diff --git a/crypto_seller/__init__.py b/crypto_seller/__init__.py
index 1a21e76..0114779 100644
--- a/crypto_seller/__init__.py
+++ b/crypto_seller/__init__.py
@@ -76,7 +76,7 @@ import random
 import time
 from decimal import Decimal
 from pathlib import Path
-from typing import Any
+from typing import Any,Callable
 
 import fin_defs
 import fin_depo
@@ -96,27 +96,28 @@ PATH_TRADES_FILE = PATH_OUTPUT / 'trades.csv'
 # Main code #
 
 
-@dataclasses.dataclass
+@dataclasses.dataclass(frozen = True)
 class AutoSellConfig:
     interval_range: tuple[datetime.timedelta, datetime.timedelta]
     input_asset: fin_defs.Asset
     input_amount_range: tuple[Decimal, Decimal]
     output_asset: fin_defs.Asset
+    seller: fin_depo.defi_kucoin.KucoinDepoFetcher
+    sleep: Callable[[float],None]
     exit_when_empty: bool = True
 
-
 def sample_from_range(rng: random.Random, range: tuple[Any, Any]) -> Any:
     multiplier = rng.random()
     if isinstance(range[0], Decimal):
         multiplier = Decimal(multiplier)
     return range[0] + (range[1] - range[0]) * multiplier
 
-def run_auto_sell(seller: fin_depo.defi_kucoin.KucoinDepoFetcher, config: AutoSellConfig):
+def run_auto_sell(config: AutoSellConfig):
     rng = random.SystemRandom()
 
     while True:
         # Check that account has tokens.
-        input_amount_available = seller.get_depo().get_amount_of_asset(config.input_asset)
+        input_amount_available = config.seller.get_depo().get_amount_of_asset(config.input_asset)
         logger.info('Currently own %s %s', input_amount_available, config.input_asset)
 
         if input_amount_available > 0:
@@ -124,7 +125,7 @@ def run_auto_sell(seller: fin_depo.defi_kucoin.KucoinDepoFetcher, config: AutoSe
             amount_to_sell = min(input_amount_available, amount_to_sell)
             logger.info('Attempting to sell %s %s', amount_to_sell, config.input_asset)
 
-            order_details =  seller.place_market_order(
+            order_details =  config.seller.place_market_order(
                 config.input_asset, amount_to_sell, config.output_asset)
 
             print(order_details)
@@ -138,6 +139,6 @@ def run_auto_sell(seller: fin_depo.defi_kucoin.KucoinDepoFetcher, config: AutoSe
         time_to_sleep = sample_from_range(rng, config.interval_range)
         time_to_sleep_secs = time_to_sleep.total_seconds()
         logger.info('Sleeping %s (%d seconds)', time_to_sleep, time_to_sleep_secs)
-        time.sleep(time_to_sleep_secs)
+        config.sleep(time_to_sleep_secs)
 
         del input_amount_available
diff --git a/crypto_seller/__main__.py b/crypto_seller/__main__.py
index 0f119bc..98c525c 100644
--- a/crypto_seller/__main__.py
+++ b/crypto_seller/__main__.py
@@ -2,6 +2,7 @@ import datetime
 import logging
 import logging.handlers
 from decimal import Decimal
+import time
 
 import fin_defs
 
@@ -41,8 +42,10 @@ def main():
         input_asset=fin_defs.MPC,
         output_asset=fin_defs.USDT,
         exit_when_empty=True,
+        seller = seller_backend,
+        sleep = time.sleep
     )
-    run_auto_sell(seller_backend, auto_sell_config)
+    run_auto_sell(auto_sell_config)
 
 
 if __name__ == '__main__':
diff --git a/test/test_auto_sell.py b/test/test_auto_sell.py
index 5271cc3..d87f4a7 100644
--- a/test/test_auto_sell.py
+++ b/test/test_auto_sell.py
@@ -32,17 +32,31 @@ class SellerMock(fin_depo.data.DepoFetcher):
         )
 
 
+class SleepMock:
+
+    def __init__(self):
+        self.time_slept = 0.0
+
+    def __call__(self, amount: float):
+        self.time_slept = self.time_slept + amount
+
 def test_auto_run():
+
+    sleep_mock = SleepMock()
+    seller_mock = SellerMock(fin_defs.USDT, Decimal('1000'))
+
     config = crypto_seller.AutoSellConfig(
         input_amount_range=(Decimal('1'), Decimal('1')),
-        interval_range=(datetime.timedelta(seconds=0), datetime.timedelta(seconds=0)),
+        interval_range=(datetime.timedelta(seconds=1), datetime.timedelta(seconds=1)),
         input_asset=fin_defs.USDT,
         output_asset=fin_defs.USD,
         exit_when_empty=True,
+        seller = seller_mock,
+        sleep = sleep_mock ,
     )
-    seller = SellerMock(fin_defs.USDT, Decimal('1000'))
 
-    crypto_seller.run_auto_sell(seller, config)
+    crypto_seller.run_auto_sell(config)
 
-    assert seller.amount_left == 0
+    assert seller_mock.amount_left == 0
+    assert sleep_mock.time_slept == 1000