diff --git a/.gitignore b/.gitignore
index 723ef36..1338523 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,4 @@
-.idea
\ No newline at end of file
+.idea
+
+RPG-Maker-ACE-Cheater-Patcher.exe
+RPGMakerDecrypter-cli.exe
diff --git a/README.md b/README.md
index 7bb517a..6f25975 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,5 @@
 # RPG Maker VX Ace Cheater
 
-Prototyping...
-
 # How to Patch on Windows
 
 - Preparing
@@ -11,7 +9,7 @@ Prototyping...
       ```shell
       ruby rvdata2-unpacker/rvunpacker.rb decode .
       ```
-      - See [README.md](rvdata2-unpacker/README.md) for more details.
+        - See [README.md](rvdata2-unpacker/README.md) for more details.
 - Use [RPGMakerDecrypter-cli.exe](https://github.com/uuksu/RPGMakerDecrypter) to unpack `Game.rgss3a`.
     - Download `RPGMakerDecrypter-cli.exe`
       from [https://github.com/uuksu/RPGMakerDecrypter/releases](https://github.com/uuksu/RPGMakerDecrypter/releases).
@@ -77,6 +75,13 @@ Prototyping...
 - `[`: Save current position
 - `]`: Load saved position
 
+# Dev
+
+- Download `RPGMakerDecrypter-cli.exe` from https://github.com/uuksu/RPGMakerDecrypter/releases, and put it in root of
+  project along
+  with [main.go](main.go).
+- Run [build.sh](build.sh) or [build.bat](build.bat) to build the patcher.
+
 # Credits
 
 - [RPGMakerDecrypter](https://github.com/uuksu/RPGMakerDecrypter)
diff --git a/build.bat b/build.bat
new file mode 100644
index 0000000..df6ef85
--- /dev/null
+++ b/build.bat
@@ -0,0 +1,3 @@
+@echo off
+
+go build -o RPG-Maker-ACE-Cheater-Patcher.exe
diff --git a/build.sh b/build.sh
new file mode 100644
index 0000000..4bc33d2
--- /dev/null
+++ b/build.sh
@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+
+export GOOS="windows"
+export GOARCH="amd64"
+
+go build -o RPG-Maker-ACE-Cheater-Patcher.exe
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..efe4efd
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module github.com/allape/RPG-Maker-ACE-Cheater
+
+go 1.23.1
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..a2cfe6a
--- /dev/null
+++ b/main.go
@@ -0,0 +1,200 @@
+package main
+
+import (
+	_ "embed"
+	"fmt"
+	"log"
+	"os"
+	"os/exec"
+	"path"
+	"runtime"
+	"strings"
+	"time"
+)
+
+const (
+	GameRGSS3A     = "Game.rgss3a"
+	ScriptsRVDARA2 = "Scripts.rvdata2"
+	MainRB         = "Main.rb"
+	SceneBaseRB    = "Scene_Base.rb"
+)
+
+const (
+	SceneBaseInjectionScript = "    AsCheater.update"
+)
+
+//go:embed AsCheater.rb
+var CheatScript string
+
+//go:embed RPGMakerDecrypter-cli.exe
+var RPGMakerDecrypterCLIBin []byte
+
+//go:embed rvdata2-unpacker/rvunpacker.exe
+var RVUnpackerBin []byte
+
+func pause() {
+	log.Println("Press [Enter] to exit...")
+	var input string
+	_, _ = fmt.Scanln(&input)
+}
+
+func Println(args ...any) {
+	log.Println(args...)
+}
+
+func Fatalln(args ...any) {
+	log.Println(args...)
+	pause()
+	os.Exit(1)
+}
+
+func createExe(name string, data []byte) string {
+	Println("Creating", name, "...")
+	file, err := os.CreateTemp(os.TempDir(), name)
+	if err != nil {
+		Fatalln("Failed to create", name, ":", err)
+	}
+	defer func() {
+		_ = file.Close()
+	}()
+	_, err = file.Write(data)
+	if err != nil {
+		Fatalln("Failed to write", name, ":", err)
+	}
+	_ = file.Close()
+
+	Println("Created", name, "at", file.Name())
+
+	return file.Name()
+}
+
+func main() {
+	if runtime.GOOS != "windows" {
+		Fatalln("This program only runs on Windows")
+	}
+
+	// print credits
+	Println("Credits:")
+	Println("RPGMakerDecrypter-cli.exe by https://github.com/uuksu/RPGMakerDecrypter")
+	Println("rvunpacker.exe by https://www.gamedev.net/forums/topic/646333-rpg-maker-vx-ace-data-conversion-utility/")
+
+	Println()
+	Println("If this program failed to patch your game, please do it manually with the instructions in README.md.")
+
+	Println()
+	Println("Booting up...")
+
+	time.Sleep(3 * time.Second)
+
+	dec := createExe("RPGMAC-RPGMakerDecrypter-cli.exe", RPGMakerDecrypterCLIBin)
+	rvu := createExe("RPGMAC-rvunpacker.exe", RVUnpackerBin)
+
+	root := "."
+	if len(os.Args) > 1 {
+		root = os.Args[1]
+	}
+
+	Println("Ready to patch Game.exe at", root)
+
+	stat, err := os.Stat(root)
+	if err != nil {
+		Fatalln("Failed to stat", root, ":", err)
+	} else if !stat.IsDir() {
+		Fatalln(root, "is not a directory")
+	}
+
+	scriptsRVDARA2 := path.Join(root, "Data", ScriptsRVDARA2)
+	_, err = os.Stat(scriptsRVDARA2)
+	if err != nil {
+		unzipGame(dec, root)
+		injectMain(rvu, root)
+	} else {
+		Println("Game already unzipped")
+		injectMain(rvu, root)
+	}
+
+	Println("Patched Game.exe at", root)
+
+	pause()
+}
+
+func run(name, cwd string, arg ...string) {
+	cmd := exec.Command(name, arg...)
+	cmd.Dir = cwd
+
+	output, err := cmd.CombinedOutput()
+	if len(output) > 0 {
+		Println(name, ":\n", string(output))
+	}
+	if err != nil {
+		Fatalln("Failed to run", name, ":", err)
+	}
+}
+
+func injectMain(exe, root string) {
+	Println("Patching Game.exe...")
+
+	// decode Scripts.rvdata2
+	run(exe, root, "decode", root)
+
+	mainRb := path.Join(root, "Scripts", MainRB)
+	sceneBaseRb := path.Join(root, "Scripts", SceneBaseRB)
+
+	if _, err := os.Stat(mainRb); err != nil {
+		Fatalln("Failed to find", mainRb)
+	}
+	if _, err := os.Stat(sceneBaseRb); err != nil {
+		Fatalln("Failed to find", sceneBaseRb)
+	}
+
+	mainText, err := os.ReadFile(mainRb)
+	if err != nil {
+		Fatalln("Failed to read", mainRb, ":", err)
+	}
+
+	if strings.Contains(string(mainText), CheatScript) {
+		Println("Game already patched")
+		return
+	}
+
+	err = os.WriteFile(mainRb, []byte(fmt.Sprintf("%s\r\n%s", CheatScript, string(mainText))), 0644)
+	if err != nil {
+		Fatalln("Failed to write", mainRb, ":", err)
+	}
+
+	sceneBaseText, err := os.ReadFile(sceneBaseRb)
+	if err != nil {
+		Fatalln("Failed to read", sceneBaseRb, ":", err)
+	}
+	sceneBaseLines := strings.Split(string(sceneBaseText), "\r\n")
+	injectPoint := -1
+	for i, line := range sceneBaseLines {
+		if strings.TrimSpace(line) == "def update" {
+			injectPoint = i
+			break
+		}
+	}
+	if injectPoint < 0 {
+		Fatalln("Failed to find 'def update' in", sceneBaseRb)
+	}
+	sceneBaseInjectedText := strings.Join(sceneBaseLines[:injectPoint+1], "\r\n")
+	sceneBaseInjectedText += "\r\n" + SceneBaseInjectionScript + "\r\n"
+	sceneBaseInjectedText += strings.Join(sceneBaseLines[injectPoint+1:], "\r\n")
+	err = os.WriteFile(sceneBaseRb, []byte(sceneBaseInjectedText+"\r\n"), 0644)
+
+	// encode Scripts.rvdata2
+	run(exe, root, "encode", root)
+}
+
+func unzipGame(exe, root string) {
+	Println("Unzipping Game.exe...")
+	src := path.Join(root, GameRGSS3A)
+	dst := path.Join(root, GameRGSS3A+"~")
+	run(exe, root, src)
+
+	Println("Renaming", src, "to", dst)
+	err := os.Rename(src, dst)
+	if err != nil {
+		Fatalln("Failed to rename", src, "to", dst, ":", err)
+	}
+}
diff --git a/rvdata2-unpacker/.gitignore b/rvdata2-unpacker/.gitignore
index 996e13a..4f87566 100644
--- a/rvdata2-unpacker/.gitignore
+++ b/rvdata2-unpacker/.gitignore
@@ -1,4 +1,3 @@
 Data
 Scripts
 YAML
-RPGMakerDecrypter-cli.exe