diff --git a/tools/protos/Android.bp b/tools/protos/Android.bp
new file mode 100644
index 0000000..c6ad19e
--- /dev/null
+++ b/tools/protos/Android.bp
@@ -0,0 +1,32 @@
+// Copyright 2023 Google Inc. All rights reserved.
+//
+// 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.
+
+package {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+python_library_host {
+    name: "metadata_file_proto_py",
+    version: {
+        py3: {
+            enabled: true,
+        },
+    },
+    srcs: [
+        "metadata_file.proto",
+    ],
+    proto: {
+        canonical_path_from_root: false,
+    },
+}
diff --git a/tools/protos/metadata_file.proto b/tools/protos/metadata_file.proto
new file mode 100644
index 0000000..ac1129a
--- /dev/null
+++ b/tools/protos/metadata_file.proto
@@ -0,0 +1,281 @@
+// Copyright (C) 2023 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.
+
+syntax = "proto2";
+
+package metadata_file;
+
+// Proto definition of METADATA files of packages in AOSP codebase.
+message Metadata {
+  // Name of the package.
+  optional string name = 1;
+
+  // A short description (a few lines) of the package.
+  // Example: "Handles location lookups, throttling, batching, etc."
+  optional string description = 2;
+
+  // Specifies additional data about third-party packages.
+  optional ThirdParty third_party = 3;
+}
+
+message ThirdParty {
+  // URL(s) associated with the package.
+  //
+  // At a minimum, all packages must specify a URL which identifies where it
+  // came from, containing a type of: ARCHIVE, GIT or OTHER. Typically,
+  // a package should contain only a single URL from these types.  Occasionally,
+  // a package may be broken across multiple archive files for whatever reason,
+  // in which case having multiple ARCHIVE URLs is okay.  However, this should
+  // not be used to combine different logical packages that are versioned and
+  // possibly licensed differently.
+  repeated URL url = 1;
+
+  // The package version.  In order of preference, this should contain:
+  //  - If the package comes from Git or another source control system,
+  //    a specific tag or revision in source control, such as "r123" or
+  //    "58e27d2".  This MUST NOT be a mutable ref such as a branch name.
+  //  - a released package version such as "1.0", "2.3-beta", etc.
+  //  - the date the package was retrieved, formatted as "As of YYYY-MM-DD".
+  optional string version = 2;
+
+  // The date of the change in which the package was last upgraded from
+  // upstream.
+  // This should only identify package upgrades from upstream, not local
+  // modifications. This may identify the date of either the original or
+  // merged change.
+  //
+  // Note: this is NOT the date that this version of the package was released
+  // externally.
+  optional Date last_upgrade_date = 3;
+
+  // License type that identifies how the package may be used.
+  optional LicenseType license_type = 4;
+
+  // An additional note explaining the licensing of this package.  This is most
+  // commonly used with commercial license.
+  optional string license_note = 5;
+
+  // Description of local changes that have been made to the package.  This does
+  // not need to (and in most cases should not) attempt to include an exhaustive
+  // list of all changes, but may instead direct readers to review the local
+  // commit history, a collection of patch files, a separate README.md (or
+  // similar) document, etc.
+  // Note: Use of this field to store IDs of advisories fixed with a backported
+  // patch is deprecated, use "security.mitigated_security_patch" instead.
+  optional string local_modifications = 6;
+
+  // Security related metadata including risk category and any special
+  // instructions for using the package, as determined by an ISE-TPS review.
+  optional Security security = 7;
+
+  // The type of directory this metadata represents.
+  optional DirectoryType type = 8 [default = PACKAGE];
+
+  // The homepage for the package. This will eventually replace
+  // `url { type: HOMEPAGE }`
+  optional string homepage = 9;
+
+  // SBOM information of the package. It is mandatory for prebuilt packages.
+  oneof sbom {
+    // Reference to external SBOM document provided as URL.
+    SBOMRef sbom_ref = 10;
+  }
+
+}
+
+// URL associated with a third-party package.
+message URL {
+  enum Type {
+    // The homepage for the package. For example, "https://bazel.io/". This URL
+    // is optional, but encouraged to help disambiguate similarly named packages
+    // or to get more information about the package. This is especially helpful
+    // when no other URLs provide human readable resources (such as git:// or
+    // sso:// URLs).
+    HOMEPAGE = 1;
+
+    // The URL of the archive containing the source code for the package, for
+    // example a zip or tgz file.
+    ARCHIVE = 2;
+
+    // The URL of the upstream git repository this package is retrieved from.
+    // For example:
+    //  - https://github.com/git/git.git
+    //  - git://git.kernel.org/pub/scm/git/git.git
+    //
+    // Use of a git URL requires that the package "version" value must specify a
+    // specific git tag or revision.
+    GIT = 3;
+
+    // The URL of the upstream SVN repository this package is retrieved from.
+    // For example:
+    //  - http://llvm.org/svn/llvm-project/llvm/
+    //
+    // Use of an SVN URL requires that the package "version" value must specify
+    // a specific SVN tag or revision.
+    SVN = 4;
+
+    // The URL of the upstream mercurial repository this package is retrieved
+    // from. For example:
+    //   - https://mercurial-scm.org/repo/evolve
+    //
+    // Use of a mercurial URL requires that the package "version" value must
+    // specify a specific tag or revision.
+    HG = 5;
+
+    // The URL of the upstream darcs repository this package is retrieved
+    // from. For example:
+    //   - https://hub.darcs.net/hu.dwim/hu.dwim.util
+    //
+    // Use of a DARCS URL requires that the package "version" value must
+    // specify a specific tag or revision.
+    DARCS = 6;
+
+    PIPER = 7;
+
+    // A URL that does not fit any other type. This may also indicate that the
+    // source code was received via email or some other out-of-band way. This is
+    // most commonly used with commercial software received directly from the
+    // vendor. In the case of email, the URL value can be used to provide
+    // additional information about how it was received.
+    OTHER = 8;
+
+    // The URL identifying where the local copy of the package source code can
+    // be found.
+    //
+    // Typically, the metadata files describing a package reside in the same
+    // directory as the source code for the package. In a few rare cases where
+    // they are separate, the LOCAL_SOURCE URL identifies where to find the
+    // source code. This only describes where to find the local copy of the
+    // source; there should always be an additional URL describing where the
+    // package was retrieved from.
+    //
+    // Examples:
+    //  - https://android.googlesource.com/platform/external/apache-http/
+    LOCAL_SOURCE = 9;
+  }
+
+  // The type of resource this URL identifies.
+  optional Type type = 1;
+
+  // The actual URL value.  URLs should be absolute and start with 'http://' or
+  // 'https://' (or occasionally 'git://' or 'ftp://' where appropriate).
+  optional string value = 2;
+}
+
+// License type that identifies how the packages may be used.
+enum LicenseType {
+  BY_EXCEPTION_ONLY = 1;
+  NOTICE = 2;
+  PERMISSIVE = 3;
+  RECIPROCAL = 4;
+  RESTRICTED_IF_STATICALLY_LINKED = 5;
+  RESTRICTED = 6;
+  UNENCUMBERED = 7;
+}
+
+// Identifies security related metadata including risk category and any special
+// instructions for using the package.
+message Security {
+  // Security risk category for a package, as determined by an ISE-TPS review.
+  enum Category {
+    CATEGORY_UNSPECIFIED = 0;
+
+    // Package should only be used in a sandboxed environment.
+    // Package should have restricted visibility.
+    SANDBOXED_ONLY = 1;
+
+    // Package should not be used to process user content. It is considered
+    // safe to use to process trusted data only. Package should have restricted
+    // visibility.
+    TRUSTED_DATA_ONLY = 2;
+
+    // Package is considered safe to use.
+    REVIEWED_AND_SECURE = 3;
+  }
+
+  // Identifies the security risk category for the package.  This will be
+  // provided by the ISE-TPS team as the result of a security review of the
+  // package.
+  optional Category category = 1;
+
+  // An additional security note for the package.
+  optional string note = 2;
+
+  // Text tag to categorize the package. It's currently used by security to:
+  // - to disable OSV (https://osv.dev)
+  // support via the `OSV:disable` tag
+  // - to attach CPE to their corresponding packages, for vulnerability
+  // monitoring:
+  //
+  // Please do document your usecase here should you want to add one.
+  repeated string tag = 3;
+
+  // ID of advisories fixed with a mitigated patch, for example CVE-2018-1111.
+  repeated string mitigated_security_patch = 4;
+}
+
+enum DirectoryType {
+  UNDEFINED = 0;
+
+  // This directory represents a package.
+  PACKAGE = 1;
+
+  // This directory is designed to organize multiple third-party PACKAGE
+  // directories.
+  GROUP = 2;
+
+  // This directory contains several PACKAGE directories representing
+  // different versions of the same third-party project.
+  VERSIONS = 3;
+}
+
+// Represents a whole or partial calendar date, such as a birthday. The time of
+// day and time zone are either specified elsewhere or are insignificant. The
+// date is relative to the Gregorian Calendar. This can represent one of the
+// following:
+//
+// * A full date, with non-zero year, month, and day values.
+// * A month and day, with a zero year (for example, an anniversary).
+// * A year on its own, with a zero month and a zero day.
+// * A year and month, with a zero day (for example, a credit card expiration
+//   date).
+message Date {
+  // Year of the date. Must be from 1 to 9999, or 0 to specify a date without
+  // a year.
+  optional int32 year = 1;
+  // Month of a year. Must be from 1 to 12, or 0 to specify a year without a
+  // month and day.
+  optional int32 month = 2;
+  // Day of a month. Must be from 1 to 31 and valid for the year and month, or 0
+  // to specify a year by itself or a year and month where the day isn't
+  // significant.
+  optional int32 day = 3;
+}
+
+// Reference to external SBOM document and element corresponding to the package.
+// See https://spdx.github.io/spdx-spec/v2.3/document-creation-information/#66-external-document-references-field
+message SBOMRef {
+  // The URL that points to the SBOM document of the upstream package of this
+  // third_party package.
+  optional string url = 1;
+  // Checksum of the SBOM document the url field points to.
+  // Format: e.g. SHA1:<checksum>, or any algorithm defined in
+  // https://spdx.github.io/spdx-spec/v2.3/file-information/#8.4
+  optional string checksum = 2;
+  // SPDXID of the upstream package/file defined in the SBOM document the url field points to.
+  // Format: SPDXRef-[a-zA-Z0-9.-]+, see
+  // https://spdx.github.io/spdx-spec/v2.3/package-information/#72-package-spdx-identifier-field or
+  // https://spdx.github.io/spdx-spec/v2.3/file-information/#82-file-spdx-identifier-field
+  optional string element_id = 3;
+}
\ No newline at end of file