diff --git a/tests/test_relation_extraction_endpoint.py b/tests/test_relation_extraction_endpoint.py
new file mode 100644
index 0000000..2e7eb88
--- /dev/null
+++ b/tests/test_relation_extraction_endpoint.py
@@ -0,0 +1,87 @@
+import pytest
+import requests
+from typing import Dict, Any
+from .conftest import BASE_URL
+
+
+class TestRelationExtractionEndpoint:
+    """Tests the /relation-extraction endpoint"""
+
+    def test_single_text_with_entities(self, api_client):
+        """Test with a single text and entities"""
+        payload = {
+            "text": "Steve Jobs founded Apple Inc. which is located in Cupertino.",
+            "relations": ["founded", "located_in"],
+            "entities": ["person", "organization", "location"],
+            "threshold": 0.3
+        }
+        response = api_client.post(f"{BASE_URL}/relation-extraction", json=payload)
+        assert response.status_code == 200
+
+        data = response.json()
+        assert "outputs" in data
+        assert isinstance(data["outputs"], list)
+
+    def test_single_text_without_entities(self, api_client):
+        """Test without explicit entities"""
+        payload = {
+            "text": "Bill Gates founded Microsoft.",
+            "relations": ["founded"],
+            "threshold": 0.3
+        }
+        response = api_client.post(f"{BASE_URL}/relation-extraction", json=payload)
+        assert response.status_code == 200
+
+    def test_batch_texts(self, api_client):
+        """Test with a batch of texts"""
+        payload = {
+            "texts": [
+                "Bill Gates founded Microsoft.",
+                "Tesla was founded by Elon Musk.",
+                "Apple is based in California."
+            ],
+            "relations": ["founded", "founded_by", "based_in"],
+            "threshold": 0.3
+        }
+        response = api_client.post(f"{BASE_URL}/relation-extraction", json=payload)
+        assert response.status_code == 200
+
+        data = response.json()
+        assert len(data["outputs"]) == 3
+
+    def test_with_optional_rules(self, api_client):
+        """Test with optional rules"""
+        payload = {
+            "text": "Steve Jobs founded Apple Inc.",
+            "relations": ["founded"],
+            "rules": [
+                {
+                    "relation": "founded",
+                    "pairs_filter": [["person", "organization"]],
+                    "distance": 10
+                }
+            ],
+            "threshold": 0.3
+        }
+        response = api_client.post(f"{BASE_URL}/relation-extraction", json=payload)
+        assert response.status_code == 200
+
+    def test_error_empty_relations(self, api_client):
+        """Test error with an empty relations list"""
+        payload = {
+            "text": "Some text",
+            "relations": []
+        }
+        response = api_client.post(f"{BASE_URL}/relation-extraction", json=payload)
+        assert response.status_code == 422
+
+    def test_error_both_text_and_texts(self, api_client):
+        """Test error when both text and texts are present"""
+        payload = {
+            "text": "Some text",
+            "texts": ["Another text"],
+            "relations": ["founded"]
+        }
+        response = api_client.post(f"{BASE_URL}/relation-extraction", json=payload)
+        assert response.status_code == 400
+