diff --git a/backend/internal/config/config_test.go b/backend/internal/config/config_test.go
index 6f1b455..2843880 100644
--- a/backend/internal/config/config_test.go
+++ b/backend/internal/config/config_test.go
@@ -65,10 +65,13 @@ func TestLoadFromEnv(t *testing.T) {
 	os.Setenv("BACKEND_PORT", "9999")
 	os.Setenv("DATABASE_URL", "postgres://test:test@localhost:5432/test")
 	os.Setenv("MARKETPLACE_COMMISSION", "5.0")
+	os.Setenv("BUYER_FEE_RATE", "0.2")
 	os.Setenv("JWT_SECRET", "super-secret")
 	os.Setenv("JWT_EXPIRES_IN", "12h")
 	os.Setenv("PASSWORD_PEPPER", "pepper123")
 	os.Setenv("CORS_ORIGINS", "https://example.com,https://app.example.com")
+	os.Setenv("BACKEND_HOST", "api.test.local")
+	os.Setenv("SWAGGER_SCHEMES", "https, http")
 	os.Setenv("ADMIN_NAME", "CustomAdmin")
 	os.Setenv("ADMIN_USERNAME", "customadmin")
 	os.Setenv("ADMIN_EMAIL", "custom@example.com")
@@ -79,10 +82,13 @@ func TestLoadFromEnv(t *testing.T) {
 		os.Unsetenv("BACKEND_PORT")
 		os.Unsetenv("DATABASE_URL")
 		os.Unsetenv("MARKETPLACE_COMMISSION")
+		os.Unsetenv("BUYER_FEE_RATE")
 		os.Unsetenv("JWT_SECRET")
 		os.Unsetenv("JWT_EXPIRES_IN")
 		os.Unsetenv("PASSWORD_PEPPER")
 		os.Unsetenv("CORS_ORIGINS")
+		os.Unsetenv("BACKEND_HOST")
+		os.Unsetenv("SWAGGER_SCHEMES")
 		os.Unsetenv("ADMIN_NAME")
 		os.Unsetenv("ADMIN_USERNAME")
 		os.Unsetenv("ADMIN_EMAIL")
@@ -103,6 +109,9 @@ func TestLoadFromEnv(t *testing.T) {
 	if cfg.MarketplaceCommission != 5.0 {
 		t.Errorf("expected MarketplaceCommission 5.0, got %f", cfg.MarketplaceCommission)
 	}
+	if cfg.BuyerFeeRate != 0.2 {
+		t.Errorf("expected BuyerFeeRate 0.2, got %f", cfg.BuyerFeeRate)
+	}
 	if cfg.JWTSecret != "super-secret" {
 		t.Errorf("expected JWTSecret 'super-secret', got '%s'", cfg.JWTSecret)
 	}
@@ -115,6 +124,12 @@ func TestLoadFromEnv(t *testing.T) {
 	if len(cfg.CORSOrigins) != 2 {
 		t.Errorf("expected 2 CORS origins, got %d", len(cfg.CORSOrigins))
 	}
+	if cfg.BackendHost != "api.test.local" {
+		t.Errorf("expected BackendHost 'api.test.local', got '%s'", cfg.BackendHost)
+	}
+	if len(cfg.SwaggerSchemes) != 2 || cfg.SwaggerSchemes[0] != "https" || cfg.SwaggerSchemes[1] != "http" {
+		t.Errorf("expected SwaggerSchemes [https http], got %v", cfg.SwaggerSchemes)
+	}
 	if cfg.AdminName != "CustomAdmin" {
 		t.Errorf("expected AdminName 'CustomAdmin', got '%s'", cfg.AdminName)
 	}
@@ -139,9 +154,13 @@ func TestAddr(t *testing.T) {
 
 func TestInvalidEnvValues(t *testing.T) {
 	os.Setenv("MARKETPLACE_COMMISSION", "invalid")
+	os.Setenv("JWT_EXPIRES_IN", "not-a-duration")
+	os.Setenv("BUYER_FEE_RATE", "invalid-rate")
 
 	defer func() {
 		os.Unsetenv("MARKETPLACE_COMMISSION")
+		os.Unsetenv("JWT_EXPIRES_IN")
+		os.Unsetenv("BUYER_FEE_RATE")
 	}()
 
 	cfg := Load()
@@ -150,6 +169,12 @@ func TestInvalidEnvValues(t *testing.T) {
 	if cfg.MarketplaceCommission != 2.5 {
 		t.Errorf("expected fallback MarketplaceCommission 2.5, got %f", cfg.MarketplaceCommission)
 	}
+	if cfg.JWTExpiresIn != 24*time.Hour {
+		t.Errorf("expected fallback JWTExpiresIn 24h, got %v", cfg.JWTExpiresIn)
+	}
+	if cfg.BuyerFeeRate != 0.12 {
+		t.Errorf("expected fallback BuyerFeeRate 0.12, got %f", cfg.BuyerFeeRate)
+	}
 }
 
 func TestEmptyCORSOrigins(t *testing.T) {
@@ -162,3 +187,14 @@ func TestEmptyCORSOrigins(t *testing.T) {
 		t.Errorf("expected fallback CORSOrigins ['*'], got %v", cfg.CORSOrigins)
 	}
 }
+
+func TestSwaggerSchemesTrimmed(t *testing.T) {
+	os.Setenv("SWAGGER_SCHEMES", " https , ,http,")
+	defer os.Unsetenv("SWAGGER_SCHEMES")
+
+	cfg := Load()
+
+	if len(cfg.SwaggerSchemes) != 2 || cfg.SwaggerSchemes[0] != "https" || cfg.SwaggerSchemes[1] != "http" {
+		t.Errorf("expected SwaggerSchemes [https http], got %v", cfg.SwaggerSchemes)
+	}
+}