diff --git a/chainqueue/db/migrations/default/versions/2215c497248b_transaction_cache.py b/chainqueue/db/migrations/default/versions/2215c497248b_transaction_cache.py
index 130239f..720f500 100644
--- a/chainqueue/db/migrations/default/versions/2215c497248b_transaction_cache.py
+++ b/chainqueue/db/migrations/default/versions/2215c497248b_transaction_cache.py
@@ -23,6 +23,7 @@ def upgrade():
             sa.Column('otx_id', sa.Integer, sa.ForeignKey('otx.id'), nullable=True),
             sa.Column('date_created', sa.DateTime, nullable=False),
             sa.Column('date_updated', sa.DateTime, nullable=False),
+            sa.Column('date_checked', sa.DateTime, nullable=False),
             sa.Column('source_token_address', sa.String(42), nullable=False),
             sa.Column('destination_token_address', sa.String(42), nullable=False),
             sa.Column('sender', sa.String(42), nullable=False),
diff --git a/chainqueue/db/models/otx.py b/chainqueue/db/models/otx.py
index 8a14b3e..6ab2aaf 100644
--- a/chainqueue/db/models/otx.py
+++ b/chainqueue/db/models/otx.py
@@ -562,10 +562,3 @@ class Otx(SessionBase):
         self.tx_hash = strip_0x(tx_hash)
         self.signed_tx = strip_0x(signed_tx)
         self.status = StatusEnum.PENDING
-        #signed_tx_bytes = bytes.fromhex(strip_0x(signed_tx))
-        #signed_tx_bytes = bytes.fromhex(strip_0x(tx_hash))
-
-       # sender_address = address_hex_from_signed_tx(signed_tx_bytes)
-       # logg.debug('decoded tx {}'.format(sender_address))
-
- 
diff --git a/chainqueue/db/models/tx.py b/chainqueue/db/models/tx.py
index c71e2e9..9f7d684 100644
--- a/chainqueue/db/models/tx.py
+++ b/chainqueue/db/models/tx.py
@@ -1,18 +1,18 @@
 # standard imports
 import datetime
 
-# third-party imports
+# external imports
 from sqlalchemy import Column, String, Integer, DateTime, Enum, ForeignKey, Boolean, NUMERIC
 from sqlalchemy.ext.hybrid import hybrid_method, hybrid_property
-#from sqlalchemy.orm import relationship, backref
-#from sqlalchemy.ext.declarative import declarative_base
+from hexathon import (
+        strip_0x,
+        )
 
 # local imports
 from .base import SessionBase
 from .otx import Otx
-from cic_eth.db.util import num_serialize
-from cic_eth.error import NotLocalTxError
-from cic_eth.db.error import TxStateChangeError
+from chainqueue.error import NotLocalTxError
+from chainqueue.db.error import TxStateChangeError
 
 
 class TxCache(SessionBase):
@@ -127,7 +127,7 @@ class TxCache(SessionBase):
     def __init__(self, tx_hash, sender, recipient, source_token_address, destination_token_address, from_value, to_value, block_number=None, tx_index=None, session=None):
         session = SessionBase.bind_session(session)
         q = session.query(Otx)
-        q = q.filter(Otx.tx_hash==tx_hash)
+        q = q.filter(Otx.tx_hash==strip_0x(tx_hash))
         tx = q.first()
         if tx == None:
             SessionBase.release_session(session)
diff --git a/chainqueue/error.py b/chainqueue/error.py
new file mode 100644
index 0000000..0ea0f02
--- /dev/null
+++ b/chainqueue/error.py
@@ -0,0 +1,4 @@
+class NotLocalTxError(Exception):
+    """Exception raised when trying to access a tx not originated from a local task
+    """
+    pass
diff --git a/tests/test_basic.py b/tests/test_basic.py
index 4c2df1f..9aca07f 100644
--- a/tests/test_basic.py
+++ b/tests/test_basic.py
@@ -11,6 +11,7 @@ from hexathon import (
 
 # local imports
 from chainqueue.db.models.otx import Otx
+from chainqueue.db.models.tx import TxCache
 
 # test imports
 from tests.base import TestBase
@@ -33,5 +34,36 @@ class TestBasic(TestBase):
         self.session.add(otx)
 
 
+    def test_tx(self):
+        tx_hash = add_0x(os.urandom(32).hex())
+        tx = add_0x(os.urandom(128).hex())
+        nonce = 42
+        otx = Otx(nonce, tx_hash, tx)
+        self.session.add(otx)
+
+        alice = add_0x(os.urandom(20).hex())
+        bob = add_0x(os.urandom(20).hex())
+        foo_token = add_0x(os.urandom(20).hex())
+        bar_token = add_0x(os.urandom(20).hex())
+        from_value = 13
+        to_value = 666
+
+        block_number = 1024
+        tx_index = 1337
+
+        txc = TxCache(
+            tx_hash,
+            alice,
+            bob,
+            foo_token,
+            bar_token,
+            from_value,
+            to_value,
+            block_number=block_number,
+            tx_index=tx_index,
+            session=self.session,
+                )
+        self.session.add(txc)
+
 if __name__ == '__main__':
     unittest.main()