diff --git a/.gitignore b/.gitignore
index 272b9bbfba849b..7dd758b61058ae 100644
--- a/.gitignore
+++ b/.gitignore
@@ -103,7 +103,6 @@ package-lock.json
 /Libraries/FBReactNativeSpec/FBReactNativeSpec
 /packages/react-native-codegen/lib
 /ReactCommon/fabric/components/rncore/
-/schema-native-modules.json
 /schema-rncore.json
 
 # Visual studio
diff --git a/Libraries/FBReactNativeSpec/FBReactNativeSpec.podspec b/Libraries/FBReactNativeSpec/FBReactNativeSpec.podspec
index de5e03607754d2..d02b4c9b84aca5 100644
--- a/Libraries/FBReactNativeSpec/FBReactNativeSpec.podspec
+++ b/Libraries/FBReactNativeSpec/FBReactNativeSpec.podspec
@@ -9,13 +9,22 @@ package = JSON.parse(File.read(File.join(__dir__, "..", "..", "package.json")))
 version = package['version']
 
 source = { :git => 'https://github.com/facebook/react-native.git' }
+codegen_path_prefix = ".."
 if version == '1000.0.0'
   # This is an unpublished version, use the latest commit hash of the react-native repo, which we’re presumably in.
   source[:commit] = `git rev-parse HEAD`.strip
+  codegen_path_prefix = "packages"
 else
   source[:tag] = "v#{version}"
 end
 
+react_native_path = File.join(__dir__, "..", "..")
+srcs_dir = File.join(__dir__, "..")
+codegen_script_path = File.join(react_native_path, "scripts", "generate-native-modules-specs.sh")
+codegen_path = File.join(react_native_path, codegen_path_prefix, "react-native-codegen")
+generated_files = [File.join(__dir__, "FBReactNativeSpec", "FBReactNativeSpec.h"), File.join(__dir__, "FBReactNativeSpec", "FBReactNativeSpec-generated.mm")]
+codegen_command = "CODEGEN_PATH=#{codegen_path} sh '#{codegen_script_path}' | tee \"${SCRIPT_OUTPUT_FILE_0}\""
+
 folly_compiler_flags = '-DFOLLY_NO_CONFIG -DFOLLY_MOBILE=1 -DFOLLY_USE_LIBCPP=1 -Wno-comma -Wno-shorten-64-to-32'
 folly_version = '2020.01.13.00'
 
@@ -44,4 +53,13 @@ Pod::Spec.new do |s|
   s.dependency "React-Core", version
   s.dependency "React-jsi", version
   s.dependency "ReactCommon/turbomodule/core", version
+
+  s.prepare_command = "touch #{generated_files.reduce() { |str, file| str + " " + file }}"
+  s.script_phase = {
+    :name => 'Generate Native Modules Code',
+    :input_files => [srcs_dir],
+    :output_files => ["$(DERIVED_FILE_DIR)/FBReactNativeSpec-codegen.log"],
+    :script => codegen_command,
+    :execution_position => :before_compile
+  }
 end
diff --git a/package.json b/package.json
index 2a1a84cfd1d77c..42df7b41226dd5 100644
--- a/package.json
+++ b/package.json
@@ -38,6 +38,7 @@
     "README.md",
     "rn-get-polyfills.js",
     "scripts/compose-source-maps.js",
+    "scripts/generate-native-modules-specs.sh",
     "scripts/generate-native-modules-specs-cli.js",
     "scripts/ios-configure-glog.sh",
     "scripts/launchPackager.bat",
diff --git a/packages/rn-tester/Podfile b/packages/rn-tester/Podfile
index e939c4f2f0b7a8..efc5c339ad5b98 100644
--- a/packages/rn-tester/Podfile
+++ b/packages/rn-tester/Podfile
@@ -60,16 +60,6 @@ def frameworks_pre_install(installer)
   end
 end
 
-pre_install do |installer|
-  frameworks_pre_install(installer) if ENV['USE_FRAMEWORKS'] == '1'
-  if ENV['USE_CODEGEN'] != '0'
-    prefix_path = "../.."
-    codegen_path = "../../packages/react-native-codegen"
-    system("./#{codegen_path}/scripts/oss/build.sh") or raise "Could not build react-native-codegen package"
-    codegen_pre_install(installer, {path:prefix_path, codegen_path:codegen_path})
-  end
-end
-
 post_install do |installer|
   flipper_post_install(installer)
 end
diff --git a/packages/rn-tester/Podfile.lock b/packages/rn-tester/Podfile.lock
index 6ba9855fd1872b..57bce624639667 100644
--- a/packages/rn-tester/Podfile.lock
+++ b/packages/rn-tester/Podfile.lock
@@ -15,12 +15,12 @@ PODS:
     - Flipper-Folly (~> 2.2)
     - Flipper-RSocket (~> 1.1)
   - Flipper-DoubleConversion (1.1.7)
-  - Flipper-Folly (2.2.0):
+  - Flipper-Folly (2.3.0):
     - boost-for-react-native
     - CocoaLibEvent (~> 1.0)
     - Flipper-DoubleConversion
     - Flipper-Glog
-    - OpenSSL-Universal (= 1.0.2.19)
+    - OpenSSL-Universal (= 1.0.2.20)
   - Flipper-Glog (0.3.6)
   - Flipper-PeerTalk (0.0.4)
   - Flipper-RSocket (1.1.0):
@@ -58,9 +58,9 @@ PODS:
     - FlipperKit/Core
     - FlipperKit/FlipperKitNetworkPlugin
   - glog (0.3.5)
-  - OpenSSL-Universal (1.0.2.19):
-    - OpenSSL-Universal/Static (= 1.0.2.19)
-  - OpenSSL-Universal/Static (1.0.2.19)
+  - OpenSSL-Universal (1.0.2.20):
+    - OpenSSL-Universal/Static (= 1.0.2.20)
+  - OpenSSL-Universal/Static (1.0.2.20)
   - RCT-Folly (2020.01.13.00):
     - boost-for-react-native
     - DoubleConversion
@@ -490,16 +490,16 @@ SPEC CHECKSUMS:
   CocoaLibEvent: 2fab71b8bd46dd33ddb959f7928ec5909f838e3f
   DoubleConversion: cde416483dac037923206447da6e1454df403714
   FBLazyVector: fe973c09b2299b5e8154186ecf1f6554b4f70987
-  FBReactNativeSpec: 20a9345af9157362b51ab0258d842cb7bb347d19
+  FBReactNativeSpec: 4b0a53603445208c324b4a23d77590c399894efc
   Flipper: be611d4b742d8c87fbae2ca5f44603a02539e365
   Flipper-DoubleConversion: 38631e41ef4f9b12861c67d17cb5518d06badc41
-  Flipper-Folly: c12092ea368353b58e992843a990a3225d4533c3
+  Flipper-Folly: e4493b013c02d9347d5e0cb4d128680239f6c78a
   Flipper-Glog: 1dfd6abf1e922806c52ceb8701a3599a79a200a6
   Flipper-PeerTalk: 116d8f857dc6ef55c7a5a75ea3ceaafe878aadc9
   Flipper-RSocket: 64e7431a55835eb953b0bf984ef3b90ae9fdddd7
   FlipperKit: ab353d41aea8aae2ea6daaf813e67496642f3d7d
   glog: 40a13f7840415b9a77023fbcae0f1e6f43192af3
-  OpenSSL-Universal: 8b48cc0d10c1b2923617dfe5c178aa9ed2689355
+  OpenSSL-Universal: ff34003318d5e1163e9529b08470708e389ffcdd
   RCT-Folly: b39288cedafe50da43317ec7d91bcc8cc0abbf33
   RCTRequired: d3d4ce60e1e2282864d7560340690a3c8c646de1
   RCTTypeSafety: 4da4f9f218727257c50fd3bf2683a06cdb4fede3
@@ -528,6 +528,6 @@ SPEC CHECKSUMS:
   Yoga: 69ef0b2bba5387523f793957a9f80dbd61e89631
   YogaKit: f782866e155069a2cca2517aafea43200b01fd5a
 
-PODFILE CHECKSUM: cd671238f92c51cd349a1c778fd089994174b101
+PODFILE CHECKSUM: 3adfe268d800503789170d1862bde422ee204fe8
 
 COCOAPODS: 1.10.0
diff --git a/scripts/generate-native-modules-specs.sh b/scripts/generate-native-modules-specs.sh
index 5edfa3e421e14d..d667c46901fe99 100755
--- a/scripts/generate-native-modules-specs.sh
+++ b/scripts/generate-native-modules-specs.sh
@@ -4,54 +4,88 @@
 # 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 native
-# modules, then uses react-native-codegen to generate native code.
-# The script will copy the generated code to the final location by
-# default. Optionally, call the script with a path to the desired
-# output location.
+# This script collects the JavaScript spec definitions for core
+# native modules, then uses react-native-codegen to generate
+# native code.
+# The script will use the local react-native-codegen package by
+# default. Optionally, set the CODEGEN_PATH to point to the
+# desired codegen library (e.g. when using react-native-codegen
+# from npm).
 #
 # Usage:
-#   ./scripts/generate-native-modules-specs.sh [output-dir]
+#   ./scripts/generate-native-modules-specs.sh
 #
 # Example:
-#   ./scripts/generate-native-modules-specs.sh ./codegen-out
+#  CODEGEN_PATH=.. ./scripts/generate-native-modules-specs.sh
 
 # shellcheck disable=SC2038
 
 set -e
 
 THIS_DIR=$(cd -P "$(dirname "$(readlink "${BASH_SOURCE[0]}" || echo "${BASH_SOURCE[0]}")")" && pwd)
+TEMP_DIR=$(mktemp -d /tmp/react-native-codegen-XXXXXXXX)
 RN_DIR=$(cd "$THIS_DIR/.." && pwd)
-CODEGEN_DIR=$(cd "$RN_DIR/packages/react-native-codegen" && pwd)
-OUTPUT_DIR="${1:-$RN_DIR/Libraries/FBReactNativeSpec/FBReactNativeSpec}"
-SCHEMA_FILE="$RN_DIR/schema-native-modules.json"
+CODEGEN_PATH="${CODEGEN_PATH:-$(cd "$RN_DIR/packages" && pwd)}"
+CODEGEN_DIR="$CODEGEN_PATH/react-native-codegen"
+
 YARN_BINARY="${YARN_BINARY:-$(command -v yarn)}"
 
+cleanup () {
+  set +e
+  rm -rf "$TEMP_DIR"
+  set -e
+}
+
 describe () {
   printf "\\n\\n>>>>> %s\\n\\n\\n" "$1"
 }
 
 step_build_codegen () {
-  describe "Building react-native-codegen package"
-  pushd "$CODEGEN_DIR" >/dev/null || exit
-    "$YARN_BINARY"
-    "$YARN_BINARY" build
-  popd >/dev/null || exit
+  if [ ! -d "$CODEGEN_DIR/lib" ]; then
+    describe "Building react-native-codegen package"
+    pushd "$CODEGEN_DIR" >/dev/null || exit
+      "$YARN_BINARY"
+      "$YARN_BINARY" build
+    popd >/dev/null || exit
+  fi
 }
 
-step_gen_schema () {
+run_codegen () {
+  SRCS_DIR=$1
+  LIBRARY_NAME=$2
+  OUTPUT_DIR=$3
+
+  SCHEMA_FILE="$TEMP_DIR/schema-$LIBRARY_NAME.json"
+
+  if [ ! -d "$CODEGEN_DIR/lib" ]; then
+    describe "Building react-native-codegen package"
+    pushd "$CODEGEN_DIR" >/dev/null || exit
+      "$YARN_BINARY"
+      "$YARN_BINARY" build
+    popd >/dev/null || exit
+  fi
+
   describe "Generating schema from flow types"
-  SRCS_DIR=$(cd "$RN_DIR/Libraries" && pwd)
   "$YARN_BINARY" node "$CODEGEN_DIR/lib/cli/combine/combine-js-to-schema-cli.js" "$SCHEMA_FILE" "$SRCS_DIR"
-}
 
-step_gen_specs () {
   describe "Generating native code from schema (iOS)"
   pushd "$RN_DIR" >/dev/null || exit
     "$YARN_BINARY" --silent node scripts/generate-native-modules-specs-cli.js ios "$SCHEMA_FILE" "$OUTPUT_DIR"
   popd >/dev/null || exit
 }
 
-step_build_codegen
-step_gen_schema
-step_gen_specs
+# Handle Core Modules
+run_codegen_core_modules () {
+  LIBRARY_NAME="FBReactNativeSpec"
+  SRCS_DIR=$(cd "$RN_DIR/Libraries" && pwd)
+  OUTPUT_DIR="$SRCS_DIR/$LIBRARY_NAME/$LIBRARY_NAME"
+
+  run_codegen "$SRCS_DIR" "$LIBRARY_NAME" "$OUTPUT_DIR"
+}
+
+main() {
+  run_codegen_core_modules
+}
+
+trap cleanup EXIT
+main "$@"
diff --git a/scripts/react_native_pods.rb b/scripts/react_native_pods.rb
index 14d6166f3da6c1..a77938c0510588 100644
--- a/scripts/react_native_pods.rb
+++ b/scripts/react_native_pods.rb
@@ -108,21 +108,3 @@ def flipper_post_install(installer)
     end
   end
 end
-
-# Pre Install processing for Native Modules
-def codegen_pre_install(installer, options={})
-  # Path to React Native
-  prefix = options[:path] ||= "../node_modules/react-native"
-
-  # Path to react-native-codegen
-  codegen_path = options[:codegen_path] ||= "#{prefix}/../react-native-codegen"
-
-  # Handle Core Modules
-  Dir.mktmpdir do |dir|
-    native_module_spec_name = "FBReactNativeSpec"
-    schema_file = dir + "/schema-#{native_module_spec_name}.json"
-    srcs_dir = "#{prefix}/Libraries"
-    schema_generated = system("node #{codegen_path}/lib/cli/combine/combine-js-to-schema-cli.js #{schema_file} #{srcs_dir}") or raise "Could not generate Native Module schema"
-    specs_generated = system("node #{prefix}/scripts/generate-native-modules-specs-cli.js ios #{schema_file} #{srcs_dir}/#{native_module_spec_name}/#{native_module_spec_name}") or raise "Could not generate code for #{native_module_spec_name}"
-  end
-end
diff --git a/template/ios/Podfile b/template/ios/Podfile
index 04f68e5431fb93..6701249e83ac20 100644
--- a/template/ios/Podfile
+++ b/template/ios/Podfile
@@ -13,10 +13,6 @@ target 'HelloWorld' do
     # Pods for testing
   end
 
-  pre_install do |installer|
-    codegen_pre_install(installer)
-  end
-
   # Enables Flipper.
   #
   # Note that if you have use_frameworks! enabled, Flipper will not work and