diff --git a/src/too/__init__.py b/src/too/__init__.py
index 205182f..a212cc5 100644
--- a/src/too/__init__.py
+++ b/src/too/__init__.py
@@ -12,13 +12,8 @@
 
 import sdssdb
 from sdsstools import get_logger, get_package_version
-from target_selection import log as ts_log
-from target_selection.exceptions import TargetSelectionImportWarning
 
 
-ts_log.setLevel(10000)  # Disable target_selection logging
-warnings.simplefilter("ignore", TargetSelectionImportWarning)
-
 sdssdb.autoconnect = False
 
 
diff --git a/src/too/__main__.py b/src/too/__main__.py
index 48367e0..0309284 100644
--- a/src/too/__main__.py
+++ b/src/too/__main__.py
@@ -12,6 +12,16 @@
 import polars
 from click_option_group import OptionGroup
 
+from too import (
+    connect_to_database,
+    load_too_targets,
+    log,
+    read_too_file,
+    run_too_carton,
+    too_dtypes,
+    xmatch_too_targets,
+)
+
 
 run_options = OptionGroup(
     "Run options",
@@ -80,15 +90,8 @@ def too_cli(
 ):
     """Command line interface for ToOs."""
 
-    from too import (
-        connect_to_database,
-        load_too_targets,
-        log,
-        read_too_file,
-        run_too_carton,
-        too_dtypes,
-        xmatch_too_targets,
-    )
+    if len(files) == 0:
+        raise click.UsageError("At least one file must be passed.")
 
     if verbose:
         log.sh.setLevel("DEBUG")
diff --git a/src/too/carton.py b/src/too/carton.py
index c42cc68..e5dd829 100644
--- a/src/too/carton.py
+++ b/src/too/carton.py
@@ -8,6 +8,8 @@
 
 from __future__ import annotations
 
+import warnings
+
 from too import log
 
 
@@ -20,6 +22,12 @@
 def run_too_carton():
     """Runs the ToO carton."""
 
+    from target_selection import log as ts_log
+    from target_selection.exceptions import TargetSelectionImportWarning
+
+    ts_log.setLevel(10000)  # Disable target_selection logging
+    warnings.simplefilter("ignore", TargetSelectionImportWarning)
+
     from target_selection.cartons.too import ToO_Carton  # Slow import
 
     too_carton = ToO_Carton(TOO_TARGET_PLAN)
diff --git a/src/too/database.py b/src/too/database.py
index 73cf94f..9aa1229 100644
--- a/src/too/database.py
+++ b/src/too/database.py
@@ -11,11 +11,9 @@
 import os
 import pathlib
 
-import polars
+from typing import TYPE_CHECKING
 
-from sdssdb.connection import PeeweeDatabaseConnection
-from sdssdb.peewee.sdss5db import catalogdb
-from sdsstools.time import get_sjd
+import polars
 
 from too import log
 from too.datamodel import too_dtypes, too_metadata_columns
@@ -23,6 +21,10 @@
 from too.validate import validate_too_targets
 
 
+if TYPE_CHECKING:
+    from sdssdb.connection import PeeweeDatabaseConnection
+
+
 __all__ = [
     "connect_to_database",
     "get_database_uri",
@@ -43,6 +45,8 @@ def connect_to_database(
 ):
     """Connects the ``sdssdb`` ``sdss5db`` models to the database."""
 
+    from sdssdb.peewee.sdss5db import catalogdb
+
     if port is None:
         port = int(os.environ.get("PGPORT", 5432))
 
@@ -204,6 +208,8 @@ def get_active_targets(database: PeeweeDatabaseConnection):
 
     """
 
+    from sdsstools.time import get_sjd
+
     assert database.connected, "Database is not connected."
 
     database_uri = database_uri_from_connection(database)
diff --git a/src/too/dump.py b/src/too/dump.py
index 4e31bc3..6d13776 100644
--- a/src/too/dump.py
+++ b/src/too/dump.py
@@ -5,18 +5,21 @@
 import os
 import pathlib
 
+from typing import TYPE_CHECKING
+
 import numpy
 import polars
 from peewee import JOIN, fn
 
-from sdssdb.connection import PeeweeDatabaseConnection
-from sdssdb.peewee.sdss5db import catalogdb, opsdb
-
 from too import log
 from too.tools import match_fields
 from too.validate import add_bright_limits_columns
 
 
+if TYPE_CHECKING:
+    from sdssdb.connection import PeeweeDatabaseConnection
+
+
 __all__ = ["dump_to_parquet"]
 
 
@@ -39,6 +42,8 @@ def dump_to_parquet(
 
     """
 
+    from sdssdb.peewee.sdss5db import catalogdb, opsdb
+
     path = pathlib.Path(path)
 
     observatory = observatory.upper()
diff --git a/src/too/tools.py b/src/too/tools.py
index 281db87..d8da8dd 100644
--- a/src/too/tools.py
+++ b/src/too/tools.py
@@ -18,9 +18,6 @@
 import httpx
 import polars
 import rich.progress
-from astropy.coordinates import SkyCoord, match_coordinates_sky
-
-from coordio.defaults import APO_MAX_FIELD_R, LCO_MAX_FIELD_R
 
 from too.datamodel import too_dtypes
 
@@ -121,6 +118,10 @@ def match_fields(
 
     """
 
+    from astropy.coordinates import SkyCoord, match_coordinates_sky
+
+    from coordio.defaults import APO_MAX_FIELD_R, LCO_MAX_FIELD_R
+
     targets = targets.clone()
 
     if rs_version is None:
diff --git a/src/too/validate.py b/src/too/validate.py
index 373f5dc..b50ea2d 100644
--- a/src/too/validate.py
+++ b/src/too/validate.py
@@ -19,13 +19,8 @@
 import polars
 from astropy.coordinates import SkyCoord
 from astropy.time import Time
-from astropy_healpix import HEALPix
 from erfa import ErfaWarning
 
-from coordio.utils import Moffat2dInterp, _offset_radec, object_offset
-from sdssdb.connection import PeeweeDatabaseConnection
-from sdssdb.peewee.sdss5db.targetdb import DesignMode as DesignModeDB
-
 from too import log
 from too.datamodel import mag_columns, too_dtypes
 from too.exceptions import ValidationError
@@ -42,9 +37,6 @@
 # load enviornment variable with path to healpix maps
 BN_HEALPIX = os.getenv("BN_HEALPIX")
 
-# add function for offseting
-fmagloss = Moffat2dInterp()
-
 
 def check_assign_mag_limit(
     mag_metric_min,
@@ -126,6 +118,8 @@ def allDesignModes(database: PeeweeDatabaseConnection):
 
     """
 
+    from sdssdb.peewee.sdss5db.targetdb import DesignMode as DesignModeDB
+
     desmodes = DesignModeDB.select()
     dmd = collections.OrderedDict()
     for desmode in desmodes:
@@ -187,6 +181,8 @@ class DesignMode:
 
     def __init__(self, database: PeeweeDatabaseConnection, label: str | None = None):
 
+        from sdssdb.peewee.sdss5db.targetdb import DesignMode as DesignModeDB
+
         DesignModeDB._meta.database(database)  # type:ignore
 
         if label is not None:
@@ -204,6 +200,8 @@ def fromdb(self, label: str):
 
         """
 
+        from sdssdb.peewee.sdss5db.targetdb import DesignMode as DesignModeDB
+
         self.desmode_label = label
 
         desmode = DesignModeDB.select().where(DesignModeDB.label == label)[0]
@@ -342,8 +340,14 @@ def calculate_offsets(
 
     offset_flag: np.array
         flags associated with the offseting
+
     """
 
+    from coordio.utils import Moffat2dInterp, object_offset
+
+    # add function for offseting
+    fmagloss = Moffat2dInterp()
+
     delta_ra = np.zeros(len(targets), dtype=float)
     delta_dec = np.zeros(len(targets), dtype=float)
     offset_flag = np.zeros(len(targets), dtype=int)
@@ -428,6 +432,10 @@ def bn_validation(
 
     """
 
+    from astropy_healpix import HEALPix
+
+    from coordio.utils import _offset_radec
+
     log.debug(
         f"Running bright neighbour validation for observatory {observatory} "
         f"and design mode {design_mode}"
diff --git a/src/too/xmatch.py b/src/too/xmatch.py
index 9303cb6..1f98326 100644
--- a/src/too/xmatch.py
+++ b/src/too/xmatch.py
@@ -8,17 +8,19 @@
 
 from __future__ import annotations
 
+from typing import TYPE_CHECKING
+
 import peewee
 import polars
 
-from sdssdb.connection import PeeweeDatabaseConnection
-from sdssdb.peewee.sdss5db.catalogdb import ToO_Target, Version
-from target_selection.xmatch import XMatchPlanner
-
 from too import log
 from too.database import get_database_uri
 
 
+if TYPE_CHECKING:
+    from sdssdb.connection import PeeweeDatabaseConnection
+
+
 __all__ = ["xmatch_too_targets"]
 
 
@@ -122,6 +124,12 @@ def xmatch_too_targets(
 
     """
 
+    from sdssdb.peewee.sdss5db.catalogdb import ToO_Target, Version
+    from target_selection import log as ts_log
+    from target_selection.xmatch import XMatchPlanner
+
+    ts_log.setLevel(10000)  # Disable target_selection logging
+
     assert database.connected, "Database is not connected"
 
     too_target_schema: str = ToO_Target._meta.schema  # type:ignore