diff --git a/.changeset/api-search-state-classes.md b/.changeset/api-search-state-classes.md
new file mode 100644
index 000000000..9817e890b
--- /dev/null
+++ b/.changeset/api-search-state-classes.md
@@ -0,0 +1,5 @@
+---
+'@fuzdev/fuz_ui': minor
+---
+
+refactor: replace the `create_api_search`/`create_module_declaration_search` getter/setter factories with `ApiSearchState`/`DeclarationSearchState` classes — nested `modules`/`declarations` `{all, filtered}` objects flatten to `modules`, `modules_filtered`, `declarations`, `declarations_filtered` (and `all` → `declarations` on `DeclarationSearchState`)
diff --git a/src/lib/ApiIndex.svelte b/src/lib/ApiIndex.svelte
index 793c733d5..7dad669a4 100644
--- a/src/lib/ApiIndex.svelte
+++ b/src/lib/ApiIndex.svelte
@@ -6,7 +6,7 @@
 	import DocsSearch from './DocsSearch.svelte';
 	import ApiModulesList from './ApiModulesList.svelte';
 	import ApiDeclarationList from './ApiDeclarationList.svelte';
-	import { create_api_search } from './api_search.svelte.ts';
+	import { ApiSearchState } from './api_search.svelte.ts';
 
 	const {
 		library: library_prop,
@@ -33,7 +33,7 @@
 	const get_library = set_library_context_with_fallback(() => library_prop, 'ApiIndex');
 	const library = $derived(get_library());
 
-	const search = $derived(create_api_search(library));
+	const search = $derived(new ApiSearchState(library));
 </script>
 
 <svelte:head>
@@ -49,21 +49,21 @@
 		<section>
 			<p>{library.pkg_json.description}</p>
 
-			{#if search.modules.all.length + search.declarations.all.length > 1}
+			{#if search.modules.length + search.declarations.length > 1}
 				<DocsSearch
-					module_count={search.modules.all.length}
-					declaration_count={search.declarations.all.length}
-					filtered_module_count={search.query.trim() ? search.modules.filtered.length : undefined}
+					module_count={search.modules.length}
+					declaration_count={search.declarations.length}
+					filtered_module_count={search.query.trim() ? search.modules_filtered.length : undefined}
 					filtered_declaration_count={search.query.trim()
-						? search.declarations.filtered.length
+						? search.declarations_filtered.length
 						: undefined}
 					bind:search_query={search.query}
 				/>
 			{/if}
 		</section>
 
-		<ApiModulesList modules={search.modules.filtered} search_query={search.query} />
+		<ApiModulesList modules={search.modules_filtered} search_query={search.query} />
 
-		<ApiDeclarationList declarations={search.declarations.filtered} search_query={search.query} />
+		<ApiDeclarationList declarations={search.declarations_filtered} search_query={search.query} />
 	{/if}
 </TomeContent>
diff --git a/src/lib/ApiModule.svelte b/src/lib/ApiModule.svelte
index d3ece3917..77cfe7760 100644
--- a/src/lib/ApiModule.svelte
+++ b/src/lib/ApiModule.svelte
@@ -17,7 +17,7 @@
 	import DocsLink from './DocsLink.svelte';
 	import DeclarationLink from './DeclarationLink.svelte';
 	import ApiDeclarationList from './ApiDeclarationList.svelte';
-	import { create_module_declaration_search } from './api_search.svelte.ts';
+	import { DeclarationSearchState } from './api_search.svelte.ts';
 
 	const {
 		module_path: module_path_param,
@@ -64,7 +64,7 @@
 		module?.path || (directory_modules ? module_path : '[missing module]')
 	);
 
-	const search = $derived(create_module_declaration_search(module?.declarations ?? []));
+	const search = $derived(new DeclarationSearchState(module?.declarations ?? []));
 
 	// GitHub source URL for the module
 	const source_url = $derived(module?.url_github);
@@ -117,11 +117,11 @@
 			<TomeSection>
 				<TomeSectionHeader text="Declarations" />
 
-				{#if search.all.length > 1}
+				{#if search.declarations.length > 1}
 					<section>
 						<DocsSearch
 							placeholder="search declarations in this module..."
-							declaration_count={search.all.length}
+							declaration_count={search.declarations.length}
 							filtered_declaration_count={search.query.trim() ? search.filtered.length : undefined}
 							bind:search_query={search.query}
 						/>
diff --git a/src/lib/api_search.svelte.ts b/src/lib/api_search.svelte.ts
index cc3243585..81734131c 100644
--- a/src/lib/api_search.svelte.ts
+++ b/src/lib/api_search.svelte.ts
@@ -2,94 +2,57 @@ import type { Declaration } from './declaration.svelte.ts';
 import type { Library } from './library.svelte.ts';
 import type { Module } from './module.svelte.ts';
 
-export interface DeclarationSearchState {
-	query: string;
-	all: Array<Declaration>;
-	filtered: Array<Declaration>;
-}
-
-export interface ApiSearchState {
-	query: string;
-	modules: {
-		all: Array<Module>;
-		filtered: Array<Module>;
-	};
-	declarations: {
-		all: Array<Declaration>;
-		filtered: Array<Declaration>;
-	};
-}
-
 /**
- * Creates unified search state for the API index page (modules and declarations).
+ * Unified search state for the API index page (modules and declarations).
  */
-export const create_api_search = (library: Library): ApiSearchState => {
-	let query = $state.raw('');
+export class ApiSearchState {
+	readonly library: Library;
+
+	query: string = $state('');
 
-	// Module filtering
-	const all_modules = $derived(library.modules_sorted);
-	const filtered_modules = $derived.by(() => {
-		if (!query.trim()) return all_modules;
-		const terms = query.trim().toLowerCase().split(/\s+/);
-		return all_modules.filter((m) => {
+	readonly modules: Array<Module> = $derived.by(() => this.library.modules_sorted);
+
+	readonly modules_filtered: Array<Module> = $derived.by(() => {
+		if (!this.query.trim()) return this.modules;
+		const terms = this.query.trim().toLowerCase().split(/\s+/);
+		return this.modules.filter((m) => {
 			const path_lower = m.path.toLowerCase();
 			const comment_lower = m.module_comment?.toLowerCase() ?? '';
 			return terms.every((term) => path_lower.includes(term) || comment_lower.includes(term));
 		});
 	});
 
-	// Declaration filtering
-	const all_declarations = $derived(library.declarations);
-	const filtered_declarations = $derived.by(() => {
-		const items = query.trim() ? library.search_declarations(query) : all_declarations;
+	readonly declarations: Array<Declaration> = $derived.by(() => this.library.declarations);
+
+	readonly declarations_filtered: Array<Declaration> = $derived.by(() => {
+		const items = this.query.trim()
+			? this.library.search_declarations(this.query)
+			: this.declarations;
 		// spread before sort — `items` may be the shared source array
 		return [...items].sort((a, b) => a.name.localeCompare(b.name));
 	});
 
-	return {
-		get query() {
-			return query;
-		},
-		set query(v: string) {
-			query = v;
-		},
-		modules: {
-			get all() {
-				return all_modules;
-			},
-			get filtered() {
-				return filtered_modules;
-			}
-		},
-		declarations: {
-			get all() {
-				return all_declarations;
-			},
-			get filtered() {
-				return filtered_declarations;
-			}
-		}
-	};
-};
+	constructor(library: Library) {
+		this.library = library;
+	}
+}
 
 /**
- * Creates search state for module-specific declaration lists.
+ * Search state for a module-specific declaration list.
  */
-export const create_module_declaration_search = (
-	declarations: Array<Declaration>
-): DeclarationSearchState => {
-	let query = $state.raw('');
+export class DeclarationSearchState {
+	readonly declarations: Array<Declaration>;
 
-	const all = $derived(declarations);
+	query: string = $state('');
 
-	const filtered = $derived.by(() => {
-		const trimmed_query = query.trim();
-		// spread before sort — `all` is the shared source array
-		if (!trimmed_query) return [...all].sort((a, b) => a.name.localeCompare(b.name));
+	readonly filtered: Array<Declaration> = $derived.by(() => {
+		const trimmed_query = this.query.trim();
+		// spread before sort — `declarations` is the shared source array
+		if (!trimmed_query) return [...this.declarations].sort((a, b) => a.name.localeCompare(b.name));
 
 		const terms = trimmed_query.toLowerCase().split(/\s+/);
 
-		const items = all.filter((d) => {
+		const items = this.declarations.filter((d) => {
 			const name_lower = d.name.toLowerCase();
 			const kind_lower = d.kind.toLowerCase();
 			const module_path_lower = d.module_path.toLowerCase();
@@ -103,18 +66,7 @@ export const create_module_declaration_search = (
 		return items.sort((a, b) => a.name.localeCompare(b.name));
 	});
 
-	return {
-		get query() {
-			return query;
-		},
-		set query(v: string) {
-			query = v;
-		},
-		get all() {
-			return all;
-		},
-		get filtered() {
-			return filtered;
-		}
-	};
-};
+	constructor(declarations: Array<Declaration>) {
+		this.declarations = declarations;
+	}
+}