Add user-message client subsystem

backend/radiance.go

@@ -21,6 +21,7 @@ import (
 	"go.opentelemetry.io/otel/trace"
 
 	C "github.com/getlantern/common"
+	wire "github.com/getlantern/common/usermessage"
 	"github.com/getlantern/publicip"
 
 	"github.com/getlantern/radiance/account"
@@ -38,6 +39,7 @@ import (
 	"github.com/getlantern/radiance/telemetry"
 	"github.com/getlantern/radiance/traces"
 	"github.com/getlantern/radiance/unbounded"
+	clientmessage "github.com/getlantern/radiance/usermessage"
 	"github.com/getlantern/radiance/vpn"
 
 	lbA "github.com/getlantern/lantern-box/adapter"
@@ -57,6 +59,7 @@ type LocalBackend struct {
 	confHandler   *config.ConfigHandler
 	issueReporter *issue.IssueReporter
 	accountClient *account.Client
+	userMessages  *clientmessage.Service
 
 	srvManager     *servers.Manager
 	vpnClient      *vpn.VPNClient
@@ -103,8 +106,9 @@ type Options struct {
 	// own device ID and ignore this value
 	DeviceID string
 	// User choice for telemetry consent
-	TelemetryConsent  bool
-	PlatformInterface vpn.PlatformInterface
+	TelemetryConsent        bool
+	PlatformInterface       vpn.PlatformInterface
+	UserMessageCapabilities wire.ClientCapabilities
 	// EnvOverrides are applied via os.Setenv before common.Init so sandboxed
 	// system extensions (macOS/iOS), which don't inherit shell env, still see
 	// RADIANCE_* vars from the host process. Entries are set verbatim — no
@@ -232,13 +236,52 @@ func NewLocalBackend(ctx context.Context, opts Options) (*LocalBackend, error) {
 	}
 	r.sessionHistory = vpn.NewSessionHistory(slog.Default().With("service", "session_history"), r.sessionInfo())
 	r.shutdownFuncs = append(r.shutdownFuncs, func() error { r.sessionHistory.Close(); return nil })
+	r.userMessages = loadUserMessageService(opts.UserMessageCapabilities, dataDir)
 	r.clearSelectedIfMissing()
 	return r, nil
 }
 
+func loadUserMessageService(capabilities wire.ClientCapabilities, dataDir string) *clientmessage.Service {
+	if capabilities.Version == "" {
+		return nil
+	}
+	if err := capabilities.Validate(); err != nil {
+		slog.Warn("User messages disabled", "reason", "invalid_capabilities")
+		return nil
+	}
+	service, err := clientmessage.New(clientmessage.Options{
+		DataDir: dataDir,
+		Fetcher: clientmessage.NewHTTPFetcher(
+			kindling.HTTPClient(),
+			clientmessage.Endpoint(common.GetBaseURL()),
+			capabilities,
+		),
+		ContextProvider: func() clientmessage.ClientContext {
+			return clientmessage.ClientContext{
+				UserID:     settings.GetString(settings.UserIDKey),
+				ProToken:   settings.GetString(settings.TokenKey),
+				Locale:     clientmessage.NormalizeLocale(settings.GetString(settings.LocaleKey)),
+				Platform:   clientmessage.NormalizePlatform(common.Platform),
+				AppVersion: common.GetVersion(),
+			}
+		},
+	})
+	if err != nil {
+		slog.Error("Loading user-message state", "error", err)
+		return nil
+	}
+	return service
+}
+
 func (r *LocalBackend) Start() {
 	// eagerly start kindling so it's ready by the time we need to make network requests
 	kindling.Init()
+	if r.userMessages != nil {
+		events.SubscribeContext(r.ctx, func(account.UserChangeEvent) {
+			r.userMessages.Refresh()
+		})
+		r.userMessages.Start(r.ctx)
+	}
 	go func() {
 		ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
 		result, err := publicip.Detect(ctx, &publicip.Config{
@@ -613,6 +656,9 @@ func (r *LocalBackend) PatchSettings(updates settings.Settings) error {
 	if err := settings.Patch(diff); err != nil {
 		return fmt.Errorf("failed to update settings: %w", err)
 	}
+	if _, ok := diff[settings.LocaleKey]; ok {
+		r.refreshUserMessages()
+	}
 	// telemetry settings
 	if _, ok := diff[settings.TelemetryKey]; ok {
 		if settings.GetBool(settings.TelemetryKey) {
@@ -1567,19 +1613,35 @@ func (r *LocalBackend) RemoveSplitTunnelItems(items vpn.SplitTunnelFilter) error
 /////////////
 
 func (r *LocalBackend) NewUser(ctx context.Context) (*account.UserData, error) {
-	return r.accountClient.NewUser(ctx)
+	userData, err := r.accountClient.NewUser(ctx)
+	if err == nil {
+		r.refreshUserMessages()
+	}
+	return userData, err
 }
 
 func (r *LocalBackend) Login(ctx context.Context, email, password string) (*account.UserData, error) {
-	return r.accountClient.Login(ctx, email, password)
+	userData, err := r.accountClient.Login(ctx, email, password)
+	if err == nil {
+		r.refreshUserMessages()
+	}
+	return userData, err
 }
 
 func (r *LocalBackend) Logout(ctx context.Context, email string) (*account.UserData, error) {
-	return r.accountClient.Logout(ctx, email)
+	userData, err := r.accountClient.Logout(ctx, email)
+	if err == nil {
+		r.refreshUserMessages()
+	}
+	return userData, err
 }
 
 func (r *LocalBackend) FetchUserData(ctx context.Context) (*account.UserData, error) {
-	return r.accountClient.FetchUserData(ctx)
+	userData, err := r.accountClient.FetchUserData(ctx)
+	if err == nil {
+		r.refreshUserMessages()
+	}
+	return userData, err
 }
 
 func (r *LocalBackend) VerifyPassword(ctx context.Context, email, password string) error {
@@ -1604,7 +1666,11 @@ func (r *LocalBackend) CompleteRecoveryByEmail(ctx context.Context, email, newPa
 }
 
 func (r *LocalBackend) DeleteAccount(ctx context.Context, email, password string) (*account.UserData, error) {
-	return r.accountClient.DeleteAccount(ctx, email, password)
+	userData, err := r.accountClient.DeleteAccount(ctx, email, password)
+	if err == nil {
+		r.refreshUserMessages()
+	}
+	return userData, err
 }
 
 func (r *LocalBackend) SignUp(ctx context.Context, email, password string) ([]byte, *account.SignupResponse, error) {
@@ -1671,7 +1737,11 @@ func (r *LocalBackend) RemoveDevice(ctx context.Context, deviceID string) (*acco
 }
 
 func (r *LocalBackend) OAuthLoginCallback(ctx context.Context, oAuthToken string) (*account.UserData, error) {
-	return r.accountClient.OAuthLoginCallback(ctx, oAuthToken)
+	userData, err := r.accountClient.OAuthLoginCallback(ctx, oAuthToken)
+	if err == nil {
+		r.refreshUserMessages()
+	}
+	return userData, err
 }
 
 func (r *LocalBackend) OAuthDeviceLimitCallback(ctx context.Context, oAuthToken string) error {
@@ -1694,6 +1764,40 @@ func (r *LocalBackend) UserData() (*account.UserData, error) {
 	return &userData, nil
 }
 
+// CurrentUserMessage returns the current account's pending message.
+func (r *LocalBackend) CurrentUserMessage() (*wire.ResolvedUserMessage, error) {
+	if r.userMessages == nil {
+		return nil, nil
+	}
+	return r.userMessages.Current()
+}
+
+// RefreshUserMessages schedules an immediate eligibility refresh.
+func (r *LocalBackend) RefreshUserMessages() {
+	r.refreshUserMessages()
+}
+
+func (r *LocalBackend) refreshUserMessages() {
+	if r.userMessages != nil {
+		r.userMessages.Refresh()
+	}
+}
+
+// AcknowledgeUserMessage records that the UI displayed displayID.
+func (r *LocalBackend) AcknowledgeUserMessage(displayID string) error {
+	if r.userMessages == nil {
+		return clientmessage.ErrMessageNotPending
+	}
+	return r.userMessages.Acknowledge(displayID)
+}
+
+// SetUserMessageActivity adjusts polling for app and network lifecycle changes.
+func (r *LocalBackend) SetUserMessageActivity(active, online bool) {
+	if r.userMessages != nil {
+		r.userMessages.SetActivity(active, online)
+	}
+}
+
 ///////////////////
 // Subscriptions //
 ///////////////////

cmd/lanternd/lanternd.go

@@ -16,6 +16,7 @@ import (
 	"time"
 
 	"github.com/alexflint/go-arg"
+	wire "github.com/getlantern/common/usermessage"
 
 	"github.com/getlantern/radiance/backend"
 	"github.com/getlantern/radiance/common"
@@ -396,9 +397,10 @@ func babysit(args []string, dataPath, logPath, logLevel string) error {
 // daemonBackendOptions overrides only staging so the production default preserves an externally configured development environment.
 func daemonBackendOptions(dataPath, logPath, logLevel string, environment daemonEnvironment) backend.Options {
 	options := backend.Options{
-		DataDir:  dataPath,
-		LogDir:   logPath,
-		LogLevel: logLevel,
+		DataDir:                 dataPath,
+		LogDir:                  logPath,
+		LogLevel:                logLevel,
+		UserMessageCapabilities: userMessageCapabilities(),
 	}
 	if environment == daemonEnvironmentStaging {
 		options.EnvOverrides = map[string]string{
@@ -408,6 +410,17 @@ func daemonBackendOptions(dataPath, logPath, logLevel string, environment daemon
 	return options
 }
 
+func userMessageCapabilities() wire.ClientCapabilities {
+	return wire.ClientCapabilities{
+		Version:  wire.CapabilityUserMessagesV1,
+		Surfaces: []wire.Surface{wire.SurfaceSnackbar},
+		Actions: []wire.ActionType{
+			wire.ActionTypeOpenHTTPSURL,
+			wire.ActionTypeOpenPlans,
+		},
+	}
+}
+
 func daemonBackendURLs(environment daemonEnvironment) (authURL, proServerURL string) {
 	if environment == daemonEnvironmentStaging {
 		return common.StageBaseURL, common.StageProServerURL

cmd/lanternd/lanternd_test.go

@@ -119,6 +119,7 @@ func TestStagingServiceRunConfigSelectsStagingAccountEndpoints(t *testing.T) {
 	require.NoError(t, err)
 
 	options := daemonBackendOptions(parsed.dataPath, parsed.logPath, parsed.logLevel, parsed.environment)
+	require.Equal(t, userMessageCapabilities(), options.UserMessageCapabilities)
 	require.Equal(t, "staging", options.EnvOverrides[commonenv.ENV.String()])
 	t.Setenv(commonenv.ENV.String(), options.EnvOverrides[commonenv.ENV.String()])
 	require.Equal(t, common.StageBaseURL, common.GetBaseURL())

go.mod

@@ -40,7 +40,7 @@ require (
 	github.com/alitto/pond v1.9.2
 	github.com/getlantern/amp v0.0.0-20260606002220-a8629924577c
 	github.com/getlantern/broflake v0.0.0-20260810172605-bef5e5234952
-	github.com/getlantern/common v1.2.1-0.20260708083946-cc657b08792c
+	github.com/getlantern/common v1.2.1-0.20260828200436-eb05c571820d
 	github.com/getlantern/dnstt v0.0.0-20260603191204-3b860502c0ac
 	github.com/getlantern/domainfront v0.0.0-20260722204513-8c1f8acfa715
 	github.com/getlantern/keepcurrent v0.0.0-20260616120552-f204338b01a3
@@ -67,6 +67,7 @@ require (
 	go.opentelemetry.io/otel/sdk v1.43.0
 	go.opentelemetry.io/otel/sdk/metric v1.43.0
 	golang.org/x/term v0.41.0
+	golang.org/x/text v0.35.0
 	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20241231184526-a9ab2273dd10
 	google.golang.org/protobuf v1.36.11
 	gopkg.in/natefinch/lumberjack.v2 v2.2.1
@@ -262,7 +263,6 @@ require (
 	golang.getoutline.org/sdk v0.0.21 // indirect
 	golang.getoutline.org/sdk/x v0.1.0 // indirect
 	golang.org/x/oauth2 v0.35.0 // indirect
-	golang.org/x/text v0.35.0 // indirect
 	golang.zx2c4.com/wireguard/windows v0.5.3 // indirect
 	google.golang.org/genproto/googleapis/api v0.0.0-20260504160031-60b97b32f348 // indirect
 	modernc.org/libc v1.22.3 // indirect

go.sum

@@ -238,8 +238,12 @@ github.com/getlantern/amp v0.0.0-20260606002220-a8629924577c h1:ZzxuhIWO295y4eE6
 github.com/getlantern/amp v0.0.0-20260606002220-a8629924577c/go.mod h1:b5teAOFT+vpBqc2CHoz74QTEM15iOv1PLdQogwXcfrM=
 github.com/getlantern/broflake v0.0.0-20260810172605-bef5e5234952 h1:nD8iJ4IpaTq/09PhoOzmaGTwatOxsR41neSmbCY6RS8=
 github.com/getlantern/broflake v0.0.0-20260810172605-bef5e5234952/go.mod h1:1+1kCIg9Zj+2CgN+vl868AlAZVUItuN4wLhFur5QakA=
-github.com/getlantern/common v1.2.1-0.20260708083946-cc657b08792c h1:Hpxu12ORnAcyYuIqV2yAqrmDAnTaY1Cd3yL7TvFB6ME=
-github.com/getlantern/common v1.2.1-0.20260708083946-cc657b08792c/go.mod h1:eSSuV4bMPgQJnczBw+KWWqWNo1itzmVxC++qUBPRTt0=
+github.com/getlantern/common v1.2.1-0.20260818065623-10c2257aa54f h1:8iZqf4mUkFXKmUnDj2Iej0WySAzLuQmHOX736b4pCYU=
+github.com/getlantern/common v1.2.1-0.20260818065623-10c2257aa54f/go.mod h1:eSSuV4bMPgQJnczBw+KWWqWNo1itzmVxC++qUBPRTt0=
+github.com/getlantern/common v1.2.1-0.20260828192811-1233a8417569 h1:NmEbD0kKiL7EDjR0vSvkW+xtKwocgDHMk4SzvKQh/lE=
+github.com/getlantern/common v1.2.1-0.20260828192811-1233a8417569/go.mod h1:eSSuV4bMPgQJnczBw+KWWqWNo1itzmVxC++qUBPRTt0=
+github.com/getlantern/common v1.2.1-0.20260828200436-eb05c571820d h1:ere/uJH2664qGRepjvircloQN7WWCY4eQ+oiw2C4Hno=
+github.com/getlantern/common v1.2.1-0.20260828200436-eb05c571820d/go.mod h1:9iL78jR5kZqr0E7oPxi38o6gPMhVa5dJBC5ngUgHzdg=
 github.com/getlantern/context v0.0.0-20220418194847-3d5e7a086201 h1:oEZYEpZo28Wdx+5FZo4aU7JFXu0WG/4wJWese5reQSA=
 github.com/getlantern/context v0.0.0-20220418194847-3d5e7a086201/go.mod h1:Y9WZUHEb+mpra02CbQ/QczLUe6f0Dezxaw5DCJlJQGo=
 github.com/getlantern/dnstt v0.0.0-20260603191204-3b860502c0ac h1:TMvkNgLVyIYAfu1dYrOuRPYMVY+cHEo1C0CYWhtSw2A=

ipc/client.go

@@ -16,6 +16,7 @@ import (
 	"syscall"
 	"time"
 
+	wire "github.com/getlantern/common/usermessage"
 	box "github.com/getlantern/lantern-box"
 
 	"github.com/getlantern/radiance/account"
@@ -227,6 +228,35 @@ func (c *Client) UpdateConfig(ctx context.Context) error {
 	return err
 }
 
+// CurrentUserMessage returns the pending message for the current account.
+func (c *Client) CurrentUserMessage(ctx context.Context) (*wire.ResolvedUserMessage, error) {
+	var response CurrentUserMessageResponse
+	if err := c.doJSON(ctx, http.MethodGet, userMessageEndpoint, nil, &response); err != nil {
+		return nil, err
+	}
+	return response.Message, nil
+}
+
+// RefreshUserMessages schedules an immediate server eligibility refresh.
+func (c *Client) RefreshUserMessages(ctx context.Context) error {
+	_, err := c.do(ctx, http.MethodPost, userMessageRefreshEndpoint, nil)
+	return err
+}
+
+// AcknowledgeUserMessage records that the UI displayed displayID.
+func (c *Client) AcknowledgeUserMessage(ctx context.Context, displayID string) error {
+	_, err := c.do(ctx, http.MethodPost, userMessageAcknowledgeEndpoint,
+		UserMessageAcknowledgeRequest{DisplayID: displayID})
+	return err
+}
+
+// SetUserMessageActivity updates the app and connectivity lifecycle used by polling.
+func (c *Client) SetUserMessageActivity(ctx context.Context, active, online bool) error {
+	_, err := c.do(ctx, http.MethodPatch, userMessageActivityEndpoint,
+		UserMessageActivityRequest{Active: active, Online: online})
+	return err
+}
+
 ///////////////////////
 // Server management //
 ///////////////////////