diff --git a/src/exchange/cancel.rs b/src/exchange/cancel.rs
index 4887c5b..2e17999 100644
--- a/src/exchange/cancel.rs
+++ b/src/exchange/cancel.rs
@@ -1,28 +1,94 @@
 use serde::{Deserialize, Serialize};
 use uuid::Uuid;
 
-#[derive(Debug)]
-pub struct ClientCancelRequest {
+// --- Shared Types and Aliases ---
+
+/// Type alias for the internal/wire format of an Asset ID.
+pub type AssetId = u32;
+
+/// Type alias for a standard Order ID (OID).
+pub type OrderId = u64;
+
+/// Type alias for a Client Order ID (CLOID) in the wire format (String representation).
+pub type ClientOrderIdWire = String;
+
+// --- API / Internal Application Structures (Public Facing) ---
+
+/// Represents an incoming API request to cancel an order by its standard ID (OID).
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub struct ApiCancelRequest {
+    /// Human-readable asset identifier (e.g., "BTC-USD").
     pub asset: String,
-    pub oid: u64,
+    /// The standard Order ID assigned by the exchange.
+    pub oid: OrderId,
+}
+
+/// Represents an incoming API request to cancel an order by its Client Order ID (CLOID).
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub struct ApiCancelRequestCloid {
+    /// Human-readable asset identifier (e.g., "BTC-USD").
+    pub asset: String,
+    /// The UUID assigned by the client.
+    pub cloid: Uuid,
 }
 
-#[derive(Serialize, Deserialize, Debug, Clone)]
-pub struct CancelRequest {
+// --- Wire / DTO Structures (Serialized Format) ---
+
+/// Wire format for canceling an order by its standard ID.
+/// Uses minimized keys ("a", "o") for efficiency over the wire.
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, Hash)]
+pub struct WireCancelRequest {
     #[serde(rename = "a", alias = "asset")]
-    pub asset: u32,
+    pub asset: AssetId,
     #[serde(rename = "o", alias = "oid")]
-    pub oid: u64,
+    pub oid: OrderId,
 }
 
-#[derive(Debug)]
-pub struct ClientCancelRequestCloid {
-    pub asset: String,
-    pub cloid: Uuid,
+/// Wire format for canceling an order by its Client Order ID.
+/// Uses minimized keys ("a", "c") for efficiency over the wire (consistent optimization).
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, Hash)]
+pub struct WireCancelRequestCloid {
+    #[serde(rename = "a", alias = "asset")]
+    pub asset: AssetId,
+    // CLOID is typically sent as a canonical hex string over the wire.
+    #[serde(rename = "c", alias = "cloid")]
+    pub cloid: ClientOrderIdWire,
+}
+
+// --- Conversion Implementations (Example mapping needed) ---
+
+// NOTE: Conversion from the public 'Api*' structures to the wire 'Wire*' 
+// structures requires business logic to map the human-readable 'asset: String' 
+// to the internal 'asset: AssetId (u32)'. The following implementations assume 
+// this mapping is external or mocked for demonstration.
+
+/// Example implementation for converting an internal OID request to the wire format.
+impl From<ApiCancelRequest> for WireCancelRequest {
+    fn from(api_req: ApiCancelRequest) -> Self {
+        // --- TODO: Implement asset name to u32 ID resolution here ---
+        // Placeholder implementation:
+        let internal_asset_id = if api_req.asset == "BTC-USD" { 101 } else { 0 }; 
+        // -----------------------------------------------------------------
+
+        WireCancelRequest {
+            asset: internal_asset_id,
+            oid: api_req.oid,
+        }
+    }
 }
 
-#[derive(Serialize, Deserialize, Debug, Clone)]
-pub struct CancelRequestCloid {
-    pub asset: u32,
-    pub cloid: String,
+/// Example implementation for converting an internal CLOID request to the wire format.
+impl From<ApiCancelRequestCloid> for WireCancelRequestCloid {
+    fn from(api_req: ApiCancelRequestCloid) -> Self {
+        // --- TODO: Implement asset name to u32 ID resolution here ---
+        // Placeholder implementation:
+        let internal_asset_id = if api_req.asset == "ETH-USD" { 202 } else { 0 }; 
+        // -----------------------------------------------------------------
+        
+        WireCancelRequestCloid {
+            asset: internal_asset_id,
+            // CLOID must be converted to its String representation for serialization.
+            cloid: api_req.cloid.to_string(), 
+        }
+    }
 }