diff --git a/.circleci/config.yml b/.circleci/config.yml
new file mode 100644
index 0000000..d709899
--- /dev/null
+++ b/.circleci/config.yml
@@ -0,0 +1,20 @@
+version: 2.1
+
+orbs:
+  python: circleci/python@1.2.0
+
+jobs:
+  build-and-test:
+    executor: python/default
+    steps:
+      - checkout
+      - python/load-cache
+      - python/install-deps
+      - python/save-cache
+workflows:
+  main:
+    jobs:
+      - python/test:
+          args: '--dev'
+          pkg-manager: pipenv
+          test-tool: pytest
diff --git a/__init__.py b/__init__.py
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/__init__.py
@@ -0,0 +1 @@
+
diff --git a/fib_test.py b/fib_test.py
new file mode 100644
index 0000000..93e783f
--- /dev/null
+++ b/fib_test.py
@@ -0,0 +1,6 @@
+import unittest
+
+class TestCase(unittest.TestCase):
+
+    def test_true(self):
+        assert True
diff --git a/fibonacci.py b/fibonacci.py
new file mode 100644
index 0000000..f8c487d
--- /dev/null
+++ b/fibonacci.py
@@ -0,0 +1,48 @@
+"""
+Fibonacci numbers function.
+"""
+
+# Copyright 2014 The University of Edinburgh.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); 
+# you may not use this file except in compliance with the License. 
+# You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software 
+# distributed under the License is distributed on an "AS IS" BASIS, 
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied. See the License for the specific language governing
+# permissions and limitations under the License.
+
+import sys
+
+def fibonacci(n):
+  """
+  Calculate the Fibonacci number of the given integer.
+  @param n If n <= 0 then 0 is assumed.
+  @return fibonacci number.
+  """
+  if n <= 0:
+    return 0
+  elif n == 1:
+    return 1
+  else:
+    return fibonacci(n - 1) + fibonacci(n - 2)
+
+def print_usage():
+  """ Print usage information. """
+  print("Usage: python fibonacci.py N")
+  print("  where N >= 0")
+
+if __name__ == '__main__':
+  if (len(sys.argv) < 2):
+    print_usage()
+    exit(1)
+  n = int(sys.argv[1])  
+  if (n < 0):
+    print_usage()
+    exit(2)
+  fib = fibonacci(n)
+  print("fibonacci(%d) = %d" % (n, fib))
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..490d735
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,2 @@
+
+pytest