = useMemo(() => (
+    (result?.items || []).filter((item) => includesSearch([
+      item.name,
+      item.description,
+      item.stream_name,
+      item.path,
+    ], search))
+  ), [result?.items, search])
+
+  const columns = useMemo<ColumnsType<ModuleDefinition>>(() => [
+    { title: 'Module', dataIndex: 'name', width: 340, render: (name: string) => <Typography.Text strong>{name}</Typography.Text> },
+    { title: 'Description', dataIndex: 'description', ellipsis: true },
+    { title: 'Stream', dataIndex: 'stream_name', width: 380, ellipsis: true },
+    { title: 'Threads', dataIndex: 'thread_num', width: 100 },
+    { title: 'Length', width: 100, render: (_, record) => record.stream_health.length },
+    { title: 'Last ID', width: 180, render: (_, record) => record.stream_health.last_id || '—' },
+    { title: 'Path', dataIndex: 'path', width: 280, render: (path: string) => <PathText path={path} /> },
+  ], [])
+
+  return (
+    <>
+      <SectionToolbar
+        search={search}
+        onSearchChange={setSearch}
+        onReload={load}
+        onRefresh={refresh}
+        loading={loading}
+        refreshing={refreshing}
+      />
+      <DefinitionErrors errors={result?.errors || []} />
+      <Table<ModuleDefinition>
+        size="small"
+        rowKey="path"
+        loading={loading}
+        columns={columns}
+        dataSource={rows}
+        onRow={(record) => ({ onClick: () => setSelected(record), style: { cursor: 'pointer' } })}
+        locale={{ emptyText: loading ? <span /> : <Empty description="No modules loaded" /> }}
+        scroll={{ x: 1600 }}
+      />
+      <ModuleDrawer module={selected} open={selected !== null} onClose={() => setSelected(null)} />
+    </>
+  )
+}
+
+function PlaybooksTab() {
+  const { result, loading, refreshing, load, refresh } = useDefinitionSection<PlaybookDefinition>('/custom/playbooks/', 'Playbooks')
+  const [source, setSource] = useState<SourceFilter>('all')
+  const [search, setSearch] = useState('')
+  const [selected, setSelected] = useState<PlaybookDefinition | null>(null)
+  const rows = useMemo(() => (
+    filterBySource(result?.items || [], source).filter((item) => includesSearch([
+      item.name,
+      item.description,
+      item.path,
+      ...item.tags,
+    ], search))
+  ), [result?.items, search, source])
+
+  const columns = useMemo<ColumnsType<PlaybookDefinition>>(() => [
+    { title: 'Playbook', dataIndex: 'name', width: 260, render: (name: string) => <Typography.Text strong>{name}</Typography.Text> },
+    { title: 'Source', dataIndex: 'source', width: 110, render: (value: SourceType) => <SourceTag source={value} /> },
+    {
+      title: 'Tags',
+      dataIndex: 'tags',
+      width: 260,
+      render: (tags: string[]) => (
+        <Space size={[4, 4]} wrap>
+          {(tags || []).map((tag) => <Tag {...comfortableTagProps} key={tag} color={PLAYBOOK_TAG_COLORS[tag] || 'blue'}>{tag}</Tag>)}
+        </Space>
+      ),
+    },
+    { title: 'Description', dataIndex: 'description', ellipsis: true },
+    { title: 'Path', dataIndex: 'path', width: 300, render: (path: string) => <PathText path={path} /> },
+  ], [])
+
+  return (
+    <>
+      <SectionToolbar
+        search={search}
+        onSearchChange={setSearch}
+        source={source}
+        onSourceChange={setSource}
+        onReload={load}
+        onRefresh={refresh}
+        loading={loading}
+        refreshing={refreshing}
+      />
+      <DefinitionErrors errors={result?.errors || []} />
+      <Table<PlaybookDefinition>
+        size="small"
+        rowKey="path"
+        loading={loading}
+        columns={columns}
+        dataSource={rows}
+        onRow={(record) => ({ onClick: () => setSelected(record), style: { cursor: 'pointer' } })}
+        locale={{ emptyText: loading ? <span /> : <Empty description="No playbooks loaded" /> }}
+        scroll={{ x: 1300 }}
+      />
+      <Drawer title={selected?.name || 'Playbook'} open={selected !== null} onClose={() => setSelected(null)} size="min(760px, calc(100vw - 48px))">
+        {selected ? (
+          <Flex vertical gap={16} style={{ width: '100%' }}>
+            <Space>
+              <SourceTag source={selected.source} />
+              {(selected.tags || []).map((tag) => <Tag {...comfortableTagProps} key={tag} color={PLAYBOOK_TAG_COLORS[tag] || 'blue'}>{tag}</Tag>)}
+            </Space>
+            <Typography.Paragraph style={{ whiteSpace: 'pre-wrap' }}>{selected.description || 'No description.'}</Typography.Paragraph>
+            <Descriptions size="small" column={1} bordered items={[
+              { key: 'path', label: 'Path', children: <PathText path={selected.path} /> },
+            ]} />
+          </Flex>
+        ) : null}
+      </Drawer>
+    </>
+  )
+}
+
+function SiemTab() {
+  const { result, loading, refreshing, load, refresh } = useDefinitionSection<SiemDefinition>('/custom/siem/', 'SIEM YAML')
+  const [backend, setBackend] = useState<'all' | 'ELK' | 'Splunk'>('all')
+  const [search, setSearch] = useState('')
+  const [selected, setSelected] = useState<SiemDefinition | null>(null)
+  const rows = useMemo(() => (
+    (result?.items || [])
+      .filter((item) => backend === 'all' || item.backend === backend)
+      .filter((item) => includesSearch([item.name, item.backend, item.description, item.path], search))
+  ), [backend, result?.items, search])
+
+  const columns = useMemo<ColumnsType<SiemDefinition>>(() => [
+    { title: 'Index', dataIndex: 'name', width: 220, render: (name: string) => <Typography.Text strong>{name}</Typography.Text> },
+    { title: 'Backend', dataIndex: 'backend', width: 120, render: (value: string) => <Tag {...comfortableTagProps} color={SIEM_BACKEND_COLORS[value] || 'default'}>{value}</Tag> },
+    { title: 'Description', dataIndex: 'description', ellipsis: true },
+    { title: 'Fields', dataIndex: 'field_count', width: 100 },
+    { title: 'Key fields', dataIndex: 'key_field_count', width: 120 },
+    { title: 'Path', dataIndex: 'path', width: 300, render: (path: string) => <PathText path={path} /> },
+  ], [])
+
+  const fieldColumns = useMemo<ColumnsType<SiemField>>(() => [
+    { title: 'Name', dataIndex: 'name', width: 220 },
+    { title: 'Type', dataIndex: 'type', width: 120 },
+    { title: 'Key field', dataIndex: 'is_key_field', width: 110, render: (value: boolean) => value ? <Tag color="blue">Key field</Tag> : '—' },
+    { title: 'Description', dataIndex: 'description' },
+    {
+      title: 'Sample values',
+      dataIndex: 'sample_values',
+      width: 260,
+      render: (values: unknown[]) => (
+        <Typography.Text type="secondary" ellipsis={{ tooltip: JSON.stringify(values || []) }}>
+          {JSON.stringify(values || [])}
+        </Typography.Text>
+      ),
+    },
+  ], [])
+
+  return (
+    <>
+      <SectionToolbar
+        search={search}
+        onSearchChange={setSearch}
+        onReload={load}
+        onRefresh={refresh}
+        loading={loading}
+        refreshing={refreshing}
+        extra={(
+          <Select<'all' | 'ELK' | 'Splunk'>
+            value={backend}
+            onChange={(value) => setBackend(value)}
+            style={{ width: 140 }}
+            options={[
+              { label: 'All backends', value: 'all' },
+              { label: 'ELK', value: 'ELK' },
+              { label: 'Splunk', value: 'Splunk' },
+            ]}
+          />
+        )}
+      />
+      <DefinitionErrors errors={result?.errors || []} />
+      <Table<SiemDefinition>
+        size="small"
+        rowKey="path"
+        loading={loading}
+        columns={columns}
+        dataSource={rows}
+        onRow={(record) => ({ onClick: () => setSelected(record), style: { cursor: 'pointer' } })}
+        locale={{ emptyText: loading ? <span /> : <Empty description="No SIEM YAML loaded" /> }}
+        scroll={{ x: 1400 }}
+      />
+      <Drawer title={selected?.name || 'SIEM YAML'} open={selected !== null} onClose={() => setSelected(null)} size="min(1080px, calc(100vw - 48px))">
+        {selected ? (
+          <Flex vertical gap={16} style={{ width: '100%' }}>
+            <Descriptions size="small" column={1} bordered items={[
+              { key: 'backend', label: 'Backend', children: <Tag {...comfortableTagProps} color={SIEM_BACKEND_COLORS[selected.backend] || 'default'}>{selected.backend}</Tag> },
+              { key: 'description', label: 'Description', children: selected.description || '—' },
+              { key: 'path', label: 'Path', children: <PathText path={selected.path} /> },
+            ]} />
+            <Table<SiemField>
+              size="small"
+              rowKey="name"
+              columns={fieldColumns}
+              dataSource={selected.fields || []}
+              pagination={false}
+              scroll={{ x: 900, y: 520 }}
+            />
+          </Flex>
+        ) : null}
+      </Drawer>
+    </>
+  )
+}
+
+export default function CustomDefinitions() {
+  return (
+    <div style={{ height: '100%', minHeight: 0, overflow: 'auto' }}>
+      <Tabs
+        items={[
+          { key: 'modules', label: <IconTabLabel icon={Boxes}>Modules</IconTabLabel>, children: <ModulesTab /> },
+          { key: 'playbooks', label: <IconTabLabel icon={BrainCircuit}>Playbooks</IconTabLabel>, children: <PlaybooksTab /> },
+          { key: 'siem', label: <IconTabLabel icon={DatabaseZap}>SIEM YAML</IconTabLabel>, children: <SiemTab /> },
+        ]}
+      />
+    </div>
+  )
+}
diff --git a/frontend/src/pages/RuntimeSettings.tsx b/frontend/src/pages/RuntimeSettings.tsx
index 40896b9..05b7d9b 100644
--- a/frontend/src/pages/RuntimeSettings.tsx
+++ b/frontend/src/pages/RuntimeSettings.tsx
@@ -1,5 +1,5 @@
 import {useCallback, useEffect, useState} from 'react'
-import {Alert, Button, Card, Col, Divider, Form, InputNumber, List, message, Row, Select, Space, Tag, Tooltip, Typography} from 'antd'
+import {Button, Card, Col, Divider, Form, InputNumber, message, Row, Select, Space, Tooltip, Typography} from 'antd'
 import {QuestionCircleOutlined} from '@ant-design/icons'
 import client from '../api/client'
 
@@ -9,43 +9,6 @@ interface RuntimeConfig {
   updated_at?: string
 }
 
-interface CustomDefinitionItem {
-  name?: string
-  source: 'official' | 'custom'
-  path: string
-  stream_name?: string
-  backend?: string
-  description?: string
-  playbook?: string
-  prompt?: string
-  language?: string
-}
-
-interface CustomDefinitionError {
-  path: string
-  error: string
-}
-
-interface CustomDefinitionSection {
-  items: CustomDefinitionItem[]
-  errors: CustomDefinitionError[]
-}
-
-interface CustomDefinitionRefreshResult {
-  success: boolean
-  counts: {
-    modules: number
-    playbooks: number
-    siem: number
-    prompts: number
-    errors: number
-  }
-  modules: CustomDefinitionSection
-  playbooks: CustomDefinitionSection
-  siem: CustomDefinitionSection
-  prompts: CustomDefinitionSection
-}
-
 function initialValues(): RuntimeConfig {
   return {
     prompt_language: 'en',
@@ -77,50 +40,10 @@ function helpLabel(label: string, help: string) {
   )
 }
 
-function CustomDefinitionSectionView({ title, section }: { title: string; section: CustomDefinitionSection }) {
-  return (
-    <div style={{ marginTop: 12 }}>
-      <Typography.Text strong>{title}</Typography.Text>
-      <List
-        size="small"
-        dataSource={section.items}
-        locale={{ emptyText: 'No definitions loaded' }}
-        renderItem={(item) => (
-          <List.Item>
-            <Space direction="vertical" size={0}>
-              <Space wrap>
-                <Typography.Text>{item.name || item.playbook || item.prompt}</Typography.Text>
-                <Tag color={item.source === 'custom' ? 'blue' : 'default'}>{item.source}</Tag>
-                {item.stream_name ? <Tag>{item.stream_name}</Tag> : null}
-                {item.backend ? <Tag>{item.backend}</Tag> : null}
-                {item.prompt ? <Tag>{item.prompt}</Tag> : null}
-                {item.language ? <Tag>{item.language}</Tag> : null}
-              </Space>
-              <Typography.Text type="secondary" style={{ fontSize: 12 }}>{item.path}</Typography.Text>
-            </Space>
-          </List.Item>
-        )}
-      />
-      {section.errors.map((error) => (
-        <Alert
-          key={`${title}-${error.path}`}
-          type="error"
-          showIcon
-          style={{ marginTop: 8 }}
-          message={error.path}
-          description={error.error}
-        />
-      ))}
-    </div>
-  )
-}
-
 export default function RuntimeSettings() {
   const [form] = Form.useForm<RuntimeConfig>()
   const [loading, setLoading] = useState(false)
   const [saving, setSaving] = useState(false)
-  const [refreshingDefinitions, setRefreshingDefinitions] = useState(false)
-  const [definitionResult, setDefinitionResult] = useState<CustomDefinitionRefreshResult | null>(null)
 
   const loadConfig = useCallback(async () => {
     setLoading(true)
@@ -153,23 +76,6 @@ export default function RuntimeSettings() {
     }
   }
 
-  const refreshDefinitions = async () => {
-    setRefreshingDefinitions(true)
-    try {
-      const { data } = await client.post<CustomDefinitionRefreshResult>('/settings/runtime/custom-definitions/refresh/')
-      setDefinitionResult(data)
-      if (data.success) {
-        message.success('Custom definitions refreshed')
-      } else {
-        message.warning(`Custom definitions refreshed with ${data.counts.errors} error(s)`)
-      }
-    } catch (error: unknown) {
-      message.error(apiErrorMessage(error, 'Failed to refresh custom definitions'))
-    } finally {
-      setRefreshingDefinitions(false)
-    }
-  }
-
   return (
     <div style={{ height: '100%', minHeight: 0, overflow: 'auto' }}>
       <Card title="Runtime" loading={loading}>
@@ -207,44 +113,6 @@ export default function RuntimeSettings() {
           <Space>
             <Button type="primary" onClick={saveConfig} loading={saving}>Save</Button>
           </Space>
-
-          <Typography.Text strong style={{ display: 'block', marginTop: 28 }}>Custom Definitions</Typography.Text>
-          <Divider style={{ margin: '8px 0 16px' }} />
-          <Typography.Paragraph type="secondary">
-            Refresh and validate Module, Playbook, and SIEM YAML definitions after updating files in the custom directory.
-            Dependency or helper module changes still require reinstalling custom packages and restarting related containers.
-          </Typography.Paragraph>
-          <Space>
-            <Button onClick={refreshDefinitions} loading={refreshingDefinitions}>Refresh / Validate</Button>
-          </Space>
-          {definitionResult ? (
-            <div style={{ marginTop: 16 }}>
-              <Alert
-                type={definitionResult.success ? 'success' : 'warning'}
-                showIcon
-                message={
-                  definitionResult.success
-                    ? 'Definitions loaded successfully'
-                    : `Definitions loaded with ${definitionResult.counts.errors} error(s)`
-                }
-                description={`Modules: ${definitionResult.counts.modules}, Playbooks: ${definitionResult.counts.playbooks}, SIEM YAML: ${definitionResult.counts.siem}, Prompts: ${definitionResult.counts.prompts}`}
-              />
-              <Row gutter={16}>
-                <Col span={6}>
-                  <CustomDefinitionSectionView title="Modules" section={definitionResult.modules} />
-                </Col>
-                <Col span={6}>
-                  <CustomDefinitionSectionView title="Playbooks" section={definitionResult.playbooks} />
-                </Col>
-                <Col span={6}>
-                  <CustomDefinitionSectionView title="SIEM YAML" section={definitionResult.siem} />
-                </Col>
-                <Col span={6}>
-                  <CustomDefinitionSectionView title="Prompts" section={definitionResult.prompts} />
-                </Col>
-              </Row>
-            </div>
-          ) : null}
         </Form>
       </Card>
     </div>