diff --git a/scripts/generate-native-modules-specs-cli.js b/scripts/generate-native-modules-specs-cli.js
new file mode 100644
index 00000000000..2b72610e21b
--- /dev/null
+++ b/scripts/generate-native-modules-specs-cli.js
@@ -0,0 +1,78 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+'use strict';
+
+const RNCodegen = require('../packages/react-native-codegen/lib/generators/RNCodegen.js');
+const fs = require('fs');
+const mkdirp = require('mkdirp');
+const os = require('os');
+const path = require('path');
+
+function generateSpec(schemaPath, outputDirectory) {
+  const libraryName = 'FBReactNativeSpec';
+  const moduleSpecName = 'FBReactNativeSpec';
+  const schemaText = fs.readFileSync(schemaPath, 'utf-8');
+
+  if (schemaText == null) {
+    throw new Error(`Can't find schema at ${schemaPath}`);
+  }
+
+  const tempOutputDirectory = fs.mkdtempSync(
+    path.join(os.tmpdir(), 'react-native-codegen-'),
+  );
+
+  let schema;
+  try {
+    schema = JSON.parse(schemaText);
+  } catch (err) {
+    throw new Error(`Can't parse schema to JSON. ${schemaPath}`);
+  }
+
+  RNCodegen.generate(
+    {libraryName, schema, outputDirectory: tempOutputDirectory, moduleSpecName},
+    {
+      generators: [
+        'descriptors',
+        'events',
+        'props',
+        'tests',
+        'shadow-nodes',
+        'modules',
+      ],
+    },
+  );
+
+  if (!outputDirectory) {
+    outputDirectory = path.resolve(
+      __dirname,
+      '..',
+      'Libraries',
+      libraryName,
+      moduleSpecName,
+    );
+  }
+  mkdirp.sync(outputDirectory);
+
+  const fileNames = [`${moduleSpecName}.h`, `${moduleSpecName}-generated.mm`];
+  fileNames.forEach(fileName => {
+    const newOutput = `${tempOutputDirectory}/${fileName}`;
+    const prevOutput = `${outputDirectory}/${fileName}`;
+    fs.copyFileSync(newOutput, prevOutput);
+  });
+}
+
+function main() {
+  const args = process.argv.slice(2);
+  const schemaPath = args[0];
+  const outputDir = args[1];
+  generateSpec(schemaPath, outputDir);
+}
+
+main();
diff --git a/scripts/generate-native-modules-specs.sh b/scripts/generate-native-modules-specs.sh
index 505a7769a33..6f77c36c503 100755
--- a/scripts/generate-native-modules-specs.sh
+++ b/scripts/generate-native-modules-specs.sh
@@ -27,26 +27,21 @@ describe () {
 THIS_DIR=$(cd -P "$(dirname "$(readlink "${BASH_SOURCE[0]}" || echo "${BASH_SOURCE[0]}")")" && pwd)
 RN_DIR=$(cd "$THIS_DIR/.." && pwd)
 
-TEMP_DIR=$(mktemp -d /tmp/react-native-codegen-XXXXXXXX)
-
 SRCS_DIR=$(cd "$RN_DIR/Libraries" && pwd)
-LIBRARY_NAME="FBReactNativeSpec"
-MODULE_SPEC_NAME="FBReactNativeSpec"
-
 SCHEMA_FILE="$RN_DIR/schema-native-modules.json"
-OUTPUT_DIR="$SRCS_DIR/$LIBRARY_NAME/$MODULE_SPEC_NAME"
-
-describe "Generating schema from flow types"
-grep --exclude NativeUIManager.js --include=Native\*.js -rnwl "$SRCS_DIR" -e 'export interface Spec extends TurboModule' -e "export default \(TurboModuleRegistry.get(Enforcing)?<Spec>\('.*\): Spec\);/" \
-  | xargs yarn flow-node packages/react-native-codegen/src/cli/combine/combine-js-to-schema-cli.js "$SCHEMA_FILE"
-
-describe "Generating native code from schema"
-yarn flow-node packages/react-native-codegen/buck_tests/generate-tests.js "$SCHEMA_FILE" "$LIBRARY_NAME" "$TEMP_DIR" "$MODULE_SPEC_NAME"
 
 if [ -n "$1" ]; then
   OUTPUT_DIR="$1"
-  mkdir -p "$OUTPUT_DIR"
 fi
 
-describe "Copying $MODULE_SPEC_NAME output  to $OUTPUT_DIR"
-cp "$TEMP_DIR"/$MODULE_SPEC_NAME* "$OUTPUT_DIR/."
+pushd "$RN_DIR/packages/react-native-codegen" >/dev/null
+  yarn
+  yarn build
+popd >/dev/null
+
+describe "Generating schema from flow types"
+grep --exclude NativeUIManager.js --include=Native\*.js -rnwl "$SRCS_DIR" -e 'export interface Spec extends TurboModule' -e "export default \(TurboModuleRegistry.get(Enforcing)?<Spec>\('.*\): Spec\);/" \
+  | xargs yarn node packages/react-native-codegen/lib/cli/combine/combine-js-to-schema-cli.js "$SCHEMA_FILE"
+
+describe "Generating native code from schema"
+yarn node scripts/generate-native-modules-specs-cli.js "$SCHEMA_FILE" "$OUTPUT_DIR"