diff --git a/include/Makefile.am b/include/Makefile.am
new file mode 100644
index 0000000..50bb399
--- /dev/null
+++ b/include/Makefile.am
@@ -0,0 +1,19 @@
+nobase_include_HEADERS = \
+	ipmid/api.h \
+	ipmid/iana.hpp \
+	ipmid/oemopenbmc.hpp \
+	ipmid/oemrouter.hpp \
+	ipmid-host/cmd.hpp \
+	ipmid-host/cmd-utils.hpp
+
+# Eventually we will split <ipmid/*> and <host-ipmid/*> headers
+# For now they will be the same during migration
+install-data-local:
+	$(MKDIR_P) $(DESTDIR)$(includedir)/host-ipmid
+	$(LN_S) ../ipmid/iana.hpp $(DESTDIR)$(includedir)/host-ipmid/iana.hpp
+	$(LN_S) ../ipmid/api.h $(DESTDIR)$(includedir)/host-ipmid/ipmid-api.h
+	$(LN_S) ../ipmid/oemopenbmc.hpp $(DESTDIR)$(includedir)/host-ipmid/oemopenbmc.hpp
+	$(LN_S) ../ipmid/oemrouter.hpp $(DESTDIR)$(includedir)/host-ipmid/oemrouter.hpp
+	$(LN_S) ../ipmid-host/cmd.hpp $(DESTDIR)$(includedir)/host-ipmid/ipmid-host-cmd.hpp
+	$(LN_S) ../ipmid-host/cmd-utils.hpp $(DESTDIR)$(includedir)/host-ipmid/ipmid-host-cmd-utils.hpp
+
diff --git a/include/ipmid-host/cmd-utils.hpp b/include/ipmid-host/cmd-utils.hpp
new file mode 100644
index 0000000..e7c6dc2
--- /dev/null
+++ b/include/ipmid-host/cmd-utils.hpp
@@ -0,0 +1,51 @@
+#pragma once
+
+#include <unistd.h>
+
+#include <functional>
+#include <tuple>
+
+namespace phosphor
+{
+namespace host
+{
+namespace command
+{
+/** @detail After sending SMS_ATN to the Host, Host comes down and
+ *          asks why an 'SMS_ATN` was sent.
+ *          BMC then sends 'There is a Message to be Read` as response.
+ *          Host then comes down asks for Message and the specified
+ *          commands and data would go as data conforming to IPMI spec.
+ *
+ *          Refer: 6.13.2 Send Message Command From System Interface
+ *          in IPMI V2.0 spec.
+ */
+
+/** @brief IPMI command */
+using IPMIcmd = uint8_t;
+
+/** @brief Data associated with command */
+using Data = uint8_t;
+
+/** @brief <IPMI command, Data> to be sent as payload when Host asks for
+ *          the message that can be associated with the previous SMS_ATN
+ */
+using IpmiCmdData = std::pair<IPMIcmd, Data>;
+
+/** @detail Implementation specific callback function to be invoked
+ *          conveying the status of the executed command. Specific
+ *          implementations may then broadcast an agreed signal
+ */
+using CallBack = std::function<void(IpmiCmdData, bool)>;
+
+/** @detail Tuple encapsulating above 2 to enable using Manager by
+ *          different implementations. Users of Manager will supply
+ *          <Ipmi command, Data> along with the callback handler.
+ *          Manager will invoke the handler onveying the status of
+ *          the command.
+ */
+using CommandHandler = std::tuple<IpmiCmdData, CallBack>;
+
+} // namespace command
+} // namespace host
+} // namespace phosphor
diff --git a/include/ipmid-host/cmd.hpp b/include/ipmid-host/cmd.hpp
new file mode 100644
index 0000000..adea960
--- /dev/null
+++ b/include/ipmid-host/cmd.hpp
@@ -0,0 +1,10 @@
+#include <ipmid-host/cmd-utils.hpp>
+#include <memory>
+#include <sdbusplus/bus.hpp>
+
+// Need this to use new sdbusplus compatible interfaces
+using sdbusPtr = std::unique_ptr<sdbusplus::bus::bus>;
+extern sdbusPtr& ipmid_get_sdbus_plus_handler();
+
+// Global Host Bound Command manager
+extern void ipmid_send_cmd_to_host(phosphor::host::command::CommandHandler&&);
diff --git a/include/ipmid/api.h b/include/ipmid/api.h
new file mode 100644
index 0000000..b1c078b
--- /dev/null
+++ b/include/ipmid/api.h
@@ -0,0 +1,155 @@
+#ifndef __HOST_IPMID_IPMI_COMMON_H__
+#define __HOST_IPMID_IPMI_COMMON_H__
+
+#include <systemd/sd-bus.h>
+
+/*
+ * Specifies the minimum privilege level required to execute the command
+ * This means the command can be executed at a given privilege level or higher
+ * privilege level. Those commands which can be executed via system interface
+ * only should use SYSTEM_INTERFACE
+ */
+enum CommandPrivilege
+{
+    PRIVILEGE_CALLBACK = 0x01,
+    PRIVILEGE_USER,
+    PRIVILEGE_OPERATOR,
+    PRIVILEGE_ADMIN,
+    PRIVILEGE_OEM,
+    SYSTEM_INTERFACE = 0xFF,
+};
+
+// length of Completion Code and its ALWAYS _1_
+#define IPMI_CC_LEN 1
+
+// IPMI Net Function number as specified by IPMI V2.0 spec.
+// Example :
+// NETFUN_APP      =   (0x06 << 2),
+typedef unsigned char ipmi_netfn_t;
+
+// IPMI Command for a Net Function number as specified by IPMI V2.0 spec.
+typedef unsigned char ipmi_cmd_t;
+
+// Buffer containing data from sender of netfn and command as part of request
+typedef void* ipmi_request_t;
+
+// This is the response buffer that the provider of [netfn,cmd] will send back
+// to the caller. Provider will allocate the memory inside the handler and then
+// will do a memcpy to this response buffer and also will set the data size
+// parameter to the size of the buffer.
+// EXAMPLE :
+// unsigned char str[] = {0x00, 0x01, 0xFE, 0xFF, 0x0A, 0x01};
+// *data_len = 6;
+// memcpy(response, &str, *data_len);
+typedef void* ipmi_response_t;
+
+// This buffer contains any *user specific* data that is of interest only to the
+// plugin. For a ipmi function router, this data is opaque. At the time of
+// registering the plugin handlers, plugin may optionally allocate a memory and
+// fill in whatever needed that will be of help during the actual handling of
+// command. IPMID will just pass the netfn, cmd and also this data to plugins
+// during the command handler invocation.
+typedef void* ipmi_context_t;
+
+// Length of request / response buffer depending on whether the data is a
+// request or a response from a plugin handler.
+typedef size_t* ipmi_data_len_t;
+
+// Plugin function return the status code
+typedef unsigned char ipmi_ret_t;
+
+typedef enum CommandPrivilege ipmi_cmd_privilege_t;
+
+// This is the callback handler that the plugin registers with IPMID. IPMI
+// function router will then make a call to this callback handler with the
+// necessary arguments of netfn, cmd, request, response, size and context.
+typedef ipmi_ret_t (*ipmid_callback_t)(ipmi_netfn_t, ipmi_cmd_t, ipmi_request_t,
+                                       ipmi_response_t, ipmi_data_len_t,
+                                       ipmi_context_t);
+
+// This is the constructor function that is called into by each plugin handlers.
+// When ipmi sets up the callback handlers, a call is made to this with
+// information of netfn, cmd, callback handler pointer and context data.
+void ipmi_register_callback(ipmi_netfn_t, ipmi_cmd_t, ipmi_context_t,
+                            ipmid_callback_t, ipmi_cmd_privilege_t);
+
+unsigned short reserveSel(void);
+bool checkSELReservation(unsigned short id);
+void cancelSELReservation(void);
+
+// These are the command network functions, the response
+// network functions are the function + 1. So to determine
+// the proper network function which issued the command
+// associated with a response, subtract 1.
+// Note: these are also shifted left to make room for the LUN.
+enum ipmi_net_fns
+{
+    NETFUN_CHASSIS = 0x00,
+    NETFUN_BRIDGE = 0x02,
+    NETFUN_SENSOR = 0x04,
+    NETFUN_APP = 0x06,
+    NETFUN_FIRMWARE = 0x08,
+    NETFUN_STORAGE = 0x0a,
+    NETFUN_TRANSPORT = 0x0c,
+    NETFUN_GRPEXT = 0x2c,
+    NETFUN_OEM_GROUP = 0x2e,
+    NETFUN_NONE = 0x30,
+    NETFUN_OEM = 0x32,
+    NETFUN_IBM_OEM = 0x3A
+};
+
+// IPMI commands for net functions. Since this is to be used both by the ipmi
+// function router and also the callback handler registration function, its put
+// in this .H file.
+enum ipmi_netfn_wild_card_cmd
+{
+    IPMI_CMD_WILDCARD = 0xFF,
+};
+
+// Return (completion) codes from a IPMI operation as needed by IPMI V2.0 spec.
+enum ipmi_return_codes
+{
+    IPMI_CC_OK = 0x00,
+    IPMI_DCMI_CC_NO_ACTIVE_POWER_LIMIT = 0x80,
+    IPMI_WDOG_CC_NOT_INIT = 0x80,
+    IPMI_CC_SYSTEM_INFO_PARAMETER_NOT_SUPPORTED = 0x80,
+    IPMI_CC_SYSTEM_INFO_PARAMETER_SET_READ_ONLY = 0x82,
+    IPMI_CC_BUSY = 0xC0,
+    IPMI_CC_INVALID = 0xC1,
+    IPMI_CC_TIMEOUT = 0xC3,
+    IPMI_CC_OUT_OF_SPACE = 0xC4,
+    IPMI_CC_INVALID_RESERVATION_ID = 0xC5,
+    IPMI_CC_REQ_DATA_TRUNCATED = 0xC6,
+    IPMI_CC_REQ_DATA_LEN_INVALID = 0xC7,
+    IPMI_CC_PARM_OUT_OF_RANGE = 0xC9,
+    IPMI_CC_REQUESTED_TOO_MANY_BYTES = 0xCA,
+    IPMI_CC_SENSOR_INVALID = 0xCB,
+    IPMI_CC_INVALID_FIELD_REQUEST = 0xCC,
+    IPMI_CC_ILLEGAL_COMMAND = 0xCD,
+    IPMI_CC_RESPONSE_ERROR = 0xCE,
+    IPMI_CC_INSUFFICIENT_PRIVILEGE = 0xD4,
+    IPMI_CC_UNSPECIFIED_ERROR = 0xFF,
+};
+
+// Temp solution: To detect the request source channel.
+// There is no stright forward way to get the exact
+// channel so we are hardcoding it to KCS in case host-ipmid
+// and LAN1 for netipmid.
+// we can't differentiate between LAN1 & LAN2 for netipmid in this logic.
+// As our current design will not be able to support the same. This is done
+// so that in all the places where ever we need to use the self channel can be
+// be implemented properly and based on new architecture.this can be updated.
+typedef enum
+{
+    interfaceKCS = 0,
+    interfaceLAN1 = 1,
+    interfaceUnknown = 0xFF
+} EInterfaceIndex;
+
+EInterfaceIndex getInterfaceIndex(void);
+
+sd_bus* ipmid_get_sd_bus_connection(void);
+sd_event* ipmid_get_sd_event_connection(void);
+sd_bus_slot* ipmid_get_sd_bus_slot(void);
+
+#endif
diff --git a/include/ipmid/iana.hpp b/include/ipmid/iana.hpp
new file mode 100644
index 0000000..aa9e173
--- /dev/null
+++ b/include/ipmid/iana.hpp
@@ -0,0 +1,19 @@
+#pragma once
+
+#include <cstdint>
+
+namespace oem
+{
+using Number = std::uint32_t; // smallest standard size >= 24.
+
+/*
+ * This is the OpenBMC IANA OEM Number
+ */
+constexpr Number obmcOemNumber = 49871;
+
+/*
+ * This is the Google IANA OEM Number
+ */
+constexpr Number googOemNumber = 11129;
+
+} // namespace oem
diff --git a/include/ipmid/oemopenbmc.hpp b/include/ipmid/oemopenbmc.hpp
new file mode 100644
index 0000000..b7b3a30
--- /dev/null
+++ b/include/ipmid/oemopenbmc.hpp
@@ -0,0 +1,22 @@
+#pragma once
+
+#include <ipmid/api.h>
+
+#include <ipmid/oemrouter.hpp>
+
+namespace oem
+{
+/*
+ * OpenBMC OEM Extension IPMI Command codes.
+ */
+enum Cmd
+{
+    gpioCmd = 1,
+    i2cCmd = 2,
+    flashCmd = 3,
+    fanManualCmd = 4,
+    ethStatsCmd = 48,
+    blobTransferCmd = 128,
+};
+
+} // namespace oem
diff --git a/include/ipmid/oemrouter.hpp b/include/ipmid/oemrouter.hpp
new file mode 100644
index 0000000..e0a9f14
--- /dev/null
+++ b/include/ipmid/oemrouter.hpp
@@ -0,0 +1,83 @@
+#pragma once
+
+#include <ipmid/api.h>
+
+#include <array>
+#include <cstdint>
+#include <functional>
+#include <ipmid/iana.hpp>
+#include <vector>
+
+namespace oem
+{
+constexpr size_t groupMagicSize = 3;
+
+using Group = std::array<uint8_t, groupMagicSize>;
+
+// Handler signature includes ipmi cmd to support wildcard cmd match.
+// Buffers and lengths exclude the OemGroup bytes in the IPMI message.
+// dataLen supplies length of reqBuf upon call, and should be set to the
+// length of replyBuf upon return - conventional in this code base.
+using Handler = std::function<ipmi_ret_t(ipmi_cmd_t,     // cmd byte
+                                         const uint8_t*, // reqBuf
+                                         uint8_t*,       // replyBuf
+                                         size_t*)>;      // dataLen
+
+/// Router Interface class.
+/// @brief Abstract Router Interface
+class Router
+{
+  public:
+    virtual ~Router()
+    {
+    }
+
+    /// Enable message routing to begin.
+    virtual void activate() = 0;
+
+    /// Register a handler for given OEMNumber & cmd.
+    /// Use IPMI_CMD_WILDCARD to catch any unregistered cmd
+    /// for the given OEMNumber.
+    ///
+    /// @param[in] oen - the OEM Number.
+    /// @param[in] cmd - the Command.
+    /// @param[in] handler - the handler to call given that OEN and
+    ///                      command.
+    virtual void registerHandler(Number oen, ipmi_cmd_t cmd,
+                                 Handler handler) = 0;
+};
+
+/// Expose mutable Router for configuration & activation.
+///
+/// @returns pointer to OEM Router to use.
+Router* mutableRouter();
+
+/// Convert a group to an OEN.
+///
+/// @param[in] oeg - request buffer for IPMI command.
+/// @return the OEN.
+constexpr Number toOemNumber(const uint8_t oeg[groupMagicSize])
+{
+    return (oeg[2] << 16) | (oeg[1] << 8) | oeg[0];
+}
+
+/// Given a Group convert to an OEN.
+///
+/// @param[in] oeg - OEM Group reference.
+/// @return the OEN.
+constexpr Number toOemNumber(const Group& oeg)
+{
+    return (oeg[2] << 16) | (oeg[1] << 8) | oeg[0];
+}
+
+/// Given an OEN, conver to the OEM Group.
+///
+/// @param[in] oen - the OEM Number.
+/// @return the OEM Group.
+constexpr Group toOemGroup(Number oen)
+{
+    return Group{static_cast<uint8_t>(oen), static_cast<uint8_t>(oen >> 8),
+                 static_cast<uint8_t>(oen >> 16)};
+}
+
+} // namespace oem