diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..62fbcbb
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,3 @@
+NEO4J_URL="localhost"
+NEO4J_USERNAME="neo4j"
+NEO4J_PASSWORD=changemeplease
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..8d19362
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+.venv
+.env
diff --git a/README.md b/README.md
index feffe92..ce6a2cf 100644
--- a/README.md
+++ b/README.md
@@ -57,15 +57,18 @@ The CTI database contains up to 2060 nodes, 27411 relationships, and 366 APTs co
 
 4. Download the MITRE Entreprise ATT&CK database in JSON format
 
-    `wget https://github.com/mitre/cti/blob/master/enterprise-attack/enterprise-attack.json`
+    `wget https://github.com/mitre/cti/raw/master/enterprise-attack/enterprise-attack.json`
 
 
-5. Configure the main.py script
-
-    ```python
-    100. # open graph connection`
-    101. graph_bolt = "bolt://127.0.0.1:7687"
-    102. graph_auth = ("neo4j","1234")
+5. Configure script with .env file
+    ```bash
+    cp .env.example .env
+    ```
+    ```env
+    # Change values according to created database 
+    NEO4J_URL=bolt://127.0.0.1:7687
+    NEO4J_USERNAME=neo4j
+    NEO4J_PASSWORD=1234
     ```
 
 6. Run the script
diff --git a/main.py b/main.py
index d50adb5..4af43cd 100644
--- a/main.py
+++ b/main.py
@@ -1,85 +1,151 @@
 #!/usr/bin/env python3
 
 import argparse
+from os import getenv
+from dotenv import load_dotenv
+
 import json
-import re
 import sys
-from py2neo import Graph, Node, Relationship, NodeMatcher, cypher
+from py2neo import Graph, Node, Relationship, NodeMatcher
 
 
 # BUILD_LABEL
 def build_label(txt):
-	if txt.startswith('intrusion-set'):		return 'Group'
-	if txt.startswith('malware'):			return 'Software'
-	if txt.startswith('tool'):				return 'Tool'
-	if txt.startswith('attack-pattern'):	return 'Technique'
-	if txt.startswith('course-of-action'):	return 'Technique'
-	return 'Unknown'
+    if txt.startswith("intrusion-set"):
+        return "Group"
+    if txt.startswith("malware"):
+        return "Software"
+    if txt.startswith("tool"):
+        return "Tool"
+    if txt.startswith("attack-pattern"):
+        return "Technique"
+    if txt.startswith("course-of-action"):
+        return "Technique"
+    return "Unknown"
 
 
 # BUILD ALIASES
-def build_objects(obj,key):
-	label = build_label(obj['type'])
-
-	# Add properties
-	props = {}
-	props['name'] = obj['name']
-	props['id'] = obj['id']
-	props['type'] = obj['type']
-	if obj.get('description'):		props['description'] = obj['description']
-	if obj.get('created'):			props['created']     = obj['created']
-	if obj.get('modified'):			props['modified']    = obj['modified']
-	if obj.get('x_mitre_version'):	props['version']     = obj['x_mitre_version']
-
-	# Create node for the group
-	node_main = Node(label, **props)
-	# Merge node to graph
-	graph.merge(node_main,label,'name')
-	print('%s: "%s"' % (label,obj['name']),end='') if dbg_mode else None
-
-	# Dealing with aliases
-	if obj.get('aliases'): 
-		aliases = obj['aliases']
-	elif obj.get('x_mitre_aliases'): 
-		aliases = obj['x_mitre_aliases']
-	else:
-		aliases = None
-	if aliases:
-		for alias in aliases:
-			if alias != obj['name']:
-				node_alias = Node('Alias', name=alias, type=obj['type'])
-				relation = Relationship.type('alias')
-				graph.merge(relation(node_main,node_alias),label,'name')
-				print(' -[alias]-> "%s"' % (alias),end='') if dbg_mode else None
-	print() if dbg_mode else None
+def build_objects(obj, key):
+    label = build_label(obj["type"])
+
+    # Add properties
+    props = {}
+    props["name"] = obj["name"]
+    props["id"] = obj["id"]
+    props["type"] = obj["type"]
+    if obj.get("description"):
+        props["description"] = obj["description"]
+    if obj.get("created"):
+        props["created"] = obj["created"]
+    if obj.get("modified"):
+        props["modified"] = obj["modified"]
+    if obj.get("x_mitre_version"):
+        props["version"] = obj["x_mitre_version"]
+    if obj.get("x_mitre_deprecated"):
+        props["deprecated"] = obj["x_mitre_deprecated"]
+    props["external_id"] = next(
+        filter(
+            lambda s: s.get("source_name", "") == "mitre-attack"
+            and s.get("external_id", None),
+            obj.get("external_references", []),
+        ),
+        {"external_id": None},
+    )["external_id"]
+    # Create node for the group
+    node_main = Node(label, **props)
+    # Merge node to graph
+    graph.merge(node_main, label, "name")
+    print('%s: "%s"' % (label, obj["name"]), end="") if dbg_mode else None
+
+    # Dealing with aliases
+    if obj.get("aliases"):
+        aliases = obj["aliases"]
+    elif obj.get("x_mitre_aliases"):
+        aliases = obj["x_mitre_aliases"]
+    else:
+        aliases = None
+    if aliases:
+        for alias in aliases:
+            if alias != obj["name"]:
+                node_alias = Node("Alias", name=alias, type=obj["type"])
+                relation = Relationship.type("alias")
+                graph.merge(relation(node_main, node_alias), label, "name")
+                print(' -[alias]-> "%s"' % (alias), end="") if dbg_mode else None
+    print() if dbg_mode else None
 
 
 # BUILD RELATIONS
 def build_relations(obj):
+    if not gnames.get(obj["source_ref"]):
+        return
+    if not gnames.get(obj["target_ref"]):
+        return
 
-	if not gnames.get(obj['source_ref']): return
-	if not gnames.get(obj['target_ref']): return
-	
-	m = NodeMatcher(graph)
+    m = NodeMatcher(graph)
 
-	source = m.match( build_label(obj['source_ref']), name=gnames[obj['source_ref']] ).first()
-	target = m.match( build_label(obj['target_ref']), name=gnames[obj['target_ref']] ).first()
+    source = m.match(
+        build_label(obj["source_ref"]), name=gnames[obj["source_ref"]]
+    ).first()
+    target = m.match(
+        build_label(obj["target_ref"]), name=gnames[obj["target_ref"]]
+    ).first()
 
-	relation = Relationship.type( obj['relationship_type'] )
+    relation = Relationship.type(obj["relationship_type"])
 
-	graph.merge(relation(source,target),build_label(obj['source_ref']),'name')
-	print('Relation: "%s" -[%s]-> "%s"' % (gnames[obj['source_ref']],obj['relationship_type'],gnames[obj['target_ref']]) ) if dbg_mode else None
+    graph.merge(relation(source, target), build_label(obj["source_ref"]), "name")
+    print(
+        'Relation: "%s" -[%s]-> "%s"'
+        % (
+            gnames[obj["source_ref"]],
+            obj["relationship_type"],
+            gnames[obj["target_ref"]],
+        )
+    ) if dbg_mode else None
 
 
 # Set command-line arguments and parsing options
 parser = argparse.ArgumentParser()
-parser.add_argument('-d','--debug', help='enter debug mode', default=False, action='store_true')
-parser.add_argument('-f', help='input file name', metavar='<filename>', action='store', required=True)
-parser.add_argument('-g','--groups', help='import Groups objects (type:intrusion-set)', default=False, action='store_true')
-parser.add_argument('-s','--softwares', help='import Softwares objects (type:malware)', default=False, action='store_true')
-parser.add_argument('-o','--tools', help='import Tools objects (type:tool)', default=False, action='store_true')
-parser.add_argument('-t','--techniques', help='import Techniques objects (type:attack-pattern and type:course-of-action)', default=False, action='store_true')
-parser.add_argument('-r','--relations', help='import Relations objects (type:relationship)', default=False, action='store_true')
+parser.add_argument(
+    "-d", "--debug", help="enter debug mode", default=False, action="store_true"
+)
+parser.add_argument(
+    "-f", help="input file name", metavar="<filename>", action="store", required=True
+)
+parser.add_argument(
+    "-g",
+    "--groups",
+    help="import Groups objects (type:intrusion-set)",
+    default=False,
+    action="store_true",
+)
+parser.add_argument(
+    "-s",
+    "--softwares",
+    help="import Softwares objects (type:malware)",
+    default=False,
+    action="store_true",
+)
+parser.add_argument(
+    "-o",
+    "--tools",
+    help="import Tools objects (type:tool)",
+    default=False,
+    action="store_true",
+)
+parser.add_argument(
+    "-t",
+    "--techniques",
+    help="import Techniques objects (type:attack-pattern and type:course-of-action)",
+    default=False,
+    action="store_true",
+)
+parser.add_argument(
+    "-r",
+    "--relations",
+    help="import Relations objects (type:relationship)",
+    default=False,
+    action="store_true",
+)
 args = parser.parse_args()
 
 # Checks arguments and options
@@ -88,54 +154,56 @@ def build_relations(obj):
 
 # Load JSON data from file
 try:
-	with open(json_file, encoding="utf8") as fh:
-		data = json.load(fh)
-	fh.close()
+    with open(json_file, encoding="utf8") as fh:
+        data = json.load(fh)
+    fh.close()
 except Exception as e:
-	sys.stderr.write( '[ERROR] reading configuration file %s\n' % json_file )
-	sys.stderr.write( '[ERROR] %s\n' % str(e) )
-	sys.exit(1)
+    sys.stderr.write("[ERROR] reading configuration file %s\n" % json_file)
+    sys.stderr.write("[ERROR] %s\n" % str(e))
+    sys.exit(1)
 
 # Open graph connection
-graph_bolt = "bolt://127.0.0.1:7687"
-graph_auth = ("neo4j","12345678")
+load_dotenv()
+
+graph_bolt = getenv("NEO4J_URL")
+graph_auth = (getenv("NEO4J_USERNAME"), getenv("NEO4J_PASSWORD"))
 
-graph = Graph(graph_bolt,auth=graph_auth)
+graph = Graph(graph_bolt, auth=graph_auth)
 
 # Delete existing nodes and edges
 graph.delete_all()
- 
+
 # Global names
 gnames = {}
 
 # Walk through JSON objects to create nodes
-for obj in data['objects']:
-
-	# if JSON object is about Groups
-	if args.groups and obj['type']=='intrusion-set':
-		gnames[ obj['id'] ] = obj['name']
-		build_objects(obj,'aliases')
-
-	# if JSON object is about Softwares
-	if args.softwares and obj['type']=='malware':
-		gnames[ obj['id'] ] = obj['name']
-		build_objects(obj,'x_mitre_aliases')
-
-	# if JSON object is about Tools
-	if args.tools and obj['type']=='tool':
-		gnames[ obj['id'] ] = obj['name']
-		build_objects(obj,'x_mitre_aliases')
-
-	# if JSON object is about Techniques
-	if args.techniques and (obj['type']=='attack-pattern' or obj['type']=='course-of-action'):
-		gnames[ obj['id'] ] = obj['name']
-		build_objects(obj,None)
+for obj in data["objects"]:
+    # if JSON object is about Groups
+    if args.groups and obj["type"] == "intrusion-set":
+        gnames[obj["id"]] = obj["name"]
+        build_objects(obj, "aliases")
+
+    # if JSON object is about Softwares
+    if args.softwares and obj["type"] == "malware":
+        gnames[obj["id"]] = obj["name"]
+        build_objects(obj, "x_mitre_aliases")
+
+    # if JSON object is about Tools
+    if args.tools and obj["type"] == "tool":
+        gnames[obj["id"]] = obj["name"]
+        build_objects(obj, "x_mitre_aliases")
+
+    # if JSON object is about Techniques
+    if args.techniques and (
+        obj["type"] == "attack-pattern" or obj["type"] == "course-of-action"
+    ):
+        gnames[obj["id"]] = obj["name"]
+        build_objects(obj, None)
 
 # Walk through JSON objects to create edges
-for obj in data['objects']:
-
-	# if JSON object is about Relationships
-	if args.relations and obj['type']=='relationship':
-		build_relations(obj)
+for obj in data["objects"]:
+    # if JSON object is about Relationships
+    if args.relations and obj["type"] == "relationship":
+        build_relations(obj)
 
-# EOF
\ No newline at end of file
+# EOF
diff --git a/requirements.txt b/requirements.txt
index 36d7163..24eeb97 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -10,3 +10,4 @@ pytz
 six
 urllib3
 wcwidth
+python-dotenv