diff --git a/docs/reference.md b/docs/reference.md
index b6b4b78..ea95bc8 100644
--- a/docs/reference.md
+++ b/docs/reference.md
@@ -143,6 +143,7 @@
     *   [partial_info_plist: [filename] Path plist from asset catalog compiler.](#var_partial_info_plist)
     *   [pool: [string] Label of the pool used by binary targets and actions.](#var_pool)
     *   [post_processing_args: [string list] Args for the post-processing script.](#var_post_processing_args)
+    *   [post_processing_manifest: [file] Name of the generated bundle manifest.](#var_post_processing_manifest)
     *   [post_processing_outputs: [file list] Outputs of the post-processing step.](#var_post_processing_outputs)
     *   [post_processing_script: [file name] Script for the post-processing step.](#var_post_processing_script)
     *   [post_processing_sources: [file list] Sources for the post-processing step.](#var_post_processing_sources)
@@ -1769,6 +1770,12 @@
   be defined and non-empty to inform when the script needs to be re-run. The
   `post_processing_args` will be passed as is to the script (so path have to be
   rebased) and additional inputs may be listed via `post_processing_sources`.
+
+  If `post_processing_manifest` is defined, then gn will write a file listing
+  the expected content of the generated bundle (one file per line). The file
+  can then be passed as a parameter to `post_processing_script` via the
+  `post_processing_args` array. This can only be set if `post_processing_script`
+  is set.
 ```
 
 #### **Variables**
@@ -1782,10 +1789,10 @@
            visibility
   Bundle vars: bundle_root_dir, bundle_contents_dir, bundle_resources_dir,
                bundle_executable_dir, bundle_deps_filter, product_type,
-               post_processing_args, post_processing_script,
-               post_processing_sources, post_processing_outputs,
-               xcode_extra_attributes, xcode_test_application_name,
-               partial_info_plist
+               post_processing_args, post_processing_manifest,
+               post_processing_script, post_processing_sources,
+               post_processing_outputs, xcode_extra_attributes,
+               xcode_test_application_name, partial_info_plist
 ```
 
 #### **Example**
@@ -1860,6 +1867,7 @@
         if (is_ios && code_signing) {
           deps += [ ":${app_name}_generate_executable" ]
           post_processing_script = "//build/config/ios/codesign.py"
+          post_processing_manifest = "$target_out_dir/$target_name.manifest"
           post_processing_sources = [
             invoker.entitlements_path,
             "$target_gen_dir/$app_name",
@@ -1878,6 +1886,7 @@
                 invoker.entitlements_path, root_build_dir),
             "-e=" + rebase_path(
                 "$target_gen_dir/$app_name.xcent", root_build_dir),
+            "-m=" + rebase_path(post_processing_manifest, root_build_dir),
             rebase_path(bundle_root_dir, root_build_dir),
           ]
         } else {
@@ -6394,6 +6403,15 @@
 
   See also "gn help create_bundle".
 ```
+### <a name="var_post_processing_manifest"></a>**post_processing_manifest**: [file] Name of the generated bundle manifest.&nbsp;[Back to Top](#gn-reference)
+
+```
+  Path where a manifest listing all the files found in the bundle will be
+  written for the post processing step. The path must be outside of the
+  bundle_root_dir.
+
+  See also "gen help create_bundle".
+```
 ### <a name="var_post_processing_outputs"></a>**post_processing_outputs**: [file list] Outputs of the post-processing step.&nbsp;[Back to Top](#gn-reference)
 
 ```
diff --git a/examples/ios/build/config/ios/scripts/check-manifest.py b/examples/ios/build/config/ios/scripts/check-manifest.py
new file mode 100644
index 0000000..1cb7771
--- /dev/null
+++ b/examples/ios/build/config/ios/scripts/check-manifest.py
@@ -0,0 +1,73 @@
+# Copyright 2025 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Check the content of a bundle according to a manifest."""
+
+import sys
+import os
+
+
+def write_if_needed(path, content):
+  """Write `content` to `path` if needed."""
+  if os.path.isfile(path):
+    # If the file exists and has the same content, skip writing.
+    with open(path, encoding='utf-8') as file:
+      if content == file.read():
+        return
+  with open(path, 'w', encoding='utf-8') as file:
+    file.write(content)
+    file.flush()
+
+
+
+def read_manifest(manifest_path):
+  """Read a manifest file."""
+  manifest_content = set()
+  with open(manifest_path, encoding='utf-8') as manifest_file:
+    for line in manifest_file:
+      assert line.endswith('\n')
+      manifest_content.add(line[:-1])
+  return manifest_content
+
+
+def main(args):
+  if len(args) != 3:
+    print(
+      f'usage: check-manifest.py bundle-dir manifest-path output-path',
+      file=sys.stderr)
+    return 1
+
+  bundle_dir, manifest_path, output_path = args
+  if not os.path.isdir(bundle_dir):
+    print(
+      f'error: {bundle_dir}: not a directory',
+      file=sys.stderr)
+    return 1
+
+  has_unexpected_files = False
+  manifest_content = read_manifest(manifest_path)
+  for dirpath, dirnames, filenames in os.walk(bundle_dir):
+    dirnames_to_skip = []
+    for dirname in dirnames:
+      subdirpath = os.path.relpath(os.path.join(dirpath, dirname), bundle_dir)
+      if subdirpath in manifest_content:
+        dirnames_to_skip.append(dirname)
+    if dirnames_to_skip:
+      dirnames[:] = list(set(dirnames) - set(dirnames_to_skip))
+    for filename in filenames:
+      filepath = os.path.relpath(os.path.join(dirpath, filename), bundle_dir)
+      if filepath not in manifest_content:
+        fullpath = os.path.normpath(os.path.join(bundle_dir, filepath))
+        print(f'error: {fullpath}: unexpected file', file=sys.stderr)
+        has_unexpected_files = True
+
+  write_if_needed(output_path, 'ko\n' if has_unexpected_files else 'ok\n')
+
+  if has_unexpected_files:
+    return 1
+
+  return 0
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv[1:]))
diff --git a/examples/ios/build/config/ios/templates/ios_binary_bundle.gni b/examples/ios/build/config/ios/templates/ios_binary_bundle.gni
index 1e7b73d..65775a0 100644
--- a/examples/ios/build/config/ios/templates/ios_binary_bundle.gni
+++ b/examples/ios/build/config/ios/templates/ios_binary_bundle.gni
@@ -119,6 +119,15 @@
     bundle_executable_dir = bundle_contents_dir
     bundle_resources_dir = bundle_contents_dir
 
+    post_processing_script = "//build/config/ios/scripts/check-manifest.py"
+    post_processing_manifest = "$target_out_dir/$target_name.manifest"
+    post_processing_outputs = [ "$post_processing_manifest.checked" ]
+    post_processing_args =
+        [
+          rebase_path(bundle_root_dir, root_build_dir),
+          rebase_path(post_processing_manifest, root_build_dir),
+        ] + rebase_path(post_processing_outputs, root_build_dir)
+
     xcode_extra_attributes = {
       CODE_SIGN_IDENTITY = ""
       CODE_SIGNING_REQUIRED = "NO"
diff --git a/misc/emacs/gn-mode.el b/misc/emacs/gn-mode.el
index f98093e..f72493a 100644
--- a/misc/emacs/gn-mode.el
+++ b/misc/emacs/gn-mode.el
@@ -85,15 +85,16 @@
     "asmflags" "assert_no_deps" "bundle_deps_filter" "bundle_executable_dir"
     "bundle_resources_dir" "bundle_root_dir" "cflags" "cflags_c" "cflags_cc"
     "cflags_objc" "cflags_objcc" "check_includes" "post_processing_args"
-    "post_processing_outputs" "post_processing_script" "post_processing_sources"
-    "complete_static_lib" "configs" "data" "data_deps" "defines" "depfile"
-    "deps" "framework_dir" "frameworks" "include_dirs" "inputs" "ldflags"
-    "lib_dirs" "libs" "output_dir" "output_extension" "output_name"
-    "output_prefix_override" "outputs" "pool" "precompiled_header"
-    "precompiled_header_type" "precompiled_source" "product_type" "public"
-    "public_configs" "public_deps" "response_file_contents" "script" "sources"
-    "testonly" "visibility" "write_runtime_deps" "bundle_contents_dir"
-    "contents" "output_conversion" "rebase" "data_keys" "walk_keys"))
+    "post_processing_manifest" "post_processing_outputs"
+    "post_processing_script" "post_processing_sources" "complete_static_lib"
+    "configs" "data" "data_deps" "defines" "depfile" "deps" "framework_dir"
+    "frameworks" "include_dirs" "inputs" "ldflags" "lib_dirs" "libs"
+    "output_dir" "output_extension" "output_name" "output_prefix_override"
+    "outputs" "pool" "precompiled_header" "precompiled_header_type"
+    "precompiled_source" "product_type" "public" "public_configs"
+    "public_deps" "response_file_contents" "script" "sources" "testonly"
+    "visibility" "write_runtime_deps" "bundle_contents_dir" "contents"
+    "output_conversion" "rebase" "data_keys" "walk_keys"))
 
 (defconst gn-font-lock-keywords
   `((,(regexp-opt gn-font-lock-reserved-keywords 'words) .
diff --git a/src/gn/bundle_data.cc b/src/gn/bundle_data.cc
index 86f7abf..2653d3a 100644
--- a/src/gn/bundle_data.cc
+++ b/src/gn/bundle_data.cc
@@ -149,6 +149,9 @@
                               post_processing_output_files.end());
   }
 
+  if (!post_processing_manifest_.is_null())
+    outputs_as_source->push_back(post_processing_manifest_);
+
   if (!root_dir_.is_null())
     outputs_as_source->push_back(GetBundleRootDirOutput(settings));
 
diff --git a/src/gn/bundle_data.h b/src/gn/bundle_data.h
index 2e03694..59e1f2d 100644
--- a/src/gn/bundle_data.h
+++ b/src/gn/bundle_data.h
@@ -149,6 +149,13 @@
     return post_processing_script_;
   }
 
+  void set_post_processing_manifest(const SourceFile& manifest_file) {
+    post_processing_manifest_ = manifest_file;
+  }
+  const SourceFile& post_processing_manifest() const {
+    return post_processing_manifest_;
+  }
+
   std::vector<SourceFile>& post_processing_sources() {
     return post_processing_sources_;
   }
@@ -236,9 +243,10 @@
   // (corresponds to {{bundle_partial_info_plist}} expansion).
   SourceFile partial_info_plist_;
 
-  // Holds the values (script name, sources, outputs, script arguments) for the
-  // post-processing step if defined.
+  // Holds the values (script name, manifest path, sources, outputs, script
+  // arguments) for the post-processing step if defined.
   SourceFile post_processing_script_;
+  SourceFile post_processing_manifest_;
   std::vector<SourceFile> post_processing_sources_;
   SubstitutionList post_processing_outputs_;
   SubstitutionList post_processing_args_;
diff --git a/src/gn/create_bundle_target_generator.cc b/src/gn/create_bundle_target_generator.cc
index 516aa0a..c4c2ac4 100644
--- a/src/gn/create_bundle_target_generator.cc
+++ b/src/gn/create_bundle_target_generator.cc
@@ -59,6 +59,9 @@
   if (!FillPostProcessingScript())
     return;
 
+  if (!FillPostProcessingManifest())
+    return;
+
   if (!FillPostProcessingSources())
     return;
 
@@ -207,6 +210,31 @@
   return true;
 }
 
+bool CreateBundleTargetGenerator::FillPostProcessingManifest() {
+  const Value* value =
+      scope_->GetValue(variables::kPostProcessingManifest, true);
+  if (!value)
+    return true;
+
+  if (target_->bundle_data().post_processing_script().is_null()) {
+    *err_ = Err(function_call_, "No post-processing script.",
+                "You must define post_processing_script if you use "
+                "post_processing_manifest.");
+    return false;
+  }
+
+  if (!value->VerifyTypeIs(Value::STRING, err_))
+    return false;
+
+  SourceFile manifest_file = scope_->GetSourceDir().ResolveRelativeFile(
+      *value, err_, scope_->settings()->build_settings()->root_path_utf8());
+  if (err_->has_error())
+    return false;
+
+  target_->bundle_data().set_post_processing_manifest(manifest_file);
+  return true;
+}
+
 bool CreateBundleTargetGenerator::FillPostProcessingSources() {
   const Value* value =
       scope_->GetValue(variables::kPostProcessingSources, true);
diff --git a/src/gn/create_bundle_target_generator.h b/src/gn/create_bundle_target_generator.h
index c713368..81d4947 100644
--- a/src/gn/create_bundle_target_generator.h
+++ b/src/gn/create_bundle_target_generator.h
@@ -35,6 +35,7 @@
   bool FillXcodeTestApplicationName();
 
   bool FillPostProcessingScript();
+  bool FillPostProcessingManifest();
   bool FillPostProcessingSources();
   bool FillPostProcessingOutputs();
   bool FillPostProcessingArgs();
diff --git a/src/gn/functions_target.cc b/src/gn/functions_target.cc
index 819dc89..9a19c41 100644
--- a/src/gn/functions_target.cc
+++ b/src/gn/functions_target.cc
@@ -402,16 +402,22 @@
   `post_processing_args` will be passed as is to the script (so path have to be
   rebased) and additional inputs may be listed via `post_processing_sources`.
 
+  If `post_processing_manifest` is defined, then gn will write a file listing
+  the expected content of the generated bundle (one file per line). The file
+  can then be passed as a parameter to `post_processing_script` via the
+  `post_processing_args` array. This can only be set if `post_processing_script`
+  is set.
+
 Variables
 
 )" DEPENDENT_CONFIG_VARS DEPS_VARS GENERAL_TARGET_VARS
 
     R"(  Bundle vars: bundle_root_dir, bundle_contents_dir, bundle_resources_dir,
                bundle_executable_dir, bundle_deps_filter, product_type,
-               post_processing_args, post_processing_script,
-               post_processing_sources, post_processing_outputs,
-               xcode_extra_attributes, xcode_test_application_name,
-               partial_info_plist
+               post_processing_args, post_processing_manifest,
+               post_processing_script, post_processing_sources,
+               post_processing_outputs, xcode_extra_attributes,
+               xcode_test_application_name, partial_info_plist
 
 Example
 
@@ -484,6 +490,7 @@
         if (is_ios && code_signing) {
           deps += [ ":${app_name}_generate_executable" ]
           post_processing_script = "//build/config/ios/codesign.py"
+          post_processing_manifest = "$target_out_dir/$target_name.manifest"
           post_processing_sources = [
             invoker.entitlements_path,
             "$target_gen_dir/$app_name",
@@ -502,6 +509,7 @@
                 invoker.entitlements_path, root_build_dir),
             "-e=" + rebase_path(
                 "$target_gen_dir/$app_name.xcent", root_build_dir),
+            "-m=" + rebase_path(post_processing_manifest, root_build_dir),
             rebase_path(bundle_root_dir, root_build_dir),
           ]
         } else {
diff --git a/src/gn/ninja_create_bundle_target_writer.cc b/src/gn/ninja_create_bundle_target_writer.cc
index 09299c7..b3a15ba 100644
--- a/src/gn/ninja_create_bundle_target_writer.cc
+++ b/src/gn/ninja_create_bundle_target_writer.cc
@@ -13,6 +13,7 @@
 #include "gn/ninja_utils.h"
 #include "gn/output_file.h"
 #include "gn/scheduler.h"
+#include "gn/string_output_buffer.h"
 #include "gn/substitution_writer.h"
 #include "gn/target.h"
 #include "gn/toolchain.h"
@@ -144,9 +145,39 @@
   out_ << "  restat = 1" << std::endl;
   out_ << std::endl;
 
+  WritePostProcessingManifestFile();
   return custom_rule_name;
 }
 
+void NinjaCreateBundleTargetWriter::WritePostProcessingManifestFile() {
+  const BundleData& bundle_data = target_->bundle_data();
+  const SourceFile& manifest_path = bundle_data.post_processing_manifest();
+  if (manifest_path.is_null()) {
+    return;
+  }
+
+  const BuildSettings* build_settings = settings_->build_settings();
+  const base::FilePath bundle_root_dir = build_settings->GetFullPath(
+      bundle_data.GetBundleRootDirOutputAsDir(settings_));
+
+  StringOutputBuffer storage;
+  std::ostream manifest(&storage);
+
+  std::vector<SourceFile> outputs;
+  bundle_data.GetOutputsAsSourceFiles(settings_, target_, &outputs, nullptr);
+  for (const SourceFile& output_file : outputs) {
+    const base::FilePath full_path = build_settings->GetFullPath(output_file);
+
+    base::FilePath relative_path;
+    if (bundle_root_dir.AppendRelativePath(full_path, &relative_path)) {
+      manifest << relative_path.As8Bit() << "\n";
+    }
+  }
+
+  storage.WriteToFileIfChanged(build_settings->GetFullPath(manifest_path),
+                               nullptr);
+}
+
 void NinjaCreateBundleTargetWriter::WriteCopyBundleDataSteps(
     const std::vector<OutputFile>& order_only_deps,
     std::vector<OutputFile>* output_files) {
diff --git a/src/gn/ninja_create_bundle_target_writer.h b/src/gn/ninja_create_bundle_target_writer.h
index ee27557..6b5d6cc 100644
--- a/src/gn/ninja_create_bundle_target_writer.h
+++ b/src/gn/ninja_create_bundle_target_writer.h
@@ -24,6 +24,9 @@
   // if defined, otherwise returns an empty string.
   std::string WritePostProcessingRuleDefinition();
 
+  // Writes the post processing manifest file if needed.
+  void WritePostProcessingManifestFile();
+
   // Writes the steps to copy files into the bundle.
   //
   // The list of newly created files will be added to |output_files|.
diff --git a/src/gn/variables.cc b/src/gn/variables.cc
index 31b3b0d..1754172 100644
--- a/src/gn/variables.cc
+++ b/src/gn/variables.cc
@@ -1673,6 +1673,19 @@
   See also "gn help create_bundle".
 )";
 
+const char kPostProcessingManifest[] = "post_processing_manifest";
+const char kPostProcessingManifest_HelpShort[] =
+    "post_processing_manifest: [file] Name of the generated bundle manifest.";
+const char kPostProcessingManifest_Help[] =
+    R"(post_processing_manifest: [file] Name of the generated bundle manifest.
+
+  Path where a manifest listing all the files found in the bundle will be
+  written for the post processing step. The path must be outside of the
+  bundle_root_dir.
+
+  See also "gen help create_bundle".
+)";
+
 const char kPostProcessingOutputs[] = "post_processing_outputs";
 const char kPostProcessingOutputs_HelpShort[] =
     "post_processing_outputs: [file list] Outputs of the post-processing step.";
@@ -2424,6 +2437,7 @@
     INSERT_VARIABLE(PartialInfoPlist)
     INSERT_VARIABLE(Pool)
     INSERT_VARIABLE(PostProcessingArgs)
+    INSERT_VARIABLE(PostProcessingManifest)
     INSERT_VARIABLE(PostProcessingOutputs)
     INSERT_VARIABLE(PostProcessingScript)
     INSERT_VARIABLE(PostProcessingSources)
diff --git a/src/gn/variables.h b/src/gn/variables.h
index a9ed6c4..b4d2862 100644
--- a/src/gn/variables.h
+++ b/src/gn/variables.h
@@ -262,6 +262,10 @@
 extern const char kPostProcessingArgs_HelpShort[];
 extern const char kPostProcessingArgs_Help[];
 
+extern const char kPostProcessingManifest[];
+extern const char kPostProcessingManifest_HelpShort[];
+extern const char kPostProcessingManifest_Help[];
+
 extern const char kPostProcessingOutputs[];
 extern const char kPostProcessingOutputs_HelpShort[];
 extern const char kPostProcessingOutputs_Help[];