diff --git a/.env.example b/.env.example
index 74a6744..3f08637 100644
--- a/.env.example
+++ b/.env.example
@@ -15,3 +15,4 @@ PAGESHIP_TOKEN_AUTHORITY=http://api.localtest.me:8001
 PAGESHIP_CLEANUP_EXPIRED_CRONTAB=* * * * *
 # PAGESHIP_HOST_ID_SCHEME=suffix
 
+# PAGESHIP_CUSTOM_DOMAIN_MESSAGE=
diff --git a/cmd/controller/app/start.go b/cmd/controller/app/start.go
index fe30599..eb26303 100644
--- a/cmd/controller/app/start.go
+++ b/cmd/controller/app/start.go
@@ -7,6 +7,7 @@ import (
 	"os"
 	"time"
 
+	"github.com/carlmjohnson/versioninfo"
 	"github.com/dustin/go-humanize"
 	"github.com/oursky/pageship/internal/command"
 	"github.com/oursky/pageship/internal/config"
@@ -59,6 +60,8 @@ func init() {
 	startCmd.PersistentFlags().String("token-authority", "pageship", "auth token authority")
 	startCmd.PersistentFlags().String("token-signing-key", "", "auth token signing key")
 
+	startCmd.PersistentFlags().String("custom-domain-message", "", "message for custom domain users")
+
 	startCmd.PersistentFlags().String("cleanup-expired-crontab", "", "cleanup expired schedule")
 	startCmd.PersistentFlags().Duration("keep-after-expired", time.Hour*24, "keep-after-expired")
 
@@ -101,6 +104,8 @@ type StartControllerConfig struct {
 	TokenAuthority    string   `mapstructure:"token-authority"`
 	ReservedApps      []string `mapstructure:"reserved-apps"`
 	APIACLFile        string   `mapstructure:"api-acl" validate:"omitempty,filepath"`
+
+	CustomDomainMessage string `mapstructure:"custom-domain-message"`
 }
 
 type StartCronConfig struct {
@@ -171,13 +176,15 @@ func (s *setup) controller(domain string, conf StartControllerConfig, sitesConf
 	}
 
 	controllerConf := controller.Config{
-		MaxDeploymentSize: int64(maxDeploymentSize),
-		StorageKeyPrefix:  conf.StorageKeyPrefix,
-		HostIDScheme:      sitesConf.HostIDScheme,
-		HostPattern:       config.NewHostPattern(sitesConf.HostPattern),
-		ReservedApps:      reservedApps,
-		TokenSigningKey:   []byte(tokenSigningKey),
-		TokenAuthority:    conf.TokenAuthority,
+		MaxDeploymentSize:   int64(maxDeploymentSize),
+		StorageKeyPrefix:    conf.StorageKeyPrefix,
+		HostIDScheme:        sitesConf.HostIDScheme,
+		HostPattern:         config.NewHostPattern(sitesConf.HostPattern),
+		ReservedApps:        reservedApps,
+		TokenSigningKey:     []byte(tokenSigningKey),
+		TokenAuthority:      conf.TokenAuthority,
+		ServerVersion:       versioninfo.Short(),
+		CustomDomainMessage: conf.CustomDomainMessage,
 	}
 
 	if conf.APIACLFile != "" {
diff --git a/cmd/pageship/app/domains.go b/cmd/pageship/app/domains.go
index 26f4269..07630aa 100644
--- a/cmd/pageship/app/domains.go
+++ b/cmd/pageship/app/domains.go
@@ -35,6 +35,11 @@ var domainsCmd = &cobra.Command{
 			return fmt.Errorf("app ID is not set")
 		}
 
+		manifest, err := API().GetManifest(cmd.Context())
+		if err != nil {
+			return fmt.Errorf("failed to get manifest: %w", err)
+		}
+
 		app, err := API().GetApp(cmd.Context(), appID)
 		if err != nil {
 			return fmt.Errorf("failed to get app: %w", err)
@@ -93,6 +98,12 @@ var domainsCmd = &cobra.Command{
 			fmt.Fprintf(w, "%s\t%s\t%s\t%s\n", domain.name, site, createdAt, status)
 		}
 		w.Flush()
+
+		if manifest.CustomDomainMessage != "" {
+			os.Stdout.WriteString("\n")
+			Info(manifest.CustomDomainMessage)
+		}
+
 		return nil
 	},
 }
diff --git a/internal/api/client.go b/internal/api/client.go
index daa0742..91996a9 100644
--- a/internal/api/client.go
+++ b/internal/api/client.go
@@ -46,6 +46,29 @@ func (c *Client) attachToken(r *http.Request) error {
 	return nil
 }
 
+func (c *Client) GetManifest(ctx context.Context) (*APIManifest, error) {
+	endpoint, err := url.JoinPath(c.endpoint, "api", "v1", "manifest")
+	if err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "GET", endpoint, nil)
+	if err != nil {
+		return nil, err
+	}
+	if err := c.attachToken(req); err != nil {
+		return nil, err
+	}
+
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	return decodeJSONResponse[*APIManifest](resp)
+}
+
 func (c *Client) CreateApp(ctx context.Context, appID string) (*APIApp, error) {
 	endpoint, err := url.JoinPath(c.endpoint, "api", "v1", "apps")
 	if err != nil {
diff --git a/internal/api/models.go b/internal/api/models.go
index 94111d7..dd9998f 100644
--- a/internal/api/models.go
+++ b/internal/api/models.go
@@ -4,6 +4,11 @@ import (
 	"github.com/oursky/pageship/internal/models"
 )
 
+type APIManifest struct {
+	Version             string `json:"version"`
+	CustomDomainMessage string `json:"customDomainMessage,omitempty"`
+}
+
 type APIApp struct {
 	*models.App
 	URL string `json:"url"`
diff --git a/internal/handler/controller/config.go b/internal/handler/controller/config.go
index 8c4b1af..cb0e0a1 100644
--- a/internal/handler/controller/config.go
+++ b/internal/handler/controller/config.go
@@ -14,4 +14,7 @@ type Config struct {
 	TokenAuthority    string
 	TokenSigningKey   []byte
 	ACL               *watch.File[config.ACL]
+
+	ServerVersion       string
+	CustomDomainMessage string
 }
diff --git a/internal/handler/controller/controller.go b/internal/handler/controller/controller.go
index cb84cba..4eeb852 100644
--- a/internal/handler/controller/controller.go
+++ b/internal/handler/controller/controller.go
@@ -100,6 +100,8 @@ func (c *Controller) Handler() http.Handler {
 			})
 		})
 
+		r.With(requireAuth).Get("/manifest", c.handleManifest)
+
 		r.With(requireAuth).Get("/auth/me", c.handleMe)
 		r.Get("/auth/github-ssh", c.handleAuthGithubSSH)
 		r.Post("/auth/github-oidc", c.handleAuthGithubOIDC)
diff --git a/internal/handler/controller/manifest.go b/internal/handler/controller/manifest.go
new file mode 100644
index 0000000..1362e8c
--- /dev/null
+++ b/internal/handler/controller/manifest.go
@@ -0,0 +1,17 @@
+package controller
+
+import (
+	"net/http"
+)
+
+type apiManifest struct {
+	Version             string `json:"version"`
+	CustomDomainMessage string `json:"customDomainMessage,omitempty"`
+}
+
+func (c *Controller) handleManifest(w http.ResponseWriter, r *http.Request) {
+	writeResponse(w, &apiManifest{
+		Version:             c.Config.ServerVersion,
+		CustomDomainMessage: c.Config.CustomDomainMessage,
+	}, nil)
+}