diff --git a/libqblock/libqblock-types.h b/libqblock/libqblock-types.h
new file mode 100644
index 0000000..3389bda
--- /dev/null
+++ b/libqblock/libqblock-types.h
@@ -0,0 +1,228 @@
+#ifndef LIBQBLOCK_TYPES_H
+#define LIBQBLOCK_TYPES_H
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+/* this library is designed around this core struct. */
+struct QBlockState;
+
+/* every thread would have a broker. */
+struct QBroker;
+
+/* flag used in open and create */
+#define LIBQBLOCK_O_RDWR        0x0002
+/* do not use the host page cache */
+#define LIBQBLOCK_O_NOCACHE     0x0020
+/* use write-back caching */
+#define LIBQBLOCK_O_CACHE_WB    0x0040
+/* don't open the backing file */
+#define LIBQBLOCK_O_NO_BACKING  0x0100
+/* disable flushing on this disk */
+#define LIBQBLOCK_O_NO_FLUSH    0x0200
+
+#define LIBQBLOCK_O_CACHE_MASK \
+   (LIBQBLOCK_O_NOCACHE | LIBQBLOCK_O_CACHE_WB | LIBQBLOCK_O_NO_FLUSH)
+
+#define LIBQBLOCK_O_VALID_MASK \
+   (LIBQBLOCK_O_RDWR | LIBQBLOCK_O_NOCACHE | LIBQBLOCK_O_CACHE_WB | \
+    LIBQBLOCK_O_NO_BACKING | LIBQBLOCK_O_NO_FLUSH)
+
+enum QBlockProtocol {
+    QB_PROTO_NONE = 0,
+    QB_PROTO_FILE,
+    QB_PROTO_MAX
+};
+
+enum QBlockFormat {
+    QB_FMT_NONE = 0,
+    QB_FMT_COW,
+    QB_FMT_QED,
+    QB_FMT_QCOW,
+    QB_FMT_QCOW2,
+    QB_FMT_RAW,
+    QB_FMT_RBD,
+    QB_FMT_SHEEPDOG,
+    QB_FMT_VDI,
+    QB_FMT_VMDK,
+    QB_FMT_VPC,
+    QB_FMT_MAX
+};
+
+struct QBlockOption_prot_file {
+    char *filename;
+};
+
+union QBlockOption_prot {
+    struct QBlockOption_prot_file o_file;
+};
+
+/**
+ * struct QBlockOptionLoc: contains information about how to find the image
+ *
+ * @prot_type: protocol type, now only support FILE.
+ * @prot_op: protocol related options.
+ */
+struct QBlockOptionLoc {
+    enum QBlockProtocol prot_type;
+    union QBlockOption_prot prot_op;
+    uint8_t reserved[512];
+};
+
+/* format related options */
+struct QBlockOption_fmt_cow {
+    size_t virt_size;
+    struct QBlockOptionLoc backing_loc;
+};
+
+struct QBlockOption_fmt_qed {
+    size_t virt_size;
+    struct QBlockOptionLoc backing_loc;
+    enum QBlockFormat backing_fmt;
+    size_t cluster_size; /* unit is bytes */
+    size_t table_size; /* unit is clusters */
+};
+
+struct QBlockOption_fmt_qcow {
+    size_t virt_size;
+    struct QBlockOptionLoc backing_loc;
+    bool encrypt;
+};
+
+/* "Compatibility level (0.10 or 1.1)" */
+enum QBlockOption_fmt_qcow2_cpt {
+    QBO_FMT_QCOW2_CPT_NONE = 0,
+    QBO_FMT_QCOW2_CPT_V010,
+    QBO_FMT_QCOW2_CPT_V110,
+};
+
+/* off or metadata */
+enum QBlockOption_fmt_qcow2_prealloc {
+    QBO_FMT_QCOW2_PREALLOC_NONE = 0,
+    QBO_FMT_QCOW2_PREALLOC_OFF,
+    QBO_FMT_QCOW2_PREALLOC_METADATA,
+};
+
+struct QBlockOption_fmt_qcow2 {
+    size_t virt_size;
+    struct QBlockOptionLoc backing_loc;
+    enum QBlockFormat backing_fmt;
+    bool encrypt;
+    size_t cluster_size; /* unit is bytes */
+    enum QBlockOption_fmt_qcow2_cpt cpt_lv;
+    enum QBlockOption_fmt_qcow2_prealloc pre_mode;
+};
+
+struct QBlockOption_fmt_raw {
+    size_t virt_size;
+};
+
+struct QBlockOption_fmt_rbd {
+    size_t virt_size;
+    size_t cluster_size;
+};
+
+/* off or full */
+enum QBlockOption_fmt_sheepdog_prealloc {
+    QBO_FMT_SD_PREALLOC_NONE = 0,
+    QBO_FMT_SD_PREALLOC_OFF,
+    QBO_FMT_SD_PREALLOC_FULL,
+};
+
+struct QBlockOption_fmt_sheepdog {
+    size_t virt_size;
+    struct QBlockOptionLoc backing_loc;
+    enum QBlockOption_fmt_sheepdog_prealloc pre_mode;
+};
+
+enum QBlockOption_fmt_vdi_prealloc {
+    QBO_FMT_VDI_PREALLOC_NONE = 0,
+    QBO_FMT_VDI_PREALLOC_FALSE,
+    QBO_FMT_VDI_PREALLOC_TRUE,
+};
+
+struct QBlockOption_fmt_vdi {
+    size_t virt_size;
+    size_t cluster_size;
+    enum QBlockOption_fmt_vdi_prealloc pre_mode;
+};
+
+/* whether compact to vmdk verion 6 */
+enum QBlockOption_fmt_vmdk_cpt {
+    QBO_FMT_VMDK_CPT_NONE = 0,
+    QBO_FMT_VMDK_CPT_VMDKV6_FALSE,
+    QBO_FMT_VMDK_CPT_VMDKV6_TRUE,
+};
+
+/* vmdk flat extent format, values:
+"{monolithicSparse (default) | monolithicFlat | twoGbMaxExtentSparse |
+twoGbMaxExtentFlat | streamOptimized} */
+enum QBlockOption_fmt_vmdk_subfmt {
+    QBO_FMT_VMDK_SUBFMT_MONOLITHIC_NONE = 0,
+    QBO_FMT_VMDK_SUBFMT_MONOLITHIC_SPARSE,
+    QBO_FMT_VMDK_SUBFMT_MONOLITHIC_FLAT,
+    QBO_FMT_VMDK_SUBFMT_TWOGBMAX_EXTENT_SPARSE,
+    QBO_FMT_VMDK_SUBFMT_TWOGBMAX_EXTENT_FLAT,
+    QBO_FMT_VMDK_SUBFMT_STREAM_OPTIMIZED,
+};
+
+struct QBlockOption_fmt_vmdk {
+    size_t virt_size;
+    struct QBlockOptionLoc backing_loc;
+    enum QBlockOption_fmt_vmdk_cpt cpt_lv;
+    enum QBlockOption_fmt_vmdk_subfmt subfmt;
+};
+
+/* "{dynamic (default) | fixed} " */
+enum QBlockOption_fmt_vpc_subfmt {
+    QBO_FMT_VPC_SUBFMT_NONE = 0,
+    QBO_FMT_VPC_SUBFMT_DYNAMIC,
+    QBO_FMT_VPC_SUBFMT_FIXED,
+};
+
+struct QBlockOption_fmt_vpc {
+    size_t virt_size;
+    enum QBlockOption_fmt_vpc_subfmt subfmt;
+};
+
+union QBlockOption_fmt {
+    struct QBlockOption_fmt_cow       o_cow;
+    struct QBlockOption_fmt_qed       o_qed;
+    struct QBlockOption_fmt_qcow      o_qcow;
+    struct QBlockOption_fmt_qcow2     o_qcow2;
+    struct QBlockOption_fmt_raw       o_raw;
+    struct QBlockOption_fmt_rbd       o_rbd;
+    struct QBlockOption_fmt_sheepdog  o_sheepdog;
+    struct QBlockOption_fmt_vdi       o_vdi;
+    struct QBlockOption_fmt_vmdk      o_vmdk;
+    struct QBlockOption_fmt_vpc       o_vpc;
+};
+
+struct QBlockOptionFormat {
+    enum QBlockFormat fmt_type;
+    union QBlockOption_fmt fmt_op;
+    uint8_t reserved[512];
+};
+
+/**
+ * QBlockInfoImageStatic: information about the block image.
+ *
+ * @loc: location info.
+ * @fmt_type: format type.
+ * @virt_size: virtual size in bytes.
+ * @backing_loc: backing file location, its type is QB_PROT_NONE if not exist.
+ * @allocated_size: allocated size in bytes, negative if not available.
+ * @encrypt: encrypt flag.
+ */
+struct QBlockInfoImageStatic {
+    struct QBlockOptionLoc loc;
+    enum QBlockFormat fmt_type;
+    size_t virt_size;
+    /* advance info */
+    struct QBlockOptionLoc backing_loc;
+    size_t allocated_size;
+    bool encrypt;
+};
+#endif
