diff --git a/cosmicweb_music/cosmICweb.py b/cosmicweb_music/cosmICweb.py
index 60a4d5a..26b68f6 100755
--- a/cosmicweb_music/cosmICweb.py
+++ b/cosmicweb_music/cosmICweb.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import os
 import sys
 import tempfile
@@ -26,7 +28,7 @@ EDITOR = os.environ.get("EDITOR", "vim")
 EDITOR_IS_VIM = EDITOR in {"vim", "nvim"}
 
 
-def query_yes_no(question, default="yes"):
+def query_yes_no(question: str, default="yes") -> bool:
     """Ask a yes/no question via raw_input() and return their answer.
 
     "question" is a string that is presented to the user.
@@ -58,7 +60,7 @@ def query_yes_no(question, default="yes"):
 
 
 # Routines
-def fetch_ellipsoids(url, api_token, attempts):
+def fetch_ellipsoids(url: str, api_token: str, attempts: int) -> list[Ellipsoid]:
     for i in range(attempts):
         try:
             r = requests.get(url, headers={"Authorization": "Token " + api_token})
@@ -79,19 +81,21 @@ def fetch_ellipsoids(url, api_token, attempts):
                 for e in content
             ]
     logging.error("Unable to download ellipsoids from {}".format(url))
-    return None
+    return []
 
 
-def fetch_ellipsoid(url, api_token, traceback_radius, attempts=3):
+def fetch_ellipsoid(
+    url: str, api_token: str, traceback_radius, attempts: int = 3
+) -> Ellipsoid | None:
     ellipsoids = fetch_ellipsoids(url, api_token, attempts)
-    if ellipsoids is not None:
+    if ellipsoids:
         return next(
             (e for e in ellipsoids if e.traceback_radius == traceback_radius), None
         )
     return None
 
 
-def fetch_downloadstore(cosmicweb_url, target):
+def fetch_downloadstore(cosmicweb_url: str, target: str) -> DownloadConfig:
     try:
         r = requests.get(cosmicweb_url + "/api/music/store/" + target)
         # This will raise an error if not successful
@@ -122,7 +126,9 @@ def fetch_downloadstore(cosmicweb_url, target):
     )
 
 
-def fetch_publication(cosmicweb_url, publication_name, traceback_radius):
+def fetch_publication(
+    cosmicweb_url: str, publication_name: str, traceback_radius
+) -> DownloadConfig:
     try:
         r = requests.get(cosmicweb_url + "/api/publications/" + publication_name)
         # This will raise an error if not successful
@@ -155,7 +161,7 @@ def fetch_publication(cosmicweb_url, publication_name, traceback_radius):
     )
 
 
-def edit_template(template):
+def edit_template(template: str) -> str:
     with tempfile.NamedTemporaryFile(suffix=".tmp.conf", mode="r+") as tf:
         tf.write(template)
         tf.flush()
@@ -169,7 +175,7 @@ def edit_template(template):
     return template
 
 
-def apply_config_parameter(config: str, parameters: dict[str, Any]):
+def apply_config_parameter(config: str, parameters: dict[str, Any]) -> str:
     new_lines = []
     for line in config.split("\n"):
         param = line.split("=")[0].strip()
@@ -179,7 +185,7 @@ def apply_config_parameter(config: str, parameters: dict[str, Any]):
     return "\n".join(new_lines)
 
 
-def music_config_to_template(config: DownloadConfig):
+def music_config_to_template(config: DownloadConfig) -> str:
     music_config = config.MUSIC
     settings = config.settings
     # TODO: apply output configuration
@@ -208,7 +214,7 @@ def compose_template(
     config: DownloadConfig,
     halo_name: str,
     halo_id: int,
-):
+) -> str:
     # TODO: add ellipsoid header (rtb, halo_name, etc)
     shape_0 = ", ".join(str(e) for e in ellipsoid.shape[0])
     shape_1 = ", ".join(str(e) for e in ellipsoid.shape[1])
@@ -243,11 +249,11 @@ def write_music_file(output_file, music_config) -> None:
         f.write(music_config)
 
 
-def call_music():
+def call_music() -> None:
     pass
 
 
-def process_config(config: DownloadConfig, args: Args):
+def process_config(config: DownloadConfig, args: Args) -> None:
     ellipsoids = []
     for halo_name, url in zip(config.halo_names, config.halo_urls):
         logging.info("Fetching ellipsoids from halo " + halo_name)
@@ -299,7 +305,7 @@ def process_config(config: DownloadConfig, args: Args):
     # TODO: Execute MUSIC?
 
 
-def downloadstore_mode(args: Args, target: str):
+def downloadstore_mode(args: Args, target: str) -> None:
     logging.info("Fetching download configuration from the cosmICweb server")
     config = fetch_downloadstore(args.url, target)
     if args.output_path == "./":
@@ -309,7 +315,7 @@ def downloadstore_mode(args: Args, target: str):
     process_config(config, args)
 
 
-def publication_mode(args: Args, publication_name: str, traceback_radius: int):
+def publication_mode(args: Args, publication_name: str, traceback_radius: int) -> None:
     logging.info(
         "Fetching publication " + publication_name + " from the cosmICweb server"
     )
@@ -320,7 +326,7 @@ def publication_mode(args: Args, publication_name: str, traceback_radius: int):
     process_config(config, args)
 
 
-def dir_path(p):
+def dir_path(p: str) -> str:
     if os.path.isdir(p):
         return p
     else:
@@ -373,54 +379,3 @@ def publication(ctx, publication_name, traceback_radius):
 
 if __name__ == "__main__":
     cli()
-
-# if __name__ == "__main__":
-#     parser = argparse.ArgumentParser()
-#     parser.add_argument(
-#         "--url",
-#         dest="cosmicweb_url",
-#         default=DEFAULT_URL,
-#         help="overwrite URL of the cosmicweb server",
-#     )
-#     parser.add_argument(
-#         "--output-path",
-#         type=dir_path,
-#         default="./",
-#         help="Download target for IC files. If downloading publication, will create a subfolder with the "
-#         "name of the publication",
-#     )
-#     parser.add_argument(
-#         "--common-directory", dest="create_subdirs", action="store_false"
-#     )
-#     parser.add_argument(
-#         "--attempts",
-#         type=int,
-#         default=3,
-#         help="number of attempts to download ellipsoids",
-#     )
-#     parser.add_argument("--verbose", action="store_true")
-
-#     subparsers = parser.add_subparsers(dest="mode")
-#     # Downloading from publications
-#     publication_parser = subparsers.add_parser(
-#         "publication", help="download publications"
-#     )
-#     publication_parser.add_argument("publication_name", help="name of the publication")
-#     publication_parser.add_argument(
-#         "--traceback_radius", type=int, choices=[1, 2, 4, 10], default=2, help=""
-#     )
-#     # Downloading from download object
-#     download_parser = subparsers.add_parser("get")
-#     download_parser.add_argument("target")
-
-#     args = parser.parse_args()
-
-#     if args.verbose:
-#         logger.setLevel("DEBUG")
-
-#     if args.mode == "get":
-#         downloadstore_mode(args)
-#     elif args.mode == "publication":
-#         publication_mode(args)
-#     else:
-#         raise NotImplementedError("unknown subparser")
diff --git a/cosmicweb_music/data_types.py b/cosmicweb_music/data_types.py
index e0afba7..0f07d1b 100644
--- a/cosmicweb_music/data_types.py
+++ b/cosmicweb_music/data_types.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from datetime import datetime
 from typing import NamedTuple, Any, List, Dict, TypedDict