diff --git a/app/main.py b/app/main.py
index f3283e7..1353471 100644
--- a/app/main.py
+++ b/app/main.py
@@ -1,6 +1,29 @@
 """
-Version 0.3
+app/main.py — mindnet API bootstrap (WP-04 Hooks)
+
+Zweck:
+    Startpunkt der FastAPI-Anwendung: Router-Registrierung und Healthcheck.
+    Ergänzt um optionale WP-04 Router (Graph/Retriever), falls vorhanden.
+Kompatibilität:
+    Python 3.12+; FastAPI 0.110+ (getestet lokal)
+Version:
+    0.4.0  (WP-04 Hooks: optionale Router, /admin/meta)
+Stand:
+    2025-10-06
+Bezug:
+    Handbuch & Knowledge Design (WP-03/04)
+Umgebung:
+    Siehe app/config.py (QDRANT_URL, MINDNET_PREFIX, usw.)
+Nutzung:
+    uvicorn app.main:app --reload --port 8000
+Änderungsverlauf:
+    0.4.0 (2025-10-06) – /admin/meta ergänzt; optionale Einbindung von graph/query/admin Routern.
+    0.3.x (vorher)  – Basisversion laut bereitgestellter Datei.
+
+Hinweise:
+    Bestehende Routen/Funktionen bleiben unverändert.
 """
+
 from __future__ import annotations
 
 from fastapi import FastAPI
@@ -8,6 +31,24 @@ from .config import get_settings
 from .routers.embed_router import router as embed_router
 from .routers.qdrant_router import router as qdrant_router
 
+# Optionale WP-04 Router dynamisch einbinden, ohne harte Abhängigkeit:
+def _maybe_include_wp04(app: FastAPI) -> None:
+    try:
+        from .routers.graph import router as graph_router  # type: ignore
+        app.include_router(graph_router, prefix="/graph", tags=["graph"])
+    except Exception:
+        pass
+    try:
+        from .routers.query import router as query_router  # type: ignore
+        app.include_router(query_router, prefix="/query", tags=["query"])
+    except Exception:
+        pass
+    try:
+        from .routers.admin import router as admin_router  # type: ignore
+        app.include_router(admin_router, prefix="/admin", tags=["admin"])
+    except Exception:
+        pass
+
 
 def create_app() -> FastAPI:
     app = FastAPI(title="mindnet API", version="0.1.0")
@@ -17,8 +58,44 @@ def create_app() -> FastAPI:
     def healthz():
         return {"status": "ok", "qdrant": s.QDRANT_URL, "prefix": s.COLLECTION_PREFIX}
 
+    # Admin-Metadaten (WP-04)
+    @app.get("/admin/meta")
+    def admin_meta():
+        # Import lokal, damit fehlende Module nicht beim Start stören
+        meta = {}
+        try:
+            import app.main as _m
+            meta["main"] = getattr(_m, "__doc__", "").splitlines()[0:1]
+        except Exception:
+            pass
+        try:
+            import app.config as _c
+            meta["config"] = {
+                "QDRANT_URL": s.QDRANT_URL,
+                "COLLECTION_PREFIX": s.COLLECTION_PREFIX,
+                "VECTOR_SIZE": s.VECTOR_SIZE,
+                "DISTANCE": s.DISTANCE,
+                "MODEL_NAME": s.MODEL_NAME,
+                "RETRIEVER": {
+                    "W_SEM": getattr(s, "RETRIEVER_W_SEM", 0.70),
+                    "W_EDGE": getattr(s, "RETRIEVER_W_EDGE", 0.25),
+                    "W_CENT": getattr(s, "RETRIEVER_W_CENT", 0.05),
+                    "TOP_K": getattr(s, "RETRIEVER_TOP_K", 10),
+                    "EXPAND_DEPTH": getattr(s, "RETRIEVER_EXPAND_DEPTH", 1),
+                },
+            }
+        except Exception:
+            pass
+        try:
+            import app.core.qdrant_points as _qp
+            meta["qdrant_points"] = getattr(_qp, "__doc__", "").splitlines()[0:1]
+        except Exception:
+            pass
+        return {"meta": meta}
+
     app.include_router(embed_router)
     app.include_router(qdrant_router)
+    _maybe_include_wp04(app)
     return app