diff --git a/scripts/OWNERS b/scripts/OWNERS
index 8f912ddf4..ae8a4cf12 100644
--- a/scripts/OWNERS
+++ b/scripts/OWNERS
@@ -3,5 +3,5 @@ danalbert@google.com
 enh@google.com
 jmgao@google.com
 rprichard@google.com
-per-file cargo2android.py,get_rust_pkg.py = chh@google.com,srhines@google.com
+per-file add3prf.py,cargo2android.py,get_rust_pkg.py = chh@google.com,srhines@google.com
 per-file codegen = eugenesusla@google.com
diff --git a/scripts/add3prf.py b/scripts/add3prf.py
new file mode 100755
index 000000000..6b1b13c11
--- /dev/null
+++ b/scripts/add3prf.py
@@ -0,0 +1,298 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2020 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.
+"""Add files to a Rust package for third party review."""
+
+import datetime
+import json
+import os
+import pathlib
+import re
+
+# patterns to match keys in Cargo.toml
+NAME_PATTERN = r"^name *= *\"(.+)\""
+NAME_MATCHER = re.compile(NAME_PATTERN)
+VERSION_PATTERN = r"^version *= *\"(.+)\""
+VERSION_MATCHER = re.compile(VERSION_PATTERN)
+DESCRIPTION_PATTERN = r"^description *= *(\".+\")"
+DESCRIPTION_MATCHER = re.compile(DESCRIPTION_PATTERN)
+# NOTE: This description one-liner pattern fails to match
+# multi-line descriptions in some Rust crates, e.g. shlex.
+
+# patterns to match year/month/day in METADATA
+YMD_PATTERN = r"^ +(year|month|day): (.+)$"
+YMD_MATCHER = re.compile(YMD_PATTERN)
+YMD_LINE_PATTERN = r"^.* year: *([^ ]+) +month: *([^ ]+) +day: *([^ ]+).*$"
+YMD_LINE_MATCHER = re.compile(YMD_LINE_PATTERN)
+
+# patterns to match Apache/MIT licence in LICENSE*
+APACHE_PATTERN = r"^.*Apache License.*$"
+APACHE_MATCHER = re.compile(APACHE_PATTERN)
+MIT_PATTERN = r"^.*MIT License.*$"
+MIT_MATCHER = re.compile(MIT_PATTERN)
+BSD_PATTERN = r"^.*BSD .*License.*$"
+BSD_MATCHER = re.compile(BSD_PATTERN)
+
+# default owners added to OWNERS
+DEFAULT_OWNERS = "include platform/prebuilts/rust:/OWNERS\n"
+
+# See b/159487435 Official policy for rust imports METADATA URLs.
+# "license_type: NOTICE" might be optional,
+# but it is already used in most rust crate METADATA.
+# This line format should match the output of external_updater.
+METADATA_CONTENT = """name: "{}"
+description: {}
+third_party {{
+  url {{
+    type: HOMEPAGE
+    value: "https://crates.io/crates/{}"
+  }}
+  url {{
+    type: ARCHIVE
+    value: "https://static.crates.io/crates/{}/{}-{}.crate"
+  }}
+  version: "{}"
+  license_type: NOTICE
+  last_upgrade_date {{
+    year: {}
+    month: {}
+    day: {}
+  }}
+}}
+"""
+
+
+def get_metadata_date():
+  """Return last_upgrade_date in METADATA or today."""
+  # When applied to existing directories to normalize METADATA,
+  # we don't want to change the last_upgrade_date.
+  year, month, day = "", "", ""
+  if os.path.exists("METADATA"):
+    with open("METADATA", "r") as inf:
+      for line in inf:
+        match = YMD_MATCHER.match(line)
+        if match:
+          if match.group(1) == "year":
+            year = match.group(2)
+          elif match.group(1) == "month":
+            month = match.group(2)
+          elif match.group(1) == "day":
+            day = match.group(2)
+        else:
+          match = YMD_LINE_MATCHER.match(line)
+          if match:
+            year, month, day = match.group(1), match.group(2), match.group(3)
+  if year and month and day:
+    print("### Reuse date in METADATA:", year, month, day)
+    return int(year), int(month), int(day)
+  today = datetime.date.today()
+  return today.year, today.month, today.day
+
+
+def add_metadata(name, version, description):
+  """Update or add METADATA file."""
+  if os.path.exists("METADATA"):
+    print("### Updating METADATA")
+  else:
+    print("### Adding METADATA")
+  year, month, day = get_metadata_date()
+  with open("METADATA", "w") as outf:
+    outf.write(METADATA_CONTENT.format(
+        name, description, name, name, name,
+        version, version, year, month, day))
+
+
+def grep_license_keyword(license_file):
+  """Find familiar patterns in a file and return the type."""
+  with open(license_file, "r") as input_file:
+    for line in input_file:
+      if APACHE_MATCHER.match(line):
+        return "APACHE2"
+      if MIT_MATCHER.match(line):
+        return "MIT"
+      if BSD_MATCHER.match(line):
+        return "BSD_LIKE"
+  print("ERROR: cannot decide license type in", license_file,
+        " assume BSD_LIKE")
+  return "BSD_LIKE"
+
+
+def decide_license_type():
+  """Check LICENSE* files to determine the license type."""
+  # Most crates.io packages have both APACHE and MIT.
+  if os.path.exists("LICENSE-APACHE"):
+    return "APACHE2"
+  if os.path.exists("LICENSE-MIT"):
+    return "MIT"
+  for license_file in ["LICENSE", "LICENSE.txt"]:
+    if os.path.exists(license_file):
+      return grep_license_keyword(license_file)
+  print("ERROR: missing LICENSE-{APACHE,MIT}; assume BSD_LIKE")
+  return "BSD_LIKE"
+
+
+def add_notice():
+  if not os.path.exists("NOTICE"):
+    if os.path.exists("LICENSE"):
+      os.symlink("LICENSE", "NOTICE")
+      print("Created link from NOTICE to LICENSE")
+    else:
+      print("ERROR: missing NOTICE and LICENSE")
+
+
+def license_link_target(license_type):
+  """Return the LICENSE-* target file for LICENSE link."""
+  if license_type == "APACHE2":
+    return "LICENSE-APACHE"
+  elif license_type == "MIT":
+    return "LICENSE-MIT"
+  elif license_type == "BSD_LIKE":
+    for name in ["LICENSE.txt"]:
+      if os.path.exists(name):
+        return name
+    print("### ERROR: cannot find LICENSE target")
+    return ""
+  else:
+    print("### ERROR; unknown license type:", license_type)
+    return ""
+
+
+def check_license_link(license_type):
+  """Check the LICENSE link, must match given type."""
+  if not os.path.islink("LICENSE"):
+    print("ERROR: LICENSE file is not a link")
+    return
+  target = os.readlink("LICENSE")
+  expected = license_link_target(license_type)
+  if target != expected:
+    print("ERROR: found LICENSE link to", target,
+          "but expected", expected)
+
+
+def add_license(license_type):
+  """Add LICENSE related file."""
+  if os.path.exists("LICENSE"):
+    if os.path.islink("LICENSE"):
+      check_license_link(license_type)
+    else:
+      print("NOTE: found LICENSE and it is not a link!")
+    return
+  target = license_link_target(license_type)
+  print("### Creating LICENSE link to", target)
+  if target:
+    os.symlink(target, "LICENSE")
+  # error reported in license_link_target
+
+
+def add_module_license(license_type):
+  """Touch MODULE_LICENSE_type file."""
+  # Do not change existing MODULE_* files.
+  for suffix in ["MIT", "APACHE", "APACHE2", "BSD_LIKE"]:
+    module_file = "MODULE_LICENSE_" + suffix
+    if os.path.exists(module_file):
+      if license_type != suffix:
+        print("### ERROR: found unexpected", module_file)
+      return
+  module_file = "MODULE_LICENSE_" + license_type
+  pathlib.Path(module_file).touch()
+  print("### Touched", module_file)
+
+
+def found_line(file_name, line):
+  """Returns true if the given line is found in a file."""
+  with open(file_name, "r") as input_file:
+    return line in input_file
+
+
+def add_owners():
+  """Create or append OWNERS with the default owner line."""
+  # Existing OWNERS file might contain more than the default owners.
+  # Only append missing default owners to existing OWNERS.
+  if os.path.isfile("OWNERS"):
+    if found_line("OWNERS", DEFAULT_OWNERS):
+      print("### No change to OWNERS, which has already default owners.")
+      return
+    else:
+      print("### Append default owners to OWNERS")
+      mode = "a"
+  else:
+    print("### Creating OWNERS with default owners")
+    mode = "w"
+  with open("OWNERS", mode) as outf:
+    outf.write(DEFAULT_OWNERS)
+
+
+def toml2json(line):
+  """Convert a quoted toml string to a json quoted string for METADATA."""
+  if line.startswith("\"\"\""):
+    return "\"()\""  # cannot handle broken multi-line description
+  # TOML string escapes: \b \t \n \f \r \" \\ (no unicode escape)
+  line = line[1:-1].replace("\\\\", "\n").replace("\\b", "")
+  line = line.replace("\\t", " ").replace("\\n", " ").replace("\\f", " ")
+  line = line.replace("\\r", "").replace("\\\"", "\"").replace("\n", "\\")
+  # replace a unicode quotation mark, used in the libloading crate
+  line = line.replace("’", "'")
+  # strip and escape single quotes
+  return json.dumps(line.strip()).replace("'", "\\'")
+
+
+def parse_cargo_toml(cargo):
+  """get description string from Cargo.toml."""
+  name = ""
+  version = ""
+  description = ""
+  with open(cargo, "r") as toml:
+    for line in toml:
+      if not name:
+        match = NAME_MATCHER.match(line)
+        if match:
+          name = match.group(1)
+      if not version:
+        match = VERSION_MATCHER.match(line)
+        if match:
+          version = match.group(1)
+      if not description:
+        match = DESCRIPTION_MATCHER.match(line)
+        if match:
+          description = toml2json(match.group(1))
+      if name and version and description:
+        break
+  return name, version, description
+
+
+def main():
+  """Add 3rd party review files."""
+  cargo = "Cargo.toml"
+  if not os.path.isfile(cargo):
+    print("ERROR: ", cargo, "is not found")
+    return
+  if not os.access(cargo, os.R_OK):
+    print("ERROR: ", cargo, "is not readable")
+    return
+  name, version, description = parse_cargo_toml(cargo)
+  if not name or not version or not description:
+    print("ERROR: Cannot find name, version, or description in", cargo)
+    return
+  add_metadata(name, version, description)
+  add_owners()
+  license_type = decide_license_type()
+  add_license(license_type)
+  add_module_license(license_type)
+  # It is unclear yet if a NOTICE file is required.
+  # add_notice()
+
+
+if __name__ == "__main__":
+  main()
diff --git a/scripts/get_rust_pkg.py b/scripts/get_rust_pkg.py
index 11b4e0752..6b402aa19 100755
--- a/scripts/get_rust_pkg.py
+++ b/scripts/get_rust_pkg.py
@@ -56,6 +56,11 @@ def parse_args():
       "-v", action="store_true", default=False, help="echo executed commands")
   parser.add_argument(
       "-o", metavar="out_dir", default=".", help="output directory")
+  parser.add_argument(
+      "-add3prf", "--add3prf",
+      action="store_true",
+      default=False,
+      help="call add3prf.py to add third party review files")
   parser.add_argument(
       "-show", "--show",
       action="store_true",
@@ -159,6 +164,12 @@ def fetch_pkg(args, pkg, dl_path):
   echo(args, "delete temp directory {}".format(tmp_dir))
   shutil.rmtree(tmp_dir)
   print("SUCCESS: downloaded package to '{}'".format(dest_dir))
+  if args.add3prf:
+    echo(args, "Calling add3prf.py in {}".format(dest_dir))
+    cwd = os.getcwd()
+    os.chdir(dest_dir)
+    os.system("add3prf.py")
+    os.chdir(cwd)
   return True