core_service.go

@@ -163,6 +163,11 @@ func (s *CoreService) Raw(messageID string, args ...any) string {
 	return s.svc.Raw(messageID, args...)
 }
 
+// AddMessages adds message strings to the wrapped service.
+func (s *CoreService) AddMessages(lang string, messages map[string]string) {
+	s.svc.AddMessages(lang, messages)
+}
+
 // SetLanguage changes the wrapped service language.
 func (s *CoreService) SetLanguage(lang string) error {
 	return s.svc.SetLanguage(lang)

hooks_test.go

@@ -402,6 +402,11 @@ func TestCoreService_DelegatesToWrappedService(t *testing.T) {
 		"locales/en.json": &fstest.MapFile{Data: []byte(`{"core.service.loaded.fs": "loaded via fs"}`)},
 	}, "locales"))
 	assert.Equal(t, "loaded via fs", coreSvc.T("core.service.loaded.fs"))
+
+	coreSvc.AddMessages("en", map[string]string{
+		"core.service.add.messages": "loaded via add messages",
+	})
+	assert.Equal(t, "loaded via add messages", coreSvc.T("core.service.add.messages"))
 }
 
 func TestInit_ReDetectsRegisteredLocales(t *testing.T) {

i18n.go

@@ -244,6 +244,15 @@ func LoadFS(fsys fs.FS, dir string) {
 	})
 }
 
+// AddMessages adds message strings to the default service for a language.
+//
+// Example:
+//
+//	i18n.AddMessages("en", map[string]string{"custom.greeting": "Hello!"})
+func AddMessages(lang string, messages map[string]string) {
+	withDefaultService(func(svc *Service) { svc.AddMessages(lang, messages) })
+}
+
 // PrependHandler inserts one or more handlers at the start of the default service's handler chain.
 //
 // Example:

i18n_test.go

@@ -108,6 +108,23 @@ func TestLoadFS_Good(t *testing.T) {
 	assert.Equal(t, "loaded via package helper", got)
 }
 
+func TestAddMessages_Good(t *testing.T) {
+	svc, err := New()
+	require.NoError(t, err)
+	prev := Default()
+	SetDefault(svc)
+	t.Cleanup(func() {
+		SetDefault(prev)
+	})
+
+	AddMessages("en", map[string]string{
+		"add.messages.key": "loaded via package helper",
+	})
+
+	got := T("add.messages.key")
+	assert.Equal(t, "loaded via package helper", got)
+}
+
 // --- SetLanguage / CurrentLanguage ---
 
 func TestSetLanguage_Good(t *testing.T) {