✨(backend) use langfuse to monitor AI actions

We want to monitor AI actions. For this we choose to use langfuse. As
this usage is optional, we load langfuse sdk only if settings are
configured. Also, the openai client from langfuse is a dropin
replacement of openai client, so we only have to change how openai is
imported.

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to
 - ✅(export) add PDF regression tests #1762
 - 📝(docs) Add language configuration documentation #1757
 - 🔒(helm) Set default security context #1750
+- ✨(backend) use langfuse to monitor AI actions
 
 ### Fixed 
 

docs/env.md

@@ -64,6 +64,9 @@ These are the environment variables you can set for the `impress-backend` contai
 | FRONTEND_HOMEPAGE_FEATURE_ENABLED               | Frontend feature flag to display the homepage                                                                                                                              | false                                                                   |
 | FRONTEND_THEME                                  | Frontend theme to use                                                                                                                                                      |                                                                         |
 | LANGUAGE_CODE                                   | Default language                                                                                                                                                           | en-us                                                                   |
+| LANGFUSE_SECRET_KEY                             | The Langfuse secret key used by the sdk                                                                                                                                    | None                                                                    |
+| LANGFUSE_PUBLIC_KEY                             | The Langfuse public key used by the sdk                                                                                                                                    | None                                                                    |
+| LANGFUSE_BASE_URL                               | The Langfuse base url used by the sdk                                                                                                                                      | None                                                                    |
 | LASUITE_MARKETING_BACKEND                       | Backend used when SIGNUP_NEW_USER_TO_MARKETING_EMAIL is True. See https://github.com/suitenumerique/django-lasuite/blob/main/documentation/how-to-use-marketing-backend.md | lasuite.marketing.backends.dummy.DummyBackend                           |   
 | LASUITE_MARKETING_PARAMETERS                    | The parameters to configure LASUITE_MARKETING_BACKEND. See https://github.com/suitenumerique/django-lasuite/blob/main/documentation/how-to-use-marketing-backend.md        | {}                                                                      |
 | LOGGING_LEVEL_LOGGERS_APP                       | Application logging level. options are "DEBUG", "INFO", "WARN", "ERROR", "CRITICAL"                                                                                        | INFO                                                                    |

src/backend/core/services/ai_services.py

@@ -3,10 +3,14 @@
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 
-from openai import OpenAI
-
 from core import enums
 
+if settings.LANGFUSE_PUBLIC_KEY:
+    from langfuse.openai import OpenAI
+else:
+    from openai import OpenAI
+
+
 AI_ACTIONS = {
     "prompt": (
         "Answer the prompt using markdown formatting for structure and emphasis. "

src/backend/impress/settings.py

@@ -699,6 +699,16 @@ class Base(Configuration):
         "day": 200,
     }
 
+    LANGFUSE_SECRET_KEY = SecretFileValue(
+        None, environ_name="LANGFUSE_SECRET_KEY", environ_prefix=None
+    )
+    LANGFUSE_PUBLIC_KEY = values.Value(
+        None, environ_name="LANGFUSE_PUBLIC_KEY", environ_prefix=None
+    )
+    LANGFUSE_BASE_URL = values.Value(
+        None, environ_name="LANGFUSE_BASE_URL", environ_prefix=None
+    )
+
     # Y provider microservice
     Y_PROVIDER_API_KEY = SecretFileValue(
         environ_name="Y_PROVIDER_API_KEY",

src/backend/pyproject.toml

@@ -48,6 +48,7 @@ dependencies = [
     "factory_boy==3.3.3",
     "gunicorn==23.0.0",
     "jsonschema==4.25.1",
+    "langfuse==3.11.2",
     "lxml==6.0.2",
     "markdown==3.10",
     "mozilla-django-oidc==5.0.2",