diff --git a/cojac/generate_sigs_nextstrains.py b/cojac/generate_sigs_nextstrains.py
new file mode 100755
index 0000000..20e48d1
--- /dev/null
+++ b/cojac/generate_sigs_nextstrains.py
@@ -0,0 +1,110 @@
+#!/usr/bin/env python3
+
+import os
+import json
+import requests
+from datetime import datetime
+import yaml
+import click
+
+
+def load_dataset(url):
+    response = requests.get(url)
+    full_data = json.loads(response.content)
+
+    return full_data
+
+
+def prepare_header(data, url):
+    return {
+        "variant": {
+            "nextstrain": data["nextstrainClade"],
+            "pangolin": data["lineage"],
+            "short": data["lineage"].lower().replace(".", "_"),
+            "reference": {
+                "address": url,
+                "accessed_at": datetime.now().strftime("%Y-%m-%d %H:%M:%S"),
+            },
+        }
+    }
+
+
+def prepare_mut(data):
+    mut_dict = {}
+    if data["nucSubstitutions"] != [""]:
+        for item in data["nucSubstitutions"]:
+            start_letter = item[0]
+            end_letter = item[-1]
+            number = int(item[1:-1])
+            mut_dict[number] = f"{start_letter}>{end_letter}"
+        return {"mut": mut_dict}
+    else:
+        return ""
+
+
+def prepare_del(data):
+    del_dict = {}
+    if data["nucDeletions"] != [""]:
+        for item in data["nucDeletions"]:
+            if "-" in item:
+                start, end = map(int, item.split("-"))
+                key = start
+                value = str((end - start) * "-")
+            else:
+                key = int(item)
+                value = "-"
+            del_dict[key] = value
+        return {"del": del_dict}
+    else:
+        return ""
+
+
+def prepare_yaml(data, url):
+    header = prepare_header(data, url)
+    mut = prepare_mut(data)
+    del_section = prepare_del(data)
+
+    output_data = header
+
+    if mut != "":
+        output_data["mut"] = mut["mut"]
+
+    if del_section != "":
+        output_data["del"] = del_section["del"]
+
+    return output_data
+
+
+def process_dataset(full_data, outdir, url):
+    if not os.path.exists(outdir):
+        os.makedirs(outdir)
+    for data in full_data.values():
+        output_data = prepare_yaml(data, url)
+        with open(f"{outdir}/{output_data['variant']['short']}.yaml", "w") as yaml_file:
+            yaml.dump(output_data, yaml_file, sort_keys=False)
+
+
+@click.command(
+    help="Generating a list of variants from nextstrain",
+    epilog="This tool fetchs a JSON from Github",
+)
+@click.option(
+    "-o",
+    "--outdir",
+    required=False,
+    default="voc_nextstrain",
+    type=str,
+    help="The output directory for the YAML files",
+)
+@click.option(
+    "-u",
+    "--url",
+    metavar="URL",
+    required=False,
+    default="https://raw.githubusercontent.com/corneliusroemer/pango-sequences/main/data/pango-consensus-sequences_summary.json",
+    type=str,
+    help="url to fetch the JSON from",
+)
+def generate_sigs_nextstrains(outdir, url):
+    full_data = load_dataset(url)
+    process_dataset(full_data, outdir, url)
diff --git a/cojac/main.py b/cojac/main.py
index b0c83ef..30b6238 100644
--- a/cojac/main.py
+++ b/cojac/main.py
@@ -10,6 +10,7 @@
 from .cooc_tabmut import cooc_tabmut
 from .phe2cojac import phe2cojac
 from .sig_generate import sig_generate
+from .generate_sigs_nextstrains import generate_sigs_nextstrains
 
 
 @click.group(context_settings=CONTEXT_SETTINGS)
@@ -26,3 +27,4 @@ def cli():
 cli.add_command(cooc_tabmut)
 cli.add_command(phe2cojac)
 cli.add_command(sig_generate)
+cli.add_command(generate_sigs_nextstrains)
diff --git a/generate_sigs_nextstrains.py b/generate_sigs_nextstrains.py
deleted file mode 100755
index 8aa178f..0000000
--- a/generate_sigs_nextstrains.py
+++ /dev/null
@@ -1,90 +0,0 @@
-import os
-import json
-import requests
-from datetime import datetime
-import yaml
-import argparse
-
-def load_dataset():
-    url = 'https://raw.githubusercontent.com/corneliusroemer/pango-sequences/main/data/pango-consensus-sequences_summary.json'
-    response = requests.get(url)
-    full_data = json.loads(response.content)
-    
-    return full_data
-
-def prepare_header(data):
-    return {
-        'variant': {
-            'nextstrain': data['nextstrainClade'],
-            'pangolin': data['lineage'],
-            'short': data['lineage'].lower().replace('.', '_'),
-            'reference': {
-                'address': 'https://raw.githubusercontent.com/corneliusroemer/pango-sequences/main/data/pango-consensus-sequences_summary.json',
-                'accessed_at': datetime.now().strftime('%Y-%m-%d %H:%M:%S')
-            }
-        }
-    }
-
-def prepare_mut(data):
-    mut_dict = {}
-    if data['nucSubstitutions'] != ['']:
-        for item in data['nucSubstitutions']:
-            start_letter = item[0]
-            end_letter = item[-1]
-            number = int(item[1:-1])
-            mut_dict[number] = f"{start_letter}>{end_letter}"
-        return {'mut': mut_dict}
-    else:
-        return ''
-
-def prepare_del(data):
-    del_dict = {}
-    if data['nucDeletions'] != ['']:
-        for item in data['nucDeletions']:
-            if '-' in item:
-                start, end = map(int, item.split('-'))
-                key = start
-                value = str((end - start) * '-')
-            else:
-                key = int(item)
-                value = '-'
-            del_dict[key] = value
-        return {'del': del_dict}
-    else:
-        return '' 
-
-def prepare_yaml(data):
-    header = prepare_header(data)
-    mut = prepare_mut(data)
-    del_section = prepare_del(data)
-
-    output_data = header
-
-    if mut != '':
-        output_data['mut'] = mut['mut']
-
-    if del_section != '':
-        output_data['del'] = del_section['del']
-
-    return output_data
-
-def process_dataset(full_data, outdir):
-    if not os.path.exists(outdir):
-        os.makedirs(outdir)
-    for data in full_data.values():
-        output_data = prepare_yaml(data)
-        with open(f"{outdir}/{output_data['variant']['short']}.yaml", "w") as yaml_file:
-            yaml.dump(output_data, yaml_file, sort_keys=False)
-
-def main():
-    parser = argparse.ArgumentParser()
-    parser.add_argument('--outdir', default='voc_nextstrain', help='The output directory for the YAML files')
-    args = parser.parse_args()
-    
-    outdir = args.outdir
-
-    full_data = load_dataset()
-    process_dataset(full_data, outdir)
-
-if __name__ == '__main__':
-    main()