diff --git a/examples/ram/ram.py b/examples/ram/ram.py
index f532b31..15765f9 100644
--- a/examples/ram/ram.py
+++ b/examples/ram/ram.py
@@ -53,7 +53,6 @@ def get_completions(self, document, complete_event):
                     yield Completion(argument, start_position=-len(word_before_cursor))
 
 
-
 load_dotenv()
 
 rpc_user = os.getenv("RPC_USER", "rpcuser")
@@ -64,10 +63,10 @@ def get_completions(self, document, complete_event):
 
 def parse_outputs(output_strings: List[str]) -> List[Tuple[str, int]]:
     """Parses a list of strings in the form "address:amount" into a list of (address, amount) tuples.
-    
+
     Args:
     - output_strings (list of str): List of strings in the form "address:amount".
-    
+
     Returns:
     - list of (str, int): List of (address, amount) tuples.
     """
@@ -148,12 +147,12 @@ def execute_command(input_line: str):
         if leaf_index not in range(len(R_inst.data_expanded)):
             raise ValueError("Invalid leaf index")
 
-        outputs=[]
+        outputs = []
         for address, amount in outputs_amounts:
             outputs.append(CTxOut(
-                    nValue=amount,
-                    scriptPubKey=addr_to_script(address)
-                )
+                nValue=amount,
+                scriptPubKey=addr_to_script(address)
+            )
             )
 
         R_inst("withdraw",
@@ -176,10 +175,10 @@ def execute_command(input_line: str):
             raise ValueError("Invalid leaf index")
 
         result = R_inst("write",
-               merkle_root=mt.root,
-               new_value=new_value,
-               merkle_proof=mt.prove_leaf(leaf_index)
-        )
+                        merkle_root=mt.root,
+                        new_value=new_value,
+                        merkle_proof=mt.prove_leaf(leaf_index)
+                        )
 
         assert len(result) == 1
 
@@ -251,7 +250,6 @@ def script_main(script_filename: str):
     # map from known ctv hashes to the corresponding template (used for withdrawals)
     ctv_templates: Dict[bytes, CTransaction] = {}
 
-
     if args.script:
         script_main(args.script)
     else:
diff --git a/examples/ram/ram_contracts.py b/examples/ram/ram_contracts.py
index c100bea..9120a8b 100644
--- a/examples/ram/ram_contracts.py
+++ b/examples/ram/ram_contracts.py
@@ -40,8 +40,8 @@ def __init__(self, size: List[bytes]):
                     # TODO: should we check that it's either exactly 0 or exactly 1?
 
                     OP_NOTIF,
-                        # left child; swap, as we want x || h_i
-                        OP_SWAP,
+                    # left child; swap, as we want x || h_i
+                    OP_SWAP,
                     OP_ENDIF,
 
                     OP_CAT,
@@ -140,10 +140,10 @@ def __init__(self, size: List[bytes]):
                 OP_SWAP,
                 OP_FROMALTSTACK,
                 OP_EQUALVERIFY,
-                
+
                 # stack: <new_root>
-                
-                # Check that new_root is committed in the next output, 
+
+                # Check that new_root is committed in the next output,
                 0,   # index
                 0,   # NUMS
                 -1,  # keep current taptree
@@ -154,7 +154,8 @@ def __init__(self, size: List[bytes]):
             ]),
             arg_specs=[
                 ("merkle_proof", MerkleProofType(n)),
-                ('new_value', BytesType()),  # the new value of the element (its index is specified by the directions in the merkle proof)
+                # the new value of the element (its index is specified by the directions in the merkle proof)
+                ('new_value', BytesType()),
                 ('merkle_root', BytesType()),
             ],
             next_output_fn=lambda args: [
diff --git a/examples/rps/rps.py b/examples/rps/rps.py
index baab9c0..9ca40a4 100644
--- a/examples/rps/rps.py
+++ b/examples/rps/rps.py
@@ -69,7 +69,8 @@ def __init__(self, env: Environment, args: dict):
         self.env = env
         self.args = args
 
-        self.priv_key = key.ExtendedKey.deserialize("tprv8ZgxMBicQKsPdpwA4vW8DcSdXzPn7GkS2RdziGXUX8k86bgDQLKhyXtB3HMbJhPFd2vKRpChWxgPe787WWVqEtjy8hGbZHqZKeRrEwMm3SN")
+        self.priv_key = key.ExtendedKey.deserialize(
+            "tprv8ZgxMBicQKsPdpwA4vW8DcSdXzPn7GkS2RdziGXUX8k86bgDQLKhyXtB3HMbJhPFd2vKRpChWxgPe787WWVqEtjy8hGbZHqZKeRrEwMm3SN")
 
     def start_session(self, m_a: int):
         assert 0 <= m_a <= 2
@@ -127,8 +128,7 @@ def start_session(self, m_a: int):
         print(f"Game result: {outcome}")
 
         self.env.prompt("Broadcasting adjudication transaction")
-        C2(outcome, m_a=m_a, m_b=m_b,r_a=r_a)
-
+        C2(outcome, m_a=m_a, m_b=m_b, r_a=r_a)
 
         s.close()
 
@@ -138,7 +138,8 @@ def __init__(self, env: Environment, args: dict):
         self.env = env
         self.args = args
 
-        self.priv_key = key.ExtendedKey.deserialize("tprv8ZgxMBicQKsPeDvaW4xxmiMXxqakLgvukT8A5GR6mRwBwjsDJV1jcZab8mxSerNcj22YPrusm2Pz5oR8LTw9GqpWT51VexTNBzxxm49jCZZ")
+        self.priv_key = key.ExtendedKey.deserialize(
+            "tprv8ZgxMBicQKsPeDvaW4xxmiMXxqakLgvukT8A5GR6mRwBwjsDJV1jcZab8mxSerNcj22YPrusm2Pz5oR8LTw9GqpWT51VexTNBzxxm49jCZZ")
 
     def join_session(self, m_b: int):
         assert 0 <= m_b <= 2
diff --git a/examples/rps/rps_contracts.py b/examples/rps/rps_contracts.py
index 1fbd853..6ae5d46 100644
--- a/examples/rps/rps_contracts.py
+++ b/examples/rps/rps_contracts.py
@@ -140,8 +140,8 @@ def make_script(diff: int, ctv_hash: bytes):
                 OP_DUP,           # if the result is negative, add 3
                 0, OP_LESSTHAN,
                 OP_IF,
-                    3,
-                    OP_ADD,
+                3,
+                OP_ADD,
                 OP_ENDIF,
 
                 diff,          # draw / Bob wins / Alice wins, respectively
@@ -166,8 +166,11 @@ def make_script(diff: int, ctv_hash: bytes):
             ('m_a', IntType()),
             ('r_a', BytesType()),
         ]
-        alice_wins = StandardClause("tie", make_script(0, tmpl_alice_wins.get_standard_template_hash(0)), arg_specs, lambda _: tmpl_alice_wins)
-        bob_wins = StandardClause("bob_wins", make_script(1, tmpl_bob_wins.get_standard_template_hash(0)), arg_specs, lambda _: tmpl_bob_wins)
-        tie = StandardClause("alice_wins", make_script(2, tmpl_tie.get_standard_template_hash(0)), arg_specs, lambda _: tmpl_tie)
+        alice_wins = StandardClause("tie", make_script(
+            0, tmpl_alice_wins.get_standard_template_hash(0)), arg_specs, lambda _: tmpl_alice_wins)
+        bob_wins = StandardClause("bob_wins", make_script(
+            1, tmpl_bob_wins.get_standard_template_hash(0)), arg_specs, lambda _: tmpl_bob_wins)
+        tie = StandardClause("alice_wins", make_script(
+            2, tmpl_tie.get_standard_template_hash(0)), arg_specs, lambda _: tmpl_tie)
 
         super().__init__(NUMS_KEY, [alice_wins, [bob_wins, tie]])
diff --git a/examples/vault/vault.py b/examples/vault/vault.py
index e10a120..3414206 100644
--- a/examples/vault/vault.py
+++ b/examples/vault/vault.py
@@ -39,7 +39,7 @@ class ActionArgumentCompleter(Completer):
         "printall": [],
         "recover": ["item="],
         "trigger": ["items=\"[", "outputs=\"["],
-        "withdraw": ["item="], # TODO: allow multiple items?
+        "withdraw": ["item="],  # TODO: allow multiple items?
     }
 
     def get_completions(self, document, complete_event):
@@ -81,10 +81,10 @@ def segwit_addr_to_scriptpubkey(addr: str) -> bytes:
 
 def parse_outputs(output_strings: List[str]) -> List[Tuple[str, int]]:
     """Parses a list of strings in the form "address:amount" into a list of (address, amount) tuples.
-    
+
     Args:
     - output_strings (list of str): List of strings in the form "address:amount".
-    
+
     Returns:
     - list of (str, int): List of (address, amount) tuples.
     """
@@ -177,7 +177,7 @@ def execute_command(input_line: str):
         ctv_tmpl = CTransaction()
         ctv_tmpl.nVersion = 2
         ctv_tmpl.vin = [CTxIn(nSequence=10)]
-        
+
         outputs = parse_outputs(json.loads(args_dict["outputs"]))
         outputs_total_amount = sum(out[1] for out in outputs)
 
@@ -191,9 +191,9 @@ def execute_command(input_line: str):
         ctv_tmpl.vout = []
         for address, amount in outputs:
             ctv_tmpl.vout.append(CTxOut(
-                    nValue=amount,
-                    scriptPubKey=segwit_addr_to_scriptpubkey(address)
-                )
+                nValue=amount,
+                scriptPubKey=segwit_addr_to_scriptpubkey(address)
+            )
             )
 
         # we assume the output is spent as first input later in the withdrawal transaction
@@ -209,7 +209,8 @@ def execute_command(input_line: str):
                 # at this time, we don't support partially revaulting from multiple UTXOs
                 # (which might perhaps be useful for UTXO management in a real vault)
                 if revault_amount > v.get_value():
-                    raise ValueError(f"Input's amount {v.get_value()} is not enough for the revault amount {revault_amount}")
+                    raise ValueError(
+                        f"Input's amount {v.get_value()} is not enough for the revault amount {revault_amount}")
                 spends.append(
                     (v, "trigger_and_revault", {"out_i": 0, "revault_out_i": 1, "ctv_hash": ctv_hash})
                 )
@@ -231,7 +232,6 @@ def execute_command(input_line: str):
                 {**args, "sig": sigs[i]}
             ))
 
-
         print("Waiting for trigger transaction to be confirmed...")
         result = manager.spend_and_wait(spending_vaults, spend_tx)
 
@@ -343,7 +343,6 @@ def script_main(script_filename: str):
     # map from known ctv hashes to the corresponding template (used for withdrawals)
     ctv_templates: Dict[bytes, CTransaction] = {}
 
-
     if args.script:
         script_main(args.script)
     else:
diff --git a/examples/vault/vault_contracts.py b/examples/vault/vault_contracts.py
index 88478a0..8a6afec 100644
--- a/examples/vault/vault_contracts.py
+++ b/examples/vault/vault_contracts.py
@@ -34,7 +34,8 @@ def __init__(self, alternate_pk: Optional[bytes], spend_delay: int, recover_pk:
                 ('ctv_hash', BytesType()),
                 ('out_i', IntType()),
             ],
-            next_output_fn=lambda args: [ClauseOutput(n=args['out_i'], next_contract=unvaulting, next_data=args['ctv_hash'])]
+            next_output_fn=lambda args: [ClauseOutput(
+                n=args['out_i'], next_contract=unvaulting, next_data=args['ctv_hash'])]
         )
 
         # witness: <sig> <ctv-hash> <trigger_out_i> <revault_out_i>
@@ -43,7 +44,7 @@ def __init__(self, alternate_pk: Optional[bytes], spend_delay: int, recover_pk:
             script=CScript([
                 0, OP_SWAP   # no data tweak
                 # <revault_out_i> from the witness
-                -1,  # current input's taptweak
+                - 1,  # current input's taptweak
                 -1,  # taptree
                 CCV_FLAG_DEDUCT_OUTPUT_AMOUNT,  # revault output
                 OP_CHECKCONTRACTVERIFY,
@@ -64,7 +65,8 @@ def __init__(self, alternate_pk: Optional[bytes], spend_delay: int, recover_pk:
                 ('revault_out_i', IntType()),
             ],
             next_output_fn=lambda args: [
-                ClauseOutput(n=args['revault_out_i'], next_contract=self,  next_amount=ClauseOutputAmountBehaviour.DEDUCT_OUTPUT),
+                ClauseOutput(n=args['revault_out_i'], next_contract=self,
+                             next_amount=ClauseOutputAmountBehaviour.DEDUCT_OUTPUT),
                 ClauseOutput(n=args['out_i'], next_contract=unvaulting, next_data=args['ctv_hash']),
             ]
         )
diff --git a/matt/argtypes.py b/matt/argtypes.py
index 7e41022..f146766 100644
--- a/matt/argtypes.py
+++ b/matt/argtypes.py
@@ -71,6 +71,7 @@ class SignerType(BytesType):
     It is encoded as bytes, but labeling it allows the ContractManager to get the correct
     signatures by calling SchnorrSigner object instances.
     """
+
     def __init__(self, pubkey: bytes):
         if len(pubkey) != 32:
             raise ValueError("pubkey must be an x-only pubkey")
diff --git a/matt/contracts.py b/matt/contracts.py
index 16a0736..c16b8ec 100644
--- a/matt/contracts.py
+++ b/matt/contracts.py
@@ -61,8 +61,6 @@ def __init__(self, name: str, script: CScript, arg_specs: List[Tuple[str, ArgTyp
 
         self.next_outputs_fn = next_output_fn
 
-
-
     def next_outputs(self, args: dict) -> Union[List[ClauseOutput], CTransaction]:
         if self.next_outputs_fn is not None:
             return self.next_outputs_fn(args)
@@ -122,6 +120,7 @@ def get_address(self) -> str:
     def __repr__(self) -> str:
         return f"{self.__class__.__name__}(pubkey={self.pubkey.hex()})"
 
+
 Tapleaf = Tuple[str, Union[CScript, bytes]]
 TaptreeDescription = List['TaptreeDescription']
 
diff --git a/matt/manager.py b/matt/manager.py
index 7211f3e..56e90b2 100644
--- a/matt/manager.py
+++ b/matt/manager.py
@@ -39,7 +39,7 @@ def sign(self, msg: bytes, pubkey: bytes) -> Optional[bytes]:
         for k in self.keys:
             if k.pubkey[1:] == pubkey:
                 return sign_schnorr(k.privkey, msg)
-        
+
         return None
 
 
@@ -54,7 +54,7 @@ def __init__(self, contract: Union[StandardP2TR, StandardAugmentedP2TR]):
         self.contract = contract
         self.data = None if not self.is_augm() else b'\0'*32
 
-        self.data_expanded = None # TODO: figure out a good API for this
+        self.data_expanded = None  # TODO: figure out a good API for this
 
         self.manager: ContractManager = None
 
@@ -151,7 +151,8 @@ def wait_for_outpoint(self, instance: ContractInstance, txid: Optional[str] = No
         if self.mine_automatically:
             self._mine_blocks(1)
 
-        instance.outpoint, instance.last_height = wait_for_output(self.rpc, scriptPubKey, txid=txid, poll_interval=self.poll_interval)
+        instance.outpoint, instance.last_height = wait_for_output(
+            self.rpc, scriptPubKey, txid=txid, poll_interval=self.poll_interval)
 
         funding_tx_raw = self.rpc.getrawtransaction(instance.outpoint.hash.to_bytes(32, byteorder="big").hex())
         funding_tx = CTransaction()
@@ -161,10 +162,10 @@ def wait_for_outpoint(self, instance: ContractInstance, txid: Optional[str] = No
         instance.status = ContractInstanceStatus.FUNDED
 
     def get_spend_tx(
-            self,
-            spends: Union[Tuple[ContractInstance, str, dict], List[Tuple[ContractInstance, str, dict]]],
-            output_amounts: Dict[int, int] = {}
-        ) -> Tuple[CTransaction, List[bytes]]:
+        self,
+        spends: Union[Tuple[ContractInstance, str, dict], List[Tuple[ContractInstance, str, dict]]],
+        output_amounts: Dict[int, int] = {}
+    ) -> Tuple[CTransaction, List[bytes]]:
         if not isinstance(spends, list):
             spends = [spends]
 
@@ -217,9 +218,11 @@ def get_spend_tx(
                         preserve_output_used = True
                     elif clause_output.next_amount == ClauseOutputAmountBehaviour.DEDUCT_OUTPUT:
                         if preserve_output_used:
-                            raise ValueError("DEDUCT_OUTPUT clause outputs must be declared before PRESERVE_OUTPUT clause outputs")
+                            raise ValueError(
+                                "DEDUCT_OUTPUT clause outputs must be declared before PRESERVE_OUTPUT clause outputs")
                         if clause_output.n not in output_amounts:
-                            raise ValueError("The output amount must be specified for clause outputs using DEDUCT_AMOUNT")
+                            raise ValueError(
+                                "The output amount must be specified for clause outputs using DEDUCT_AMOUNT")
 
                         outputs_map[clause_output.n].nValue = output_amounts[clause_output.n]
                         ccv_amount -= output_amounts[clause_output.n]
@@ -301,7 +304,7 @@ def wait_for_spend(self, instances: Union[ContractInstance, List[ContractInstanc
                 self.rpc,
                 instance.outpoint,
                 starting_height=instance.last_height,
-                poll_interval = self.poll_interval
+                poll_interval=self.poll_interval
             )
             tx.rehash()
 
diff --git a/matt/merkle.py b/matt/merkle.py
index edcdf71..56cac80 100644
--- a/matt/merkle.py
+++ b/matt/merkle.py
@@ -157,7 +157,7 @@ def to_wit_stack(self):
     def from_wit_stack(wit_stack: List[bytes]):
         """
         Constructs a MerkleProof instance from a given witness stack.
-        
+
         Args:
             wit_stack (list): A list of hashes and directions followed by an element x, structured as
                             [<h_1>, <d_1>, <h_2>, <d_2>, ..., <h_n>, <d_n>, <x>]
diff --git a/tests/conftest.py b/tests/conftest.py
index 5dc7dc0..d2fd80c 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -28,7 +28,8 @@ def rpc_test_wallet():
 def manager(rpc):
     return ContractManager([], rpc, mine_automatically=True, poll_interval=0.01)
 
+
 @pytest.fixture(scope="session")
 def report_file():
     with open("report.md", "w") as file:
-        yield file
\ No newline at end of file
+        yield file
diff --git a/tests/test_ram.py b/tests/test_ram.py
index 424b0e4..95320d2 100644
--- a/tests/test_ram.py
+++ b/tests/test_ram.py
@@ -27,10 +27,10 @@ def test_withdraw(rpc, manager: ContractManager):
             ]
 
             out_instances = R_inst("withdraw",
-                outputs = outputs,
-                merkle_root = mt.root,
-                merkle_proof = mt.prove_leaf(leaf_index)
-            )
+                                   outputs=outputs,
+                                   merkle_root=mt.root,
+                                   merkle_proof=mt.prove_leaf(leaf_index)
+                                   )
 
             assert len(out_instances) == 0
 
@@ -47,10 +47,10 @@ def test_write(manager: ContractManager):
     R_inst = manager.fund_instance(RAM(len(data)), AMOUNT, data=mt.root)
 
     out_instances = R_inst("write",
-        merkle_root = mt.root,
-        new_value = new_value,
-        merkle_proof = mt.prove_leaf(leaf_index)
-    )
+                           merkle_root=mt.root,
+                           new_value=new_value,
+                           merkle_proof=mt.prove_leaf(leaf_index)
+                           )
 
     assert len(out_instances) == 1
 
@@ -75,10 +75,10 @@ def test_write_loop(manager: ContractManager):
         new_value = sha256((100 + i).to_bytes(1, byteorder='little'))
 
         out_instances = R_inst("write",
-            merkle_root = MerkleTree(data).root,
-            new_value = new_value,
-            merkle_proof = MerkleTree(data).prove_leaf(leaf_index)
-        )
+                               merkle_root=MerkleTree(data).root,
+                               new_value=new_value,
+                               merkle_proof=MerkleTree(data).prove_leaf(leaf_index)
+                               )
 
         assert len(out_instances) == 1
 
diff --git a/tests/test_rps.py b/tests/test_rps.py
index ec57e7e..72020fc 100644
--- a/tests/test_rps.py
+++ b/tests/test_rps.py
@@ -12,8 +12,10 @@
 random.seed(0)
 
 
-alice_key = key.ExtendedKey.deserialize("tprv8ZgxMBicQKsPdpwA4vW8DcSdXzPn7GkS2RdziGXUX8k86bgDQLKhyXtB3HMbJhPFd2vKRpChWxgPe787WWVqEtjy8hGbZHqZKeRrEwMm3SN")
-bob_key = key.ExtendedKey.deserialize("tprv8ZgxMBicQKsPeDvaW4xxmiMXxqakLgvukT8A5GR6mRwBwjsDJV1jcZab8mxSerNcj22YPrusm2Pz5oR8LTw9GqpWT51VexTNBzxxm49jCZZ")
+alice_key = key.ExtendedKey.deserialize(
+    "tprv8ZgxMBicQKsPdpwA4vW8DcSdXzPn7GkS2RdziGXUX8k86bgDQLKhyXtB3HMbJhPFd2vKRpChWxgPe787WWVqEtjy8hGbZHqZKeRrEwMm3SN")
+bob_key = key.ExtendedKey.deserialize(
+    "tprv8ZgxMBicQKsPeDvaW4xxmiMXxqakLgvukT8A5GR6mRwBwjsDJV1jcZab8mxSerNcj22YPrusm2Pz5oR8LTw9GqpWT51VexTNBzxxm49jCZZ")
 
 moves = {
     "rock": 0,
@@ -41,12 +43,11 @@ def test_rps(manager: ContractManager):
 
     # cheating attempt
     with pytest.raises(JSONRPCException, match='Script failed an OP_EQUALVERIFY operation'):
-        S1_inst("alice_wins", m_a = m_a, m_b = m_b, r_a = r_a)
+        S1_inst("alice_wins", m_a=m_a, m_b=m_b, r_a=r_a)
 
     # cheat a bit less
     with pytest.raises(JSONRPCException, match='Script failed an OP_EQUALVERIFY operation'):
-        S1_inst("tie", m_a = m_a, m_b = m_b, r_a = r_a)
+        S1_inst("tie", m_a=m_a, m_b=m_b, r_a=r_a)
 
     # correct adjudication
-    S1_inst("bob_wins", m_a = m_a, m_b = m_b, r_a = r_a)
-
+    S1_inst("bob_wins", m_a=m_a, m_b=m_b, r_a=r_a)
diff --git a/tests/test_vault.py b/tests/test_vault.py
index e7e6f06..e5154cd 100644
--- a/tests/test_vault.py
+++ b/tests/test_vault.py
@@ -26,7 +26,7 @@ def test_vault_recover(manager: ContractManager, report_file: TextIOWrapper):
 
     V_inst = manager.fund_instance(V, amount)
 
-    out_instances = V_inst("recover", out_i = 0)
+    out_instances = V_inst("recover", out_i=0)
 
     out: CTxOut = V_inst.spending_tx.vout[0]
 
@@ -37,6 +37,7 @@ def test_vault_recover(manager: ContractManager, report_file: TextIOWrapper):
 
     assert len(out_instances) == 0
 
+
 def test_vault_trigger_and_recover(manager: ContractManager, report_file: TextIOWrapper):
     locktime = 10
     V = Vault(None, locktime, recover_priv_key.pubkey[1:], unvault_priv_key.pubkey[1:])
@@ -53,13 +54,12 @@ def test_vault_trigger_and_recover(manager: ContractManager, report_file: TextIO
         ("bcrt1q6vqduw24yjjll6nfkxlfy2twwt52w58tnvnd46", 4999990000),
     ], nSequence=locktime)
 
-    [U_inst] =  V_inst("trigger", signer = signer,
-                       out_i = 0, ctv_hash = ctv_tmpl.get_standard_template_hash(0))
+    [U_inst] = V_inst("trigger", signer=signer,
+                      out_i=0, ctv_hash=ctv_tmpl.get_standard_template_hash(0))
 
     report_file.write(format_tx_markdown(V_inst.spending_tx, "Trigger [3 vault inputs]"))
 
-
-    out_instances = U_inst("recover", out_i = 0)
+    out_instances = U_inst("recover", out_i=0)
 
     assert len(out_instances) == 0
 
@@ -82,8 +82,8 @@ def test_vault_trigger_and_withdraw(rpc: AuthServiceProxy, manager: ContractMana
         ("bcrt1q6vqduw24yjjll6nfkxlfy2twwt52w58tnvnd46", 1666663334),
     ], nSequence=locktime)
 
-    [U_inst] =  V_inst("trigger", signer = signer,
-                       out_i = 0, ctv_hash = ctv_tmpl.get_standard_template_hash(0))
+    [U_inst] = V_inst("trigger", signer=signer,
+                      out_i=0, ctv_hash=ctv_tmpl.get_standard_template_hash(0))
 
     report_file.write(format_tx_markdown(V_inst.spending_tx, "Trigger [3 vault inputs]"))
 
@@ -115,7 +115,6 @@ def test_vault_trigger_and_withdraw(rpc: AuthServiceProxy, manager: ContractMana
     report_file.write(format_tx_markdown(U_inst.spending_tx, "Withdraw [3 outputs]"))
 
 
-
 def test_vault_trigger_with_revault_and_withdraw(rpc: AuthServiceProxy, manager: ContractManager, report_file: TextIOWrapper):
     # get coins on 3 different Vaults, then trigger with partial withdrawal
     # one of the vault uses "trigger_with_revault", the others us normal "trigger"
@@ -157,7 +156,6 @@ def test_vault_trigger_with_revault_and_withdraw(rpc: AuthServiceProxy, manager:
             {**args, "sig": sigs[i]}
         ))
 
-
     [U_inst] = manager.spend_and_wait([V_inst_1, V_inst_2, V_inst_3], spend_tx)
 
     report_file.write(format_tx_markdown(spend_tx, "Trigger (with revault) [3 vault inputs]"))
@@ -184,4 +182,4 @@ def test_vault_trigger_with_revault_and_withdraw(rpc: AuthServiceProxy, manager:
 
     manager.spend_and_wait(U_inst, spend_tx)
 
-    report_file.write(format_tx_markdown(U_inst.spending_tx, "Withdraw (3 outputs)"))
\ No newline at end of file
+    report_file.write(format_tx_markdown(U_inst.spending_tx, "Withdraw (3 outputs)"))