diff --git a/backend/api/v1/modules/a76/classes/service.py b/backend/api/v1/modules/a76/classes/service.py
index 107faaf9..e62d619d 100644
--- a/backend/api/v1/modules/a76/classes/service.py
+++ b/backend/api/v1/modules/a76/classes/service.py
@@ -48,18 +48,30 @@ class ClassService:
             query = query.filter(Class.company_id == company_id)
 
         if filters:
-            if filters.get("class_code"):
-                query = query.filter(
-                    Class.class_code.ilike(f"%{filters['class_code']}%")
-                )
-            if filters.get("description"):
-                description_pattern = f"%{filters['description']}%"
+            # Búsqueda libre: OR en clave y descripciones (selectores / listados)
+            search_raw = filters.get("search") or filters.get("q")
+            if search_raw and str(search_raw).strip():
+                pattern = f"%{str(search_raw).strip()}%"
                 query = query.filter(
                     or_(
-                        Class.description_es.ilike(description_pattern),
-                        Class.description_en.ilike(description_pattern),
+                        Class.class_code.ilike(pattern),
+                        Class.description_es.ilike(pattern),
+                        Class.description_en.ilike(pattern),
                     )
                 )
+            else:
+                if filters.get("class_code"):
+                    query = query.filter(
+                        Class.class_code.ilike(f"%{filters['class_code']}%")
+                    )
+                if filters.get("description"):
+                    description_pattern = f"%{filters['description']}%"
+                    query = query.filter(
+                        or_(
+                            Class.description_es.ilike(description_pattern),
+                            Class.description_en.ilike(description_pattern),
+                        )
+                    )
             if filters.get("material_key"):
                 query = query.filter(
                     Class.material_key.ilike(f"%{filters['material_key']}%")
diff --git a/frontend/src/lib/api/dashboard/a76/classes.ts b/frontend/src/lib/api/dashboard/a76/classes.ts
index 00c1cc4a..6f0eb86b 100644
--- a/frontend/src/lib/api/dashboard/a76/classes.ts
+++ b/frontend/src/lib/api/dashboard/a76/classes.ts
@@ -58,7 +58,9 @@ export interface A76ClassListParams {
     page_size?: number;
     class_code?: string;
     description?: string;
-    q?: string; // Agregado por si usas búsqueda general
+    /** Búsqueda OR en class_code, description_es y description_en (backend ClassService) */
+    search?: string;
+    q?: string;
     sort_by?: string;
     sort_order?: 'asc' | 'desc';
 }
diff --git a/frontend/src/lib/components/dashboard/goods/parts/class-selector-dialog.svelte b/frontend/src/lib/components/dashboard/goods/parts/class-selector-dialog.svelte
index 7a954a0a..cfa9e69c 100644
--- a/frontend/src/lib/components/dashboard/goods/parts/class-selector-dialog.svelte
+++ b/frontend/src/lib/components/dashboard/goods/parts/class-selector-dialog.svelte
@@ -1,156 +1,220 @@
 <script lang="ts">
-    import { Button } from "$lib/components/ui/button";
-    import { Input } from "$lib/components/ui/input";
-    import * as Dialog from "$lib/components/ui/dialog";
-    import { Search, Loader2, Tag, Ruler } from "lucide-svelte";
-    import { classesApi, type A76Class } from "$lib/api/dashboard/a76/classes"; // Ajusta ruta
-    import { companyStore } from "$lib/stores/company.svelte";
+	import { Button } from '$lib/components/ui/button';
+	import { Input } from '$lib/components/ui/input';
+	import * as Dialog from '$lib/components/ui/dialog';
+	import { Search, Loader2, Tag, Ruler } from 'lucide-svelte';
+	import { classesApi, type A76Class } from '$lib/api/dashboard/a76/classes';
+	import { companyStore } from '$lib/stores/company.svelte';
 
-    // --- PROPS ---
-    let { 
-        open = $bindable(false), 
-        onSelect 
-    }: { 
-        open: boolean, 
-        onSelect: (item: A76Class) => void 
-    } = $props();
+	let {
+		open = $bindable(false),
+		onSelect
+	}: {
+		open: boolean;
+		onSelect: (item: A76Class) => void;
+	} = $props();
 
-    // --- ESTADO ---
-    let items = $state<A76Class[]>([]);
-    let loading = $state(false);
-    let searchTerm = $state("");
-    let loaded = $state(false);
+	let items = $state<A76Class[]>([]);
+	let total = $state(0);
+	let currentPage = $state(1);
+	let loading = $state(false);
+	let loadingMore = $state(false);
+	let searchTerm = $state('');
 
-    // Filtro local: Busca por Clave (class_code) o Descripción (description_es)
-    let filteredItems = $derived(
-        items.filter(i => 
-            (i.class_code || "").toLowerCase().includes(searchTerm.toLowerCase()) || 
-            (i.description_es || "").toLowerCase().includes(searchTerm.toLowerCase())
-        )
-    );
+	const PAGE_SIZE = 100;
 
-    // Cargar datos al abrir
-    $effect(() => {
-        if (open && !loaded && companyStore.activeCompany?.id) {
-            loadClasses();
-        }
-    });
+	const hasMore = $derived(items.length < total && total > 0);
 
-    async function loadClasses() {
-        if (!companyStore.activeCompany?.id) return;
-        
-        loading = true;
-        try {
-            
-            const res = await classesApi.list({ 
-                company_id: companyStore.activeCompany.id,
-                page: 1,
-                page_size: 100
-            });
-            
-           
-            const data = (res as any).data || res;
-            
-            
-            const list = data.items || data.classes || [];
-            
-            if (Array.isArray(list)) {
-                items = list;
-                loaded = true;
-            } else {
-                console.warn("No encontré lista de clases en la respuesta:", data);
-            }
+	async function loadPage(trimmed: string, page: number, append: boolean) {
+		const companyId = companyStore.activeCompany?.id;
+		if (!companyId) return;
 
-        } catch (e) {
-            console.error("Error cargando clases:", e);
-        } finally {
-            loading = false;
-        }
-    }
+		if (append) {
+			if (loadingMore || loading || !hasMore) return;
+		} else if (loading) {
+			return;
+		}
 
-    function handleSelect(item: A76Class) {
-        if (onSelect) onSelect(item);
-        open = false;
-    }
+		if (page === 1) {
+			loading = true;
+		} else {
+			loadingMore = true;
+		}
+
+		try {
+			const res = await classesApi.list({
+				company_id: companyId,
+				page,
+				page_size: PAGE_SIZE,
+				...(trimmed ? { search: trimmed } : {})
+			});
+
+			const data = (res as { data?: { items?: A76Class[]; total?: number } }).data ?? res;
+			const raw = (data as { items?: A76Class[] }).items ?? [];
+			const newItems = Array.isArray(raw) ? raw : [];
+
+			if (append && newItems.length === 0) {
+				total = items.length;
+				return;
+			}
+
+			const t =
+				typeof (data as { total?: number }).total === 'number'
+					? (data as { total: number }).total
+					: append
+						? items.length + newItems.length
+						: newItems.length;
+
+			if (append) {
+				items = [...items, ...newItems];
+			} else {
+				items = newItems;
+			}
+			total = t;
+			currentPage = page;
+		} catch (e) {
+			console.error('Error cargando clases:', e);
+			if (!append) {
+				items = [];
+				total = 0;
+			}
+		} finally {
+			loading = false;
+			loadingMore = false;
+		}
+	}
+
+	function handleScroll(e: Event) {
+		const target = e.currentTarget as HTMLDivElement;
+		const threshold = 80;
+		if (target.scrollHeight - target.scrollTop - target.clientHeight > threshold) return;
+		if (!hasMore || loading || loadingMore) return;
+		const term = searchTerm.trim();
+		loadPage(term, currentPage + 1, true);
+	}
+
+	$effect(() => {
+		if (!open) {
+			searchTerm = '';
+			items = [];
+			total = 0;
+			currentPage = 1;
+		}
+	});
+
+	$effect(() => {
+		if (!open) return;
+		const companyId = companyStore.activeCompany?.id;
+		if (!companyId) return;
+
+		const term = searchTerm.trim();
+		const delayMs = term === '' ? 0 : 300;
+		const handle = setTimeout(() => {
+			loadPage(term, 1, false);
+		}, delayMs);
+		return () => clearTimeout(handle);
+	});
+
+	function handleSelect(item: A76Class) {
+		if (onSelect) onSelect(item);
+		open = false;
+	}
 </script>
 
 <Dialog.Root bind:open={open}>
-    <Dialog.Content class="sm:max-w-[700px] max-h-[80vh] flex flex-col z-[300]">
-        <Dialog.Header>
-            <Dialog.Title>Seleccionar Clase (Anexo 24)</Dialog.Title>
-            <Dialog.Description>
-                Seleccione la clasificación del material.
-            </Dialog.Description>
-        </Dialog.Header>
+	<Dialog.Content class="sm:max-w-[700px] max-h-[80vh] flex flex-col z-[300]">
+		<Dialog.Header>
+			<Dialog.Title>Seleccionar Clase (Anexo 24)</Dialog.Title>
+			<Dialog.Description>
+				Seleccione la clasificación del material. Desplace hacia abajo para cargar más resultados.
+			</Dialog.Description>
+		</Dialog.Header>
 
-        <div class="relative w-full my-2">
-            <Search class="absolute left-2.5 top-2.5 h-4 w-4 text-muted-foreground" />
-            <Input 
-                type="search" 
-                placeholder="Buscar por Clave o Descripción..." 
-                class="pl-9" 
-                bind:value={searchTerm}
-            />
-        </div>
+		<div class="relative w-full my-2">
+			<Search class="absolute left-2.5 top-2.5 h-4 w-4 text-muted-foreground" />
+			<Input
+				type="search"
+				placeholder="Buscar por Clave o Descripción..."
+				class="pl-9"
+				bind:value={searchTerm}
+			/>
+		</div>
 
-        <div class="flex-1 overflow-y-auto border rounded-md min-h-[300px]">
-            {#if loading}
-                <div class="flex flex-col items-center justify-center h-48 gap-2 text-muted-foreground">
-                    <Loader2 class="h-8 w-8 animate-spin text-primary" />
-                    <p>Cargando catálogo...</p>
-                </div>
-            {:else if filteredItems.length === 0}
-                <div class="flex flex-col items-center justify-center h-48 text-muted-foreground">
-                    <p>No se encontraron clases.</p>
-                </div>
-            {:else}
-                <table class="w-full text-sm">
-                    <thead class="bg-muted/50 sticky top-0 backdrop-blur-sm">
-                        <tr class="text-left border-b">
-                            <th class="p-3 font-medium text-muted-foreground w-[100px]">Clave</th>
-                            <th class="p-3 font-medium text-muted-foreground">Descripción</th>
-                            <th class="p-3 font-medium text-muted-foreground w-[80px]">UM</th>
-                        </tr>
-                    </thead>
-                    <tbody>
-                        {#each filteredItems as item}
-                            <tr 
-                                class="border-b hover:bg-accent/50 transition-colors cursor-pointer"
-                                onclick={() => handleSelect(item)}
-                            >
-                                <td class="p-3">
-                                    <span class="font-mono font-bold text-primary bg-primary/10 px-2 py-1 rounded text-xs">
-                                        {item.class_code}
-                                    </span>
-                                </td>
-                                
-                                <td class="p-3">
-                                    <div class="flex items-center gap-2">
-                                        <Tag class="h-3 w-3 text-muted-foreground shrink-0" />
-                                        <span class="truncate max-w-[300px]" title={item.description_es || ''}>
-                                            {item.description_es || 'Sin descripción'}
-                                        </span>
-                                    </div>
-                                </td>
+		<div
+			class="flex-1 overflow-y-auto border rounded-md min-h-[300px]"
+			onscroll={handleScroll}
+		>
+			{#if loading}
+				<div class="flex flex-col items-center justify-center h-48 gap-2 text-muted-foreground">
+					<Loader2 class="h-8 w-8 animate-spin text-primary" />
+					<p>Cargando catálogo...</p>
+				</div>
+			{:else if items.length === 0}
+				<div class="flex flex-col items-center justify-center h-48 text-muted-foreground">
+					<p>No se encontraron clases.</p>
+				</div>
+			{:else}
+				<table class="w-full text-sm">
+					<thead class="bg-muted/50 sticky top-0 backdrop-blur-sm">
+						<tr class="text-left border-b">
+							<th class="p-3 font-medium text-muted-foreground w-[100px]">Clave</th>
+							<th class="p-3 font-medium text-muted-foreground">Descripción</th>
+							<th class="p-3 font-medium text-muted-foreground w-[80px]">UM</th>
+						</tr>
+					</thead>
+					<tbody>
+						{#each items as item}
+							<tr
+								class="border-b hover:bg-accent/50 transition-colors cursor-pointer"
+								onclick={() => handleSelect(item)}
+							>
+								<td class="p-3">
+									<span
+										class="font-mono font-bold text-primary bg-primary/10 px-2 py-1 rounded text-xs"
+									>
+										{item.class_code}
+									</span>
+								</td>
 
-                                <td class="p-3">
-                                    <div class="flex items-center gap-1 text-xs text-muted-foreground">
-                                        <Ruler class="h-3 w-3" />
-                                        {item.unit_of_measure || '-'}
-                                    </div>
-                                </td>
-                            </tr>
-                        {/each}
-                    </tbody>
-                </table>
-            {/if}
-        </div>
+								<td class="p-3">
+									<div class="flex items-center gap-2">
+										<Tag class="h-3 w-3 text-muted-foreground shrink-0" />
+										<span
+											class="truncate max-w-[300px]"
+											title={item.description_es || item.description_en || ''}
+										>
+											{item.description_es || item.description_en || 'Sin descripción'}
+										</span>
+									</div>
+								</td>
 
-        <Dialog.Footer>
-            <div class="text-xs text-muted-foreground self-center mr-auto">
-                {filteredItems.length} registros encontrados
-            </div>
-            <Button variant="outline" onclick={() => open = false}>Cancelar</Button>
-        </Dialog.Footer>
-    </Dialog.Content>
-</Dialog.Root>
\ No newline at end of file
+								<td class="p-3">
+									<div class="flex items-center gap-1 text-xs text-muted-foreground">
+										<Ruler class="h-3 w-3" />
+										{item.unit_of_measure || '-'}
+									</div>
+								</td>
+							</tr>
+						{/each}
+					</tbody>
+				</table>
+				{#if loadingMore}
+					<div class="flex justify-center py-3 text-muted-foreground">
+						<Loader2 class="h-6 w-6 animate-spin" />
+					</div>
+				{/if}
+			{/if}
+		</div>
+
+		<Dialog.Footer>
+			<div class="text-xs text-muted-foreground self-center mr-auto">
+				{#if loading}
+					…
+				{:else}
+					Mostrando {items.length} de {total} registros
+				{/if}
+			</div>
+			<Button variant="outline" onclick={() => (open = false)}>Cancelar</Button>
+		</Dialog.Footer>
+	</Dialog.Content>
+</Dialog.Root>
diff --git a/frontend/src/lib/components/dashboard/invoices/edit/items/fa/class-dialog.svelte b/frontend/src/lib/components/dashboard/invoices/edit/items/fa/class-dialog.svelte
index 1e74393d..05a4ad42 100644
--- a/frontend/src/lib/components/dashboard/invoices/edit/items/fa/class-dialog.svelte
+++ b/frontend/src/lib/components/dashboard/invoices/edit/items/fa/class-dialog.svelte
@@ -6,6 +6,7 @@
 	import { Search, Loader2 } from 'lucide-svelte';
 	import { toast } from 'svelte-sonner';
 	import { companyStore } from '$lib/stores/company.svelte';
+	import { classesApi } from '$lib/api/dashboard/a76/classes';
 
 	let {
 		open = $bindable(false),
@@ -16,86 +17,109 @@
 	} = $props();
 
 	let searchQuery = $state('');
-	let isSearching = $state(false);
 	let classes = $state<any[]>([]);
-	let displayedClasses = $state<any[]>([]);
+	let total = $state(0);
 	let currentPage = $state(1);
-	let itemsPerPage = 10;
+	let loading = $state(false);
+	let loadingMore = $state(false);
 
-	const filteredClasses = $derived(
-		searchQuery
-			? classes.filter(
-					(c) =>
-						c.class_code?.toLowerCase().includes(searchQuery.toLowerCase()) ||
-						c.description_es?.toLowerCase().includes(searchQuery.toLowerCase())
-				)
-			: classes
-	);
+	const PAGE_SIZE = 100;
 
-	$effect(() => {
-		if (open) {
-			searchClasses();
-		}
-	});
+	const hasMore = $derived(classes.length < total && total > 0);
 
-	$effect(() => {
-		currentPage = 1;
-		loadMoreClasses();
-	});
-
-	async function searchClasses() {
+	async function loadPage(trimmed: string, page: number, append: boolean) {
 		const activeCompanyId = companyStore?.activeCompany?.id;
 		if (!activeCompanyId) {
 			toast.error('No hay compañía activa');
 			return;
 		}
 
-		isSearching = true;
-		try {
-			const response = await fetch(
-				`/api-sveltekit/classes?company_id=${activeCompanyId}&limit=100`,
-				{
-					method: 'GET',
-					headers: {
-						'Content-Type': 'application/json'
-					}
-				}
-			);
+		if (append) {
+			if (loadingMore || loading || !hasMore) return;
+		} else if (loading) {
+			return;
+		}
 
-			if (!response.ok) {
-				throw new Error('Error al buscar clases');
+		if (page === 1) {
+			loading = true;
+		} else {
+			loadingMore = true;
+		}
+
+		try {
+			const res = await classesApi.list({
+				company_id: activeCompanyId,
+				page,
+				page_size: PAGE_SIZE,
+				...(trimmed ? { search: trimmed } : {})
+			});
+			const data = (res as { data?: { items?: any[]; total?: number } }).data ?? res;
+			const raw = (data as { items?: any[] }).items ?? [];
+			const newItems = Array.isArray(raw) ? raw : [];
+
+			if (append && newItems.length === 0) {
+				total = classes.length;
+				return;
 			}
 
-			const data = await response.json();
-			classes = data.items || [];
-			loadMoreClasses();
+			const t =
+				typeof (data as { total?: number }).total === 'number'
+					? (data as { total: number }).total
+					: append
+						? classes.length + newItems.length
+						: newItems.length;
+
+			if (append) {
+				classes = [...classes, ...newItems];
+			} else {
+				classes = newItems;
+			}
+			total = t;
+			currentPage = page;
 		} catch (error) {
 			console.error('Error searching classes:', error);
 			toast.error('Error al buscar clases');
-			classes = [];
+			if (!append) {
+				classes = [];
+				total = 0;
+			}
 		} finally {
-			isSearching = false;
+			loading = false;
+			loadingMore = false;
 		}
 	}
 
-	function loadMoreClasses() {
-		const start = 0;
-		const end = currentPage * itemsPerPage;
-		displayedClasses = filteredClasses.slice(start, end);
-	}
-
 	function handleScroll(e: Event) {
-		const target = e.target as HTMLDivElement;
-		const threshold = 100;
-		const scrolledToBottom =
-			target.scrollHeight - target.scrollTop - target.clientHeight < threshold;
-
-		if (scrolledToBottom && displayedClasses.length < filteredClasses.length) {
-			currentPage++;
-			loadMoreClasses();
-		}
+		const target = e.currentTarget as HTMLDivElement;
+		const threshold = 80;
+		if (target.scrollHeight - target.scrollTop - target.clientHeight > threshold) return;
+		if (!hasMore || loading || loadingMore) return;
+		const term = searchQuery.trim();
+		loadPage(term, currentPage + 1, true);
 	}
 
+	$effect(() => {
+		if (!open) {
+			searchQuery = '';
+			classes = [];
+			total = 0;
+			currentPage = 1;
+		}
+	});
+
+	$effect(() => {
+		if (!open) return;
+		const activeCompanyId = companyStore?.activeCompany?.id;
+		if (!activeCompanyId) return;
+
+		const term = searchQuery.trim();
+		const delayMs = term === '' ? 0 : 300;
+		const handle = setTimeout(() => {
+			loadPage(term, 1, false);
+		}, delayMs);
+		return () => clearTimeout(handle);
+	});
+
 	function handleSelect(classItem: any) {
 		if (onSelect) {
 			onSelect(classItem);
@@ -108,7 +132,9 @@
 	<Dialog.Content class="max-w-4xl max-h-[80vh] flex flex-col">
 		<Dialog.Header>
 			<Dialog.Title>Seleccionar Clase</Dialog.Title>
-			<Dialog.Description>Busca y selecciona una clase para la partida</Dialog.Description>
+			<Dialog.Description>
+				Busca y selecciona una clase para la partida. Desplázate hacia abajo para más resultados.
+			</Dialog.Description>
 		</Dialog.Header>
 
 		<div class="flex gap-2 mb-4">
@@ -122,8 +148,11 @@
 			</div>
 		</div>
 
-		<div class="flex-1 overflow-auto border rounded-md" onscroll={handleScroll}>
-			{#if isSearching}
+		<div
+			class="flex-1 overflow-auto border rounded-md max-h-[55vh]"
+			onscroll={handleScroll}
+		>
+			{#if loading}
 				<div class="flex items-center justify-center py-8">
 					<Loader2 class="w-6 h-6 animate-spin text-muted-foreground" />
 				</div>
@@ -138,14 +167,14 @@
 						</Table.Row>
 					</Table.Header>
 					<Table.Body>
-						{#if displayedClasses.length === 0}
+						{#if classes.length === 0}
 							<Table.Row>
 								<Table.Cell colspan={4} class="text-center py-8 text-muted-foreground">
 									No se encontraron clases
 								</Table.Cell>
 							</Table.Row>
 						{:else}
-							{#each displayedClasses as classItem}
+							{#each classes as classItem}
 								<Table.Row
 									class="cursor-pointer hover:bg-muted/50"
 									onclick={() => handleSelect(classItem)}
@@ -165,11 +194,19 @@
 						{/if}
 					</Table.Body>
 				</Table.Root>
+				{#if loadingMore}
+					<div class="flex justify-center py-3">
+						<Loader2 class="w-6 h-6 animate-spin text-muted-foreground" />
+					</div>
+				{/if}
 			{/if}
 		</div>
 
-		<Dialog.Footer>
-			<Button variant="outline" onclick={() => (open = false)}>Cancelar</Button>
+		<Dialog.Footer class="flex flex-wrap items-center gap-2 justify-between">
+			{#if !loading && classes.length > 0}
+				<span class="text-xs text-muted-foreground">Mostrando {classes.length} de {total}</span>
+			{/if}
+			<Button variant="outline" class="ml-auto" onclick={() => (open = false)}>Cancelar</Button>
 		</Dialog.Footer>
 	</Dialog.Content>
 </Dialog.Root>