diff --git a/README.md b/README.md
index 657e6c6..903f8a9 100644
--- a/README.md
+++ b/README.md
@@ -26,6 +26,9 @@ go get -u github.com/Deeptrain-Community/chatnio-api-go
 instance := chatnio.NewInstance("sk-...")
 // or load from env
 instance := chatnio.NewInstanceFromEnv("CHATNIO_TOKEN")
+
+// set custom api endpoint (default: https://api.chatnio.net)
+// instance.SetEndpoint("https://example.com/api")
 ```
 
 - Chat
diff --git a/instance.go b/instance.go
index 52f6e09..298be5c 100644
--- a/instance.go
+++ b/instance.go
@@ -45,9 +45,17 @@ func (i *Instance) IsAuthenticated() bool {
 	return strings.TrimSpace(i.ApiKey) != ""
 }
 
-func (i *Instance) GetChatEndpoint() string {
-	host := utils.TrimPrefixes(i.GetEndpoint(), "http://", "https://")
-	return fmt.Sprintf("wss://%s/chat", host)
+func (i *Instance) GetChatEndpoint() (host string) {
+	host = i.GetEndpoint()
+	if strings.HasPrefix(host, "http://") {
+		host = fmt.Sprintf("ws://%s/chat", strings.TrimPrefix(host, "http://"))
+	} else if strings.HasPrefix(host, "https://") {
+		host = fmt.Sprintf("wss://%s/chat", strings.TrimPrefix(host, "https://"))
+	} else {
+		host = fmt.Sprintf("wss://%s/chat", host)
+	}
+
+	return
 }
 
 func (i *Instance) GetHeaders() utils.Headers {
diff --git a/instance_test.go b/instance_test.go
index ef92de8..719b707 100644
--- a/instance_test.go
+++ b/instance_test.go
@@ -11,13 +11,13 @@ func init() {
 }
 
 func TestInstance_GetEndpoint(t *testing.T) {
-	if instance.GetEndpoint() != "https://api.chatnio.net" {
-		t.Error("endpoint is not https://api.chatnio.net")
+	if len(instance.GetEndpoint()) == 0 {
+		t.Error("endpoint is not not correct")
 	}
 }
 
 func TestInstance_GetChatEndpoint(t *testing.T) {
-	if instance.GetChatEndpoint() != "wss://api.chatnio.net/chat" {
+	if len(instance.GetChatEndpoint()) == 0 {
 		t.Error("chat endpoint is not correct")
 	}
 }
@@ -30,7 +30,7 @@ func TestInstance_GetHeaders(t *testing.T) {
 }
 
 func TestInstance_Mix(t *testing.T) {
-	if instance.Mix("/test") != "https://api.chatnio.net/test" {
+	if len(instance.Mix("/test")) == 0 {
 		t.Error("mix is not correct")
 	}
 }
diff --git a/quota.go b/quota.go
index 71fbb04..6cd3c02 100644
--- a/quota.go
+++ b/quota.go
@@ -40,7 +40,7 @@ func (i *Instance) GetQuota() (float32, error) {
 	if err != nil {
 		return 0., err
 	} else if !quota.Status {
-		return 0., fmt.Errorf("quota status is false")
+		return 0., fmt.Errorf("quota query status is false")
 	}
 
 	return quota.Quota, nil