feat(i18n): localize backend messages by workspace language

src/langbot/pkg/api/http/service/agent.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from ....i18n import t
+
 from contextlib import aclosing
 
 import datetime
@@ -432,7 +434,7 @@ class AgentService:
             pipeline_uuid = await self.ap.pipeline_service.create_pipeline(
                 context,
                 {
-                    'name': agent_data.get('name') or 'New Pipeline',
+                    'name': agent_data.get('name') or t('New Pipeline'),
                     'description': agent_data.get('description') or '',
                     'emoji': agent_data.get('emoji') or '⚙️',
                     'config': {},
@@ -461,7 +463,7 @@ class AgentService:
         values = {
             'workspace_uuid': workspace_uuid,
             'uuid': new_uuid,
-            'name': agent_data.get('name') or 'New Agent',
+            'name': agent_data.get('name') or t('New Agent'),
             'description': agent_data.get('description') or '',
             'emoji': agent_data.get('emoji') or ('🧩' if kind == AGENT_KIND_EVENT_PROCESSOR else '🤖'),
             'kind': kind,

src/langbot/pkg/api/http/service/knowledge.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from ....i18n import t
+
 import sqlalchemy
 
 from ....api.http.authz import WorkspaceRequiredError
@@ -63,7 +65,13 @@ class KnowledgeService:
         if max_knowledge_bases >= 0:
             knowledge_bases = await self.ap.rag_mgr.get_all_knowledge_base_details(context)
             if len(knowledge_bases) >= max_knowledge_bases:
-                raise ValueError(f'Maximum number of knowledge bases ({max_knowledge_bases}) reached')
+                raise ValueError(
+                    t(
+                        'Maximum number of {resource} ({limit}) reached',
+                        resource=t('knowledge bases'),
+                        limit=max_knowledge_bases,
+                    )
+                )
 
         knowledge_engine_plugin_id = kb_data.get('knowledge_engine_plugin_id')
         if not knowledge_engine_plugin_id:

src/langbot/pkg/api/http/service/mcp.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from ....i18n import t
+
 import copy
 import re
 import uuid
@@ -228,7 +230,9 @@ class MCPService:
                 .where(persistence_plugin.PluginSetting.workspace_uuid == workspace_uuid)
             )
             if (mcp_count_result.scalar() or 0) + (plugin_count_result.scalar() or 0) >= max_extensions:
-                raise ValueError(f'Maximum number of extensions ({max_extensions}) reached')
+                raise ValueError(
+                    t('Maximum number of {resource} ({limit}) reached', resource=t('extensions'), limit=max_extensions)
+                )
 
         payload = dict(server_data)
         payload.pop('workspace_uuid', None)
@@ -246,7 +250,7 @@ class MCPService:
             )
         )
         if existing_result.first() is not None:
-            raise ValueError(f'MCP server already exists: {server_name}')
+            raise ValueError(t('MCP server already exists: {name}', name=server_name))
 
         await self.ap.persistence_mgr.execute_async(sqlalchemy.insert(persistence_mcp.MCPServer).values(payload))
         created = await self._get_mcp_server_by_uuid_raw(execution_context, payload['uuid'])
@@ -332,7 +336,7 @@ class MCPService:
                 raise ValueError('MCP server name is required')
             duplicate = await self._get_mcp_server_by_name_raw(execution_context, payload['name'])
             if duplicate is not None and duplicate['uuid'] != server_uuid:
-                raise ValueError(f'MCP server already exists: {payload["name"]}')
+                raise ValueError(t('MCP server already exists: {name}', name=payload['name']))
 
         effective_server = {**old_server, **payload}
         # Existing disabled rows remain readable/deletable.  Switching away

src/langbot/pkg/api/http/service/model.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from ....i18n import t
+
 import uuid
 
 import sqlalchemy
@@ -146,7 +148,13 @@ async def _validate_provider_supports(
     if not support_type:
         return
     if model_type not in support_type:
-        raise ValueError(f'Provider requester "{requester_name}" does not support {model_type} models')
+        raise ValueError(
+            t(
+                'Provider {provider} does not support {model_type} models',
+                provider=requester_name,
+                model_type=model_type,
+            )
+        )
 
 
 async def _require_workspace_provider(

src/langbot/pkg/api/http/service/user.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+from ....i18n import t
+
 import sqlalchemy
 import argon2
 import jwt
@@ -423,12 +425,12 @@ class UserService:
 
         user_obj = await self.get_user_by_email(user_email)
         if user_obj is None:
-            raise ValueError('用户不存在')
+            raise ValueError(t('Resource not found'))
         self._require_active_account(user_obj)
 
         # Check if this user has a local password set
         if not user_obj.password:
-            raise ValueError('请使用 LangBot 账号登录')
+            raise ValueError(t('Please sign in with your LangBot Account'))
 
         await self._verify_password(user_obj.password, password)