diff --git a/React/FBReactNativeSpec/FBReactNativeSpec.podspec b/React/FBReactNativeSpec/FBReactNativeSpec.podspec
index 32a4bf8cb41..bdbf1023319 100644
--- a/React/FBReactNativeSpec/FBReactNativeSpec.podspec
+++ b/React/FBReactNativeSpec/FBReactNativeSpec.podspec
@@ -4,7 +4,9 @@
 # LICENSE file in the root directory of this source tree.
 
 require "json"
-require_relative "../../scripts/react_native_pods.rb"
+
+react_native_path = "../.."
+require_relative "#{react_native_path}/scripts/react_native_pods.rb"
 
 package = JSON.parse(File.read(File.join(__dir__, "..", "..", "package.json")))
 version = package['version']
@@ -46,5 +48,13 @@ Pod::Spec.new do |s|
   s.dependency "React-jsi", version
   s.dependency "ReactCommon/turbomodule/core", version
 
-  use_react_native_codegen! (s)
+  use_react_native_codegen!(s, {
+    :react_native_path => react_native_path,
+    :js_srcs_dir => "#{react_native_path}/Libraries",
+    :library_name => "FBReactNativeSpec",
+    :output_dir => "#{react_native_path}/React/FBReactNativeSpec",
+    :component_library_name => "rncore",
+    # TODO: component_output_dir should be programmatically specified, and may change with use_frameworks! support.
+    :component_output_dir => "#{react_native_path}/ReactCommon/react/renderer/components/"
+  })
 end
diff --git a/scripts/codegen.js b/scripts/codegen.js
deleted file mode 100644
index 12ff0917dd6..00000000000
--- a/scripts/codegen.js
+++ /dev/null
@@ -1,54 +0,0 @@
-#!/usr/bin/env node
-/**
- * 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';
-
-require('shelljs/global');
-const yargs = require('yargs');
-const execSync = require('child_process').execSync;
-
-let argv = yargs.option('srcs', {
-    alias: 'srcs_dir',
-    type: 'string',
-    description: 'Path to JavaScript sources',
-}).option('modules_library_name', {
-    type: 'string',
-    description: 'Native modules interfaces library name',
-}).option('modules_output_dir', {
-    type: 'string',
-    description: 'Native modules interfaces output dir',
-}).option('components_library_name', {
-    type: 'string',
-    description: 'Native components interfaces library name',
-}).option('components_output_dir', {
-    type: 'string',
-    description: 'Native components interfaces output dir',
-}).argv;
-
-let env_vars = [];
-const { srcs_dir, modules_library_name, modules_output_dir, components_library_name, components_output_dir } = argv;
-
-if (srcs_dir) {
-    env_vars.push(`SRCS_DIR=${srcs_dir}`);
-}
-if (modules_library_name) {
-    env_vars.push(`MODULES_LIBRARY_NAME=${modules_library_name}`);
-}
-if (modules_output_dir) {
-    env_vars.push(`MODULES_OUTPUT_DIR=${modules_output_dir}`);
-}
-if (components_library_name) {
-    env_vars.push(`COMPONENTS_LIBRARY_NAME=${components_library_name}`);
-}
-if (components_output_dir) {
-    env_vars.push(`COMPONENTS_OUTPUT_DIR=${components_output_dir}`);
-}
-
-execSync(`${env_vars.join(' ')} ./generate-specs.sh`);
diff --git a/scripts/generate-specs.sh b/scripts/generate-specs.sh
index 4456557dfbb..d3ea448e175 100755
--- a/scripts/generate-specs.sh
+++ b/scripts/generate-specs.sh
@@ -4,20 +4,12 @@
 # This source code is licensed under the MIT license found in the
 # LICENSE file in the root directory of this source tree.
 
-# This script collects the JavaScript spec definitions for core
+# This script collects the JavaScript spec definitions for
 # native modules and components, then uses react-native-codegen
 # to generate native code.
 #
-# Optionally, set these envvars to override defaults:
-# - SRCS_DIR: Path to JavaScript sources
-# - MODULES_LIBRARY_NAME: Defaults to FBReactNativeSpec
-# - MODULES_OUTPUT_DIR: Defaults to React/$MODULES_LIBRARY_NAME/$MODULES_LIBRARY_NAME
-# - COMPONENTS_LIBRARY_NAME: Defaults to rncore
-# - COMPONENTS_OUTPUT_DIR: Defaults to ReactCommon/react/renderer/components/$COMPONENTS_LIBRARY_NAME
-#
 # Usage:
 #   ./scripts/generate-specs.sh
-#   SRCS_DIR=myapp/js MODULES_LIBRARY_NAME=MySpecs MODULES_OUTPUT_DIR=myapp/MySpecs ./scripts/generate-specs.sh
 #
 
 # shellcheck disable=SC2038
@@ -44,27 +36,45 @@ describe () {
   printf "\\n\\n>>>>> %s\\n\\n\\n" "$1" >&2
 }
 
+print_usage () {
+  printf "\\nNAME\\n\\t%s -- generate specs\\n" "$1" >&2
+  printf "\\nSYNOPSIS\\n" >&2
+  printf "\\t%s javascript_sources_directory specs_library_name output_directory\\n" "$1" >&2
+  printf "\\t%s javascript_sources_directory specs_library_name output_directory component_library_name [component_output_directory]\\n" "$1" >&2
+  printf "\\n\\nDESCRIPTION\\n\\tIn the first synopsis form, this script collects native module and native component JavaScript spec definitions in javascript_sources_directory, then uses react-native-codegen to generate the native interface code into a library named specs_library_name, which is copied to the destination output_directory.\\n" >&2
+  printf "\\n\\tIn the second synopsis form, the component_library_name will be used as the name of the component native interface code library. If provided, the component output will be copied to the component_output_directory, otherwise it will be copied to the output_directory.\\n" >&2
+}
+
 main() {
-  SRCS_DIR=${SRCS_DIR:-$(cd "$RN_DIR/Libraries" && pwd)}
-  MODULES_LIBRARY_NAME=${MODULES_LIBRARY_NAME:-FBReactNativeSpec}
-
-  COMPONENTS_LIBRARY_NAME=${COMPONENTS_LIBRARY_NAME:-rncore}
-  MODULES_OUTPUT_DIR=${MODULES_OUTPUT_DIR:-"$RN_DIR/React/$MODULES_LIBRARY_NAME/$MODULES_LIBRARY_NAME"}
-  # TODO: $COMPONENTS_PATH should be programmatically specified, and may change with use_frameworks! support.
-  COMPONENTS_PATH="ReactCommon/react/renderer/components"
-  COMPONENTS_OUTPUT_DIR=${COMPONENTS_OUTPUT_DIR:-"$RN_DIR/$COMPONENTS_PATH/$COMPONENTS_LIBRARY_NAME"}
-
-  TEMP_OUTPUT_DIR="$TEMP_DIR/out"
-  SCHEMA_FILE="$TEMP_DIR/schema.json"
-
-  CODEGEN_REPO_PATH="$RN_DIR/packages/react-native-codegen"
-  CODEGEN_NPM_PATH="$RN_DIR/../react-native-codegen"
+  MIN_ARG_NUM=3
+  if [ "$#" -eq 0 ]; then
+    print_usage "$0"
+    exit 1
+  fi
 
   if [ -z "$NODE_BINARY" ]; then
     echo "Error: Could not find node. Make sure it is in bash PATH or set the NODE_BINARY environment variable." 1>&2
     exit 1
   fi
 
+  if [ "$#" -lt "$MIN_ARG_NUM" ]; then
+    echo "Error: Expected $MIN_ARG_NUM arguments, got $# instead. Run $0 with no arguments to learn more." 1>&2
+    exit 1
+  fi
+
+  SRCS_DIR=$1
+  LIBRARY_NAME=$2
+  OUTPUT_DIR=$3
+  COMPONENT_LIBRARY_NAME_OVERRIDE=$4
+  COMPONENT_OUTPUT_DIR_OVERRIDE=$5
+
+  PLATFORM="ios"
+  TEMP_OUTPUT_DIR="$TEMP_DIR/out"
+  SCHEMA_FILE="$TEMP_DIR/schema.json"
+
+  CODEGEN_REPO_PATH="$RN_DIR/packages/react-native-codegen"
+  CODEGEN_NPM_PATH="$RN_DIR/../react-native-codegen"
+
   if [ -d "$CODEGEN_REPO_PATH" ]; then
     CODEGEN_PATH=$(cd "$CODEGEN_REPO_PATH" && pwd)
   elif [ -d "$CODEGEN_NPM_PATH" ]; then
@@ -82,15 +92,38 @@ main() {
   describe "Generating schema from Flow types"
   "$NODE_BINARY" "$CODEGEN_PATH/lib/cli/combine/combine-js-to-schema-cli.js" "$SCHEMA_FILE" "$SRCS_DIR"
 
-  describe "Generating native code from schema (iOS)"
-  pushd "$RN_DIR" >/dev/null || exit 1
-    "$NODE_BINARY" scripts/generate-specs-cli.js ios "$SCHEMA_FILE" "$TEMP_OUTPUT_DIR" "$MODULES_LIBRARY_NAME"
-  popd >/dev/null || exit 1
+  describe "Generating native code from schema ($PLATFORM)"
+  pushd "$RN_DIR" >/dev/null
+    "$NODE_BINARY" scripts/generate-specs-cli.js "$PLATFORM" "$SCHEMA_FILE" "$TEMP_OUTPUT_DIR" "$LIBRARY_NAME"
+  popd >/dev/null
 
-  mkdir -p "$COMPONENTS_OUTPUT_DIR" "$MODULES_OUTPUT_DIR"
-  cp -R "$TEMP_OUTPUT_DIR/$MODULES_LIBRARY_NAME.h" "$TEMP_OUTPUT_DIR/$MODULES_LIBRARY_NAME-generated.mm" "$MODULES_OUTPUT_DIR" || exit 1
-  find "$TEMP_OUTPUT_DIR" -type f | xargs sed -i.bak "s/$MODULES_LIBRARY_NAME/$COMPONENTS_LIBRARY_NAME/g" || exit 1
-  find "$TEMP_OUTPUT_DIR" -type f -not -iname "$MODULES_LIBRARY_NAME*" -exec cp '{}' "$COMPONENTS_OUTPUT_DIR/" ';' || exit 1
+
+  mkdir -p "$OUTPUT_DIR"
+
+  if [ -z "$COMPONENT_LIBRARY_NAME_OVERRIDE" ]; then
+    # Copy all output to output_dir
+    cp -R "$TEMP_OUTPUT_DIR/" "$OUTPUT_DIR"
+    echo >&2 "$LIBRARY_NAME output has been written to $OUTPUT_DIR:"
+    ls -1 "$OUTPUT_DIR" 2>&1
+  else
+    # Copy modules output to output_dir
+    cp "$TEMP_OUTPUT_DIR/$LIBRARY_NAME.h" "$TEMP_OUTPUT_DIR/$LIBRARY_NAME-generated.mm" "$OUTPUT_DIR"
+    echo >&2 "$LIBRARY_NAME output has been written to $OUTPUT_DIR:"
+    ls -1 "$OUTPUT_DIR" 2>&1
+
+    # Rename library name used in components output files
+    find "$TEMP_OUTPUT_DIR" -type f | xargs sed -i.bak "s/$LIBRARY_NAME/$COMPONENT_LIBRARY_NAME_OVERRIDE/g"
+
+    if [ -n "$COMPONENT_OUTPUT_DIR_OVERRIDE" ]; then
+      # Components codegen output to be moved to separate directory
+      mkdir -p "$COMPONENT_OUTPUT_DIR_OVERRIDE"
+      OUTPUT_DIR="$COMPONENT_OUTPUT_DIR_OVERRIDE"
+    fi
+
+    find "$TEMP_OUTPUT_DIR" -type f -not -iname "$LIBRARY_NAME.h" -not -iname "$LIBRARY_NAME-generated.mm" -not -iname "*.bak" -exec cp '{}' "$OUTPUT_DIR/" ';'
+    echo >&2 "$COMPONENT_LIBRARY_NAME_OVERRIDE output has been written to $OUTPUT_DIR:"
+    ls -1 "$OUTPUT_DIR" 2>&1
+  fi
 
   echo >&2 'Done.'
 }
diff --git a/scripts/react_native_pods.rb b/scripts/react_native_pods.rb
index a4131f3ec29..02b04e1e4f7 100644
--- a/scripts/react_native_pods.rb
+++ b/scripts/react_native_pods.rb
@@ -161,38 +161,38 @@ def use_react_native_codegen!(spec, options={})
   js_srcs = options[:js_srcs_dir] ||= "#{prefix}/Libraries"
 
   # Library name (e.g. FBReactNativeSpec)
-  modules_library_name = options[:library_name] ||= spec.name
+  library_name = options[:library_name] ||= "#{spec.name}Spec"
 
   # Output dir, relative to podspec that invoked this method
-  modules_output_dir = options[:modules_output_dir] ||= "#{prefix}/React/#{modules_library_name}/#{modules_library_name}"
+  output_dir = options[:output_dir] ||= "#{prefix}/React/#{library_name}"
 
-  generated_dirs = [ modules_output_dir ]
-  generated_filenames = [ "#{modules_library_name}.h", "#{modules_library_name}-generated.mm" ]
-  generated_files = generated_filenames.map { |filename| "#{modules_output_dir}/#{filename}" }
+  generated_dirs = [ "#{output_dir}/#{library_name}" ]
+  generated_filenames = [ "#{library_name}.h", "#{library_name}-generated.mm" ]
+  generated_files = generated_filenames.map { |filename| "#{output_dir}/#{library_name}/#{filename}" }
 
   # Run the codegen as part of the Xcode build pipeline.
-  env_vars = "SRCS_DIR='${PODS_TARGET_SRCROOT}/#{js_srcs}'"
-  env_vars += " MODULES_OUTPUT_DIR='${PODS_TARGET_SRCROOT}/#{modules_output_dir}'"
-  env_vars += " MODULES_LIBRARY_NAME='#{modules_library_name}'"
+  codegen_script_args = [ "'${PODS_TARGET_SRCROOT}/#{js_srcs}'" ]
+  codegen_script_args.push "'#{library_name}'"
+  codegen_script_args.push "'${PODS_TARGET_SRCROOT}/#{output_dir}/#{library_name}'"
 
-  if ENV['USE_FABRIC'] == '1'
-    # We use a different library name for components, as well as an additional set of files.
-    # Eventually, we want these to be part of the same library as #{modules_library_name} above.
-    components_output_dir = options[:components_output_dir] ||= "#{prefix}/ReactCommon/react/renderer/components/rncore/"
-    generated_dirs.push components_output_dir
-    env_vars += " COMPONENTS_OUTPUT_DIR='${PODS_TARGET_SRCROOT}/#{components_output_dir}'"
-    components_generated_filenames = [
-      "ComponentDescriptors.h",
-      "EventEmitters.cpp",
-      "EventEmitters.h",
-      "Props.cpp",
-      "Props.h",
-      "RCTComponentViewHelpers.h",
-      "ShadowNodes.cpp",
-      "ShadowNodes.h"
-    ]
-    generated_files = generated_files.concat(components_generated_filenames.map { |filename| "#{components_output_dir}/#{filename}" })
-  end
+  # We use a different library name for components, as well as an additional set of files.
+  # Eventually, we want these to be part of the same library as #{library_name} above.
+  component_library_name = options[:component_library_name] ||= library_name
+  component_output_dir = options[:component_output_dir] ||= output_dir
+  generated_dirs.push "#{component_output_dir}/#{component_library_name}"
+  codegen_script_args.push "'#{component_library_name}'"
+  codegen_script_args.push "'${PODS_TARGET_SRCROOT}/#{component_output_dir}/#{component_library_name}'"
+  components_generated_filenames = [
+    "ComponentDescriptors.h",
+    "EventEmitters.cpp",
+    "EventEmitters.h",
+    "Props.cpp",
+    "Props.h",
+    "RCTComponentViewHelpers.h",
+    "ShadowNodes.cpp",
+    "ShadowNodes.h"
+  ]
+  generated_files = generated_files.concat(components_generated_filenames.map { |filename| "#{component_output_dir}/#{component_library_name}/#{filename}" })
 
   # Prepare filesystem by creating empty files that will be picked up as references by CocoaPods.
   prepare_command = "mkdir -p #{generated_dirs.join(" ")} && touch -a #{generated_files.join(" ")}"
@@ -202,11 +202,11 @@ def use_react_native_codegen!(spec, options={})
   spec.script_phase = {
     :name => 'Generate Specs',
     :input_files => [ "${PODS_TARGET_SRCROOT}/#{js_srcs}" ], # This also needs to be relative to Xcode
-    :output_files => ["${DERIVED_FILE_DIR}/codegen-#{modules_library_name}.log"].concat(generated_files.map { |filename| " ${PODS_TARGET_SRCROOT}/#{filename}"} ),
+    :output_files => ["${DERIVED_FILE_DIR}/codegen-#{library_name}.log"].concat(generated_files.map { |filename| " ${PODS_TARGET_SRCROOT}/#{filename}"} ),
     # The final generated files will be created when this script is invoked at Xcode build time.
     :script => %{set -o pipefail
 
-bash -l -c '#{env_vars} $\{PODS_TARGET_SRCROOT\}/#{prefix}/scripts/generate-specs.sh' 2>&1 | tee "${SCRIPT_OUTPUT_FILE_0}"
+bash -l -c '$\{PODS_TARGET_SRCROOT\}/#{prefix}/scripts/generate-specs.sh #{codegen_script_args.join(" ")}' 2>&1 | tee "${SCRIPT_OUTPUT_FILE_0}"
     },
     :execution_position => :before_compile,
     :show_env_vars_in_log => true