diff --git a/dev/issues/completed/0017-frontend-hooks.md b/dev/issues/completed/0017-frontend-hooks.md
new file mode 100644
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+# 0017 — Frontend Data Hooks
+
+## Metadata
+
+| Campo | Valor |
+|-------|-------|
+| **ID** | 0017 |
+| **Estado** | pendiente |
+| **Prioridad** | alta |
+| **Tipo** | feature |
+
+## Dependencias
+
+Ninguna.
+
+---
+
+## Objetivo
+
+Crear hooks React genericos para comunicacion con APIs HTTP (REST, SSE, WebSocket) que sirvan como base para cualquier frontend web. Actualmente solo existen hooks Wails (`use_wails_query`, `use_wails_mutation`, `use_wails_event`, `use_wails_stream`) que dependen de IPC Wails — no hay nada para apps web estandar que usan `fetch` contra un servidor HTTP.
+
+## Contexto
+
+- Los hooks Wails (`frontend/functions/ui/`) implementan un patron solido: cache, stale-while-revalidate, retry, optimistic updates. Pero estan atados a `window.runtime` de Wails.
+- El registry tiene 70+ componentes Mantine en `frontend/functions/ui/` pero cero infraestructura de data-fetching para web.
+- Cualquier app web nueva (dashboards, admin panels, SPAs) necesita reinventar el fetching desde cero o tirar de react-query/swr como dependencia externa.
+- Con estos hooks, una app web solo importa `use_fetch`, `use_mutation`, etc. del registry y tiene todo resuelto. Misma filosofia que los hooks Wails pero sobre HTTP.
+- El issue 0009 (HTTP Server) crea las primitivas del servidor. Este issue crea las primitivas del cliente que las consume.
+
+## Arquitectura
+
+```
+frontend/functions/core/
+├── api_client.ts              — NEW: fetch wrapper configurable
+├── api_client.md              — NEW
+├── use_fetch.tsx              — NEW: hook GET con cache + SWR
+├── use_fetch.md               — NEW
+├── use_mutation.tsx           — NEW: hook POST/PUT/DELETE
+├── use_mutation.md            — NEW
+├── use_infinite_scroll.tsx    — NEW: hook paginacion infinita
+├── use_infinite_scroll.md     — NEW
+├── use_form.tsx               — NEW: hook formularios
+├── use_form.md                — NEW
+├── use_debounced_search.tsx   — NEW: hook busqueda con debounce
+├── use_debounced_search.md    — NEW
+├── use_sse.tsx                — NEW: hook Server-Sent Events
+├── use_sse.md                 — NEW
+├── use_websocket.tsx          — NEW: hook WebSocket
+├── use_websocket.md           — NEW
+
+frontend/types/core/
+├── fetch_state.ts             — NEW: tipo FetchState
+├── fetch_state.md             — NEW
+├── mutation_state.ts          — NEW: tipo MutationState
+├── mutation_state.md          — NEW
+├── form_state.ts              — NEW: tipo FormState
+├── form_state.md              — NEW
+├── api_client_config.ts       — NEW: tipo APIClientConfig
+├── api_client_config.md       — NEW
+```
+
+Todas las funciones van en `frontend/functions/core/` (dominio `core`) porque son TypeScript puro, framework-agnostic en el sentido de que no dependen de Wails, Electron, Tauri, ni ningun runtime especifico. Solo usan React + `fetch` nativo del browser.
+
+### Patron pure core / impure shell
+
+No hay funciones puras en este issue — todos los hooks manejan estado (React) y/o I/O (HTTP, SSE, WebSocket). `api_client` es una funcion impura (hace `fetch`), no un hook.
+
+## Diseno
+
+### Tipos
+
+```typescript
+/** Estado de un fetch GET */
+interface FetchState<T> {
+  data: T | null
+  error: Error | null
+  loading: boolean
+  /** Re-ejecutar la peticion */
+  refetch: () => Promise<T>
+  /** Si los datos son stale (cache viejo mostrando mientras refetch) */
+  is_stale: boolean
+}
+
+/** Estado de una mutacion POST/PUT/DELETE */
+interface MutationState<TData, TVariables> {
+  /** Ejecutar la mutacion */
+  mutate: (variables: TVariables) => void
+  /** Ejecutar la mutacion (async, retorna Promise) */
+  mutate_async: (variables: TVariables) => Promise<TData>
+  data: TData | null
+  error: Error | null
+  loading: boolean
+  /** Resetear al estado inicial */
+  reset: () => void
+}
+
+/** Estado de un formulario */
+interface FormState<T extends Record<string, unknown>> {
+  /** Valores actuales del form */
+  values: T
+  /** Errores por campo */
+  errors: Partial<Record<keyof T, string>>
+  /** Campos que el usuario ha tocado */
+  touched: Partial<Record<keyof T, boolean>>
+  /** Si todos los campos pasan validacion */
+  is_valid: boolean
+  /** Si el submit esta en progreso */
+  is_submitting: boolean
+}
+
+/** Configuracion del cliente HTTP */
+interface APIClientConfig {
+  /** URL base para todas las peticiones (ej: "http://localhost:8484/api") */
+  base_url: string
+  /** Headers fijos para todas las peticiones */
+  headers?: Record<string, string>
+  /** Callback global de error */
+  on_error?: (error: Error, url: string, init?: RequestInit) => void
+  /** Callback cuando el server responde 401 */
+  on_unauthorized?: () => void
+}
+```
+
+### Funciones
+
+| Funcion | Kind | Purity | Firma (simplificada) |
+|---------|------|--------|---------------------|
+| `api_client` | function | impure | `(config: APIClientConfig) => { get, post, put, del, patch }` |
+| `use_fetch` | component | impure | `useFetch<T>(url, opts?): FetchState<T>` |
+| `use_mutation` | component | impure | `useMutation<TData, TVars>(opts): MutationState<TData, TVars>` |
+| `use_infinite_scroll` | component | impure | `useInfiniteScroll<T>(url, opts?): { data, loading, has_more, load_more, reset }` |
+| `use_form` | component | impure | `useForm<T>(opts): { values, errors, touched, set_field, validate, submit, reset }` |
+| `use_debounced_search` | component | impure | `useDebouncedSearch<T>(url, opts?): { query, set_query, results, loading }` |
+| `use_sse` | component | impure | `useSSE<T>(url, opts?): { data, last_event, status, close }` |
+| `use_websocket` | component | impure | `useWebSocket<TSend, TRecv>(url, opts?): { send, last_message, status, close }` |
+
+### Detalle de cada funcion
+
+**`api_client`** — Factory que retorna un objeto con metodos HTTP. No es un hook, es una funcion normal que crea un cliente reutilizable. Cada metodo hace `fetch` con los headers y base_url configurados, parsea JSON automaticamente, y llama a `on_error`/`on_unauthorized` segun el status code.
+
+```typescript
+const api = apiClient({ base_url: 'http://localhost:8484/api' })
+const users = await api.get<User[]>('/users')
+await api.post('/users', { name: 'Lucas' })
+await api.del('/users/123')
+```
+
+**`use_fetch`** — Hook para GET requests. Hace fetch al montar (configurable con `enabled`). Cache en memoria con stale-while-revalidate: muestra datos viejos inmediatamente y refetchea en background. Soporta `refetch_interval`, `refetch_on_focus`, `stale_time`, `retry`. Recibe una URL string o una funcion que retorna `Promise<T>` (para usar con `api_client`).
+
+**`use_mutation`** — Hook para operaciones de escritura. No ejecuta al montar — expone `mutate()` y `mutate_async()`. Soporta `on_mutate` para optimistic updates (retorna rollback context), `on_success`, `on_error`, `on_settled`. Opcionalmente invalida queries del cache al completar.
+
+**`use_infinite_scroll`** — Hook para paginacion infinita. Soporta cursor-based (`next_cursor` en response) y offset-based (`page` incrementando). Expone `load_more()`, `has_more`, `reset()`. Concatena paginas en un solo array plano.
+
+**`use_form`** — Hook para formularios. Recibe `initial_values` y opcionalmente `validate` (funcion que retorna errores por campo). Expone `set_field(name, value)`, `set_fields(partial)`, `validate()`, `submit(handler)`, `reset()`. El submit llama a `validate()` primero y solo ejecuta el handler si pasa. Marca campos como `touched` al hacer set.
+
+**`use_debounced_search`** — Hook que combina un input debounced con fetch. Recibe la URL base y el debounce delay (default 300ms). Mientras el usuario escribe, espera N ms sin actividad y luego hace GET con el query como parametro. Expone `query`, `set_query`, `results`, `loading`.
+
+**`use_sse`** — Hook para Server-Sent Events. Crea un `EventSource` al montar, parsea cada evento como JSON, auto-reconecta con backoff exponencial si se pierde la conexion. Expone `data` (array de eventos), `last_event`, `status` (connecting/open/closed), `close()`.
+
+**`use_websocket`** — Hook para WebSocket. Conecta al montar, auto-reconecta con backoff. Expone `send(data)`, `last_message`, `messages` (buffer), `status` (connecting/open/closing/closed), `close()`. Soporta tipado separado para envio (`TSend`) y recepcion (`TRecv`).
+
+## Tareas
+
+### Fase 1: Tipos y api_client
+
+- [ ] **1.1** Crear tipo `FetchState` en `frontend/types/core/fetch_state.ts` + `.md`
+- [ ] **1.2** Crear tipo `MutationState` en `frontend/types/core/mutation_state.ts` + `.md`
+- [ ] **1.3** Crear tipo `FormState` en `frontend/types/core/form_state.ts` + `.md`
+- [ ] **1.4** Crear tipo `APIClientConfig` en `frontend/types/core/api_client_config.ts` + `.md`
+- [ ] **1.5** Crear `api_client` en `frontend/functions/core/api_client.ts` + `.md` — fetch wrapper con base_url, headers, error handling, interceptors
+
+### Fase 2: Hooks de datos (core HTTP)
+
+- [ ] **2.1** `use_fetch` — GET con cache in-memory, stale-while-revalidate, retry, refetch por intervalo/foco
+- [ ] **2.2** `use_mutation` — POST/PUT/DELETE con optimistic updates, invalidacion de queries
+- [ ] **2.3** `use_debounced_search` — input con debounce + fetch automatico
+- [ ] **2.4** `use_form` — state de formulario con validacion, touched, submit handler
+
+### Fase 3: Hooks de streaming y paginacion
+
+- [ ] **3.1** `use_infinite_scroll` — paginacion infinita (cursor y offset), concatenacion de paginas
+- [ ] **3.2** `use_sse` — Server-Sent Events con auto-reconnect y parsing JSON
+- [ ] **3.3** `use_websocket` — WebSocket con auto-reconnect, send tipado, buffer de mensajes
+
+### Fase 4: Integracion y verificacion
+
+- [ ] **4.1** `fn index` y verificar que todas las funciones y tipos aparecen en registry.db
+- [ ] **4.2** Verificar que los IDs siguen el patron `{name}_ts_core`
+- [ ] **4.3** Verificar imports cruzados: los hooks importan los tipos de `frontend/types/core/`
+- [ ] **4.4** Verificar que `api_client` se puede pasar como `fetch_fn` a `use_fetch` y `use_mutation`
+
+---
+
+## Ejemplo de uso
+
+Pagina CRUD completa usando los hooks con el layout `crud_page_ts_ui` existente:
+
+```tsx
+import { apiClient } from '@fn_library/core/api_client'
+import { useFetch } from '@fn_library/core/use_fetch'
+import { useMutation } from '@fn_library/core/use_mutation'
+import { useForm } from '@fn_library/core/use_form'
+import { useDebouncedSearch } from '@fn_library/core/use_debounced_search'
+import { crudPage } from '@fn_library/ui/crud_page'
+import { Stack, Modal, TextInput, Button, Group } from '@mantine/core'
+import { useDisclosure } from '@mantine/hooks'
+
+// 1. Configurar cliente HTTP una vez
+const api = apiClient({
+  base_url: 'http://localhost:8484/api',
+  on_unauthorized: () => window.location.href = '/login',
+})
+
+interface User {
+  id: string
+  name: string
+  email: string
+  role: string
+}
+
+function UsersPage() {
+  const [opened, { open, close }] = useDisclosure(false)
+
+  // 2. Fetch lista de usuarios con cache
+  const { data: users, loading, refetch } = useFetch<User[]>({
+    url: '/users',
+    fetch_fn: api.get,
+    stale_time: 10_000,        // Fresh por 10s
+    refetch_on_focus: true,    // Refetch al volver a la tab
+  })
+
+  // 3. Busqueda con debounce
+  const { query, set_query, results: searchResults, loading: searching } = useDebouncedSearch<User[]>({
+    url: '/users/search',
+    fetch_fn: api.get,
+    delay: 300,
+    param_name: 'q',
+  })
+
+  // 4. Mutacion para crear usuario
+  const { mutate: createUser, loading: creating } = useMutation<User, Partial<User>>({
+    mutation_fn: (data) => api.post('/users', data),
+    on_success: () => {
+      refetch()
+      close()
+      form.reset()
+    },
+  })
+
+  // 5. Mutacion para eliminar usuario
+  const { mutate: deleteUser } = useMutation<void, string>({
+    mutation_fn: (id) => api.del(`/users/${id}`),
+    on_success: () => refetch(),
+  })
+
+  // 6. Form con validacion
+  const form = useForm<Partial<User>>({
+    initial_values: { name: '', email: '', role: 'user' },
+    validate: (values) => ({
+      name: !values.name ? 'Nombre requerido' : undefined,
+      email: !values.email?.includes('@') ? 'Email invalido' : undefined,
+    }),
+  })
+
+  const displayedUsers = query ? searchResults : users
+
+  return (
+    <Stack>
+      {/* Barra de busqueda */}
+      <TextInput
+        placeholder="Buscar usuarios..."
+        value={query}
+        onChange={(e) => set_query(e.currentTarget.value)}
+      />
+
+      {/* Tabla CRUD usando crud_page del registry */}
+      {crudPage<User>({
+        title: 'Users',
+        subtitle: `${displayedUsers?.length ?? 0} usuarios`,
+        data: displayedUsers ?? [],
+        fields: [
+          { key: 'name', label: 'Nombre', type: 'text', required: true },
+          { key: 'email', label: 'Email', type: 'email', required: true },
+          { key: 'role', label: 'Rol', type: 'select', options: [
+            { label: 'Admin', value: 'admin' },
+            { label: 'User', value: 'user' },
+          ]},
+        ],
+        columns: [
+          { key: 'name', label: 'Nombre' },
+          { key: 'email', label: 'Email' },
+          { key: 'role', label: 'Rol' },
+        ],
+        onAdd: open,
+        onDelete: (user) => deleteUser(user.id),
+      })}
+
+      {/* Modal de creacion */}
+      <Modal opened={opened} onClose={close} title="Nuevo usuario">
+        <Stack>
+          <TextInput
+            label="Nombre"
+            value={form.values.name ?? ''}
+            error={form.errors.name}
+            onChange={(e) => form.set_field('name', e.currentTarget.value)}
+          />
+          <TextInput
+            label="Email"
+            value={form.values.email ?? ''}
+            error={form.errors.email}
+            onChange={(e) => form.set_field('email', e.currentTarget.value)}
+          />
+          <Group justify="flex-end">
+            <Button variant="default" onClick={close}>Cancelar</Button>
+            <Button
+              loading={creating}
+              onClick={() => form.submit((values) => createUser(values))}
+            >
+              Crear
+            </Button>
+          </Group>
+        </Stack>
+      </Modal>
+    </Stack>
+  )
+}
+```
+
+### Ejemplo con SSE (logs en tiempo real)
+
+```tsx
+import { useSSE } from '@fn_library/core/use_sse'
+import { Paper, Code, ScrollArea, Badge, Group } from '@mantine/core'
+
+function LogViewer() {
+  const { data: logs, last_event, status, close } = useSSE<string>({
+    url: 'http://localhost:8484/api/logs/stream',
+    reconnect: true,
+    reconnect_interval: 3000,
+  })
+
+  return (
+    <Paper withBorder p="md">
+      <Group mb="sm">
+        <Badge color={status === 'open' ? 'green' : 'red'}>{status}</Badge>
+      </Group>
+      <ScrollArea h={400}>
+        <Code block>{logs.join('\n')}</Code>
+      </ScrollArea>
+    </Paper>
+  )
+}
+```
+
+### Ejemplo con WebSocket (chat)
+
+```tsx
+import { useWebSocket } from '@fn_library/core/use_websocket'
+import { TextInput, Paper, Stack, Text } from '@mantine/core'
+import { useState } from 'react'
+
+interface ChatMessage { user: string; text: string; ts: number }
+
+function Chat() {
+  const [input, setInput] = useState('')
+  const { send, messages, status } = useWebSocket<{ text: string }, ChatMessage>({
+    url: 'ws://localhost:8484/ws/chat',
+    reconnect: true,
+  })
+
+  return (
+    <Stack>
+      <Paper withBorder p="md" h={300} style={{ overflow: 'auto' }}>
+        {messages.map((msg, i) => (
+          <Text key={i} size="sm"><b>{msg.user}:</b> {msg.text}</Text>
+        ))}
+      </Paper>
+      <TextInput
+        placeholder="Escribir mensaje..."
+        value={input}
+        disabled={status !== 'open'}
+        onChange={(e) => setInput(e.currentTarget.value)}
+        onKeyDown={(e) => {
+          if (e.key === 'Enter' && input.trim()) {
+            send({ text: input })
+            setInput('')
+          }
+        }}
+      />
+    </Stack>
+  )
+}
+```
+
+## Decisiones de diseno
+
+- **Zero dependencias externas:** No se usa react-query, swr, axios, ni ninguna libreria de fetching. Los hooks implementan un patron SWR-like minimalista con `fetch` nativo y `useState`/`useEffect`/`useRef`/`useCallback` de React. Esto mantiene el bundle pequeno y elimina dependencias que evolucionan independientemente.
+- **Cache in-memory simple (Map):** Los hooks Wails ya tienen un cache propio (`wails_cache.ts`). Los nuevos hooks usan un `Map<string, { data, timestamp }>` simple compartido via un modulo singleton. No se necesita un cache manager complejo — el patron stale-while-revalidate con un Map cubre el 90% de los casos.
+- **`api_client` es funcion, no hook:** El cliente HTTP es una factory pura (en el sentido de React) que retorna metodos. Se puede usar fuera de componentes: en event handlers, en funciones de utilidad, en tests. Los hooks lo consumen opcionalmente via `fetch_fn`.
+- **Dominio `core`, no `ui`:** Los hooks Wails viven en `ui` porque dependen de `wails_provider` y el runtime Wails (infraestructura de UI especifica). Estos hooks solo dependen de React + fetch nativo, asi que van en `core` — son TypeScript puro reutilizable en cualquier proyecto React, no atados a un framework de UI.
+- **`kind: component` para hooks:** Siguiendo el mismo patron que los hooks Wails en el registry. Un hook React es un componente funcional que tiene estado (`has_state: true`), emite callbacks (`emits`), y declara props. El `kind: component` con `framework: react` es el mapping correcto.
+- **Tipado generico pero no over-engineered:** Cada hook acepta 1-2 genericos (`T` para data, `TVariables` para inputs). No se introducen abstractions como query keys jerarquicos, cache normalization, ni infinite query cursors tipados. Si se necesita TanStack Query, se instala — estos hooks cubren el 80% sin la complejidad.
+- **`use_form` minimalista:** No reemplaza a Mantine `useForm` ni a formik/react-hook-form. Es un hook ligero para formularios simples: valores, errores, touched, validacion sincrona, submit. Para formularios complejos (arrays de campos, validacion async, schemas zod) se usa la solucion de Mantine directamente.
+
+## Riesgos
+
+- **Duplicacion con hooks Wails:** Los hooks de datos HTTP y los hooks Wails resuelven el mismo problema con diferente transporte. Mitigado manteniendo interfaces similares (`FetchState` vs `QueryState`, `MutationState` en ambos) para que migrar de uno a otro sea trivial. A futuro se podria abstraer el transporte detras de una interfaz comun, pero por ahora es premature abstraction.
+- **Cache sin persistencia ni invalidacion cross-tab:** El cache es un `Map` en memoria. Si el usuario abre dos tabs, cada una tiene su cache independiente. Mitigado porque para el 90% de las apps del registry (tools internas, dashboards, admin panels) esto es aceptable. Si se necesita cache persistente o broadcast, se anade como iteracion futura.
+- **Scope creep hacia framework de fetching:** Estos hooks deben mantenerse simples. Si el uso crece hasta necesitar normalized cache, query deduplication, garbage collection, o suspense — en ese punto se migra a TanStack Query. El valor de estos hooks es zero-dep y cubrir los casos comunes.
+- **`use_form` puede solaparse con Mantine `useForm`:** Documentar claramente que `use_form` es para formularios simples sin dependencia de Mantine. Si la app ya usa Mantine (que es el caso comun en este registry), `@mantine/form` puede ser mejor opcion. El hook del registry es util cuando se quiere evitar la dependencia de Mantine en un proyecto core.
diff --git a/frontend/functions/core/api_client.md b/frontend/functions/core/api_client.md
new file mode 100644
index 00000000..2c489273
--- /dev/null
+++ b/frontend/functions/core/api_client.md
@@ -0,0 +1,56 @@
+---
+name: api_client
+kind: function
+lang: ts
+domain: core
+version: "1.0.0"
+purity: impure
+signature: "apiClient(config: APIClientConfig): { get<T>(path, params?): Promise<T>; post<T>(path, body?): Promise<T>; put<T>(path, body?): Promise<T>; patch<T>(path, body?): Promise<T>; del<T>(path): Promise<T> }"
+description: "Factory HTTP que retorna un cliente con get/post/put/patch/del. Usa fetch nativo con base_url+headers, parsea JSON automaticamente, llama on_error/on_unauthorized segun status code. Zero dependencias externas."
+tags: [http, fetch, client, rest, api, factory, core]
+uses_functions: []
+uses_types: [APIClientConfig_ts_core]
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: []
+params:
+  - name: config
+    desc: "Configuracion: base_url (URL base sin slash final), headers opcionales, callbacks on_error y on_unauthorized"
+output: "Objeto con metodos get/post/put/patch/del que hacen fetch con la config aplicada"
+tested: false
+tests: []
+test_file_path: ""
+file_path: "frontend/functions/core/api_client.ts"
+---
+
+## Ejemplo
+
+```typescript
+import { apiClient } from './api_client'
+
+const api = apiClient({
+  base_url: 'http://localhost:8484/api',
+  headers: { 'X-Client': 'dashboard' },
+  on_unauthorized: () => (window.location.href = '/login'),
+})
+
+const users = await api.get<User[]>('/users')
+const user = await api.post<User>('/users', { name: 'Lucas', email: 'lucas@example.com' })
+await api.del('/users/123')
+```
+
+## Con parametros de query
+
+```typescript
+const results = await api.get<User[]>('/users', { search: 'lucas', role: 'admin' })
+// GET /users?search=lucas&role=admin
+```
+
+## Notas
+
+- `del` es un alias de DELETE para evitar colision con la keyword `delete` de JS
+- Si la respuesta no es `application/json`, retorna el texto crudo como `T`
+- `on_unauthorized` se llama ANTES de `on_error` en status 401
+- Los errores de red (sin conexion, CORS) tambien llaman a `on_error`
+- Creado una vez a nivel de modulo/app, pasado a hooks via `fetch_fn`
diff --git a/frontend/functions/core/api_client.ts b/frontend/functions/core/api_client.ts
new file mode 100644
index 00000000..f0237c4c
--- /dev/null
+++ b/frontend/functions/core/api_client.ts
@@ -0,0 +1,88 @@
+import type { APIClientConfig } from '../../types/core/api_client_config'
+
+/** Metodos que retorna el factory api_client. */
+export interface APIClient {
+  get: <T>(path: string, params?: Record<string, string>) => Promise<T>
+  post: <T>(path: string, body?: unknown) => Promise<T>
+  put: <T>(path: string, body?: unknown) => Promise<T>
+  patch: <T>(path: string, body?: unknown) => Promise<T>
+  del: <T>(path: string) => Promise<T>
+}
+
+/**
+ * Factory que crea un cliente HTTP configurado con base_url y headers fijos.
+ * Parsea JSON automaticamente. Llama a on_error/on_unauthorized segun el status.
+ */
+export function apiClient(config: APIClientConfig): APIClient {
+  const { base_url, headers: baseHeaders = {}, on_error, on_unauthorized } = config
+
+  const buildUrl = (path: string, params?: Record<string, string>): string => {
+    const url = `${base_url}${path}`
+    if (!params || Object.keys(params).length === 0) return url
+    const qs = new URLSearchParams(params).toString()
+    return `${url}?${qs}`
+  }
+
+  const buildHeaders = (extra: Record<string, string> = {}): HeadersInit => ({
+    'Accept': 'application/json',
+    ...baseHeaders,
+    ...extra,
+  })
+
+  const handleResponse = async <T>(res: Response, url: string, init?: RequestInit): Promise<T> => {
+    if (res.status === 401) {
+      on_unauthorized?.()
+      const err = new Error(`Unauthorized: ${url}`)
+      on_error?.(err, url, init)
+      throw err
+    }
+
+    if (!res.ok) {
+      const text = await res.text().catch(() => '')
+      const err = new Error(`HTTP ${res.status}: ${text.slice(0, 200)}`)
+      on_error?.(err, url, init)
+      throw err
+    }
+
+    const contentType = res.headers.get('content-type') ?? ''
+    if (contentType.includes('application/json')) {
+      return res.json() as Promise<T>
+    }
+    return res.text() as unknown as T
+  }
+
+  const request = async <T>(
+    method: string,
+    path: string,
+    body?: unknown,
+    params?: Record<string, string>,
+  ): Promise<T> => {
+    const url = buildUrl(path, params)
+    const hasBody = body !== undefined
+    const init: RequestInit = {
+      method,
+      headers: buildHeaders(hasBody ? { 'Content-Type': 'application/json' } : {}),
+      body: hasBody ? JSON.stringify(body) : undefined,
+    }
+
+    try {
+      const res = await fetch(url, init)
+      return handleResponse<T>(res, url, init)
+    } catch (err) {
+      if (err instanceof Error && err.message.startsWith('HTTP ')) throw err
+      if (err instanceof Error && err.message.startsWith('Unauthorized')) throw err
+      const error = err instanceof Error ? err : new Error(String(err))
+      on_error?.(error, url, init)
+      throw error
+    }
+  }
+
+  return {
+    get: <T>(path: string, params?: Record<string, string>) =>
+      request<T>('GET', path, undefined, params),
+    post: <T>(path: string, body?: unknown) => request<T>('POST', path, body),
+    put: <T>(path: string, body?: unknown) => request<T>('PUT', path, body),
+    patch: <T>(path: string, body?: unknown) => request<T>('PATCH', path, body),
+    del: <T>(path: string) => request<T>('DELETE', path),
+  }
+}
diff --git a/frontend/functions/core/http_cache.md b/frontend/functions/core/http_cache.md
new file mode 100644
index 00000000..94a8eca0
--- /dev/null
+++ b/frontend/functions/core/http_cache.md
@@ -0,0 +1,41 @@
+---
+name: http_cache
+kind: function
+lang: ts
+domain: core
+version: "1.0.0"
+purity: pure
+signature: "cacheGet<T>(key: string): T | null; cacheSet<T>(key: string, data: T): void; cacheHas(key: string): boolean; cacheIsStale(key: string, staleTime: number): boolean; cacheDelete(key: string): void; cacheInvalidatePrefix(prefix: string): void; cacheClear(): void; cacheSize(): number"
+description: "Cache in-memory singleton para use_fetch. Map con funciones de get/set/has/isStale/invalidate por prefijo. Compartido entre todas las instancias de use_fetch."
+tags: [cache, http, fetch, swr, singleton, memory]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: ""
+imports: []
+params:
+  - name: key
+    desc: "Clave de cache (string serializado desde url + params)"
+  - name: staleTime
+    desc: "Tiempo en ms antes de considerar una entrada stale"
+output: "Modulo con funciones de lectura/escritura/invalidacion del cache in-memory compartido"
+tested: false
+tests: []
+test_file_path: ""
+file_path: "frontend/functions/core/http_cache.ts"
+---
+
+## Ejemplo
+
+```typescript
+import { cacheGet, cacheSet, cacheIsStale } from './http_cache'
+
+cacheSet('users:list', [{ id: '1', name: 'Lucas' }])
+const users = cacheGet<User[]>('users:list')
+const stale = cacheIsStale('users:list', 30_000) // > 30s?
+```
+
+## Notas
+
+Singleton de modulo — el `Map` vive mientras dure la sesion de la SPA. No se persiste en localStorage ni IndexedDB. Para invalidacion jerarquica, `cacheInvalidatePrefix('users')` elimina `users`, `users:list`, `users:123`, etc.
diff --git a/frontend/functions/core/http_cache.ts b/frontend/functions/core/http_cache.ts
new file mode 100644
index 00000000..6510124e
--- /dev/null
+++ b/frontend/functions/core/http_cache.ts
@@ -0,0 +1,55 @@
+/** Cache in-memory compartido para use_fetch. Singleton de modulo. */
+
+interface CacheEntry {
+  data: unknown
+  timestamp: number
+}
+
+const cache = new Map<string, CacheEntry>()
+
+/** Obtener dato del cache. Retorna null si no existe. */
+export function cacheGet<T>(key: string): T | null {
+  const entry = cache.get(key)
+  return entry !== undefined ? (entry.data as T) : null
+}
+
+/** Guardar dato en el cache. */
+export function cacheSet<T>(key: string, data: T): void {
+  cache.set(key, { data, timestamp: Date.now() })
+}
+
+/** Verificar si existe una entrada en el cache. */
+export function cacheHas(key: string): boolean {
+  return cache.has(key)
+}
+
+/** Verificar si una entrada esta stale (supera staleTime en ms). */
+export function cacheIsStale(key: string, staleTime: number): boolean {
+  const entry = cache.get(key)
+  if (!entry) return true
+  return Date.now() - entry.timestamp > staleTime
+}
+
+/** Eliminar una entrada del cache. */
+export function cacheDelete(key: string): void {
+  cache.delete(key)
+}
+
+/** Eliminar todas las entradas cuya key empiece con prefix. */
+export function cacheInvalidatePrefix(prefix: string): void {
+  for (const key of cache.keys()) {
+    if (key === prefix || key.startsWith(prefix + ':')) {
+      cache.delete(key)
+    }
+  }
+}
+
+/** Vaciar el cache completo. */
+export function cacheClear(): void {
+  cache.clear()
+}
+
+/** Numero de entradas en cache. */
+export function cacheSize(): number {
+  return cache.size
+}
diff --git a/frontend/functions/core/use_debounced_search.md b/frontend/functions/core/use_debounced_search.md
new file mode 100644
index 00000000..a5d6b42d
--- /dev/null
+++ b/frontend/functions/core/use_debounced_search.md
@@ -0,0 +1,90 @@
+---
+name: use_debounced_search
+kind: component
+lang: ts
+domain: core
+version: "1.0.0"
+purity: impure
+signature: "useDebouncedSearch<T>(opts: UseDebouncedSearchOptions<T>): UseDebouncedSearchResult<T>"
+description: "Hook que combina input con debounce y fetch automatico. Espera N ms de inactividad tras el ultimo cambio antes de fetchear. Expone query, set_query, results, loading, error y clear."
+tags: [search, debounce, hook, input, fetch, autocomplete, core, component]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: [react]
+params:
+  - name: fetch_fn
+    desc: "Funcion que recibe la query string y retorna Promise<T> con los resultados"
+  - name: delay
+    desc: "Ms de inactividad antes de ejecutar el fetch (default 300)"
+  - name: initial_query
+    desc: "Query inicial (default string vacio)"
+  - name: fetch_on_empty
+    desc: "Si hace fetch cuando la query es string vacio (default true)"
+output: "Objeto con query, set_query, results, loading, error y clear"
+tested: false
+tests: []
+test_file_path: ""
+file_path: "frontend/functions/core/use_debounced_search.tsx"
+props:
+  - name: fetch_fn
+    type: "(query: string) => Promise<T>"
+    required: true
+    description: "Funcion de fetch que recibe la query"
+  - name: delay
+    type: "number"
+    required: false
+    description: "Ms de debounce (default 300)"
+  - name: initial_query
+    type: "string"
+    required: false
+    description: "Query inicial (default '')"
+  - name: fetch_on_empty
+    type: "boolean"
+    required: false
+    description: "Fetch cuando query es vacio (default true)"
+emits: []
+has_state: true
+framework: react
+variant: [default]
+---
+
+## Ejemplo
+
+```tsx
+import { useDebouncedSearch } from '@/functions/core/use_debounced_search'
+import { apiClient } from '@/functions/core/api_client'
+
+const api = apiClient({ base_url: 'http://localhost:8484/api' })
+
+interface User { id: string; name: string; email: string }
+
+function UserSearch() {
+  const { query, set_query, results, loading } = useDebouncedSearch<User[]>({
+    fetch_fn: (q) => api.get('/users/search', { q }),
+    delay: 300,
+    fetch_on_empty: false,  // No buscar cuando el input esta vacio
+  })
+
+  return (
+    <div>
+      <input
+        value={query}
+        onChange={(e) => set_query(e.currentTarget.value)}
+        placeholder="Buscar usuarios..."
+      />
+      {loading && <span>Buscando...</span>}
+      {results?.map((u) => <div key={u.id}>{u.name}</div>)}
+    </div>
+  )
+}
+```
+
+## Notas
+
+- Cancela el timer anterior en cada keystroke — solo ejecuta el fetch tras N ms de silencio
+- `clear()` cancela el timer pendiente y limpia estado
+- `fetch_on_empty: false` es util para autocomplete (no buscar con input vacio)
+- `fetch_on_empty: true` (default) es util para filtros (mostrar todos sin query)
diff --git a/frontend/functions/core/use_debounced_search.tsx b/frontend/functions/core/use_debounced_search.tsx
new file mode 100644
index 00000000..44fb4083
--- /dev/null
+++ b/frontend/functions/core/use_debounced_search.tsx
@@ -0,0 +1,102 @@
+import { useCallback, useEffect, useRef, useState } from 'react'
+
+export interface UseDebouncedSearchOptions<T> {
+  /** Funcion de fetch que recibe la query y retorna resultados */
+  fetch_fn: (query: string) => Promise<T>
+  /** Delay en ms antes de ejecutar la busqueda tras el ultimo cambio (default 300) */
+  delay?: number
+  /** Query inicial (default "") */
+  initial_query?: string
+  /** Si false no hace fetch cuando query es empty string (default true = fetch con "") */
+  fetch_on_empty?: boolean
+}
+
+export interface UseDebouncedSearchResult<T> {
+  /** Valor actual del input de busqueda */
+  query: string
+  /** Actualizar la query (dispara el debounce) */
+  set_query: (q: string) => void
+  /** Resultados de la ultima busqueda exitosa */
+  results: T | null
+  /** Si hay una busqueda en curso */
+  loading: boolean
+  /** Error si la ultima busqueda fallo */
+  error: Error | null
+  /** Limpiar query y resultados */
+  clear: () => void
+}
+
+/**
+ * Hook que combina un input con debounce y fetch automatico.
+ * Espera N ms de inactividad tras el ultimo cambio de query antes de hacer la peticion.
+ */
+export function useDebouncedSearch<T>(
+  opts: UseDebouncedSearchOptions<T>,
+): UseDebouncedSearchResult<T> {
+  const { fetch_fn, delay = 300, initial_query = '', fetch_on_empty = true } = opts
+
+  const [query, setQuery] = useState(initial_query)
+  const [results, setResults] = useState<T | null>(null)
+  const [loading, setLoading] = useState(false)
+  const [error, setError] = useState<Error | null>(null)
+
+  const mountedRef = useRef(true)
+  const timerRef = useRef<ReturnType<typeof setTimeout> | null>(null)
+
+  useEffect(() => {
+    mountedRef.current = true
+    return () => {
+      mountedRef.current = false
+    }
+  }, [])
+
+  useEffect(() => {
+    if (!fetch_on_empty && query === '') {
+      setResults(null)
+      setLoading(false)
+      return
+    }
+
+    setLoading(true)
+    setError(null)
+
+    if (timerRef.current !== null) {
+      clearTimeout(timerRef.current)
+    }
+
+    timerRef.current = setTimeout(async () => {
+      try {
+        const data = await fetch_fn(query)
+        if (!mountedRef.current) return
+        setResults(data)
+      } catch (err) {
+        if (!mountedRef.current) return
+        setError(err instanceof Error ? err : new Error(String(err)))
+      } finally {
+        if (mountedRef.current) setLoading(false)
+      }
+    }, delay)
+
+    return () => {
+      if (timerRef.current !== null) {
+        clearTimeout(timerRef.current)
+      }
+    }
+  }, [query, delay, fetch_on_empty]) // eslint-disable-line react-hooks/exhaustive-deps
+
+  const setQueryDebounced = useCallback((q: string) => {
+    setQuery(q)
+  }, [])
+
+  const clear = useCallback(() => {
+    if (timerRef.current !== null) {
+      clearTimeout(timerRef.current)
+    }
+    setQuery('')
+    setResults(null)
+    setLoading(false)
+    setError(null)
+  }, [])
+
+  return { query, set_query: setQueryDebounced, results, loading, error, clear }
+}
diff --git a/frontend/functions/core/use_fetch.md b/frontend/functions/core/use_fetch.md
new file mode 100644
index 00000000..911d282b
--- /dev/null
+++ b/frontend/functions/core/use_fetch.md
@@ -0,0 +1,112 @@
+---
+name: use_fetch
+kind: component
+lang: ts
+domain: core
+version: "1.0.0"
+purity: impure
+signature: "useFetch<T>(opts: UseFetchOptions<T>): FetchState<T>"
+description: "Hook GET con cache in-memory stale-while-revalidate. Muestra datos cacheados inmediatamente y refetchea en background. Soporta refetch_interval, refetch_on_focus, stale_time y retry."
+tags: [fetch, hook, cache, swr, get, http, core, component]
+uses_functions: [http_cache_ts_core]
+uses_types: [FetchState_ts_core]
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: [react]
+params:
+  - name: url
+    desc: "URL a fetchear (string). Actua como cache key."
+  - name: fetch_fn
+    desc: "Funcion de fetch alternativa que recibe la URL (ej: api.get de api_client). Si se omite usa fetch nativo."
+  - name: enabled
+    desc: "Si false no hace fetch automatico al montar (default true)"
+  - name: stale_time
+    desc: "Tiempo en ms antes de considerar datos stale y refetchear (default 30000)"
+  - name: refetch_interval
+    desc: "Intervalo en ms para refetch automatico. 0 desactiva (default 0)"
+  - name: refetch_on_focus
+    desc: "Si refetchea al recuperar foco de la ventana (default true)"
+  - name: retry
+    desc: "Numero de reintentos ante error (default 0)"
+  - name: retry_delay
+    desc: "Delay en ms entre reintentos (default 1000)"
+output: "FetchState<T> con data, error, loading, is_stale y refetch"
+tested: false
+tests: []
+test_file_path: ""
+file_path: "frontend/functions/core/use_fetch.tsx"
+props:
+  - name: url
+    type: "string"
+    required: false
+    description: "URL a fetchear"
+  - name: fetch_fn
+    type: "(url: string) => Promise<T>"
+    required: false
+    description: "Funcion de fetch alternativa (ej: api.get)"
+  - name: enabled
+    type: "boolean"
+    required: false
+    description: "Habilitar fetch automatico (default true)"
+  - name: stale_time
+    type: "number"
+    required: false
+    description: "Ms antes de considerar datos stale (default 30000)"
+  - name: refetch_interval
+    type: "number"
+    required: false
+    description: "Ms entre refetches automaticos (0 = off)"
+  - name: refetch_on_focus
+    type: "boolean"
+    required: false
+    description: "Refetch al recuperar foco (default true)"
+  - name: retry
+    type: "number"
+    required: false
+    description: "Reintentos ante error (default 0)"
+  - name: retry_delay
+    type: "number"
+    required: false
+    description: "Ms entre reintentos (default 1000)"
+emits: []
+has_state: true
+framework: react
+variant: [default]
+---
+
+## Ejemplo
+
+```tsx
+import { useFetch } from '@/functions/core/use_fetch'
+import { apiClient } from '@/functions/core/api_client'
+
+const api = apiClient({ base_url: 'http://localhost:8484/api' })
+
+function UsersList() {
+  const { data: users, loading, error, is_stale, refetch } = useFetch<User[]>({
+    url: '/users',
+    fetch_fn: api.get,
+    stale_time: 10_000,
+    refetch_on_focus: true,
+  })
+
+  if (loading && !users) return <div>Cargando...</div>
+  if (error) return <div>Error: {error.message}</div>
+
+  return (
+    <div>
+      {is_stale && <span>Actualizando...</span>}
+      {users?.map((u) => <div key={u.id}>{u.name}</div>)}
+      <button onClick={refetch}>Refrescar</button>
+    </div>
+  )
+}
+```
+
+## Notas
+
+- La URL actua como cache key — misma URL = mismos datos cacheados
+- Stale-while-revalidate: si hay datos en cache y son stale, los muestra (`is_stale: true`) y refetchea en background
+- Si no se pasa `fetch_fn`, usa `fetch` nativo con `Accept: application/json`
+- Usar `enabled: false` para fetch condicional (ej: cuando falta un parametro)
diff --git a/frontend/functions/core/use_fetch.tsx b/frontend/functions/core/use_fetch.tsx
new file mode 100644
index 00000000..19ace721
--- /dev/null
+++ b/frontend/functions/core/use_fetch.tsx
@@ -0,0 +1,136 @@
+import { useCallback, useEffect, useRef, useState } from 'react'
+import { cacheGet, cacheHas, cacheIsStale, cacheSet } from './http_cache'
+import type { FetchState } from '../../types/core/fetch_state'
+
+export interface UseFetchOptions<T> {
+  /** URL a fetchear, o funcion que retorna una Promise con los datos */
+  url?: string
+  /** Funcion de fetch alternativa (ej: api.get de api_client). Recibe la URL. */
+  fetch_fn?: (url: string) => Promise<T>
+  /** Si false, no hace fetch automatico al montar (default true) */
+  enabled?: boolean
+  /** Tiempo en ms antes de considerar datos stale (default 30000) */
+  stale_time?: number
+  /** Intervalo en ms para refetch automatico (0 = desactivado) */
+  refetch_interval?: number
+  /** Si refetchea al recuperar foco de la ventana (default true) */
+  refetch_on_focus?: boolean
+  /** Numero de reintentos ante error (default 0) */
+  retry?: number
+  /** Delay en ms entre reintentos (default 1000) */
+  retry_delay?: number
+}
+
+/**
+ * Hook GET con cache in-memory stale-while-revalidate.
+ * Muestra datos cacheados inmediatamente mientras refetchea en background.
+ */
+export function useFetch<T>(opts: UseFetchOptions<T>): FetchState<T> {
+  const {
+    url = '',
+    fetch_fn,
+    enabled = true,
+    stale_time = 30_000,
+    refetch_interval = 0,
+    refetch_on_focus = true,
+    retry = 0,
+    retry_delay = 1000,
+  } = opts
+
+  const cacheKey = url
+
+  type FetchInternalState = Omit<FetchState<T>, 'refetch'>
+
+  const [state, setState] = useState<FetchInternalState>(() => ({
+    data: cacheHas(cacheKey) ? cacheGet<T>(cacheKey) : null,
+    error: null,
+    loading: enabled && (!cacheHas(cacheKey) || cacheIsStale(cacheKey, stale_time)),
+    is_stale: cacheHas(cacheKey) && cacheIsStale(cacheKey, stale_time),
+  }))
+
+  const mountedRef = useRef(true)
+  const retryCountRef = useRef(0)
+
+  const doFetch = useCallback(async (): Promise<T> => {
+    if (!mountedRef.current) throw new Error('unmounted')
+
+    setState((s: FetchInternalState) => ({ ...s, loading: true, error: null }))
+
+    try {
+      const data = fetch_fn
+        ? await fetch_fn(url)
+        : await fetch(url, { headers: { Accept: 'application/json' } }).then((r) => {
+            if (!r.ok) throw new Error(`HTTP ${r.status}`)
+            return r.json() as Promise<T>
+          })
+
+      if (!mountedRef.current) throw new Error('unmounted')
+
+      cacheSet(cacheKey, data)
+      retryCountRef.current = 0
+
+      setState({ data, loading: false, error: null, is_stale: false })
+      return data
+    } catch (err) {
+      if (!mountedRef.current) throw err
+
+      if (retryCountRef.current < retry) {
+        retryCountRef.current += 1
+        await new Promise((resolve) => setTimeout(resolve, retry_delay))
+        return doFetch()
+      }
+
+      const error = err instanceof Error ? err : new Error(String(err))
+      setState((s: FetchInternalState) => ({ ...s, loading: false, error }))
+      throw error
+    }
+  }, [url, fetch_fn, cacheKey, stale_time, retry, retry_delay])
+
+  // Fetch inicial
+  useEffect(() => {
+    mountedRef.current = true
+
+    if (enabled && url && (!cacheHas(cacheKey) || cacheIsStale(cacheKey, stale_time))) {
+      doFetch().catch(() => {})
+    } else if (enabled && url && cacheHas(cacheKey)) {
+      // Datos en cache no stale — actualizar estado si es necesario
+      setState((s: FetchInternalState) => ({
+        ...s,
+        data: cacheGet<T>(cacheKey),
+        loading: false,
+        is_stale: false,
+      }))
+    }
+
+    return () => {
+      mountedRef.current = false
+    }
+  }, [enabled, url, stale_time]) // eslint-disable-line react-hooks/exhaustive-deps
+
+  // Refetch por intervalo
+  useEffect(() => {
+    if (!refetch_interval || !enabled || !url) return
+
+    const id = setInterval(() => {
+      doFetch().catch(() => {})
+    }, refetch_interval)
+
+    return () => clearInterval(id)
+  }, [refetch_interval, enabled, url, doFetch])
+
+  // Refetch al recuperar foco
+  useEffect(() => {
+    if (!refetch_on_focus || !enabled || !url) return
+
+    const handler = () => {
+      if (cacheIsStale(cacheKey, stale_time)) {
+        doFetch().catch(() => {})
+      }
+    }
+
+    window.addEventListener('focus', handler)
+    return () => window.removeEventListener('focus', handler)
+  }, [refetch_on_focus, enabled, url, cacheKey, stale_time, doFetch])
+
+  return { ...state, refetch: doFetch }
+}
diff --git a/frontend/functions/core/use_form.md b/frontend/functions/core/use_form.md
new file mode 100644
index 00000000..de6d3673
--- /dev/null
+++ b/frontend/functions/core/use_form.md
@@ -0,0 +1,94 @@
+---
+name: use_form
+kind: component
+lang: ts
+domain: core
+version: "1.0.0"
+purity: impure
+signature: "useForm<T extends Record<string, unknown>>(opts: UseFormOptions<T>): UseFormResult<T>"
+description: "Hook de formulario con validacion sincrona, touched tracking y submit handler. Minimalista: set_field, set_fields, validate, submit, reset. Para formularios simples sin dependencia de Mantine."
+tags: [form, hook, validation, touched, submit, core, component]
+uses_functions: []
+uses_types: [FormState_ts_core]
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: [react]
+params:
+  - name: initial_values
+    desc: "Valores iniciales del formulario tipados con T"
+  - name: validate
+    desc: "Funcion de validacion sincrona: recibe values, retorna errores por campo (undefined = campo valido)"
+output: "UseFormResult<T> con values, errors, touched, is_valid, is_submitting, set_field, set_fields, validate, submit y reset"
+tested: false
+tests: []
+test_file_path: ""
+file_path: "frontend/functions/core/use_form.tsx"
+props:
+  - name: initial_values
+    type: "T"
+    required: true
+    description: "Valores iniciales del formulario"
+  - name: validate
+    type: "(values: T) => Partial<Record<keyof T, string | undefined>>"
+    required: false
+    description: "Funcion de validacion sincrona"
+emits: []
+has_state: true
+framework: react
+variant: [default]
+---
+
+## Ejemplo
+
+```tsx
+import { useForm } from '@/functions/core/use_form'
+
+interface LoginForm {
+  email: string
+  password: string
+}
+
+function LoginPage() {
+  const form = useForm<LoginForm>({
+    initial_values: { email: '', password: '' },
+    validate: (values) => ({
+      email: !values.email.includes('@') ? 'Email invalido' : undefined,
+      password: values.password.length < 8 ? 'Minimo 8 caracteres' : undefined,
+    }),
+  })
+
+  return (
+    <form onSubmit={(e) => {
+      e.preventDefault()
+      form.submit(async (values) => {
+        await loginApi(values.email, values.password)
+      })
+    }}>
+      <input
+        value={form.values.email}
+        onChange={(e) => form.set_field('email', e.currentTarget.value)}
+      />
+      {form.touched.email && form.errors.email && <span>{form.errors.email}</span>}
+
+      <input
+        type="password"
+        value={form.values.password}
+        onChange={(e) => form.set_field('password', e.currentTarget.value)}
+      />
+      {form.touched.password && form.errors.password && <span>{form.errors.password}</span>}
+
+      <button type="submit" disabled={form.is_submitting || !form.is_valid}>
+        {form.is_submitting ? 'Cargando...' : 'Entrar'}
+      </button>
+    </form>
+  )
+}
+```
+
+## Notas
+
+- `touched` permite mostrar errores solo despues de que el usuario modifica un campo
+- `submit(handler)` llama a `validate()` primero y solo ejecuta el handler si pasa
+- `is_valid` es true si no hay errores (incluso antes de tocar campos)
+- Para formularios complejos con validacion async, arrays de campos o schemas zod, usar `@mantine/form`
diff --git a/frontend/functions/core/use_form.tsx b/frontend/functions/core/use_form.tsx
new file mode 100644
index 00000000..366e65e1
--- /dev/null
+++ b/frontend/functions/core/use_form.tsx
@@ -0,0 +1,133 @@
+import { useCallback, useState } from 'react'
+import type { FormState } from '../../types/core/form_state'
+
+export interface UseFormOptions<T extends Record<string, unknown>> {
+  /** Valores iniciales del formulario */
+  initial_values: T
+  /** Funcion de validacion sincrona. Retorna errores por campo (undefined = sin error). */
+  validate?: (values: T) => Partial<Record<keyof T, string | undefined>>
+}
+
+/** Resultado del hook use_form, extiende FormState con metodos de control */
+export interface UseFormResult<T extends Record<string, unknown>> extends FormState<T> {
+  /** Actualizar un campo individual */
+  set_field: <K extends keyof T>(name: K, value: T[K]) => void
+  /** Actualizar multiples campos a la vez */
+  set_fields: (partial: Partial<T>) => void
+  /** Ejecutar validacion manualmente. Retorna true si pasa. */
+  validate: () => boolean
+  /** Ejecutar validacion y llamar al handler solo si pasa */
+  submit: (handler: (values: T) => Promise<void> | void) => Promise<void>
+  /** Resetear al estado inicial */
+  reset: () => void
+}
+
+/**
+ * Hook para formularios con validacion sincrona, touched tracking y submit handler.
+ * Minimalista: no reemplaza @mantine/form. Para formularios simples sin Mantine.
+ */
+export function useForm<T extends Record<string, unknown>>(
+  opts: UseFormOptions<T>,
+): UseFormResult<T> {
+  const { initial_values, validate: validateFn } = opts
+
+  const [values, setValues] = useState<T>(initial_values)
+  const [errors, setErrors] = useState<Partial<Record<keyof T, string>>>({})
+  const [touched, setTouched] = useState<Partial<Record<keyof T, boolean>>>({})
+  const [isSubmitting, setIsSubmitting] = useState(false)
+
+  const runValidation = useCallback(
+    (vals: T): Partial<Record<keyof T, string>> => {
+      if (!validateFn) return {}
+      const result = validateFn(vals)
+      const filtered: Partial<Record<keyof T, string>> = {}
+      for (const key in result) {
+        const val = result[key as keyof T]
+        if (val !== undefined) {
+          filtered[key as keyof T] = val
+        }
+      }
+      return filtered
+    },
+    [validateFn],
+  )
+
+  const setField = useCallback(
+    <K extends keyof T>(name: K, value: T[K]) => {
+      setValues((prev: T) => {
+        const next = { ...prev, [name]: value }
+        if (validateFn) {
+          const newErrors = runValidation(next)
+          setErrors(newErrors)
+        }
+        return next
+      })
+      setTouched((prev: Partial<Record<keyof T, boolean>>) => ({ ...prev, [name]: true }))
+    },
+    [validateFn, runValidation],
+  )
+
+  const setFields = useCallback(
+    (partial: Partial<T>) => {
+      setValues((prev: T) => {
+        const next = { ...prev, ...partial }
+        if (validateFn) {
+          const newErrors = runValidation(next)
+          setErrors(newErrors)
+        }
+        return next
+      })
+      const newTouched: Partial<Record<keyof T, boolean>> = {}
+      for (const key in partial) {
+        newTouched[key as keyof T] = true
+      }
+      setTouched((prev: Partial<Record<keyof T, boolean>>) => ({ ...prev, ...newTouched }))
+    },
+    [validateFn, runValidation],
+  )
+
+  const validate = useCallback((): boolean => {
+    const newErrors = runValidation(values)
+    setErrors(newErrors)
+    return Object.keys(newErrors).length === 0
+  }, [values, runValidation])
+
+  const submit = useCallback(
+    async (handler: (values: T) => Promise<void> | void): Promise<void> => {
+      const newErrors = runValidation(values)
+      setErrors(newErrors)
+
+      if (Object.keys(newErrors).length > 0) return
+
+      setIsSubmitting(true)
+      try {
+        await handler(values)
+      } finally {
+        setIsSubmitting(false)
+      }
+    },
+    [values, runValidation],
+  )
+
+  const reset = useCallback(() => {
+    setValues(initial_values)
+    setErrors({})
+    setTouched({})
+    setIsSubmitting(false)
+  }, [initial_values])
+
+  const isValid = Object.keys(errors).length === 0
+
+  return {
+    values,
+    errors,
+    touched,
+    is_valid: isValid,
+    is_submitting: isSubmitting,
+    set_field: setField,
+    set_fields: setFields,
+    validate,
+    submit,
+    reset,
+  }
+}
diff --git a/frontend/functions/core/use_infinite_scroll.md b/frontend/functions/core/use_infinite_scroll.md
new file mode 100644
index 00000000..caa88e9e
--- /dev/null
+++ b/frontend/functions/core/use_infinite_scroll.md
@@ -0,0 +1,104 @@
+---
+name: use_infinite_scroll
+kind: component
+lang: ts
+domain: core
+version: "1.0.0"
+purity: impure
+signature: "useInfiniteScroll<T>(opts: UseInfiniteScrollOptions<T>): UseInfiniteScrollResult<T>"
+description: "Hook de paginacion infinita cursor-based y offset-based. Concatena paginas en array plano. Expone load_more, has_more y reset. Zero dependencias externas."
+tags: [infinite, scroll, pagination, cursor, hook, http, core, component]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: [react]
+params:
+  - name: fetch_fn
+    desc: "Funcion que recibe el cursor actual (string, number o null) y retorna Promise<{items, next_cursor}>"
+  - name: initial_cursor
+    desc: "Cursor inicial, null para empezar desde el principio (default null)"
+  - name: enabled
+    desc: "Si hace fetch automatico al montar (default true)"
+output: "Objeto con data (array concatenado), loading, error, has_more, load_more() y reset()"
+tested: false
+tests: []
+test_file_path: ""
+file_path: "frontend/functions/core/use_infinite_scroll.tsx"
+props:
+  - name: fetch_fn
+    type: "(cursor: string | number | null) => Promise<InfiniteScrollPage<T>>"
+    required: true
+    description: "Funcion de fetch que recibe cursor y retorna pagina con items y next_cursor"
+  - name: initial_cursor
+    desc: "Cursor inicial (default null)"
+    type: "string | number | null"
+    required: false
+    description: "Cursor/offset inicial"
+  - name: enabled
+    type: "boolean"
+    required: false
+    description: "Fetch automatico al montar (default true)"
+emits: []
+has_state: true
+framework: react
+variant: [default]
+---
+
+## Ejemplo cursor-based
+
+```tsx
+import { useInfiniteScroll } from '@/functions/core/use_infinite_scroll'
+import { apiClient } from '@/functions/core/api_client'
+
+const api = apiClient({ base_url: 'http://localhost:8484/api' })
+
+function EventsList() {
+  const { data, loading, has_more, load_more } = useInfiniteScroll<Event>({
+    fetch_fn: async (cursor) => {
+      const res = await api.get<{ items: Event[]; next_cursor: string | null }>(
+        '/events',
+        cursor ? { after: String(cursor) } : undefined,
+      )
+      return { items: res.items, next_cursor: res.next_cursor }
+    },
+  })
+
+  return (
+    <div>
+      {data.map((e) => <div key={e.id}>{e.name}</div>)}
+      {has_more && (
+        <button disabled={loading} onClick={load_more}>
+          {loading ? 'Cargando...' : 'Cargar mas'}
+        </button>
+      )}
+    </div>
+  )
+}
+```
+
+## Ejemplo offset-based
+
+```tsx
+const { data, load_more, has_more } = useInfiniteScroll<Product>({
+  fetch_fn: async (cursor) => {
+    const page = typeof cursor === 'number' ? cursor : 0
+    const items = await api.get<Product[]>('/products', {
+      offset: String(page * 20),
+      limit: '20',
+    })
+    return {
+      items,
+      next_cursor: items.length === 20 ? page + 1 : null,
+    }
+  },
+  initial_cursor: 0,
+})
+```
+
+## Notas
+
+- `InfiniteScrollPage.next_cursor = null` indica que no hay mas paginas
+- `reset()` vuelve al cursor inicial y refetchea desde el principio
+- `load_more` es no-op si `loading` o `!has_more`
diff --git a/frontend/functions/core/use_infinite_scroll.tsx b/frontend/functions/core/use_infinite_scroll.tsx
new file mode 100644
index 00000000..2a140690
--- /dev/null
+++ b/frontend/functions/core/use_infinite_scroll.tsx
@@ -0,0 +1,106 @@
+import { useCallback, useRef, useState } from 'react'
+
+export interface UseInfiniteScrollOptions<T> {
+  /** Funcion de fetch que recibe el cursor/pagina actual y retorna la pagina de datos */
+  fetch_fn: (cursor: string | number | null) => Promise<InfiniteScrollPage<T>>
+  /** Cursor inicial (null para empezar desde el principio) */
+  initial_cursor?: string | number | null
+  /** Si el primer fetch es automatico al montar (default true) */
+  enabled?: boolean
+}
+
+/** Pagina retornada por fetch_fn */
+export interface InfiniteScrollPage<T> {
+  /** Datos de esta pagina */
+  items: T[]
+  /** Cursor para la siguiente pagina. null/undefined = no hay mas paginas. */
+  next_cursor?: string | number | null
+}
+
+/** Estado del hook de paginacion infinita */
+export interface UseInfiniteScrollResult<T> {
+  /** Todos los items concatenados de todas las paginas */
+  data: T[]
+  /** Si hay una peticion en curso */
+  loading: boolean
+  /** Error si la ultima peticion fallo */
+  error: Error | null
+  /** Si hay mas paginas disponibles */
+  has_more: boolean
+  /** Cargar la siguiente pagina */
+  load_more: () => void
+  /** Resetear al estado inicial y refetchear desde el principio */
+  reset: () => void
+}
+
+/**
+ * Hook para paginacion infinita cursor-based y offset-based.
+ * Concatena paginas en un solo array. Expone load_more, has_more y reset.
+ */
+export function useInfiniteScroll<T>(
+  opts: UseInfiniteScrollOptions<T>,
+): UseInfiniteScrollResult<T> {
+  const { fetch_fn, initial_cursor = null, enabled = true } = opts
+
+  const [data, setData] = useState<T[]>([])
+  const [loading, setLoading] = useState(enabled)
+  const [error, setError] = useState<Error | null>(null)
+  const [hasMore, setHasMore] = useState(true)
+
+  const cursorRef = useRef<string | number | null>(initial_cursor)
+  const loadingRef = useRef(false)
+  const mountedRef = useRef(true)
+
+  const fetchPage = useCallback(
+    async (cursor: string | number | null): Promise<void> => {
+      if (loadingRef.current) return
+      loadingRef.current = true
+
+      setLoading(true)
+      setError(null)
+
+      try {
+        const page = await fetch_fn(cursor)
+
+        if (!mountedRef.current) return
+
+        setData((prev: T[]) => (cursor === initial_cursor ? page.items : [...prev, ...page.items]))
+
+        const nextCursor = page.next_cursor ?? null
+        cursorRef.current = nextCursor
+        setHasMore(nextCursor !== null && nextCursor !== undefined)
+      } catch (err) {
+        if (!mountedRef.current) return
+        setError(err instanceof Error ? err : new Error(String(err)))
+      } finally {
+        if (mountedRef.current) setLoading(false)
+        loadingRef.current = false
+      }
+    },
+    [fetch_fn, initial_cursor],
+  )
+
+  // Fetch inicial
+  const initializedRef = useRef(false)
+  if (!initializedRef.current && enabled) {
+    initializedRef.current = true
+    // eslint-disable-next-line @typescript-eslint/no-floating-promises
+    fetchPage(initial_cursor)
+  }
+
+  const loadMore = useCallback(() => {
+    if (!hasMore || loadingRef.current) return
+    fetchPage(cursorRef.current).catch(() => {})
+  }, [fetchPage, hasMore])
+
+  const reset = useCallback(() => {
+    cursorRef.current = initial_cursor
+    loadingRef.current = false
+    setData([])
+    setError(null)
+    setHasMore(true)
+    fetchPage(initial_cursor).catch(() => {})
+  }, [fetchPage, initial_cursor])
+
+  return { data, loading, error, has_more: hasMore, load_more: loadMore, reset }
+}
diff --git a/frontend/functions/core/use_mutation.md b/frontend/functions/core/use_mutation.md
new file mode 100644
index 00000000..630c4910
--- /dev/null
+++ b/frontend/functions/core/use_mutation.md
@@ -0,0 +1,120 @@
+---
+name: use_mutation
+kind: component
+lang: ts
+domain: core
+version: "1.0.0"
+purity: impure
+signature: "useMutation<TData, TVariables>(opts: UseMutationOptions<TData, TVariables>): MutationState<TData, TVariables>"
+description: "Hook POST/PUT/DELETE con optimistic updates, invalidacion de cache, retry y callbacks completos. No ejecuta al montar — expone mutate y mutate_async."
+tags: [mutation, hook, post, put, delete, http, optimistic, cache, core, component]
+uses_functions: [http_cache_ts_core]
+uses_types: [MutationState_ts_core]
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: [react]
+params:
+  - name: mutation_fn
+    desc: "Funcion que ejecuta la mutacion, recibe variables y retorna Promise<TData>"
+  - name: on_mutate
+    desc: "Callback antes de la mutacion para optimistic updates. Retorna contexto de rollback."
+  - name: on_success
+    desc: "Callback al exito con data, variables y context"
+  - name: on_error
+    desc: "Callback al error con error, variables y context para rollback"
+  - name: on_settled
+    desc: "Callback siempre (exito o error)"
+  - name: invalidate_cache
+    desc: "Prefijos de cache a invalidar en exito (ej: 'users' invalida users, users:list, etc.)"
+  - name: retry
+    desc: "Numero de reintentos ante error (default 0)"
+  - name: retry_delay
+    desc: "Delay en ms entre reintentos (default 1000)"
+output: "MutationState<TData, TVariables> con mutate, mutate_async, data, error, loading y reset"
+tested: false
+tests: []
+test_file_path: ""
+file_path: "frontend/functions/core/use_mutation.tsx"
+props:
+  - name: mutation_fn
+    type: "(variables: TVariables) => Promise<TData>"
+    required: true
+    description: "Funcion que ejecuta la mutacion"
+  - name: on_mutate
+    type: "(variables: TVariables) => Promise<unknown> | unknown"
+    required: false
+    description: "Optimistic update antes de la mutacion"
+  - name: on_success
+    type: "(data: TData, variables: TVariables, context: unknown) => void"
+    required: false
+    description: "Callback al exito"
+  - name: on_error
+    type: "(error: Error, variables: TVariables, context: unknown) => void"
+    required: false
+    description: "Callback al error (para rollback de optimistic updates)"
+  - name: invalidate_cache
+    type: "string[]"
+    required: false
+    description: "Prefijos de cache a invalidar en exito"
+  - name: retry
+    type: "number"
+    required: false
+    description: "Reintentos ante error (default 0)"
+  - name: retry_delay
+    type: "number"
+    required: false
+    description: "Ms entre reintentos (default 1000)"
+emits: [on_success, on_error, on_settled]
+has_state: true
+framework: react
+variant: [default]
+---
+
+## Ejemplo
+
+```tsx
+import { useMutation } from '@/functions/core/use_mutation'
+import { apiClient } from '@/functions/core/api_client'
+
+const api = apiClient({ base_url: 'http://localhost:8484/api' })
+
+function DeleteButton({ userId }: { userId: string }) {
+  const { mutate: deleteUser, loading } = useMutation<void, string>({
+    mutation_fn: (id) => api.del(`/users/${id}`),
+    invalidate_cache: ['users'],
+    on_success: () => console.log('Eliminado'),
+  })
+
+  return (
+    <button disabled={loading} onClick={() => deleteUser(userId)}>
+      {loading ? 'Eliminando...' : 'Eliminar'}
+    </button>
+  )
+}
+```
+
+## Optimistic update
+
+```tsx
+const { mutate } = useMutation<User, Partial<User>>({
+  mutation_fn: (data) => api.post('/users', data),
+  on_mutate: (newUser) => {
+    // Guardar snapshot para rollback
+    const prev = cacheGet<User[]>('users')
+    cacheSet('users', [...(prev ?? []), { ...newUser, id: 'temp' }])
+    return { prev }
+  },
+  on_error: (_err, _vars, context) => {
+    // Rollback
+    const ctx = context as { prev: User[] }
+    cacheSet('users', ctx.prev)
+  },
+})
+```
+
+## Notas
+
+- `mutate` es fire-and-forget (no lanza, silencia el error)
+- `mutate_async` retorna Promise (puede rechazar — usar try/catch)
+- `invalidate_cache` usa `cacheInvalidatePrefix` — invalida prefijos jerarquicos
diff --git a/frontend/functions/core/use_mutation.tsx b/frontend/functions/core/use_mutation.tsx
new file mode 100644
index 00000000..96fb48f3
--- /dev/null
+++ b/frontend/functions/core/use_mutation.tsx
@@ -0,0 +1,117 @@
+import { useCallback, useRef, useState } from 'react'
+import { cacheInvalidatePrefix } from './http_cache'
+import type { MutationState } from '../../types/core/mutation_state'
+
+export interface UseMutationOptions<TData, TVariables> {
+  /** Funcion que ejecuta la mutacion (POST/PUT/DELETE) */
+  mutation_fn: (variables: TVariables) => Promise<TData>
+  /** Callback antes de la mutacion — permite optimistic updates. Retorna contexto de rollback. */
+  on_mutate?: (variables: TVariables) => Promise<unknown> | unknown
+  /** Callback al exito */
+  on_success?: (data: TData, variables: TVariables, context: unknown) => void
+  /** Callback al error */
+  on_error?: (error: Error, variables: TVariables, context: unknown) => void
+  /** Callback siempre (exito o error) */
+  on_settled?: (data: TData | undefined, error: Error | null, variables: TVariables, context: unknown) => void
+  /** Prefijos de cache a invalidar en exito (ej: ['users'] invalida users, users:list, etc.) */
+  invalidate_cache?: string[]
+  /** Numero de reintentos ante error (default 0) */
+  retry?: number
+  /** Delay en ms entre reintentos (default 1000) */
+  retry_delay?: number
+}
+
+/**
+ * Hook para operaciones de escritura POST/PUT/DELETE.
+ * No ejecuta al montar. Expone mutate() y mutate_async().
+ * Soporta optimistic updates via on_mutate y invalidacion de cache.
+ */
+export function useMutation<TData, TVariables = void>(
+  opts: UseMutationOptions<TData, TVariables>,
+): MutationState<TData, TVariables> {
+  const {
+    mutation_fn,
+    on_mutate,
+    on_success,
+    on_error,
+    on_settled,
+    invalidate_cache = [],
+    retry = 0,
+    retry_delay = 1000,
+  } = opts
+
+  type MutationInternalState = {
+    status: 'idle' | 'loading' | 'success' | 'error'
+    data: TData | null
+    error: Error | null
+  }
+
+  const [state, setState] = useState<MutationInternalState>({ status: 'idle', data: null, error: null })
+
+  const retryCountRef = useRef(0)
+
+  const execute = useCallback(
+    async (variables: TVariables): Promise<TData> => {
+      setState((s: MutationInternalState) => ({ ...s, status: 'loading', error: null }))
+
+      let context: unknown
+
+      try {
+        if (on_mutate) {
+          context = await on_mutate(variables)
+        }
+
+        const data = await mutation_fn(variables)
+
+        retryCountRef.current = 0
+        setState({ status: 'success', data, error: null })
+
+        // Invalidar cache en exito
+        for (const prefix of invalidate_cache) {
+          cacheInvalidatePrefix(prefix)
+        }
+
+        on_success?.(data, variables, context)
+        on_settled?.(data, null, variables, context)
+
+        return data
+      } catch (err) {
+        if (retryCountRef.current < retry) {
+          retryCountRef.current += 1
+          await new Promise((resolve) => setTimeout(resolve, retry_delay))
+          return execute(variables)
+        }
+
+        const error = err instanceof Error ? err : new Error(String(err))
+        setState((s: MutationInternalState) => ({ ...s, status: 'error', error }))
+
+        on_error?.(error, variables, context)
+        on_settled?.(undefined, error, variables, context)
+
+        throw error
+      }
+    },
+    [mutation_fn, on_mutate, on_success, on_error, on_settled, invalidate_cache, retry, retry_delay],
+  )
+
+  const mutate = useCallback(
+    (variables: TVariables) => {
+      execute(variables).catch(() => {})
+    },
+    [execute],
+  )
+
+  const reset = useCallback(() => {
+    setState({ status: 'idle', data: null, error: null })
+    retryCountRef.current = 0
+  }, [])
+
+  return {
+    mutate,
+    mutate_async: execute,
+    data: state.data,
+    error: state.error,
+    loading: state.status === 'loading',
+    reset,
+  }
+}
diff --git a/frontend/functions/core/use_sse.md b/frontend/functions/core/use_sse.md
new file mode 100644
index 00000000..b5999d2f
--- /dev/null
+++ b/frontend/functions/core/use_sse.md
@@ -0,0 +1,104 @@
+---
+name: use_sse
+kind: component
+lang: ts
+domain: core
+version: "1.0.0"
+purity: impure
+signature: "useSSE<T>(opts: UseSSEOptions<T>): UseSSEResult<T>"
+description: "Hook para Server-Sent Events con auto-reconexion y backoff exponencial. Parsea eventos como JSON. Acumula todos los eventos en data[]. Expone last_event, status y close."
+tags: [sse, server-sent-events, stream, hook, realtime, reconnect, core, component]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: [react]
+params:
+  - name: url
+    desc: "URL del endpoint SSE (ej: http://localhost:8484/api/logs/stream)"
+  - name: enabled
+    desc: "Si conecta automaticamente al montar (default true)"
+  - name: reconnect
+    desc: "Si reconecta automaticamente con backoff exponencial (default true)"
+  - name: reconnect_interval
+    desc: "Delay inicial de reconexion en ms (default 1000). Se duplica hasta max_reconnect_interval."
+  - name: max_reconnect_interval
+    desc: "Delay maximo de reconexion en ms (default 30000)"
+  - name: event_name
+    desc: "Nombre del evento SSE a escuchar (default 'message')"
+  - name: on_event
+    desc: "Callback por cada evento recibido con el dato parseado"
+output: "Objeto con data[], last_event, status (connecting/open/closed), error, close() y connect()"
+tested: false
+tests: []
+test_file_path: ""
+file_path: "frontend/functions/core/use_sse.tsx"
+props:
+  - name: url
+    type: "string"
+    required: true
+    description: "URL del endpoint SSE"
+  - name: enabled
+    type: "boolean"
+    required: false
+    description: "Conectar al montar (default true)"
+  - name: reconnect
+    type: "boolean"
+    required: false
+    description: "Auto-reconectar (default true)"
+  - name: reconnect_interval
+    type: "number"
+    required: false
+    description: "Delay inicial reconexion en ms (default 1000)"
+  - name: max_reconnect_interval
+    type: "number"
+    required: false
+    description: "Delay maximo reconexion en ms (default 30000)"
+  - name: event_name
+    type: "string"
+    required: false
+    description: "Nombre evento SSE (default 'message')"
+emits: [on_event, on_error]
+has_state: true
+framework: react
+variant: [default]
+---
+
+## Ejemplo
+
+```tsx
+import { useSSE } from '@/functions/core/use_sse'
+
+interface LogEntry { level: string; msg: string; ts: number }
+
+function LogViewer() {
+  const { data: logs, last_event, status, close } = useSSE<LogEntry>({
+    url: 'http://localhost:8484/api/logs/stream',
+    reconnect: true,
+    reconnect_interval: 2000,
+  })
+
+  return (
+    <div>
+      <span>Status: {status}</span>
+      <div style={{ overflow: 'auto', height: 400 }}>
+        {logs.map((log, i) => (
+          <div key={i} style={{ color: log.level === 'error' ? 'red' : 'inherit' }}>
+            [{log.level}] {log.msg}
+          </div>
+        ))}
+      </div>
+      <button onClick={close}>Cerrar conexion</button>
+    </div>
+  )
+}
+```
+
+## Notas
+
+- El backoff exponencial duplica el delay hasta `max_reconnect_interval`
+- Si el evento no es JSON valido, se guarda como string
+- `close()` previene reconexion automatica
+- `connect()` fuerza reconexion manual aunque haya sido cerrado manualmente
+- `data` acumula todos los eventos de la sesion. Para limpiar, desmontar y remontar el componente.
diff --git a/frontend/functions/core/use_sse.tsx b/frontend/functions/core/use_sse.tsx
new file mode 100644
index 00000000..4055d78e
--- /dev/null
+++ b/frontend/functions/core/use_sse.tsx
@@ -0,0 +1,163 @@
+import { useCallback, useEffect, useRef, useState } from 'react'
+
+export type SSEStatus = 'connecting' | 'open' | 'closed'
+
+export interface UseSSEOptions<T> {
+  /** URL del endpoint SSE */
+  url: string
+  /** Si conecta automaticamente al montar (default true) */
+  enabled?: boolean
+  /** Si reconecta automaticamente al perder la conexion (default true) */
+  reconnect?: boolean
+  /** Delay inicial de reconexion en ms (default 1000). Se duplica con backoff hasta max_reconnect_interval. */
+  reconnect_interval?: number
+  /** Delay maximo de reconexion en ms (default 30000) */
+  max_reconnect_interval?: number
+  /** Nombre del evento a escuchar (default 'message'). Para multiples eventos usar on_event. */
+  event_name?: string
+  /** Callback por evento recibido. Recibe el dato parseado. */
+  on_event?: (data: T) => void
+  /** Callback al error */
+  on_error?: (error: Event) => void
+}
+
+export interface UseSSEResult<T> {
+  /** Todos los eventos recibidos en esta sesion */
+  data: T[]
+  /** Ultimo evento recibido */
+  last_event: T | null
+  /** Estado de la conexion */
+  status: SSEStatus
+  /** Error de conexion si ocurrio */
+  error: Event | null
+  /** Cerrar la conexion manualmente */
+  close: () => void
+  /** Reconectar manualmente */
+  connect: () => void
+}
+
+/**
+ * Hook para Server-Sent Events con auto-reconexion y backoff exponencial.
+ * Parsea cada evento como JSON. Acumula todos los eventos en data[].
+ */
+export function useSSE<T>(opts: UseSSEOptions<T>): UseSSEResult<T> {
+  const {
+    url,
+    enabled = true,
+    reconnect = true,
+    reconnect_interval = 1000,
+    max_reconnect_interval = 30_000,
+    event_name = 'message',
+    on_event,
+    on_error,
+  } = opts
+
+  const [data, setData] = useState<T[]>([])
+  const [lastEvent, setLastEvent] = useState<T | null>(null)
+  const [status, setStatus] = useState<SSEStatus>('closed')
+  const [error, setError] = useState<Event | null>(null)
+
+  const esRef = useRef<EventSource | null>(null)
+  const reconnectTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null)
+  const currentIntervalRef = useRef(reconnect_interval)
+  const mountedRef = useRef(true)
+  const closedManuallyRef = useRef(false)
+
+  const clearReconnectTimer = () => {
+    if (reconnectTimerRef.current !== null) {
+      clearTimeout(reconnectTimerRef.current)
+      reconnectTimerRef.current = null
+    }
+  }
+
+  const connect = useCallback(() => {
+    if (!mountedRef.current) return
+
+    // Cerrar conexion previa si existe
+    if (esRef.current) {
+      esRef.current.close()
+      esRef.current = null
+    }
+
+    closedManuallyRef.current = false
+    currentIntervalRef.current = reconnect_interval
+
+    setStatus('connecting')
+    setError(null)
+
+    const es = new EventSource(url)
+    esRef.current = es
+
+    es.addEventListener(event_name, (e: MessageEvent) => {
+      if (!mountedRef.current) return
+
+      let parsed: T
+      try {
+        parsed = JSON.parse(e.data) as T
+      } catch {
+        parsed = e.data as unknown as T
+      }
+
+      setData((prev: T[]) => [...prev, parsed])
+      setLastEvent(parsed)
+      on_event?.(parsed)
+      // Reset backoff on successful message
+      currentIntervalRef.current = reconnect_interval
+    })
+
+    es.onopen = () => {
+      if (!mountedRef.current) return
+      setStatus('open')
+      currentIntervalRef.current = reconnect_interval
+    }
+
+    es.onerror = (e) => {
+      if (!mountedRef.current) return
+      setError(e)
+      on_error?.(e)
+      setStatus('closed')
+      es.close()
+      esRef.current = null
+
+      if (reconnect && !closedManuallyRef.current) {
+        const delay = Math.min(currentIntervalRef.current, max_reconnect_interval)
+        currentIntervalRef.current = Math.min(delay * 2, max_reconnect_interval)
+
+        reconnectTimerRef.current = setTimeout(() => {
+          if (mountedRef.current && !closedManuallyRef.current) {
+            connect()
+          }
+        }, delay)
+      }
+    }
+  }, [url, event_name, reconnect, reconnect_interval, max_reconnect_interval, on_event, on_error])
+
+  const close = useCallback(() => {
+    closedManuallyRef.current = true
+    clearReconnectTimer()
+    if (esRef.current) {
+      esRef.current.close()
+      esRef.current = null
+    }
+    setStatus('closed')
+  }, [])
+
+  useEffect(() => {
+    mountedRef.current = true
+
+    if (enabled) {
+      connect()
+    }
+
+    return () => {
+      mountedRef.current = false
+      clearReconnectTimer()
+      if (esRef.current) {
+        esRef.current.close()
+        esRef.current = null
+      }
+    }
+  }, [enabled, url]) // eslint-disable-line react-hooks/exhaustive-deps
+
+  return { data, last_event: lastEvent, status, error, close, connect }
+}
diff --git a/frontend/functions/core/use_websocket.md b/frontend/functions/core/use_websocket.md
new file mode 100644
index 00000000..5a72f0c3
--- /dev/null
+++ b/frontend/functions/core/use_websocket.md
@@ -0,0 +1,115 @@
+---
+name: use_websocket
+kind: component
+lang: ts
+domain: core
+version: "1.0.0"
+purity: impure
+signature: "useWebSocket<TSend, TRecv>(opts: UseWebSocketOptions<TSend, TRecv>): UseWebSocketResult<TSend, TRecv>"
+description: "Hook WebSocket con auto-reconexion y backoff exponencial. Serializa envios como JSON, parsea recepcion como JSON. Buffer de mensajes con limite configurable. Mensajes en vuelo se bufferean hasta reconectar."
+tags: [websocket, ws, hook, realtime, reconnect, stream, core, component]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: [react]
+params:
+  - name: url
+    desc: "URL del WebSocket (ej: ws://localhost:8484/ws/chat)"
+  - name: enabled
+    desc: "Si conecta automaticamente al montar (default true)"
+  - name: reconnect
+    desc: "Si reconecta automaticamente con backoff exponencial (default true)"
+  - name: reconnect_interval
+    desc: "Delay inicial de reconexion en ms (default 1000)"
+  - name: max_reconnect_interval
+    desc: "Delay maximo de reconexion en ms (default 30000)"
+  - name: max_messages
+    desc: "Numero maximo de mensajes a mantener en buffer (default 100)"
+  - name: on_message
+    desc: "Callback por cada mensaje recibido con el dato parseado"
+output: "Objeto con send, last_message, messages[], status (connecting/open/closing/closed), close() y connect()"
+tested: false
+tests: []
+test_file_path: ""
+file_path: "frontend/functions/core/use_websocket.tsx"
+props:
+  - name: url
+    type: "string"
+    required: true
+    description: "URL del WebSocket"
+  - name: enabled
+    type: "boolean"
+    required: false
+    description: "Conectar al montar (default true)"
+  - name: reconnect
+    type: "boolean"
+    required: false
+    description: "Auto-reconectar (default true)"
+  - name: reconnect_interval
+    type: "number"
+    required: false
+    description: "Delay inicial reconexion en ms (default 1000)"
+  - name: max_reconnect_interval
+    type: "number"
+    required: false
+    description: "Delay maximo reconexion en ms (default 30000)"
+  - name: max_messages
+    type: "number"
+    required: false
+    description: "Tamano del buffer de mensajes (default 100)"
+emits: [on_message, on_open, on_close, on_error]
+has_state: true
+framework: react
+variant: [default]
+---
+
+## Ejemplo
+
+```tsx
+import { useWebSocket } from '@/functions/core/use_websocket'
+
+interface ChatMessage { user: string; text: string; ts: number }
+interface SendMessage { text: string }
+
+function Chat() {
+  const { send, messages, status } = useWebSocket<SendMessage, ChatMessage>({
+    url: 'ws://localhost:8484/ws/chat',
+    reconnect: true,
+    max_messages: 50,
+  })
+
+  const [input, setInput] = useState('')
+
+  return (
+    <div>
+      <div>Status: {status}</div>
+      <div style={{ height: 300, overflow: 'auto' }}>
+        {messages.map((msg, i) => (
+          <div key={i}><b>{msg.user}:</b> {msg.text}</div>
+        ))}
+      </div>
+      <input
+        value={input}
+        disabled={status !== 'open'}
+        onChange={(e) => setInput(e.currentTarget.value)}
+        onKeyDown={(e) => {
+          if (e.key === 'Enter' && input.trim()) {
+            send({ text: input })
+            setInput('')
+          }
+        }}
+      />
+    </div>
+  )
+}
+```
+
+## Notas
+
+- Genericos separados: `TSend` para envio, `TRecv` para recepcion (pueden diferir)
+- Mensajes enviados antes de `open` se bufferean y envian al conectar
+- El buffer `messages` se limita a `max_messages` (FIFO, elimina el mas viejo)
+- El backoff exponencial duplica el delay hasta `max_reconnect_interval`
+- `close()` previene reconexion automatica; `connect()` fuerza reconexion manual
diff --git a/frontend/functions/core/use_websocket.tsx b/frontend/functions/core/use_websocket.tsx
new file mode 100644
index 00000000..e19c5b53
--- /dev/null
+++ b/frontend/functions/core/use_websocket.tsx
@@ -0,0 +1,198 @@
+import { useCallback, useEffect, useRef, useState } from 'react'
+
+export type WebSocketStatus = 'connecting' | 'open' | 'closing' | 'closed'
+
+export interface UseWebSocketOptions<TRecv> {
+  /** URL del WebSocket (ej: ws://localhost:8484/ws/chat) */
+  url: string
+  /** Si conecta automaticamente al montar (default true) */
+  enabled?: boolean
+  /** Si reconecta automaticamente al perder la conexion (default true) */
+  reconnect?: boolean
+  /** Delay inicial de reconexion en ms (default 1000) */
+  reconnect_interval?: number
+  /** Delay maximo de reconexion en ms (default 30000) */
+  max_reconnect_interval?: number
+  /** Numero maximo de mensajes a mantener en el buffer (default 100) */
+  max_messages?: number
+  /** Callback por cada mensaje recibido */
+  on_message?: (data: TRecv) => void
+  /** Callback al conectar */
+  on_open?: () => void
+  /** Callback al cerrar */
+  on_close?: (event: CloseEvent) => void
+  /** Callback al error */
+  on_error?: (error: Event) => void
+}
+
+export interface UseWebSocketResult<TSend, TRecv> {
+  /** Enviar un mensaje (serializado como JSON) */
+  send: (data: TSend) => void
+  /** Ultimo mensaje recibido */
+  last_message: TRecv | null
+  /** Buffer de mensajes recibidos (limitado a max_messages) */
+  messages: TRecv[]
+  /** Estado de la conexion */
+  status: WebSocketStatus
+  /** Cerrar la conexion manualmente */
+  close: () => void
+  /** Reconectar manualmente */
+  connect: () => void
+}
+
+/**
+ * Hook WebSocket con auto-reconexion y backoff exponencial.
+ * Serializa mensajes enviados como JSON. Parsea mensajes recibidos como JSON.
+ * Mantiene buffer de los ultimos N mensajes.
+ */
+export function useWebSocket<TSend, TRecv>(
+  opts: UseWebSocketOptions<TRecv>,
+): UseWebSocketResult<TSend, TRecv> {
+  const {
+    url,
+    enabled = true,
+    reconnect = true,
+    reconnect_interval = 1000,
+    max_reconnect_interval = 30_000,
+    max_messages = 100,
+    on_message,
+    on_open,
+    on_close,
+    on_error,
+  } = opts
+
+  const [messages, setMessages] = useState<TRecv[]>([])
+  const [lastMessage, setLastMessage] = useState<TRecv | null>(null)
+  const [status, setStatus] = useState<WebSocketStatus>('closed')
+
+  const wsRef = useRef<WebSocket | null>(null)
+  const reconnectTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null)
+  const currentIntervalRef = useRef(reconnect_interval)
+  const mountedRef = useRef(true)
+  const closedManuallyRef = useRef(false)
+  const pendingMessages = useRef<TSend[]>([])
+
+  const clearReconnectTimer = () => {
+    if (reconnectTimerRef.current !== null) {
+      clearTimeout(reconnectTimerRef.current)
+      reconnectTimerRef.current = null
+    }
+  }
+
+  const connect = useCallback(() => {
+    if (!mountedRef.current) return
+
+    if (wsRef.current) {
+      wsRef.current.close()
+      wsRef.current = null
+    }
+
+    closedManuallyRef.current = false
+    currentIntervalRef.current = reconnect_interval
+
+    setStatus('connecting')
+
+    const ws = new WebSocket(url)
+    wsRef.current = ws
+
+    ws.onopen = () => {
+      if (!mountedRef.current) return
+      setStatus('open')
+      currentIntervalRef.current = reconnect_interval
+      on_open?.()
+
+      // Enviar mensajes pendientes
+      for (const msg of pendingMessages.current) {
+        ws.send(JSON.stringify(msg))
+      }
+      pendingMessages.current = []
+    }
+
+    ws.onmessage = (e: MessageEvent) => {
+      if (!mountedRef.current) return
+
+      let parsed: TRecv
+      try {
+        parsed = JSON.parse(e.data as string) as TRecv
+      } catch {
+        parsed = e.data as unknown as TRecv
+      }
+
+      setLastMessage(parsed)
+      setMessages((prev: TRecv[]) => {
+        const next = [...prev, parsed]
+        return next.length > max_messages ? next.slice(next.length - max_messages) : next
+      })
+      on_message?.(parsed)
+    }
+
+    ws.onclose = (e) => {
+      if (!mountedRef.current) return
+      setStatus('closed')
+      wsRef.current = null
+      on_close?.(e)
+
+      if (reconnect && !closedManuallyRef.current) {
+        const delay = Math.min(currentIntervalRef.current, max_reconnect_interval)
+        currentIntervalRef.current = Math.min(delay * 2, max_reconnect_interval)
+
+        reconnectTimerRef.current = setTimeout(() => {
+          if (mountedRef.current && !closedManuallyRef.current) {
+            connect()
+          }
+        }, delay)
+      }
+    }
+
+    ws.onerror = (e) => {
+      if (!mountedRef.current) return
+      on_error?.(e)
+    }
+  }, [url, reconnect, reconnect_interval, max_reconnect_interval, max_messages, on_message, on_open, on_close, on_error])
+
+  const close = useCallback(() => {
+    closedManuallyRef.current = true
+    clearReconnectTimer()
+    if (wsRef.current) {
+      setStatus('closing')
+      wsRef.current.close()
+      wsRef.current = null
+    }
+    setStatus('closed')
+  }, [])
+
+  const send = useCallback((data: TSend) => {
+    if (wsRef.current?.readyState === WebSocket.OPEN) {
+      wsRef.current.send(JSON.stringify(data))
+    } else {
+      // Buffer el mensaje para enviarlo cuando conecte
+      pendingMessages.current.push(data)
+    }
+  }, [])
+
+  useEffect(() => {
+    mountedRef.current = true
+
+    if (enabled) {
+      connect()
+    }
+
+    return () => {
+      mountedRef.current = false
+      clearReconnectTimer()
+      if (wsRef.current) {
+        wsRef.current.close()
+        wsRef.current = null
+      }
+    }
+  }, [enabled, url]) // eslint-disable-line react-hooks/exhaustive-deps
+
+  return {
+    send,
+    last_message: lastMessage,
+    messages,
+    status,
+    close,
+    connect,
+  }
+}
diff --git a/frontend/types/core/api_client_config.md b/frontend/types/core/api_client_config.md
new file mode 100644
index 00000000..0f346e1f
--- /dev/null
+++ b/frontend/types/core/api_client_config.md
@@ -0,0 +1,43 @@
+---
+name: APIClientConfig
+lang: ts
+domain: core
+version: "1.0.0"
+algebraic: product
+definition: |
+  interface APIClientConfig {
+    base_url: string
+    headers?: Record<string, string>
+    on_error?: (error: Error, url: string, init?: RequestInit) => void
+    on_unauthorized?: () => void
+  }
+description: "Configuracion del cliente HTTP. Define base_url, headers fijos, callback de error global y callback de 401 Unauthorized."
+tags: [api, client, config, http, fetch, auth]
+uses_types: []
+file_path: "frontend/types/core/api_client_config.ts"
+---
+
+## Campos
+
+- `base_url` — prefijo de URL para todos los requests, sin slash final (ej: `"http://localhost:8484/api"`)
+- `headers` — headers HTTP fijos que se mergeaan en cada peticion (ej: `{ Authorization: 'Bearer ...' }`)
+- `on_error` — callback global llamado cuando cualquier peticion falla, recibe el error, la URL y el RequestInit
+- `on_unauthorized` — callback llamado cuando el servidor responde 401, tipicamente redirige al login
+
+## Uso
+
+```typescript
+import type { APIClientConfig } from '@/types/core/api_client_config'
+import { apiClient } from '@/functions/core/api_client'
+
+const config: APIClientConfig = {
+  base_url: 'http://localhost:8484/api',
+  headers: { 'X-Client': 'dashboard' },
+  on_unauthorized: () => (window.location.href = '/login'),
+}
+const api = apiClient(config)
+```
+
+## Notas
+
+Pasado como primer argumento a `api_client_ts_core`. Los interceptors `on_error` y `on_unauthorized` son globales — aplican a todos los metodos (get, post, put, del, patch) del cliente creado.
diff --git a/frontend/types/core/api_client_config.ts b/frontend/types/core/api_client_config.ts
new file mode 100644
index 00000000..c8d244a2
--- /dev/null
+++ b/frontend/types/core/api_client_config.ts
@@ -0,0 +1,11 @@
+/** Configuracion del cliente HTTP creado por api_client. */
+export interface APIClientConfig {
+  /** URL base para todas las peticiones (ej: "http://localhost:8484/api"). Sin slash final. */
+  base_url: string
+  /** Headers fijos que se incluyen en todas las peticiones */
+  headers?: Record<string, string>
+  /** Callback global de error — llamado en cualquier peticion fallida */
+  on_error?: (error: Error, url: string, init?: RequestInit) => void
+  /** Callback llamado cuando el servidor responde 401 Unauthorized */
+  on_unauthorized?: () => void
+}
diff --git a/frontend/types/core/fetch_state.md b/frontend/types/core/fetch_state.md
new file mode 100644
index 00000000..051910a2
--- /dev/null
+++ b/frontend/types/core/fetch_state.md
@@ -0,0 +1,41 @@
+---
+name: FetchState
+lang: ts
+domain: core
+version: "1.0.0"
+algebraic: product
+definition: |
+  interface FetchState<T> {
+    data: T | null
+    error: Error | null
+    loading: boolean
+    refetch: () => Promise<T>
+    is_stale: boolean
+  }
+description: "Estado de un fetch GET con cache stale-while-revalidate. Incluye datos, error, loading, refetch y flag de staleness."
+tags: [fetch, state, http, cache, swr, hook]
+uses_types: []
+file_path: "frontend/types/core/fetch_state.ts"
+---
+
+## Campos
+
+- `data` — datos obtenidos, null hasta que llega la primera respuesta
+- `error` — error de red o de parsing, null si no hubo error
+- `loading` — true mientras hay una peticion en vuelo
+- `refetch` — funcion para re-ejecutar la peticion manualmente
+- `is_stale` — true cuando se muestran datos del cache mientras se refetchea en background
+
+## Uso
+
+```typescript
+import type { FetchState } from '@/types/core/fetch_state'
+
+function useMyHook(): FetchState<User[]> {
+  // ...
+}
+```
+
+## Notas
+
+Retornado por `use_fetch_ts_core`. El patron stale-while-revalidate permite mostrar datos viejos inmediatamente mientras se actualizan en background, mejorando la UX percibida.
diff --git a/frontend/types/core/fetch_state.ts b/frontend/types/core/fetch_state.ts
new file mode 100644
index 00000000..2acd8c40
--- /dev/null
+++ b/frontend/types/core/fetch_state.ts
@@ -0,0 +1,13 @@
+/** Estado de un fetch GET con cache stale-while-revalidate. */
+export interface FetchState<T> {
+  /** Datos obtenidos, null si todavia no se han cargado */
+  data: T | null
+  /** Error si la peticion fallo */
+  error: Error | null
+  /** Si la peticion esta en progreso */
+  loading: boolean
+  /** Re-ejecutar la peticion manualmente */
+  refetch: () => Promise<T>
+  /** Si los datos son stale (cache viejo mostrando mientras refetch en background) */
+  is_stale: boolean
+}
diff --git a/frontend/types/core/form_state.md b/frontend/types/core/form_state.md
new file mode 100644
index 00000000..82de44c7
--- /dev/null
+++ b/frontend/types/core/form_state.md
@@ -0,0 +1,43 @@
+---
+name: FormState
+lang: ts
+domain: core
+version: "1.0.0"
+algebraic: product
+definition: |
+  interface FormState<T extends Record<string, unknown>> {
+    values: T
+    errors: Partial<Record<keyof T, string>>
+    touched: Partial<Record<keyof T, boolean>>
+    is_valid: boolean
+    is_submitting: boolean
+  }
+description: "Estado de un formulario con validacion sincrona, tracking de touched y flag de submit en progreso."
+tags: [form, state, validation, touched, hook]
+uses_types: []
+file_path: "frontend/types/core/form_state.ts"
+---
+
+## Campos
+
+- `values` — valores actuales del formulario, tipados con el generico T
+- `errors` — errores de validacion por campo (string con mensaje), undefined si el campo es valido
+- `touched` — true por campo cuando el usuario lo ha modificado (util para mostrar errores solo al tocar)
+- `is_valid` — true cuando no hay ningun error de validacion en ningun campo
+- `is_submitting` — true mientras el handler de submit esta en ejecucion
+
+## Uso
+
+```typescript
+import type { FormState } from '@/types/core/form_state'
+
+interface LoginForm { email: string; password: string }
+
+function LoginPage() {
+  const form: FormState<LoginForm> = useForm({ initial_values: { email: '', password: '' } })
+}
+```
+
+## Notas
+
+Retornado por `use_form_ts_core`. El generico `T extends Record<string, unknown>` permite tipado completo de los campos y sus errores. Para formularios complejos con validacion async o arrays de campos, usar `@mantine/form` directamente.
diff --git a/frontend/types/core/form_state.ts b/frontend/types/core/form_state.ts
new file mode 100644
index 00000000..f9c63328
--- /dev/null
+++ b/frontend/types/core/form_state.ts
@@ -0,0 +1,13 @@
+/** Estado de un formulario con validacion sincrona. */
+export interface FormState<T extends Record<string, unknown>> {
+  /** Valores actuales del formulario */
+  values: T
+  /** Errores por campo (undefined si el campo no tiene error) */
+  errors: Partial<Record<keyof T, string>>
+  /** Campos que el usuario ha modificado al menos una vez */
+  touched: Partial<Record<keyof T, boolean>>
+  /** Si todos los campos pasan la validacion */
+  is_valid: boolean
+  /** Si el submit esta en progreso */
+  is_submitting: boolean
+}
diff --git a/frontend/types/core/mutation_state.md b/frontend/types/core/mutation_state.md
new file mode 100644
index 00000000..5e35940c
--- /dev/null
+++ b/frontend/types/core/mutation_state.md
@@ -0,0 +1,43 @@
+---
+name: MutationState
+lang: ts
+domain: core
+version: "1.0.0"
+algebraic: product
+definition: |
+  interface MutationState<TData, TVariables> {
+    mutate: (variables: TVariables) => void
+    mutate_async: (variables: TVariables) => Promise<TData>
+    data: TData | null
+    error: Error | null
+    loading: boolean
+    reset: () => void
+  }
+description: "Estado de una mutacion POST/PUT/DELETE. Expone mutate, mutate_async, data, error, loading y reset."
+tags: [mutation, state, http, post, put, delete, hook]
+uses_types: []
+file_path: "frontend/types/core/mutation_state.ts"
+---
+
+## Campos
+
+- `mutate` — ejecutar la mutacion de forma fire-and-forget (no lanza excepciones)
+- `mutate_async` — ejecutar la mutacion y obtener una Promise (puede rechazar)
+- `data` — resultado de la ultima mutacion exitosa, null si aun no hubo exito
+- `error` — error de la ultima mutacion fallida, null si fue exitosa o no se ha ejecutado
+- `loading` — true mientras la mutacion esta en vuelo
+- `reset` — volver al estado inicial (idle, data null, error null)
+
+## Uso
+
+```typescript
+import type { MutationState } from '@/types/core/mutation_state'
+
+function useCreateUser(): MutationState<User, CreateUserInput> {
+  // ...
+}
+```
+
+## Notas
+
+Retornado por `use_mutation_ts_core`. El patron `mutate` / `mutate_async` permite usar el hook tanto en event handlers (sin async/await) como en funciones que necesitan esperar el resultado.
diff --git a/frontend/types/core/mutation_state.ts b/frontend/types/core/mutation_state.ts
new file mode 100644
index 00000000..ec46136f
--- /dev/null
+++ b/frontend/types/core/mutation_state.ts
@@ -0,0 +1,15 @@
+/** Estado de una mutacion POST/PUT/DELETE. */
+export interface MutationState<TData, TVariables> {
+  /** Ejecutar la mutacion (fire-and-forget) */
+  mutate: (variables: TVariables) => void
+  /** Ejecutar la mutacion y esperar el resultado */
+  mutate_async: (variables: TVariables) => Promise<TData>
+  /** Datos del resultado de la ultima mutacion exitosa */
+  data: TData | null
+  /** Error si la ultima mutacion fallo */
+  error: Error | null
+  /** Si hay una mutacion en progreso */
+  loading: boolean
+  /** Resetear al estado inicial (idle) */
+  reset: () => void
+}