diff --git a/.vscode/launch.json b/.vscode/launch.json
new file mode 100644
index 0000000..6deb9a6
--- /dev/null
+++ b/.vscode/launch.json
@@ -0,0 +1,15 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Launch Package",
+            "type": "go",
+            "request": "launch",
+            "mode": "auto",
+            "program": "main.go"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/app/api/api.go b/app/api/api.go
index 778f64e..5499b44 100644
--- a/app/api/api.go
+++ b/app/api/api.go
@@ -1 +1,49 @@
 package api
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/rayaman/bdo-market/app/types"
+)
+
+var items []types.MarketItem
+var lastUpdated time.Time = time.Now()
+
+// GetMarketItems retrieves market items from the API and updates them if necessary.
+//
+// It returns a slice of MarketItem and an error.
+func GetMarketItems() ([]types.MarketItem, error) {
+	// The api only updates every 30 minutes, so let's only update it every 30 minutes
+	if len(items) > 0 && time.Since(lastUpdated) < 30*time.Minute {
+		return items, nil
+	}
+	var marketdata []types.MarketItem
+
+	client := &http.Client{}
+	req, err := http.NewRequest("GET", "https://api.arsha.io/v2/na/market", nil)
+
+	if err != nil {
+		return marketdata, err
+	}
+
+	res, err := client.Do(req)
+
+	if err != nil {
+		return marketdata, err
+	}
+
+	defer res.Body.Close()
+
+	body, err := io.ReadAll(res.Body)
+
+	if err != nil {
+		return marketdata, err
+	}
+
+	json.Unmarshal(body, &marketdata)
+	items = marketdata
+	return marketdata, nil
+}
diff --git a/app/data/data.go b/app/data/data.go
new file mode 100644
index 0000000..5fba4c9
--- /dev/null
+++ b/app/data/data.go
@@ -0,0 +1,27 @@
+package data
+
+import (
+	"fmt"
+
+	"github.com/rayaman/bdo-market/app/types"
+)
+
+// Filter filters the items using the provided filter function.
+//
+// Parameters:
+// - items []types.MarketItem
+// - filter func(types.MarketItem) bool
+// Return type: []types.MarketItem
+func Filter(items []types.MarketItem, filter func(types.MarketItem) bool) []types.MarketItem {
+	var filteredItems []types.MarketItem
+	for _, item := range items {
+		if filter(item) {
+			filteredItems = append(filteredItems, item)
+		}
+	}
+	return filteredItems
+}
+
+func SprintMarketItem(item types.MarketItem) string {
+	return fmt.Sprintf("Name: %s\n    Id: %d\n    Current Stock: %d\n    Total Trades: %d\n    Base Price: %d\n    Main Category: %d\n    Sub Category: %d\n    Market Category: %d", item.Name, item.Id, item.CurrentStock, item.TotalTrades, item.BasePrice, item.MainCategory, item.SubCategory, item.MarketCategory)
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..6ffc7d7
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module github.com/rayaman/bdo-market
+
+go 1.22.0
diff --git a/main.go b/main.go
index ad94284..e578c7b 100644
--- a/main.go
+++ b/main.go
@@ -1,33 +1,26 @@
 package main
 
 import (
-	"app/types"
 	"fmt"
-	"json"
-	"net/http"
+
+	"github.com/rayaman/bdo-market/app/api"
+	"github.com/rayaman/bdo-market/app/data"
+	"github.com/rayaman/bdo-market/app/types"
 )
 
 func main() {
-
-}
-
-func GetMarketItems() []types.MarketItem {
-	var marketdata []types.MarketItem
-	url := "https://api.arsha.io/v2/na/market"
-
-	client := &http.Client{}
-	req, err := http.NewRequest("GET", url, nil)
-
+	marketdata, err := api.GetMarketItems()
 	if err != nil {
-		fmt.Println(err)
-		return
+		panic(err)
 	}
-	res, err := client.Do(req)
-	if err != nil {
-		fmt.Println(err)
-		return
+	fmt.Printf("Total length: %d\n", len(marketdata))
+
+	filtered_items := data.Filter(marketdata, func(item types.MarketItem) bool {
+		return item.CurrentStock > 100000
+	})
+
+	fmt.Printf("Filtered length: %d\n", len(filtered_items))
+	for _, item := range filtered_items {
+		fmt.Println(data.SprintMarketItem(item))
 	}
-	defer res.Body.Close()
-	json.UnMarshal(res.Body, &marketdata)
-	return marketdata
 }