diff --git a/mboxd.h b/mboxd.h
new file mode 100644
index 0000000..8fd3183
--- /dev/null
+++ b/mboxd.h
@@ -0,0 +1,116 @@
+/* SPDX-License-Identifier: Apache-2.0 */
+/* Copyright (C) 2018 IBM Corp. */
+
+#ifndef MBOX_H
+#define MBOX_H
+
+#include <mtd/mtd-abi.h>
+#include <systemd/sd-bus.h>
+#include <poll.h>
+#include <stdbool.h>
+
+#include "protocol.h"
+#include "transport.h"
+#include "vpnor/mboxd_pnor_partition_table.h"
+#include "windows.h"
+
+enum api_version {
+	API_VERSION_INVAL	= 0,
+	API_VERSION_1		= 1,
+	API_VERSION_2		= 2
+};
+
+#define API_MIN_VERSION			API_VERSION_1
+#define API_MAX_VERSION			API_VERSION_2
+
+#define THIS_NAME			"Mailbox Daemon"
+
+/* Argument Flags */
+#define FLAGS_NONE			0x00
+#define FLAGS_SHORT_LIFETIME		0x01
+
+/* BMC Event Notification */
+#define BMC_EVENT_REBOOT		0x01
+#define BMC_EVENT_WINDOW_RESET		0x02
+#define BMC_EVENT_ACK_MASK		(BMC_EVENT_REBOOT | \
+					BMC_EVENT_WINDOW_RESET)
+#define BMC_EVENT_FLASH_CTRL_LOST	0x40
+#define BMC_EVENT_DAEMON_READY		0x80
+#define BMC_EVENT_V1_MASK		BMC_EVENT_REBOOT
+#define BMC_EVENT_V2_MASK		(BMC_EVENT_REBOOT | \
+					BMC_EVENT_WINDOW_RESET | \
+					BMC_EVENT_FLASH_CTRL_LOST | \
+					BMC_EVENT_DAEMON_READY)
+
+/* Put polled file descriptors first */
+#define DBUS_FD			0
+#define MBOX_FD			1
+#define SIG_FD			2
+#define POLL_FDS		3 /* Number of FDs we poll on */
+#define LPC_CTRL_FD		3
+#define MTD_FD			4
+#define TOTAL_FDS		5
+
+#define MAPS_FLASH		(1 << 0)
+#define MAPS_MEM		(1 << 1)
+#define STATE_SUSPENDED		(1 << 7)
+
+enum mbox_state {
+	/* Still Initing */
+	UNINITIALISED = 0,
+	/* Active and LPC Maps Flash */
+	ACTIVE_MAPS_FLASH = MAPS_FLASH,
+	/* Suspended and LPC Maps Flash */
+	SUSPEND_MAPS_FLASH = STATE_SUSPENDED | MAPS_FLASH,
+	/* Active and LPC Maps Memory */
+	ACTIVE_MAPS_MEM = MAPS_MEM,
+	/* Suspended and LPC Maps Memory */
+	SUSPEND_MAPS_MEM = STATE_SUSPENDED | MAPS_MEM
+};
+
+struct mbox_context {
+	enum api_version version;
+	const struct protocol_ops *protocol;
+	const struct transport_ops *transport;
+
+/* System State */
+	enum mbox_state state;
+	struct pollfd fds[TOTAL_FDS];
+	sd_bus *bus;
+	bool terminate;
+	uint8_t bmc_events;
+	uint8_t prev_seq;
+
+/* Window State */
+	/* The window list struct containing all current "windows" */
+	struct window_list windows;
+	/* The window the host is currently pointed at */
+	struct window_context *current;
+	/* Is the current window a write one */
+	bool current_is_write;
+
+/* Memory & Flash State */
+	/* Reserved Memory Region */
+	void *mem;
+	/* Reserved Mem Size (bytes) */
+	uint32_t mem_size;
+	/* LPC Bus Base Address (bytes) */
+	uint32_t lpc_base;
+	/* Flash size from command line (bytes) */
+	uint32_t flash_size;
+	/* Bytemap of the erased state of the entire flash */
+	uint8_t *flash_bmap;
+	/* Erase size (as a shift) */
+	uint32_t erase_size_shift;
+	/* Block size (as a shift) */
+	uint32_t block_size_shift;
+	/* Actual Flash Info */
+	struct mtd_info_user mtd_info;
+#ifdef VIRTUAL_PNOR_ENABLED
+	/* Virtual PNOR partition table */
+	struct vpnor_partition_table *vpnor;
+	struct vpnor_partition_paths paths;
+#endif
+};
+
+#endif /* MBOX_H */