diff --git a/src/ncsi_util.hpp b/src/ncsi_util.hpp
index 048bb71..0ca0df1 100644
--- a/src/ncsi_util.hpp
+++ b/src/ncsi_util.hpp
@@ -16,6 +16,7 @@
 
 constexpr auto DEFAULT_VALUE = -1;
 constexpr auto NONE = 0;
+constexpr uint8_t CHANNEL_ID_NONE = 0x1f;
 
 struct ChannelInfo
 {
@@ -40,10 +41,37 @@
     std::vector<PackageInfo> packages;
 };
 
+struct NCSICommand
+{
+    /* constructs a message; the payload span is copied into the internal
+     * command vector */
+    NCSICommand(uint8_t opcode, uint8_t package, std::optional<uint8_t> channel,
+                std::span<unsigned char> payload);
+
+    uint8_t getChannel();
+
+    uint8_t opcode;
+    uint8_t package;
+    std::optional<uint8_t> channel;
+    std::vector<unsigned char> payload;
+};
+
+struct NCSIResponse
+{
+    uint8_t opcode;
+    uint8_t response, reason;
+    std::span<unsigned char> payload;
+    std::vector<unsigned char> full_payload;
+
+    /* Given an incoming response with full_payload set, check that we have
+     * enough data for a correct response, and populate the rest of the struct
+     * to suit
+     */
+    int parseFullPayload();
+};
+
 struct Interface
 {
-    using ncsiMessage = std::span<const unsigned char>;
-
     /* @brief  This function will ask underlying NCSI driver
      *         to send an OEM command (command type 0x50) with
      *         the specified payload as the OEM data.
@@ -55,8 +83,7 @@
      * @param[in] payload - OEM data to send.
      * @returns the NCSI response message to this command, or no value on error.
      */
-    std::optional<std::vector<unsigned char>> sendOemCommand(
-        int package, int channel, int opcode, ncsiMessage payload);
+    std::optional<NCSIResponse> sendCommand(NCSICommand& cmd);
 
     /* @brief  This function will ask underlying NCSI driver
      *         to set a specific  package or package/channel