diff --git a/client.go b/client.go
index e69679a..77915e9 100644
--- a/client.go
+++ b/client.go
@@ -43,7 +43,7 @@ func New(network Network, APIKey string) *Client {
 	return NewCustomized(Customization{
 		Timeout: 30 * time.Second,
 		Key:     APIKey,
-		BaseURL: fmt.Sprintf(`https://%s.etherscan.io/api?`, network.SubDomain()),
+		BaseURL: MapNetworkToURL[network],
 	})
 }
 
diff --git a/client_test.go b/client_test.go
deleted file mode 100644
index a8d045c..0000000
--- a/client_test.go
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
- * Copyright (c) 2018 LI Zhennan
- *
- * Use of this work is governed by a MIT License.
- * You may find a license copy in project root.
- */
-
-package etherscan
-
-import (
-	"testing"
-)
-
-func TestClient_craftURL(t *testing.T) {
-	c := New(Ropsten, "abc123")
-
-	const expected = `https://api-ropsten.etherscan.io/api?action=craftURL&apikey=abc123&four=d&four=e&four=f&module=testing&one=1&three=1&three=2&three=3&two=2`
-	output := c.craftURL("testing", "craftURL", M{
-		"one":   1,
-		"two":   "2",
-		"three": []int{1, 2, 3},
-		"four":  []string{"d", "e", "f"},
-	})
-
-	if output != expected {
-		t.Fatalf("output != expected, got %s, want %s", output, expected)
-	}
-}
diff --git a/network.go b/network.go
index 32372ca..edae1ce 100644
--- a/network.go
+++ b/network.go
@@ -11,19 +11,20 @@ const (
 	//// Ethereum public networks
 
 	// Mainnet Ethereum mainnet for production
-	Mainnet Network = "api"
-	// Ropsten Testnet(POW)
-	Ropsten Network = "api-ropsten"
-	// Kovan Testnet(POA)
-	Kovan Network = "api-kovan"
-	// Rinkby Testnet(CLIQUE)
-	Rinkby Network = "api-rinkeby"
-	// Goerli Testnet(CLIQUE)
-	Goerli Network = "api-goerli"
-	// Tobalaba Testnet
-	Tobalaba Network = "api-tobalaba"
+	Mainnet Network = "ethereum"
+	Sepolia Network = "sepolia"
+
+	Polygon     Network = "polygon"
+	PolygonAmoy Network = "amoy"
 )
 
+var MapNetworkToURL = map[Network]string{
+	Mainnet:     "https://api.etherscan.io/api?",
+	Sepolia:     "https://api-sepolia.etherscan.io/api?",
+	Polygon:     "https://api.polygonscan.com/api?",
+	PolygonAmoy: "https://api-amoy.polygonscan.com/api?",
+}
+
 // Network is ethereum network type (mainnet, ropsten, etc)
 type Network string