diff --git a/Makefile b/Makefile
index fb3cbfa8..6c63bf01 100644
--- a/Makefile
+++ b/Makefile
@@ -5,10 +5,10 @@ ruff-check:
 	poetry run ruff check .
 
 black:
-	poetry run black . --exclude cashu/nostr
+	poetry run black .
 
 black-check:
-	poetry run black . --exclude cashu/nostr --check
+	poetry run black . --check
 
 mypy:
 	poetry run mypy cashu --ignore-missing
diff --git a/cashu/nostr/bech32.py b/cashu/nostr/bech32.py
index b068de77..0ae6c808 100644
--- a/cashu/nostr/bech32.py
+++ b/cashu/nostr/bech32.py
@@ -23,21 +23,25 @@
 
 from enum import Enum
 
+
 class Encoding(Enum):
     """Enumeration type to list the various supported encodings."""
+
     BECH32 = 1
     BECH32M = 2
 
+
 CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
-BECH32M_CONST = 0x2bc830a3
+BECH32M_CONST = 0x2BC830A3
+
 
 def bech32_polymod(values):
     """Internal function that computes the Bech32 checksum."""
-    generator = [0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3]
+    generator = [0x3B6A57B2, 0x26508E6D, 0x1EA119FA, 0x3D4233DD, 0x2A1462B3]
     chk = 1
     for value in values:
         top = chk >> 25
-        chk = (chk & 0x1ffffff) << 5 ^ value
+        chk = (chk & 0x1FFFFFF) << 5 ^ value
         for i in range(5):
             chk ^= generator[i] if ((top >> i) & 1) else 0
     return chk
@@ -57,6 +61,7 @@ def bech32_verify_checksum(hrp, data):
         return Encoding.BECH32M
     return None
 
+
 def bech32_create_checksum(hrp, data, spec):
     """Compute the checksum values given HRP and data."""
     values = bech32_hrp_expand(hrp) + data
@@ -68,26 +73,29 @@ def bech32_create_checksum(hrp, data, spec):
 def bech32_encode(hrp, data, spec):
     """Compute a Bech32 string given HRP and data values."""
     combined = data + bech32_create_checksum(hrp, data, spec)
-    return hrp + '1' + ''.join([CHARSET[d] for d in combined])
+    return hrp + "1" + "".join([CHARSET[d] for d in combined])
+
 
 def bech32_decode(bech):
     """Validate a Bech32/Bech32m string, and determine HRP and data."""
-    if ((any(ord(x) < 33 or ord(x) > 126 for x in bech)) or
-            (bech.lower() != bech and bech.upper() != bech)):
+    if (any(ord(x) < 33 or ord(x) > 126 for x in bech)) or (
+        bech.lower() != bech and bech.upper() != bech
+    ):
         return (None, None, None)
     bech = bech.lower()
-    pos = bech.rfind('1')
+    pos = bech.rfind("1")
     if pos < 1 or pos + 7 > len(bech) or len(bech) > 90:
         return (None, None, None)
-    if not all(x in CHARSET for x in bech[pos+1:]):
+    if not all(x in CHARSET for x in bech[pos + 1 :]):
         return (None, None, None)
     hrp = bech[:pos]
-    data = [CHARSET.find(x) for x in bech[pos+1:]]
+    data = [CHARSET.find(x) for x in bech[pos + 1 :]]
     spec = bech32_verify_checksum(hrp, data)
     if spec is None:
         return (None, None, None)
     return (hrp, data[:-6], spec)
 
+
 def convertbits(data, frombits, tobits, pad=True):
     """General power-of-2 base conversion."""
     acc = 0
@@ -123,7 +131,12 @@ def decode(hrp, addr):
         return (None, None)
     if data[0] == 0 and len(decoded) != 20 and len(decoded) != 32:
         return (None, None)
-    if data[0] == 0 and spec != Encoding.BECH32 or data[0] != 0 and spec != Encoding.BECH32M:
+    if (
+        data[0] == 0
+        and spec != Encoding.BECH32
+        or data[0] != 0
+        and spec != Encoding.BECH32M
+    ):
         return (None, None)
     return (data[0], decoded)
 
diff --git a/cashu/nostr/client/cbc.py b/cashu/nostr/client/cbc.py
index a41dbc07..e69e8b5b 100644
--- a/cashu/nostr/client/cbc.py
+++ b/cashu/nostr/client/cbc.py
@@ -1,4 +1,3 @@
-
 from Cryptodome import Random
 from Cryptodome.Cipher import AES
 
@@ -11,10 +10,10 @@
 
 BLOCK_SIZE = 16
 
+
 class AESCipher(object):
-    """This class is compatible with crypto.createCipheriv('aes-256-cbc')
+    """This class is compatible with crypto.createCipheriv('aes-256-cbc')"""
 
-    """
     def __init__(self, key=None):
         self.key = key
 
@@ -33,9 +32,10 @@ def encrypt(self, plain_text):
     def decrypt(self, iv, enc_text):
         cipher = AES.new(self.key, AES.MODE_CBC, iv=iv)
         return self.unpad(cipher.decrypt(enc_text).decode("UTF-8"))
-        
+
+
 if __name__ == "__main__":
     aes = AESCipher(key=key)
     iv, enc_text = aes.encrypt(plain_text)
     dec_text = aes.decrypt(iv, enc_text)
-    print(dec_text)
\ No newline at end of file
+    print(dec_text)
diff --git a/cashu/nostr/delegation.py b/cashu/nostr/delegation.py
index 94801f5c..8b1c3114 100644
--- a/cashu/nostr/delegation.py
+++ b/cashu/nostr/delegation.py
@@ -7,23 +7,23 @@ class Delegation:
     delegator_pubkey: str
     delegatee_pubkey: str
     event_kind: int
-    duration_secs: int = 30*24*60  # default to 30 days
+    duration_secs: int = 30 * 24 * 60  # default to 30 days
     signature: str = None  # set in PrivateKey.sign_delegation
 
     @property
     def expires(self) -> int:
         return int(time.time()) + self.duration_secs
-    
+
     @property
     def conditions(self) -> str:
         return f"kind={self.event_kind}&created_at<{self.expires}"
-    
+
     @property
     def delegation_token(self) -> str:
         return f"nostr:delegation:{self.delegatee_pubkey}:{self.conditions}"
 
     def get_tag(self) -> list[str]:
-        """ Called by Event """
+        """Called by Event"""
         return [
             "delegation",
             self.delegator_pubkey,
diff --git a/cashu/nostr/event.py b/cashu/nostr/event.py
index b903e0ee..0ee7ad0b 100644
--- a/cashu/nostr/event.py
+++ b/cashu/nostr/event.py
@@ -121,6 +121,7 @@ def __post_init__(self):
     def id(self) -> str:
         if self.content is None:
             raise Exception(
-                "EncryptedDirectMessage `id` is undefined until its message is encrypted and stored in the `content` field"
+                "EncryptedDirectMessage `id` is undefined until its message is"
+                " encrypted and stored in the `content` field"
             )
         return super().id
diff --git a/cashu/nostr/message_type.py b/cashu/nostr/message_type.py
index 3f5206bd..9f3be785 100644
--- a/cashu/nostr/message_type.py
+++ b/cashu/nostr/message_type.py
@@ -3,6 +3,7 @@ class ClientMessageType:
     REQUEST = "REQ"
     CLOSE = "CLOSE"
 
+
 class RelayMessageType:
     EVENT = "EVENT"
     NOTICE = "NOTICE"
@@ -10,6 +11,10 @@ class RelayMessageType:
 
     @staticmethod
     def is_valid(type: str) -> bool:
-        if type == RelayMessageType.EVENT or type == RelayMessageType.NOTICE or type == RelayMessageType.END_OF_STORED_EVENTS:
+        if (
+            type == RelayMessageType.EVENT
+            or type == RelayMessageType.NOTICE
+            or type == RelayMessageType.END_OF_STORED_EVENTS
+        ):
             return True
-        return False
\ No newline at end of file
+        return False
diff --git a/cashu/nostr/pow.py b/cashu/nostr/pow.py
index e0062884..c1795fcc 100644
--- a/cashu/nostr/pow.py
+++ b/cashu/nostr/pow.py
@@ -2,6 +2,7 @@
 from .event import Event
 from .key import PrivateKey
 
+
 def zero_bits(b: int) -> int:
     n = 0
 
@@ -14,10 +15,11 @@ def zero_bits(b: int) -> int:
 
     return 7 - n
 
+
 def count_leading_zero_bits(hex_str: str) -> int:
     total = 0
     for i in range(0, len(hex_str) - 2, 2):
-        bits = zero_bits(int(hex_str[i:i+2], 16))
+        bits = zero_bits(int(hex_str[i : i + 2], 16))
         total += bits
 
         if bits != 8:
@@ -25,7 +27,10 @@ def count_leading_zero_bits(hex_str: str) -> int:
 
     return total
 
-def mine_event(content: str, difficulty: int, public_key: str, kind: int, tags: list=[]) -> Event:
+
+def mine_event(
+    content: str, difficulty: int, public_key: str, kind: int, tags: list = []
+) -> Event:
     all_tags = [["nonce", "1", str(difficulty)]]
     all_tags.extend(tags)
 
@@ -43,6 +48,7 @@ def mine_event(content: str, difficulty: int, public_key: str, kind: int, tags:
 
     return Event(public_key, content, created_at, kind, all_tags, event_id)
 
+
 def mine_key(difficulty: int) -> PrivateKey:
     sk = PrivateKey()
     num_leading_zero_bits = count_leading_zero_bits(sk.public_key.hex())
diff --git a/cashu/nostr/relay_manager.py b/cashu/nostr/relay_manager.py
index 5b92d8d4..98e1abeb 100644
--- a/cashu/nostr/relay_manager.py
+++ b/cashu/nostr/relay_manager.py
@@ -64,6 +64,7 @@ def publish_event(self, event: Event):
 
         if not event.verify():
             raise RelayException(
-                f"Could not publish {event.id}: failed to verify signature {event.signature}"
+                f"Could not publish {event.id}: failed to verify signature"
+                f" {event.signature}"
             )
         self.publish_message(event.to_message())
diff --git a/cashu/nostr/subscription.py b/cashu/nostr/subscription.py
index 7afba204..10b53631 100644
--- a/cashu/nostr/subscription.py
+++ b/cashu/nostr/subscription.py
@@ -1,12 +1,10 @@
 from .filter import Filters
 
+
 class Subscription:
-    def __init__(self, id: str, filters: Filters=None) -> None:
+    def __init__(self, id: str, filters: Filters = None) -> None:
         self.id = id
         self.filters = filters
 
     def to_json_object(self):
-        return { 
-            "id": self.id, 
-            "filters": self.filters.to_json_array() 
-        }
+        return {"id": self.id, "filters": self.filters.to_json_array()}