diff --git a/config/config.go b/config/config.go
index 14bc2e6..17adf75 100644
--- a/config/config.go
+++ b/config/config.go
@@ -105,11 +105,13 @@ type AmConfig struct {
 		VeniceCompatibleImageURLs bool `yaml:"veniceCompatibleImageURLs"`
 	} `yaml:"rendering"`
 	Resources struct {
-		ViewTemplateDir      string `yaml:"viewTemplateDir"`
-		DialogTemplateDir    string `yaml:"dialogTemplateDir"`
-		EmailTemplateDir     string `yaml:"emailTemplateDir"`
-		ExternalContentPath  string `yaml:"externalContentPath"`
-		ExternalResourcePath string `yaml:"externalResourcePath"`
+		ViewTemplateDir            string `yaml:"viewTemplateDir"`
+		DialogTemplateDir          string `yaml:"dialogTemplateDir"`
+		EmailTemplateDir           string `yaml:"emailTemplateDir"`
+		ExternalContentPath        string `yaml:"externalContentPath"`
+		ExternalResourcePath       string `yaml:"externalResourcePath"`
+		ExternalMenuDefinitions    string `yaml:"externalMenuDefinitions"`
+		ExternalMessageDefinitions string `yaml:"externalMessageDefinitions"`
 	} `yaml:"resources"`
 	Posting struct {
 		ExternalDictionary string `yaml:"externalDictionary"`
diff --git a/config/default.yaml b/config/default.yaml
index 350062b..888a0ff 100644
--- a/config/default.yaml
+++ b/config/default.yaml
@@ -55,6 +55,8 @@ resources:
   emailTemplateDir: ""
   externalContentPath: ""
   externalResourcePath: ""
+  externalMenuDefinitions: ""
+  externalMessageDefinitions: ""
 posting:
   externalDictionary: ""
   uploads:
diff --git a/ui/menus.go b/ui/menus.go
index 884fbe9..cef082d 100644
--- a/ui/menus.go
+++ b/ui/menus.go
@@ -13,6 +13,7 @@ import (
 	"context"
 	_ "embed"
 	"fmt"
+	"os"
 	"slices"
 	"strconv"
 	"strings"
@@ -22,6 +23,7 @@ import (
 	"git.erbosoft.com/amy/amsterdam/database"
 	"git.erbosoft.com/amy/amsterdam/util"
 	lru "github.com/hashicorp/golang-lru"
+	log "github.com/sirupsen/logrus"
 	"gopkg.in/yaml.v3"
 )
 
@@ -156,12 +158,31 @@ func init() {
 	}
 }
 
-// setupMenuCache sets up the menu cache.
-func setupMenuCache() {
+// setupMenus sets up the menu cache and the external menus.
+func setupMenus() {
 	var err error
 	if menuCache, err = lru.New(config.GlobalConfig.Tuning.Caches.Menus); err != nil {
 		panic(err)
 	}
+	if config.GlobalConfig.Resources.ExternalMenuDefinitions != "" {
+		b, err := os.ReadFile(config.GlobalConfig.Resources.ExternalMenuDefinitions)
+		if err == nil {
+			md := new(MenuDefs)
+			err = yaml.Unmarshal(b, md)
+			if err == nil {
+				for i, d := range md.D {
+					menuDefinitions.table[d.ID] = &(md.D[i])
+					for j := range md.D[i].Items {
+						md.D[i].Items[j].P = &(md.D[i])
+					}
+				}
+			} else {
+				log.Errorf("cannot parse external menu definition file %s, ignored (%v)", config.GlobalConfig.Resources.ExternalMenuDefinitions, err)
+			}
+		} else {
+			log.Errorf("cannot read external menu definition file %s, ignored (%v)", config.GlobalConfig.Resources.ExternalMenuDefinitions, err)
+		}
+	}
 }
 
 // AmMenu returns a menu definition.
diff --git a/ui/messagebox.go b/ui/messagebox.go
index 0d0853a..456c2c2 100644
--- a/ui/messagebox.go
+++ b/ui/messagebox.go
@@ -15,9 +15,12 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
+	"os"
 	"strings"
 
+	"git.erbosoft.com/amy/amsterdam/config"
 	"git.erbosoft.com/amy/amsterdam/util"
+	log "github.com/sirupsen/logrus"
 	"gopkg.in/yaml.v3"
 )
 
@@ -80,6 +83,33 @@ func init() {
 	}
 }
 
+// setupMessageBoxes loads external message box definitions.
+func setupMessageBoxes() {
+	if config.GlobalConfig.Resources.ExternalMessageDefinitions != "" {
+		b, err := os.ReadFile(config.GlobalConfig.Resources.ExternalMessageDefinitions)
+		if err == nil {
+			mb := new(MessageBoxDefs)
+			err = yaml.Unmarshal(b, mb)
+			if err == nil {
+				for i, def := range mb.D {
+					messageBoxDefs.table[def.Id] = &(mb.D[i])
+					mb.D[i].useConfirm = false
+					for _, b := range mb.D[i].Buttons {
+						if b.Confirm {
+							mb.D[i].useConfirm = true
+							break
+						}
+					}
+				}
+			} else {
+				log.Errorf("cannot parse external message definition file %s, ignored (%v)", config.GlobalConfig.Resources.ExternalMessageDefinitions, err)
+			}
+		} else {
+			log.Errorf("cannot read external message definition file %s, ignored (%v)", config.GlobalConfig.Resources.ExternalMessageDefinitions, err)
+		}
+	}
+}
+
 // MessageBox is the structure for a working message box.
 type MessageBox struct {
 	def         *MessageBoxDefinition
diff --git a/ui/setup.go b/ui/setup.go
index 8494ade..88871be 100644
--- a/ui/setup.go
+++ b/ui/setup.go
@@ -17,7 +17,8 @@ func SetupUILayer() func() {
 	exitfuncs := make([]func(), 0, 2)
 	setupTemplates()
 	setupDialogs()
-	setupMenuCache()
+	setupMenus()
+	setupMessageBoxes()
 	setupResources()
 	exitfuncs = append(exitfuncs, setupSessionManager())
 	exitfuncs = append(exitfuncs, setupContext())