take env var and use the With rather than assignment

Author: SamMorrowDrums

cmd/github-mcp-server/main.go

@@ -102,7 +102,14 @@ func runStdioServer(readOnly bool, logger *log.Logger, logCommands bool, exportT
 logger.Fatal("GITHUB_PERSONAL_ACCESS_TOKEN not set")
 }
 ghClient := gogithub.NewClient(nil).WithAuthToken(token)
-if host := viper.GetString("gh-host"); host != "" {
+
+// Check GH_HOST env var first, then fall back to viper config
+host := os.Getenv("GH_HOST")
+if host == "" {
+host = viper.GetString("gh-host")
+}
+
+if host != "" {
 parsedURL, err := url.Parse(fmt.Sprintf("https://api.%s/", host))
 if err != nil {
 return fmt.Errorf("failed to parse provided GitHub host URL: %w", err)
@@ -113,8 +120,10 @@ func runStdioServer(readOnly bool, logger *log.Logger, logCommands bool, exportT
 return fmt.Errorf("failed to parse provided GitHub host URL: %w", err)
 }
 
-ghClient.BaseURL = parsedURL
-ghClient.UploadURL = uploadURL
+ghClient, err = ghClient.WithEnterpriseURLs(parsedURL.String(), uploadURL.String())
+if err != nil {
+return fmt.Errorf("failed to create GitHub client with host: %w", err)
+}
 }
 
 t, dumpTranslations := translations.TranslationHelper()