diff --git a/cashu/core/base.py b/cashu/core/base.py
index ec7022d..d68e760 100644
--- a/cashu/core/base.py
+++ b/cashu/core/base.py
@@ -6,6 +6,8 @@ from pydantic import BaseModel
 from cashu.core.crypto import derive_keys, derive_keyset_id, derive_pubkeys
 from cashu.core.secp import PrivateKey, PublicKey
 
+# ------- PROOFS -------
+
 
 class P2SHScript(BaseModel):
     script: str
@@ -40,9 +42,13 @@ class Proof(BaseModel):
 
 
 class Proofs(BaseModel):
+    # NOTE: not used in Pydantic validation
     __root__: List[Proof]
 
 
+# ------- LIGHTNING INVOICE -------
+
+
 class Invoice(BaseModel):
     amount: int
     pr: str
@@ -54,15 +60,10 @@ class Invoice(BaseModel):
     time_paid: Union[None, str, int, float] = ""
 
 
-class BlindedMessage(BaseModel):
-    amount: int
-    B_: str
+# ------- API -------
 
 
-class BlindedSignature(BaseModel):
-    id: Union[str, None] = None
-    amount: int
-    C_: str
+# ------- API: KEYS -------
 
 
 class KeysResponse(BaseModel):
@@ -73,8 +74,13 @@ class KeysetsResponse(BaseModel):
     keysets: list[str]
 
 
-class BlindedMessages(BaseModel):
-    blinded_messages: List[BlindedMessage] = []
+# ------- API: MINT -------
+
+
+class BlindedSignature(BaseModel):
+    id: Union[str, None] = None
+    amount: int
+    C_: str
 
 
 class PostMintResponseLegacy(BaseModel):
@@ -91,11 +97,31 @@ class GetMintResponse(BaseModel):
     hash: str
 
 
+# ------- API: MELT -------
+
+
+class MeltRequest(BaseModel):
+    proofs: List[Proof]
+    invoice: str
+
+
 class GetMeltResponse(BaseModel):
     paid: Union[bool, None]
     preimage: Union[str, None]
 
 
+# ------- API: SPLIT -------
+
+
+class BlindedMessage(BaseModel):
+    amount: int
+    B_: str
+
+
+class BlindedMessages(BaseModel):
+    blinded_messages: List[BlindedMessage] = []
+
+
 class SplitRequest(BaseModel):
     proofs: List[Proof]
     amount: int
@@ -120,6 +146,9 @@ class PostSplitResponse(BaseModel):
     snd: List[BlindedSignature]
 
 
+# ------- API: CHECK -------
+
+
 class CheckRequest(BaseModel):
     proofs: List[Proof]
 
@@ -132,18 +161,24 @@ class CheckFeesResponse(BaseModel):
     fee: Union[int, None]
 
 
-class MeltRequest(BaseModel):
-    proofs: List[Proof]
-    invoice: str
+# ------- KEYSETS -------
 
 
 class KeyBase(BaseModel):
+    """
+    Public key from a keyset id for a given amount.
+    """
+
     id: str
     amount: int
     pubkey: str
 
 
 class WalletKeyset:
+    """
+    Contains the keyset from the wallets's perspective.
+    """
+
     id: Union[str, None]
     public_keys: Union[Dict[int, PublicKey], None]
     mint_url: Union[str, None] = None
@@ -174,6 +209,10 @@ class WalletKeyset:
 
 
 class MintKeyset:
+    """
+    Contains the keyset from the mint's perspective.
+    """
+
     id: Union[str, None]
     derivation_path: str
     private_keys: Dict[int, PrivateKey]
@@ -221,6 +260,10 @@ class MintKeyset:
 
 
 class MintKeysets:
+    """
+    Collection of keyset IDs and the corresponding keyset of the mint.
+    """
+
     keysets: Dict[str, MintKeyset]
 
     def __init__(self, keysets: List[MintKeyset]):
@@ -230,6 +273,9 @@ class MintKeysets:
         return [k for k, _ in self.keysets.items()]
 
 
+# ------- TOKEN -------
+
+
 class TokenMintJson(BaseModel):
     url: str
     ks: List[str]
diff --git a/docs/specs/00.md b/docs/specs/00.md
index 6761d70..52b2776 100644
--- a/docs/specs/00.md
+++ b/docs/specs/00.md
@@ -61,7 +61,7 @@ A `Proof` is also called a `Token` and has the following form:
 ```
 
 ### `Proofs`
-A list of `Proof`'s. In general, this will be used for most operations instead of a single `Proof`. `Proofs` can be serialized (see Methods/Serialization [TODO: Link Serialization])
+An array (list) of `Proof`'s. In general, this will be used for most operations instead of a single `Proof`. `Proofs` can be serialized (see Methods/Serialization [TODO: Link Serialization])
 
 ## 0.2 - Methods