diff --git a/server/intelligence-service/app/detector/bad_practice_detector.py b/server/intelligence-service/app/detector/bad_practice_detector.py
new file mode 100644
index 000000000..89c890c1c
--- /dev/null
+++ b/server/intelligence-service/app/detector/bad_practice_detector.py
@@ -0,0 +1,25 @@
+from typing import List
+
+class PullRequest:
+    id: str
+    title: str
+    description: str
+
+class Rule:
+    name: str
+    description: str
+    bad_practice_id: str
+
+class PullRequestWithBadPractices:
+    pull_request_id: str
+    bad_practice_ids: List[str]
+
+def detectbadpractices(pull_requests: List[PullRequest], rules: List[Rule]) -> List[PullRequestWithBadPractices]:
+    bad_practices = []
+    for pull_request in pull_requests:
+        bad_practice_ids = []
+        for rule in rules:
+            if rule.bad_practice_id in pull_request.description:
+                bad_practice_ids.append(rule.bad_practice_id)
+        bad_practices.append(PullRequestWithBadPractices(pull_request_id=pull_request.id, bad_practice_ids=bad_practice_ids))
+    return bad_practices
\ No newline at end of file
diff --git a/server/intelligence-service/app/main.py b/server/intelligence-service/app/main.py
index 17fbcc5a9..cc682d91d 100644
--- a/server/intelligence-service/app/main.py
+++ b/server/intelligence-service/app/main.py
@@ -1,6 +1,7 @@
 from fastapi import FastAPI
 from .routers.mentor import router as mentor_router
 from .routers.health import router as health_router
+from .routers.detector import router as detector_router
 
 app = FastAPI(
     title="Hephaestus Intelligence Service API",
@@ -11,3 +12,5 @@
 
 app.include_router(mentor_router)
 app.include_router(health_router)
+
+app.include_router(detector_router)
diff --git a/server/intelligence-service/app/routers/detector.py b/server/intelligence-service/app/routers/detector.py
new file mode 100644
index 000000000..a7d011347
--- /dev/null
+++ b/server/intelligence-service/app/routers/detector.py
@@ -0,0 +1,22 @@
+from typing import List
+from fastapi import APIRouter
+from pydantic import BaseModel
+
+from app.detector.bad_practice_detector import PullRequestWithBadPractices, PullRequest, Rule, detectbadpractices
+
+router = APIRouter(prefix="/detector", tags=["detector"])
+
+class DetectorRequest(BaseModel):
+    pull_requests: List[PullRequest]
+    rules: List[Rule]
+
+class DetectorResponse(BaseModel):
+    detectBadPractices: List[PullRequestWithBadPractices]
+
+@router.post(
+    "/",
+    response_model=DetectorResponse,
+    summary="Detect bad practices given rules.",
+)
+def detect(request: DetectorRequest):
+    return detectbadpractices(request.pull_requests, request.rules)