🔧 fix(getters.py): add import statement for PluginService in getters.py to fix import error

✨ feat(plugins/base.py): add BasePlugin class with initialize, teardown, and get methods to serve as base class for plugins
✨ feat(plugins/factory.py): add PluginServiceFactory class to create PluginService instance and load plugins
✨ feat(plugins/langfuse.py): add LangfusePlugin class with initialize, teardown, and get methods to serve as a plugin for Langfuse
✨ feat(plugins/service.py): add PluginService class to manage plugins, load plugins, register plugins, get plugins, and teardown plugins
✨ feat(schema.py): add PLUGIN_SERVICE to ServiceType enum to support plugin service
🔧 fix(settings/base.py): add PLUGIN_DIR optional setting to support specifying plugin directory
🔧 fix(utils.py): add import statement for plugins_factory in utils.py to fix import error

src/backend/langflow/services/getters.py

@@ -9,9 +9,14 @@ if TYPE_CHECKING:
     from langflow.services.session.service import SessionService
     from langflow.services.task.service import TaskService
     from langflow.services.chat.service import ChatService
+    from langflow.services.plugins.service import PluginService
     from sqlmodel import Session
 
 
+def get_plugins_service() -> "PluginService":
+    return service_manager.get(ServiceType.PLUGIN_SERVICE)
+
+
 def get_settings_service() -> "SettingsService":
     try:
         return service_manager.get(ServiceType.SETTINGS_SERVICE)

src/backend/langflow/services/plugins/base.py

@@ -0,0 +1,12 @@
+from typing import Any
+
+
+class BasePlugin:
+    def initialize(self):
+        pass
+
+    def teardown(self):
+        pass
+
+    def get(self) -> Any:
+        pass

src/backend/langflow/services/plugins/factory.py

@@ -0,0 +1,16 @@
+from typing import TYPE_CHECKING
+from langflow.services.plugins.service import PluginService
+from langflow.services.factory import ServiceFactory
+
+if TYPE_CHECKING:
+    from langflow.services.settings.service import SettingsService
+
+
+class PluginServiceFactory(ServiceFactory):
+    def __init__(self):
+        super().__init__(PluginService)
+
+    def create(self, settings_service: "SettingsService"):
+        service = PluginService(settings_service)
+        service.load_plugins()
+        return service

src/backend/langflow/services/plugins/langfuse.py

@@ -1,4 +1,5 @@
 from langflow.services.getters import get_settings_service
+from langflow.services.plugins.base import BasePlugin
 from langflow.utils.logger import logger
 
 ### Temporary implementation
@@ -52,3 +53,14 @@ class LangfuseInstance:
         if cls._instance is not None:
             cls._instance.flush()
         cls._instance = None
+
+
+class LangfusePlugin(BasePlugin):
+    def initialize(self):
+        LangfuseInstance.create()
+
+    def teardown(self):
+        LangfuseInstance.teardown()
+
+    def get(self):
+        return LangfuseInstance.get()

src/backend/langflow/services/plugins/service.py

@@ -0,0 +1,50 @@
+import importlib
+import inspect
+import os
+from langflow.services.base import Service
+from langflow.services.plugins.base import BasePlugin
+from typing import TYPE_CHECKING, Union
+
+if TYPE_CHECKING:
+    from langflow.services.settings.service import SettingsService
+
+
+class PluginService(Service):
+    name = "plugin_service"
+
+    def __init__(self, settings_service: "SettingsService"):
+        self.plugins = {}
+        plugin_dir = settings_service.settings.PLUGIN_DIR
+        self.plugin_dir = plugin_dir or os.path.dirname(__file__)
+
+    def load_plugins(self):
+        base_files = ["base.py", "service.py", "factory.py", "__init__.py"]
+        for module in os.listdir(self.plugin_dir):
+            if module.endswith(".py") and module not in base_files:
+                plugin_name = module[:-3]
+                module_path = f"{self.plugin_dir}.{plugin_name}"
+                mod = importlib.import_module(module_path)
+                for attr_name in dir(mod):
+                    attr = getattr(mod, attr_name)
+                    if (
+                        inspect.isclass(attr)
+                        and issubclass(attr, BasePlugin)
+                        and attr is not BasePlugin
+                    ):
+                        self.register_plugin(plugin_name, attr())
+
+    def register_plugin(self, plugin_name, plugin_instance):
+        self.plugins[plugin_name] = plugin_instance
+        plugin_instance.initialize()
+
+    def get_plugin(self, plugin_name) -> Union[BasePlugin, None]:
+        return self.plugins.get(plugin_name)
+
+    def get(self, plugin_name):
+        if plugin := self.get_plugin(plugin_name):
+            return plugin.get()
+        return None
+
+    def teardown(self):
+        for plugin in self.plugins.values():
+            plugin.teardown()

src/backend/langflow/services/schema.py

@@ -14,3 +14,4 @@ class ServiceType(str, Enum):
     CHAT_SERVICE = "chat_service"
     SESSION_SERVICE = "session_service"
     TASK_SERVICE = "task_service"
+    PLUGIN_SERVICE = "plugin_service"

src/backend/langflow/services/settings/base.py

@@ -48,6 +48,8 @@ class Settings(BaseSettings):
     REDIS_DB: int = 0
     REDIS_CACHE_EXPIRE: int = 3600
 
+    PLUGIN_DIR: Optional[str] = None
+
     LANGFUSE_SECRET_KEY: Optional[str] = None
     LANGFUSE_PUBLIC_KEY: Optional[str] = None
     LANGFUSE_HOST: Optional[str] = None

src/backend/langflow/services/utils.py

@@ -19,6 +19,7 @@ def get_factories_and_deps():
     from langflow.services.auth import factory as auth_factory
     from langflow.services.task import factory as task_factory
     from langflow.services.session import factory as session_service_factory  # type: ignore
+    from langflow.services.plugins import factory as plugins_factory
 
     return [
         (settings_factory.SettingsServiceFactory(), []),
@@ -40,6 +41,7 @@ def get_factories_and_deps():
             session_service_factory.SessionServiceFactory(),
             [ServiceType.CACHE_SERVICE],
         ),
+        (plugins_factory.PluginServiceFactory(), [ServiceType.SETTINGS_SERVICE]),
     ]