diff --git a/microdroid/payload/metadata/Android.bp b/microdroid/payload/metadata/Android.bp
new file mode 100644
index 0000000..4b23394
--- /dev/null
+++ b/microdroid/payload/metadata/Android.bp
@@ -0,0 +1,16 @@
+package {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+rust_library {
+    name: "libmicrodroid_metadata",
+    host_supported: true,
+    crate_name: "microdroid_metadata",
+    srcs: ["src/lib.rs"],
+    prefer_rlib: true,
+    edition: "2018",
+    rustlibs: [
+        "libmicrodroid_metadata_proto_rust",
+        "libprotobuf",
+    ],
+}
diff --git a/microdroid/payload/metadata/src/lib.rs b/microdroid/payload/metadata/src/lib.rs
new file mode 100644
index 0000000..9c97411
--- /dev/null
+++ b/microdroid/payload/metadata/src/lib.rs
@@ -0,0 +1,42 @@
+// Copyright 2021, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Read/write metadata blob for VM payload image. The blob is supposed to be used as a metadata
+//! partition in the VM payload image.
+//! The layout of metadata blob is like:
+//!   4 bytes : size(N) in big endian
+//!   N bytes : protobuf message for Metadata
+
+use protobuf::Message;
+use std::io;
+use std::io::Read;
+use std::io::Write;
+
+pub use microdroid_metadata::metadata::{ApexPayload, ApkPayload, Metadata};
+
+/// Reads a metadata from a reader
+pub fn read_metadata<T: Read>(mut r: T) -> io::Result<Metadata> {
+    let mut buf = [0u8; 4];
+    r.read_exact(&mut buf)?;
+    let size = i32::from_be_bytes(buf);
+    Ok(Metadata::parse_from_reader(&mut r.take(size as u64))?)
+}
+
+/// Writes a metadata to a writer
+pub fn write_metadata<T: Write>(metadata: &Metadata, mut w: T) -> io::Result<()> {
+    let mut buf = Vec::new();
+    metadata.write_to_writer(&mut buf)?;
+    w.write_all(&(buf.len() as i32).to_be_bytes())?;
+    w.write_all(&buf)
+}