feat: set the chat read limit from the admin settings

The limit on how much of an earlier chat a model can read could only be set with an environment variable. It is now a Chat Read Limit field in Admin Settings under General, next to the skill limits. The environment variable still works as the starting value, and the setting saved in the panel takes precedence.

backend/open_webui/config.py

@@ -2067,6 +2067,10 @@ SKILL_PREVIEW_MAX_CHARS = int(os.environ['SKILL_PREVIEW_MAX_CHARS']) if os.geten
 if SKILL_PREVIEW_MAX_CHARS is not None and SKILL_PREVIEW_MAX_CHARS <= 0:
     raise ValueError('SKILL_PREVIEW_MAX_CHARS must be a positive integer or unset')
 
+VIEW_CHAT_MAX_CHARS = int(os.environ['VIEW_CHAT_MAX_CHARS']) if os.getenv('VIEW_CHAT_MAX_CHARS') else None
+if VIEW_CHAT_MAX_CHARS is not None and VIEW_CHAT_MAX_CHARS <= 0:
+    raise ValueError('VIEW_CHAT_MAX_CHARS must be a positive integer or unset')
+
 ENABLE_CHANNELS = os.getenv('ENABLE_CHANNELS', 'False').lower() == 'true'
 
 ENABLE_ENCRYPTED_CHANNELS = os.getenv('ENABLE_ENCRYPTED_CHANNELS', 'False').lower() == 'true'
@@ -2929,6 +2933,7 @@ DEFAULT_CONFIG = {
     'skills.lazy_loading.enable': ENABLE_SKILL_LAZY_LOADING,
     'skills.content_max_chars': SKILL_CONTENT_MAX_CHARS,
     'skills.preview_max_chars': SKILL_PREVIEW_MAX_CHARS,
+    'chats.view_max_chars': VIEW_CHAT_MAX_CHARS,
     'direct.enable': ENABLE_DIRECT_CONNECTIONS,
     'direct.integrations.enable': ENABLE_DIRECT_INTEGRATIONS,
     'ollama.enable': ENABLE_OLLAMA_API,

backend/open_webui/env.py

@@ -1176,8 +1176,6 @@ KNOWLEDGE_GREP_MAX_MATCHES = _int_env('KNOWLEDGE_GREP_MAX_MATCHES', 50)
 # Characters returned by view_file / view_knowledge_file.
 VIEW_FILE_MAX_CHARS = _int_env('VIEW_FILE_MAX_CHARS', 100_000)
 VIEW_FILE_DEFAULT_MAX_CHARS = _int_env('VIEW_FILE_DEFAULT_MAX_CHARS', 10_000)
-# Characters returned by view_chat; unset returns the full chat.
-VIEW_CHAT_MAX_CHARS = int(os.getenv('VIEW_CHAT_MAX_CHARS')) if os.getenv('VIEW_CHAT_MAX_CHARS') else None
 
 # Tools/functions pip options
 

backend/open_webui/routers/auths.py

@@ -140,6 +140,7 @@ ADMIN_CONFIG_KEYS = {
     'ENABLE_SKILL_LAZY_LOADING': 'skills.lazy_loading.enable',
     'SKILL_CONTENT_MAX_CHARS': 'skills.content_max_chars',
     'SKILL_PREVIEW_MAX_CHARS': 'skills.preview_max_chars',
+    'VIEW_CHAT_MAX_CHARS': 'chats.view_max_chars',
     'ENABLE_NOTES': 'notes.enable',
     'ENABLE_USER_WEBHOOKS': 'ui.enable_user_webhooks',
     'ENABLE_USER_STATUS': 'users.enable_status',
@@ -1182,6 +1183,7 @@ class AdminConfig(MfaConfigForm):
     ENABLE_SKILL_LAZY_LOADING: bool = False
     SKILL_CONTENT_MAX_CHARS: int | None = Field(default=None, gt=0, strict=True)
     SKILL_PREVIEW_MAX_CHARS: int | None = Field(default=None, gt=0, strict=True)
+    VIEW_CHAT_MAX_CHARS: int | None = Field(default=None, gt=0, strict=True)
     ENABLE_NOTES: bool
     ENABLE_USER_WEBHOOKS: bool
     ENABLE_USER_STATUS: bool
@@ -1240,6 +1242,8 @@ async def update_admin_config(request: Request, form_data: AdminConfig, user=Dep
         updates.pop('skills.content_max_chars', None)
     if 'SKILL_PREVIEW_MAX_CHARS' not in form_data.model_fields_set:
         updates.pop('skills.preview_max_chars', None)
+    if 'VIEW_CHAT_MAX_CHARS' not in form_data.model_fields_set:
+        updates.pop('chats.view_max_chars', None)
     updates['ui.default_interface_settings'] = form_data.DEFAULT_INTERFACE_SETTINGS or {}
     updates['folders.max_file_count'] = int(form_data.FOLDER_MAX_FILE_COUNT) if form_data.FOLDER_MAX_FILE_COUNT else ''
     updates['automations.max_count'] = int(form_data.AUTOMATION_MAX_COUNT) if form_data.AUTOMATION_MAX_COUNT else ''

backend/open_webui/tools/builtin.py

@@ -16,7 +16,6 @@ from fastapi import HTTPException, Request
 
 from open_webui.env import (
     KNOWLEDGE_GREP_MAX_MATCHES,
-    VIEW_CHAT_MAX_CHARS,
     VIEW_FILE_DEFAULT_MAX_CHARS,
     VIEW_FILE_MAX_CHARS,
 )
@@ -1752,8 +1751,9 @@ async def view_chat(
             current_id = msg.get('parentId') if msg else None
 
         truncation = {}
-        if VIEW_CHAT_MAX_CHARS and sum(len(message['content']) for message in messages) > VIEW_CHAT_MAX_CHARS:
-            remaining_chars = VIEW_CHAT_MAX_CHARS
+        max_chars = await Config.get('chats.view_max_chars')
+        if max_chars and sum(len(message['content']) for message in messages) > max_chars:
+            remaining_chars = max_chars
             kept_messages = []
             for message in messages:
                 if remaining_chars <= 0:

src/lib/components/admin/Settings/General.svelte

@@ -86,6 +86,7 @@
 				...adminConfig,
 				SKILL_CONTENT_MAX_CHARS: adminConfig.SKILL_CONTENT_MAX_CHARS ?? null,
 				SKILL_PREVIEW_MAX_CHARS: adminConfig.SKILL_PREVIEW_MAX_CHARS ?? null,
+				VIEW_CHAT_MAX_CHARS: adminConfig.VIEW_CHAT_MAX_CHARS ?? null,
 				DEFAULT_INTERFACE_SETTINGS: defaultInterfaceSettings,
 				I18N: cleaned
 			});
@@ -378,6 +379,21 @@
 						bind:value={adminConfig.SKILL_PREVIEW_MAX_CHARS}
 					/>
 				</AdminSettingField>
+				<AdminSettingField
+					forId="view-chat-max-chars"
+					label={$i18n.t('settings.admin.general.viewChatMaxChars.label')}
+					description={$i18n.t('settings.admin.general.viewChatMaxChars.description')}
+				>
+					<input
+						id="view-chat-max-chars"
+						class={inputClass}
+						type="number"
+						min="1"
+						step="1"
+						placeholder={$i18n.t('No limit')}
+						bind:value={adminConfig.VIEW_CHAT_MAX_CHARS}
+					/>
+				</AdminSettingField>
 				<AdminSettingRow
 					label={$i18n.t('settings.admin.general.notes.label')}
 					description={$i18n.t('settings.admin.general.notes.description')}

src/lib/i18n/locales/en-US/translation.json

@@ -3170,6 +3170,8 @@
 	"settings.admin.general.userWebhooks.description": "Allow users to configure webhooks from their account.",
 	"settings.admin.general.userWebhooks.label": "User Webhooks",
 	"settings.admin.general.version.label": "Version",
+	"settings.admin.general.viewChatMaxChars.description": "Maximum characters returned when a model reads a previous chat. The newest messages are kept. Leave empty for no limit.",
+	"settings.admin.general.viewChatMaxChars.label": "Chat Read Limit",
 	"settings.admin.general.webuiUrl.description": "Enter the public URL of your WebUI. This URL will be used to generate links in the notifications.",
 	"settings.admin.general.webuiUrl.label": "WebUI URL",
 	"settings.admin.images.apiAuthString.description": "Provide the --api-auth username and password when required.",