diff --git a/doc/ue_manifest.ksy b/doc/ue_manifest.ksy
new file mode 100644
index 0000000..216c0f1
--- /dev/null
+++ b/doc/ue_manifest.ksy
@@ -0,0 +1,249 @@
+meta:
+  id: ue_manifest
+  file-extension: manifest
+  endian: le
+seq:
+  - id: magic
+    contents: [0x0C, 0xC0, 0xBE, 0x44]
+  - id: header_size
+    type: u4
+  - id: header
+    size: header_size - 8
+    type: header
+  - id: body_compressed
+    size-eos: true
+    type: body
+    process: zlib
+    if: header.stored_as == stored_as_flag::compressed
+  - id: body_uncompressed
+    size-eos: true
+    type: body
+    if: header.stored_as == stored_as_flag::uncompressed
+types:
+  header:
+    seq:
+      - id: size_uncompressed
+        type: u4
+      - id: size_compressed
+        type: u4
+      - id: sha1_hash
+        size: 20
+      - id: stored_as
+        type: u1
+        enum: stored_as_flag
+      - id: version
+        type: u4
+  body:
+    seq:
+      - id: meta_size
+        type: u4
+      - id: metadata
+        size: meta_size - 4
+        type: metadata
+      - id: cdl_size
+        type: u4
+      - id: chunk_data_list
+        type: chunk_data_list
+        size: cdl_size - 4
+      - id: fml_size
+        type: u4
+      - id: file_manifest_list
+        type: file_manifest_list
+        size: fml_size - 4
+      - id: custom_data_size
+        type: u4
+      - id: custom_fields
+        type: custom_fields
+        size: custom_data_size - 4
+  metadata:
+    seq:
+      - id: data_version
+        type: u1
+      - id: feature_level
+        type: u4
+      - id: is_file_data
+        type: u1
+      - id: app_id
+        type: u4
+      - id: app_name
+        type: fstring
+      - id: build_version
+        type: fstring
+      - id: launch_exe
+        type: fstring
+      - id: launch_command
+        type: fstring
+      - id: prereq_ids_num
+        type: u4
+      - id: prereq_ids
+        type: fstring
+        repeat: expr
+        repeat-expr: prereq_ids_num
+      - id: prereq_name 
+        type: fstring
+      - id: prereq_path 
+        type: fstring
+      - id: prereq_args 
+        type: fstring
+      - id: build_id
+        type: fstring
+        if: data_version > 0
+  chunk_data_list:
+    seq:
+      - id: version
+        type: u1
+      - id: count
+        type: u4
+      - id: guids
+        size: 16
+        repeat: expr
+        repeat-expr: count
+      - id: ue_hashes
+        type: u8
+        repeat: expr
+        repeat-expr: count
+      - id: sha_hashes
+        size: 20
+        repeat: expr
+        repeat-expr: count
+      - id: group_nums
+        type: u1
+        repeat: expr
+        repeat-expr: count
+      - id: window_sizes
+        type: u4
+        repeat: expr
+        repeat-expr: count
+      - id: file_sizes
+        type: u4
+        repeat: expr
+        repeat-expr: count
+  file_manifest_list:
+    seq:
+      - id: version
+        type: u1
+      - id: count
+        type: u4
+      - id: filenames
+        type: fstring
+        repeat: expr
+        repeat-expr: count
+      - id: symlink_targets
+        type: fstring
+        repeat: expr
+        repeat-expr: count
+      - id: sha_hashes
+        size: 20
+        repeat: expr
+        repeat-expr: count
+      - id: flags
+        type: u1
+        enum: file_flags
+        repeat: expr
+        repeat-expr: count
+      - id: tags
+        type: tags
+        repeat: expr
+        repeat-expr: count
+      - id: chunk_parts
+        type: chunk_parts
+        repeat: expr
+        repeat-expr: count
+      - id: md5_hashes
+        if: version > 0
+        type: md5_hash
+        repeat: expr
+        repeat-expr: count
+      - id: mime_types
+        if: version > 0
+        type: fstring
+        repeat: expr
+        repeat-expr: count
+      - id: sha256_hashes
+        if: version > 1
+        size: 32
+        repeat: expr
+        repeat-expr: count
+  custom_fields:
+    seq:
+      - id: version
+        type: u1
+      - id: count
+        type: u4
+      - id: keys
+        type: fstring
+        repeat: expr
+        repeat-expr: count
+      - id: values
+        type: fstring
+        repeat: expr
+        repeat-expr: count
+  fstring:
+    seq:
+      - id: length
+        type: s4
+      - id: value_ascii
+        size: length
+        type: str
+        encoding: 'ASCII'
+        if: length >= 0
+      - id: value_utf16
+        size: -2 * length
+        type: str
+        encoding: 'UTF-16LE'
+        if: length < 0
+    instances:
+      value:
+        value: 'length >= 0 ? value_ascii : value_utf16'
+        if: length >= 0 or length < 0
+  tags:
+    seq:
+      - id: count
+        type: u4
+      - id: tag
+        type: fstring
+        repeat: expr
+        repeat-expr: count
+  chunk_parts:
+    seq:
+      - id: count
+        type: u4
+      - id: elements
+        type: chunk_part_entry
+        repeat: expr
+        repeat-expr: count
+  chunk_part_entry:
+    seq:
+      - id: entry_size
+        type: u4
+      - id: chunk_part
+        type: chunk_part
+        size: entry_size - 4
+  chunk_part:
+    seq:
+      - id: guid
+        size: 16
+      - id: offset
+        type: u4
+      - id: size
+        type: u4
+  md5_hash:
+    seq:
+      - id: has_md5
+        type: u4
+      - id: md5
+        size: 16
+        if: has_md5 != 0
+instances:
+  body:
+    value: 'header.stored_as == stored_as_flag::compressed ? body_compressed : body_uncompressed'
+    if: header.stored_as == stored_as_flag::compressed or header.stored_as == stored_as_flag::uncompressed
+enums:
+  stored_as_flag:
+    0x0: uncompressed
+    0x1: compressed
+  file_flags:
+    0x0: none
+    0x1: read_only
+    0x2: compressed
+    0x4: unix_executable
\ No newline at end of file