diff --git a/packages/react-native-codegen/src/cli/combine/combine-schemas-cli.js b/packages/react-native-codegen/src/cli/combine/combine-schemas-cli.js
new file mode 100644
index 00000000000000..2a93215d2a14e5
--- /dev/null
+++ b/packages/react-native-codegen/src/cli/combine/combine-schemas-cli.js
@@ -0,0 +1,81 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+'use strict';
+
+import type {ComponentSchema, NativeModuleSchema} from '../../CodegenSchema.js';
+
+const assert = require('assert');
+const fs = require('fs');
+const util = require('util');
+
+const {values: args} = util.parseArgs({
+  options: {
+    platform: {
+      type: 'string',
+    },
+    output: {
+      type: 'string',
+    },
+    ['schema-query']: {
+      type: 'string',
+    },
+  },
+});
+if (!['iOS', 'android'].includes(args.platform)) {
+  throw new Error(`Invalid platform ${args.platform}`);
+}
+const platform = args.platform;
+const output = args.output;
+const schemaQuery = args['schema-query'];
+
+if (!schemaQuery.startsWith('@')) {
+  throw new Error(
+    "The argument provided to --schema-query must be a filename that starts with '@'.",
+  );
+}
+
+const schemaQueryOutputFile = schemaQuery.replace(/^@/, '');
+const schemaQueryOutput = fs.readFileSync(schemaQueryOutputFile, 'utf8');
+
+const schemaFiles = schemaQueryOutput.split(' ');
+const modules: {
+  [hasteModuleName: string]: NativeModuleSchema | ComponentSchema,
+} = {};
+const specNameToFile: {[hasteModuleName: string]: string} = {};
+
+for (const file of schemaFiles) {
+  const schema = JSON.parse(fs.readFileSync(file, 'utf8'));
+
+  if (schema.modules) {
+    for (const specName in schema.modules) {
+      const module = schema.modules[specName];
+      if (modules[specName]) {
+        assert.deepEqual(
+          module,
+          modules[specName],
+          `App contained two specs with the same file name '${specName}'. Schemas: ${specNameToFile[specName]}, ${file}. Please rename one of the specs.`,
+        );
+      }
+
+      if (
+        module.excludedPlatforms &&
+        module.excludedPlatforms.indexOf(platform) >= 0
+      ) {
+        continue;
+      }
+
+      modules[specName] = module;
+      specNameToFile[specName] = file;
+    }
+  }
+}
+
+fs.writeFileSync(output, JSON.stringify({modules}, null, 2));