diff --git a/.github/workflows/pull_request.yaml b/.github/workflows/pull_request.yaml
index 6e9cfea..4e916a0 100644
--- a/.github/workflows/pull_request.yaml
+++ b/.github/workflows/pull_request.yaml
@@ -25,3 +25,10 @@ jobs:
           black --check ./
       - name: Type Check (mypy)
         run: mypy src
+      - name: Run Pytest
+        env:
+          MORALIS_API_KEY: ${{ secrets.MORALIS_API_KEY }}
+          CHAIN_SLEEP_TIME: ${{ secrets.CHAIN_SLEEP_TIME }}
+          NODE_URL: ${{ secrets.NODE_URL }}
+          CHAIN_NAME: ${{ secrets.CHAIN_NAME }}
+        run: pytest
\ No newline at end of file
diff --git a/src/price_providers/coingecko_pricing.py b/src/price_providers/coingecko_pricing.py
index f296180..efbbbfc 100644
--- a/src/price_providers/coingecko_pricing.py
+++ b/src/price_providers/coingecko_pricing.py
@@ -14,8 +14,6 @@
     COINGECKO_BUFFER_TIME,
 )
 
-coingecko_api_key = os.getenv("COINGECKO_API_KEY")
-
 
 class CoingeckoPriceProvider(AbstractPriceProvider):
     """
@@ -24,18 +22,26 @@ class CoingeckoPriceProvider(AbstractPriceProvider):
 
     def __init__(self) -> None:
         self.web3 = get_web3_instance()
-        self.filtered_token_list = self.fetch_coingecko_list()
-        self.last_reload_time = time.time()  # current time in seconds since epoch
+        self.last_reload_time = time.time()
+        self.coingecko_api_key = os.getenv("COINGECKO_API_KEY")
+        try:
+            self.filtered_token_list = self.fetch_coingecko_list()
+            self.last_reload_time = time.time()  # current time in seconds since epoch
+        except Exception as e:
+            logger.warning(f"Failed to fetch initial token list: {e}")
 
     @property
     def name(self) -> str:
         return "Coingecko"
 
-    def fetch_coingecko_list(self) -> list[dict]:
+    def fetch_coingecko_list(self) -> list[dict] | None:
         """
         Fetch and filter the list of tokens (currently filters only Ethereum)
         from the Coingecko API.
         """
+        if not self.coingecko_api_key:
+            return None
+
         url = (
             f"https://pro-api.coingecko.com/api/v3/coins/"
             f"list?include_platform=true&status=active"
@@ -43,9 +49,8 @@ def fetch_coingecko_list(self) -> list[dict]:
         headers = {
             "accept": "application/json",
         }
-        if coingecko_api_key:
-            headers["x-cg-pro-api-key"] = coingecko_api_key
 
+        headers["x-cg-pro-api-key"] = self.coingecko_api_key
         response = requests.get(url, headers=headers)
         tokens_list = json.loads(response.text)
         return [
@@ -71,6 +76,9 @@ def get_token_id_by_address(self, token_address: str) -> str | None:
             self.last_reload_time = (
                 time.time()
             )  # update the last reload time to current time
+        if not self.filtered_token_list:
+            return None
+
         for token in self.filtered_token_list:
             if token["platforms"].get("ethereum") == token_address:
                 return token["id"]
@@ -82,7 +90,7 @@ def fetch_api_price(
         """
         Makes call to Coingecko API to fetch price, between a start and end timestamp.
         """
-        if not coingecko_api_key:
+        if not self.coingecko_api_key:
             logger.warning("Coingecko API key is not set.")
             return None
         # price of token is returned in ETH
@@ -92,7 +100,7 @@ def fetch_api_price(
         )
         headers = {
             "accept": "application/json",
-            "x-cg-pro-api-key": coingecko_api_key,
+            "x-cg-pro-api-key": self.coingecko_api_key,
         }
         try:
             response = requests.get(url, headers=headers)
@@ -122,6 +130,12 @@ def get_price(self, price_params: dict) -> float | None:
         Function returns coingecko price for a token address,
         closest to and at least as large as the block timestamp for a given tx hash.
         """
+        if not self.filtered_token_list:
+            logger.warning(
+                "Token list is empty, possibly the Coingecko API key isn't set."
+            )
+            return None
+
         token_address, block_number = extract_params(price_params, is_block=True)
         block_start_timestamp = self.web3.eth.get_block(block_number)["timestamp"]
         if self.price_not_retrievable(block_start_timestamp):
diff --git a/src/price_providers/moralis_pricing.py b/src/price_providers/moralis_pricing.py
index 9cdd968..6cecec5 100644
--- a/src/price_providers/moralis_pricing.py
+++ b/src/price_providers/moralis_pricing.py
@@ -53,6 +53,6 @@ def get_price(self, price_params: dict) -> float | None:
             self.logger.warning(f"Error: {e}")
         except Exception as e:
             self.logger.warning(
-                f"Price retrieval for token: {token_address} returned: {e}"
+                f"Price retrieval for token: {token_address} returned: {e}. Possibly the Moralis API key is missing."
             )
         return None
diff --git a/tests/test_fees.py b/tests/test_fees.py
new file mode 100644
index 0000000..a5d4ce1
--- /dev/null
+++ b/tests/test_fees.py
@@ -0,0 +1,28 @@
+import pytest
+from hexbytes import HexBytes
+from src.fees.compute_fees import batch_fee_imbalances
+
+
+def test_batch_fee_imbalances():
+    """
+    Test the batch_fee_imbalances function with a valid transaction hash.
+    """
+    tx_hash = "0x714bb3b1a804af7a493bcfa991b9859e03c52387b027783f175255885fa97dbd"
+    protocol_fees, network_fees = batch_fee_imbalances(HexBytes(tx_hash))
+
+    # verify that the returned fees are dicts
+    assert isinstance(protocol_fees, dict), "Protocol fees should be a dict."
+    assert isinstance(network_fees, dict), "Network fees should be a dict."
+
+    # Check that keys and values in the dict have the correct types
+    for token, fee in protocol_fees.items():
+        assert isinstance(token, str), "Token address should be string."
+        assert isinstance(fee, int), "Fee amount should be int."
+
+    for token, fee in network_fees.items():
+        assert isinstance(token, str), "Token address should be string."
+        assert isinstance(fee, int), "Fee amount should be int."
+
+
+if __name__ == "__main__":
+    pytest.main()
diff --git a/tests/basic_test.py b/tests/test_imbalances.py
similarity index 94%
rename from tests/basic_test.py
rename to tests/test_imbalances.py
index b01ca9e..f5cd49d 100644
--- a/tests/basic_test.py
+++ b/tests/test_imbalances.py
@@ -53,7 +53,7 @@ def test_imbalances(tx_hash, expected_imbalances):
     Asserts imbalances match for main script with test values provided.
     """
     chain_name = os.getenv("CHAIN_NAME")
-    rt = RawTokenImbalances(get_web3_instance(), chain_name)
-    imbalances = rt.compute_imbalances(tx_hash)
+    compute = RawTokenImbalances(get_web3_instance(), chain_name)
+    imbalances = compute.compute_imbalances(tx_hash)
     for token_address, expected_imbalance in expected_imbalances.items():
         assert imbalances.get(token_address) == expected_imbalance
diff --git a/tests/test_pricefeed.py b/tests/test_pricefeed.py
new file mode 100644
index 0000000..76c198b
--- /dev/null
+++ b/tests/test_pricefeed.py
@@ -0,0 +1,65 @@
+import pytest
+from src.price_providers.price_feed import PriceFeed
+
+
+@pytest.fixture
+def price_feed():
+    return PriceFeed()
+
+
+def test_get_price_real(price_feed):
+    """Test with legitimate parameters."""
+
+    # Test parameters
+    tx_hash = "0x94af3d98b0af4ca6bf41e85c05ed42fccd71d5aaa04cbe01fab00d1b2268c4e1"
+    token_address = "0xd1d2Eb1B1e90B638588728b4130137D262C87cae"
+    block_number = 20630508
+    price_params = {
+        "tx_hash": tx_hash,
+        "token_address": token_address,
+        "block_number": block_number,
+    }
+
+    # Get the price
+    result = price_feed.get_price(price_params)
+    assert result is not None
+
+    price, source = result
+    # Assert that the price is a positive float
+    assert isinstance(price, float)
+    assert price > 0
+    assert source in ["Coingecko", "Dune", "Moralis", "AuctionPrices"]
+
+
+def test_get_price_unknown_token(price_feed):
+    """Test with an unknown token address."""
+
+    tx_hash = "0x94af3d98b0af4ca6bf41e85c05ed42fccd71d5aaa04cbe01fab00d1b2268c4e1"
+    unknown_token = "0xd1d2Eb1B1e90B638588728b4130137D262C87cad"
+    price_params = {
+        "tx_hash": tx_hash,
+        "token_address": unknown_token,
+        "block_number": 20630508,
+    }
+    result = price_feed.get_price(price_params)
+
+    #  expect None for an unknown token
+    assert result is None
+
+
+def test_get_price_future_block(price_feed):
+    """Test with a block number in the future."""
+    future_block = 99999999
+    price_params = {
+        "token_address": "0x6B175474E89094C44Da98b954EedeAC495271d0F",
+        "block_number": future_block,
+    }
+
+    result = price_feed.get_price(price_params)
+
+    # expect None for a future block
+    assert result is None
+
+
+if __name__ == "__main__":
+    pytest.main()