diff --git a/Functionality-for-Factorial-Calculation.py b/Functionality-for-Factorial-Calculation.py
new file mode 100644
index 0000000..c83e778
--- /dev/null
+++ b/Functionality-for-Factorial-Calculation.py
@@ -0,0 +1,37 @@
+from flask import Flask, request, jsonify
+import math
+import unittest
+
+app = Flask(__name)
+
+@app.route('/math/factorial', methods=['POST'])
+def calculate_factorial():
+    try:
+        data = request.get_json()
+        n = data['number']
+        result = math.factorial(n)
+        return jsonify({'result': result})
+    except (KeyError, ValueError):
+        return jsonify({'error': 'Invalid input'}), 400
+
+class TestFactorialEndpoint(unittest.TestCase):
+    def setUp(self):
+        app.testing = True
+        self.app = app.test_client()
+
+    def test_valid_factorial_request(self):
+        data = {'number': 5}
+        response = self.app.post('/math/factorial', json=data)
+        data = response.get_json()
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(data['result'], 120)
+
+    def test_invalid_factorial_request(self):
+        data = {'num': 5}  # Invalid key
+        response = self.app.post('/math/factorial', json=data)
+        self.assertEqual(response.status_code, 400)
+        data = response.get_json()
+        self.assertEqual(data['error'], 'Invalid input')
+
+if __name__ == '__main__':
+    app.run()