diff --git a/README.md b/README.md
index 027e963..564b71d 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,26 @@
 # mikrotik-geoipblock
 
-Generate RouterOS Address Lists based on country code.
\ No newline at end of file
+Generate RouterOS Address Lists based on country code.  
+
+```sh
+# Example usage
+./mikrotik-geoipblock myAddressList example.json
+```
+
+Createa a config file containing the address lists you want to block
+
+```json
+{
+    "countries": [
+        {
+            "name": "CANADA",
+            "url": "https://raw.githubusercontent.com/herrbischoff/country-ip-blocks/refs/heads/master/ipv4/ca.cidr"
+        },
+        {
+            "name": "AUSTRALIA",
+            "url": "https://raw.githubusercontent.com/herrbischoff/country-ip-blocks/refs/heads/master/ipv4/au.cidr"
+        }
+    ]
+}
+```
+
diff --git a/example.json b/example.json
new file mode 100644
index 0000000..4ef95c8
--- /dev/null
+++ b/example.json
@@ -0,0 +1,12 @@
+{
+    "countries": [
+        {
+            "name": "CANADA",
+            "url": "https://raw.githubusercontent.com/herrbischoff/country-ip-blocks/refs/heads/master/ipv4/ca.cidr"
+        },
+        {
+            "name": "AUSTRALIA",
+            "url": "https://raw.githubusercontent.com/herrbischoff/country-ip-blocks/refs/heads/master/ipv4/au.cidr"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..0f90c88
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module code.stevenpolley.net/steven/mikrotik-geoipblock
+
+go 1.23.0
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..3672b9b
--- /dev/null
+++ b/main.go
@@ -0,0 +1,107 @@
+package main
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"os"
+)
+
+type Country struct {
+	Name        string `json:"name"`
+	Url         string `json:"url"`
+	v4Addresses []string
+}
+
+type JsonListFile struct {
+	Countries []Country `json:"countries"`
+}
+
+func main() {
+
+	// Validate arguments
+	if len(os.Args) < 3 {
+		log.Fatalf("usage: %s <blocklistname> <jsonlistfile>", os.Args[0])
+	}
+	blockListName := os.Args[1]
+	jsonListFile := os.Args[2]
+	fmt.Printf("generating blocklist %s\n", blockListName)
+
+	// Load blocklist config file
+	countries, err := readJsonListFile(jsonListFile)
+	if err != nil {
+		log.Fatalf("failed to read jsonlistfile '%s': %v", jsonListFile, err)
+	}
+
+	// Download up to date geoip CIDR data
+	for i := range countries {
+		countries[i].v4Addresses, err = downloadAddressList(countries[i].Url)
+		if err != nil {
+			log.Fatalf("failed to download address list for county'%s': %v", countries[i].Name, err)
+		}
+	}
+
+	// Generate mikrotik block list
+	err = generateOutput(countries, blockListName)
+	if err != nil {
+		log.Fatalf("failed to generate output file: %v", err)
+	}
+}
+
+func generateOutput(countries []Country, blockListName string) error {
+	output := "/ip firewall address-list\n"
+	for _, country := range countries {
+		for _, v4Address := range country.v4Addresses {
+			output += fmt.Sprintf("add address=%s comment=\"%s\" list=%s\n", v4Address, country.Name, blockListName)
+		}
+	}
+
+	err := os.WriteFile(fmt.Sprintf("%s.rsc", blockListName), []byte(output), os.ModePerm)
+	if err != nil {
+		return fmt.Errorf("failed to write file '%s.rsc': %v", blockListName, err)
+	}
+	return nil
+}
+
+func downloadAddressList(url string) ([]string, error) {
+	resp, err := http.Get(url)
+	if err != nil {
+		return nil, fmt.Errorf("http get error on url '%s': %v", url, err)
+	}
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("unexpected http status - expected '%d' but got '%d'", http.StatusOK, resp.StatusCode)
+	}
+	scanner := bufio.NewScanner(resp.Body)
+	scanner.Split(bufio.ScanLines)
+	v4Addresses := make([]string, 0)
+	for scanner.Scan() {
+		line := scanner.Text()
+		_, ipnet, err := net.ParseCIDR(line)
+		if err != nil {
+			log.Printf("skippine line: failed to parse line '%s' to cidr: %v", line, err)
+			continue
+		}
+		v4Addresses = append(v4Addresses, ipnet.String())
+	}
+	return v4Addresses, nil
+}
+
+// reads the json config file containing the lists of countries you want to block
+func readJsonListFile(filename string) ([]Country, error) {
+	b, err := os.ReadFile(filename)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open file %s: %v", filename, err)
+	}
+
+	jsonListFile := JsonListFile{}
+
+	err = json.Unmarshal(b, &jsonListFile)
+	if err != nil {
+		return nil, fmt.Errorf("failed to unmarshal json file to jsonListFile struct: %v", err)
+	}
+
+	return jsonListFile.Countries, nil
+}