fix: surface registry fetch errors in GET /templates/registries (#2342)

backend/internal/huma/handlers/templates.go

@@ -705,6 +705,16 @@ func (h *TemplateHandler) GetRegistries(ctx context.Context, _ *GetTemplateRegis
 		return nil, huma.Error500InternalServerError((&common.RegistryFetchError{Err: mapErr}).Error())
 	}
 
+	// Overlay the last fetch error from the in-memory tracker so the UI can
+	// display why a registry is not returning templates without requiring the
+	// user to check server logs.
+	fetchErrors := h.templateService.GetRegistryFetchErrors()
+	for i := range out {
+		if msg, ok := fetchErrors[out[i].ID]; ok {
+			out[i].LastFetchError = &msg
+		}
+	}
+
 	return &GetTemplateRegistriesOutput{
 		Body: base.ApiResponse[[]template.TemplateRegistry]{
 			Success: true,

backend/internal/services/template_service.go

@@ -55,6 +55,7 @@ type TemplateService struct {
 
 	registryMu        sync.RWMutex
 	registryFetchMeta map[string]*registryFetchMeta
+	registryErrors    map[string]string // last fetch error per registry ID, cleared on success
 
 	fsSyncMu   sync.Mutex
 	lastFsSync time.Time
@@ -91,6 +92,7 @@ func NewTemplateService(ctx context.Context, db *database.DB, httpClient *http.C
 		settingsService:   settingsService,
 		remoteCache:       remoteCache{},
 		registryFetchMeta: make(map[string]*registryFetchMeta),
+		registryErrors:    make(map[string]string),
 	}
 	service.safeHTTPClient = service.newSafeHTTPClientInternal()
 	return service
@@ -404,6 +406,18 @@ func (s *TemplateService) GetRegistries(ctx context.Context) ([]models.TemplateR
 	return registries, nil
 }
 
+// GetRegistryFetchErrors returns a snapshot of the last fetch error per registry ID.
+// An absent entry means the registry fetched successfully (or has never been attempted).
+func (s *TemplateService) GetRegistryFetchErrors() map[string]string {
+	s.registryMu.RLock()
+	defer s.registryMu.RUnlock()
+	out := make(map[string]string, len(s.registryErrors))
+	for k, v := range s.registryErrors {
+		out[k] = v
+	}
+	return out
+}
+
 func (s *TemplateService) CreateRegistry(ctx context.Context, registry *models.TemplateRegistry) error {
 	// Hydrate metadata if needed
 	if registry.Name == "" || registry.Description == "" {
@@ -534,9 +548,16 @@ func (s *TemplateService) loadRemoteTemplates(ctx context.Context) ([]models.Com
 			remoteTemplates, err := s.fetchRegistryTemplates(groupCtx, &reg)
 			if err != nil {
 				slog.WarnContext(groupCtx, "failed to fetch templates from registry", "registry", reg.Name, "url", reg.URL, "error", err)
+				s.registryMu.Lock()
+				s.registryErrors[reg.ID] = err.Error()
+				s.registryMu.Unlock()
 				return nil // Don't fail the whole group if one registry fails
 			}
 
+			s.registryMu.Lock()
+			delete(s.registryErrors, reg.ID)
+			s.registryMu.Unlock()
+
 			mu.Lock()
 			defer mu.Unlock()
 			for _, template := range remoteTemplates {

frontend/src/lib/types/template.type.ts

@@ -6,6 +6,7 @@ export interface TemplateRegistry {
 	description: string;
 	createdAt?: string;
 	updatedAt?: string;
+	lastFetchError?: string;
 }
 
 export interface Template {

frontend/src/routes/(app)/customize/templates/components/RegistryManager.svelte

@@ -7,7 +7,7 @@
 	import { Snippet } from '$lib/components/ui/snippet';
 	import { m } from '$lib/paraglide/messages';
 	import type { TemplateRegistry } from '$lib/types/template.type';
-	import { TrashIcon, RegistryIcon, CommunityIcon, RefreshIcon, ExternalLinkIcon, AddIcon } from '$lib/icons';
+	import { TrashIcon, RegistryIcon, CommunityIcon, RefreshIcon, ExternalLinkIcon, AddIcon, AlertTriangleIcon } from '$lib/icons';
 
 	let {
 		registries,
@@ -76,6 +76,12 @@
 							{#if registry.description}
 								<p class="text-muted-foreground mt-1 text-sm">{registry.description}</p>
 							{/if}
+							{#if registry.lastFetchError}
+								<div class="mt-2 flex items-start gap-1.5 rounded-md border border-destructive/30 bg-destructive/10 px-2 py-1.5">
+									<AlertTriangleIcon class="text-destructive mt-0.5 size-3.5 shrink-0" />
+									<p class="text-destructive text-xs break-all">{registry.lastFetchError}</p>
+								</div>
+							{/if}
 						</div>
 						<div class="flex items-center gap-2 self-end sm:self-center">
 							<Switch

types/template/template.go

@@ -114,6 +114,11 @@ type TemplateRegistry struct {
 	//
 	// Required: true
 	Enabled bool `json:"enabled"`
+
+	// LastFetchError is the error message from the most recent failed fetch, if any.
+	//
+	// Required: false
+	LastFetchError *string `json:"lastFetchError,omitempty"`
 }
 
 // TemplateContent contains a template with its associated content and metadata.