diff --git a/apps/api/pyproject.toml b/apps/api/pyproject.toml
index 1a6444bd..61c32949 100644
--- a/apps/api/pyproject.toml
+++ b/apps/api/pyproject.toml
@@ -26,6 +26,8 @@ dependencies = [
     "opentelemetry-instrumentation-logging>=0.41b0",
     # Sentry (Error Tracking - 補強 SignOz，Self-Hosted @ 192.168.0.110)
     "sentry-sdk[fastapi]>=2.0.0",
+    # Langfuse (LLMOps - Phase 15.1，Self-Hosted @ 192.168.0.110:3100)
+    "langfuse>=2.0.0",
     # Phase 6.4g: leWOOOgo Brain - 積木化決策引擎
     # NOTE: Local packages 透過 Dockerfile 預先安裝，無需在此列出
     # 請參閱 apps/api/Dockerfile Phase 6.4i 註解