From a04116d41f41640a7d1060e3d0a69ae6a6a3c03a Mon Sep 17 00:00:00 2001
From: Jakub Zych <jakub@keios.eu>
Date: Tue, 6 Oct 2026 12:32:54 +0200
Subject: [PATCH] feat(14.2.1-03): add markdown and multilingual cabana fields

Lift locale maps before ProjectWritableFields so a Journal-shaped save can persist the default host scalar and non-default locales through TranslationWriter without dropping nested JSON.

Co-authored-by: Cursor <cursoragent@cursor.com>
---
 .../form/fields/MLMarkdownField.vue           | 109 ++++++++
 .../components/form/fields/MLTextField.vue    | 108 ++++++++
 .../components/form/fields/MarkdownField.vue  |  51 ++++
 admin/src/components/form/formState.ts        |   9 +
 admin/src/components/form/mlLocale.ts         |  24 ++
 admin/src/components/form/registry.ts         |   8 +-
 admin/tests/form/MLFields.test.ts             |  95 +++++++
 modules/cabana/crud.go                        |  18 +-
 modules/cabana/field_markdown.go              |  46 +++
 modules/cabana/field_ml.go                    | 160 +++++++++++
 modules/cabana/form_schema.go                 |   1 +
 modules/cabana/http.go                        |   8 +-
 modules/cabana/ml_smoke_test.go               | 261 ++++++++++++++++++
 13 files changed, 895 insertions(+), 3 deletions(-)
 create mode 100644 admin/src/components/form/fields/MLMarkdownField.vue
 create mode 100644 admin/src/components/form/fields/MLTextField.vue
 create mode 100644 admin/src/components/form/fields/MarkdownField.vue
 create mode 100644 admin/src/components/form/mlLocale.ts
 create mode 100644 admin/tests/form/MLFields.test.ts
 create mode 100644 modules/cabana/field_markdown.go
 create mode 100644 modules/cabana/field_ml.go
 create mode 100644 modules/cabana/ml_smoke_test.go

diff --git a/admin/src/components/form/fields/MLMarkdownField.vue b/admin/src/components/form/fields/MLMarkdownField.vue
new file mode 100644
index 0000000..b32ed8f
--- /dev/null
+++ b/admin/src/components/form/fields/MLMarkdownField.vue
@@ -0,0 +1,109 @@
+<script setup lang="ts">
+import { computed, onMounted, onUnmounted, ref } from 'vue'
+import type { FieldControlProps } from '../control'
+import MarkdownField from './MarkdownField.vue'
+import { ML_LOCALE_CHANGE, broadcastMLLocale, localeRecord } from '../mlLocale'
+
+const props = defineProps<FieldControlProps>()
+const emit = defineEmits<{ 'update:modelValue': [value: Record<string, string>] }>()
+
+const values = computed(() => localeRecord(props.modelValue))
+const locales = computed(() => {
+  const keys = Object.keys(values.value)
+  return keys.length > 0 ? keys : ['en']
+})
+const activeLocale = ref(locales.value[0] ?? 'en')
+const copyFrom = ref('')
+
+const labelledBy = computed(() => `${props.controlId}-label`)
+const editorId = computed(() => `${props.controlId}-editor`)
+const activeText = computed(() => values.value[activeLocale.value] ?? '')
+const otherLocales = computed(() => locales.value.filter((code) => code !== activeLocale.value))
+const markdownField = computed(() => ({ ...props.field, type: 'markdown' }))
+
+function setLocale(locale: string) {
+  if (!locale) {
+    return
+  }
+  activeLocale.value = locale
+  if (!copyFrom.value || copyFrom.value === locale) {
+    copyFrom.value = otherLocales.value[0] ?? ''
+  }
+}
+
+function onLocaleInput(event: Event) {
+  const locale = (event.target as HTMLSelectElement).value
+  setLocale(locale)
+  broadcastMLLocale(locale)
+}
+
+function onText(text: string) {
+  emit('update:modelValue', { ...values.value, [activeLocale.value]: text })
+}
+
+function copyLocale() {
+  const from = copyFrom.value
+  if (!from || from === activeLocale.value) {
+    return
+  }
+  emit('update:modelValue', { ...values.value, [activeLocale.value]: values.value[from] ?? '' })
+}
+
+function onBroadcast(event: Event) {
+  const locale = (event as CustomEvent<string>).detail
+  if (typeof locale === 'string' && locale !== '') {
+    setLocale(locale)
+  }
+}
+
+onMounted(() => {
+  window.addEventListener(ML_LOCALE_CHANGE, onBroadcast)
+  copyFrom.value = otherLocales.value[0] ?? ''
+})
+onUnmounted(() => {
+  window.removeEventListener(ML_LOCALE_CHANGE, onBroadcast)
+})
+</script>
+
+<template>
+  <div class="flex flex-col gap-1.5" role="group" :aria-labelledby="labelledBy" data-ml-field="mlmarkdown">
+    <div class="flex flex-wrap items-center gap-2">
+      <select
+        data-ml-locale
+        class="rounded-control border border-border-strong bg-surface px-2 py-1 text-[13px]"
+        :value="activeLocale"
+        :aria-label="`Locale for ${field.label || field.name}`"
+        @change="onLocaleInput"
+      >
+        <option v-for="code in locales" :key="code" :value="code">{{ code }}</option>
+      </select>
+      <select
+        v-if="otherLocales.length > 0"
+        data-ml-copy-from
+        class="rounded-control border border-border-strong bg-surface px-2 py-1 text-[13px]"
+        :value="copyFrom"
+        aria-label="Copy from locale"
+        @change="copyFrom = ($event.target as HTMLSelectElement).value"
+      >
+        <option v-for="code in otherLocales" :key="code" :value="code">{{ code }}</option>
+      </select>
+      <button
+        v-if="otherLocales.length > 0"
+        type="button"
+        data-ml-copy
+        class="rounded-pager px-2 py-1 text-[13px] text-muted hover:bg-hover hover:text-text"
+        @click="copyLocale"
+      >
+        Copy
+      </button>
+    </div>
+    <MarkdownField
+      :field="markdownField"
+      :model-value="activeText"
+      :control-id="editorId"
+      :invalid="invalid"
+      :described-by="describedBy"
+      @update:model-value="onText"
+    />
+  </div>
+</template>
diff --git a/admin/src/components/form/fields/MLTextField.vue b/admin/src/components/form/fields/MLTextField.vue
new file mode 100644
index 0000000..a514374
--- /dev/null
+++ b/admin/src/components/form/fields/MLTextField.vue
@@ -0,0 +1,108 @@
+<script setup lang="ts">
+import { computed, onMounted, onUnmounted, ref } from 'vue'
+import type { FieldControlProps } from '../control'
+import TextField from './TextField.vue'
+import { ML_LOCALE_CHANGE, broadcastMLLocale, localeRecord } from '../mlLocale'
+
+const props = defineProps<FieldControlProps>()
+const emit = defineEmits<{ 'update:modelValue': [value: Record<string, string>] }>()
+
+const values = computed(() => localeRecord(props.modelValue))
+const locales = computed(() => {
+  const keys = Object.keys(values.value)
+  return keys.length > 0 ? keys : ['en']
+})
+const activeLocale = ref(locales.value[0] ?? 'en')
+const copyFrom = ref('')
+
+const labelledBy = computed(() => `${props.controlId}-label`)
+const editorId = computed(() => `${props.controlId}-editor`)
+const activeText = computed(() => values.value[activeLocale.value] ?? '')
+const otherLocales = computed(() => locales.value.filter((code) => code !== activeLocale.value))
+
+function setLocale(locale: string) {
+  if (!locale) {
+    return
+  }
+  activeLocale.value = locale
+  if (!copyFrom.value || copyFrom.value === locale) {
+    copyFrom.value = otherLocales.value[0] ?? ''
+  }
+}
+
+function onLocaleInput(event: Event) {
+  const locale = (event.target as HTMLSelectElement).value
+  setLocale(locale)
+  broadcastMLLocale(locale)
+}
+
+function onText(text: string) {
+  emit('update:modelValue', { ...values.value, [activeLocale.value]: text })
+}
+
+function copyLocale() {
+  const from = copyFrom.value
+  if (!from || from === activeLocale.value) {
+    return
+  }
+  emit('update:modelValue', { ...values.value, [activeLocale.value]: values.value[from] ?? '' })
+}
+
+function onBroadcast(event: Event) {
+  const locale = (event as CustomEvent<string>).detail
+  if (typeof locale === 'string' && locale !== '') {
+    setLocale(locale)
+  }
+}
+
+onMounted(() => {
+  window.addEventListener(ML_LOCALE_CHANGE, onBroadcast)
+  copyFrom.value = otherLocales.value[0] ?? ''
+})
+onUnmounted(() => {
+  window.removeEventListener(ML_LOCALE_CHANGE, onBroadcast)
+})
+</script>
+
+<template>
+  <div class="flex flex-col gap-1.5" role="group" :aria-labelledby="labelledBy" data-ml-field="mltext">
+    <div class="flex flex-wrap items-center gap-2">
+      <select
+        data-ml-locale
+        class="rounded-control border border-border-strong bg-surface px-2 py-1 text-[13px]"
+        :value="activeLocale"
+        :aria-label="`Locale for ${field.label || field.name}`"
+        @change="onLocaleInput"
+      >
+        <option v-for="code in locales" :key="code" :value="code">{{ code }}</option>
+      </select>
+      <select
+        v-if="otherLocales.length > 0"
+        data-ml-copy-from
+        class="rounded-control border border-border-strong bg-surface px-2 py-1 text-[13px]"
+        :value="copyFrom"
+        aria-label="Copy from locale"
+        @change="copyFrom = ($event.target as HTMLSelectElement).value"
+      >
+        <option v-for="code in otherLocales" :key="code" :value="code">{{ code }}</option>
+      </select>
+      <button
+        v-if="otherLocales.length > 0"
+        type="button"
+        data-ml-copy
+        class="rounded-pager px-2 py-1 text-[13px] text-muted hover:bg-hover hover:text-text"
+        @click="copyLocale"
+      >
+        Copy
+      </button>
+    </div>
+    <TextField
+      :field="{ ...field, type: 'text' }"
+      :model-value="activeText"
+      :control-id="editorId"
+      :invalid="invalid"
+      :described-by="describedBy"
+      @update:model-value="onText"
+    />
+  </div>
+</template>
diff --git a/admin/src/components/form/fields/MarkdownField.vue b/admin/src/components/form/fields/MarkdownField.vue
new file mode 100644
index 0000000..010c552
--- /dev/null
+++ b/admin/src/components/form/fields/MarkdownField.vue
@@ -0,0 +1,51 @@
+<script setup lang="ts">
+import { computed, ref } from 'vue'
+import { controlAttributes, controlClass, type FieldControlProps } from '../control'
+
+// Source editor for type: markdown. Preview interpolates text (never v-html)
+// so translated raw HTML/script cannot execute in the admin SPA. Server
+// preview uses cabana.RenderMarkdown (goldmark without html.WithUnsafe).
+const props = defineProps<FieldControlProps>()
+const emit = defineEmits<{ 'update:modelValue': [value: string] }>()
+
+const rowsBySize: Record<string, number> = { tiny: 2, small: 4, large: 8, huge: 12, giant: 18 }
+const rows = computed(() => rowsBySize[props.field.size ?? ''] ?? 8)
+const text = computed(() => (props.modelValue === null || props.modelValue === undefined ? '' : String(props.modelValue)))
+const attrs = computed(() => controlAttributes(props.field))
+const preview = ref(false)
+</script>
+
+<template>
+  <div class="flex flex-col gap-1.5">
+    <button
+      type="button"
+      data-markdown-preview
+      class="self-start rounded-pager px-2 py-1 text-[13px] text-muted hover:bg-hover hover:text-text"
+      :aria-pressed="preview ? 'true' : 'false'"
+      @click="preview = !preview"
+    >
+      Preview
+    </button>
+    <pre
+      v-if="preview"
+      data-markdown-preview-pane
+      :class="controlClass(invalid)"
+      class="min-h-input overflow-auto px-3.5 py-2.5 whitespace-pre-wrap"
+    >{{ text }}</pre>
+    <textarea
+      v-else
+      :id="controlId"
+      v-bind="attrs"
+      :name="field.name"
+      :rows="rows"
+      :value="text"
+      :required="field.required || undefined"
+      :aria-required="field.required ? 'true' : undefined"
+      :aria-invalid="invalid ? 'true' : undefined"
+      :aria-describedby="describedBy || undefined"
+      :class="controlClass(invalid)"
+      class="min-h-input resize-y py-2.5"
+      @input="emit('update:modelValue', ($event.target as HTMLTextAreaElement).value)"
+    />
+  </div>
+</template>
diff --git a/admin/src/components/form/formState.ts b/admin/src/components/form/formState.ts
index 0f841ae..2635d9b 100644
--- a/admin/src/components/form/formState.ts
+++ b/admin/src/components/form/formState.ts
@@ -2,8 +2,11 @@
 // filtering, the save payload, 422 detail mapping and focus.
 import type { AdminRecord, ErrorBody, FormField } from '../../api/types'
 import { permissionValues } from './control'
+import { localeRecord } from './mlLocale'
 import { isRegistered } from './registry'
 
+export { ML_LOCALE_CHANGE, broadcastMLLocale, localeRecord } from './mlLocale'
+
 /** The screen a field is filtered for: the two form modes and the read-only preview (D-11). */
 export type FormMode = 'create' | 'update' | 'preview'
 
@@ -62,6 +65,10 @@ export function editablePayload(fields: FormField[], values: AdminRecord, mode:
       out[field.name] = permissionValues(field, value)
       continue
     }
+    if (field.type === 'mltext' || field.type === 'mlmarkdown') {
+      out[field.name] = localeRecord(value)
+      continue
+    }
     if (value !== undefined) {
       out[field.name] = value
     }
@@ -95,6 +102,8 @@ export function initialValues(fields: FormField[]): AdminRecord {
       out[field.name] = false
     } else if (field.type === 'relation' && field.multiple) {
       out[field.name] = []
+    } else if (field.type === 'mltext' || field.type === 'mlmarkdown') {
+      out[field.name] = {}
     }
   }
   return out
diff --git a/admin/src/components/form/mlLocale.ts b/admin/src/components/form/mlLocale.ts
new file mode 100644
index 0000000..7071d44
--- /dev/null
+++ b/admin/src/components/form/mlLocale.ts
@@ -0,0 +1,24 @@
+/** Window event that keeps every ML control on one active locale. */
+export const ML_LOCALE_CHANGE = 'summer:ml-locale'
+
+/** Broadcast the locale the administrator selected on any ML control. */
+export function broadcastMLLocale(locale: string): void {
+  if (typeof window === 'undefined' || locale === '') {
+    return
+  }
+  window.dispatchEvent(new CustomEvent(ML_LOCALE_CHANGE, { detail: locale }))
+}
+
+/** Locale → text map as it is sent on save: only string values. */
+export function localeRecord(value: unknown): Record<string, string> {
+  const out: Record<string, string> = {}
+  if (value === null || typeof value !== 'object' || Array.isArray(value)) {
+    return out
+  }
+  for (const [locale, text] of Object.entries(value as Record<string, unknown>)) {
+    if (typeof text === 'string') {
+      out[locale] = text
+    }
+  }
+  return out
+}
diff --git a/admin/src/components/form/registry.ts b/admin/src/components/form/registry.ts
index a3a8a27..429058b 100644
--- a/admin/src/components/form/registry.ts
+++ b/admin/src/components/form/registry.ts
@@ -28,6 +28,9 @@ import RelationField from './fields/RelationField.vue'
 import SwitchField from './fields/SwitchField.vue'
 import TextField from './fields/TextField.vue'
 import TextareaField from './fields/TextareaField.vue'
+import MarkdownField from './fields/MarkdownField.vue'
+import MLTextField from './fields/MLTextField.vue'
+import MLMarkdownField from './fields/MLMarkdownField.vue'
 import UnsupportedField from './fields/UnsupportedField.vue'
 import WidgetField from './fields/WidgetField.vue'
 
@@ -60,6 +63,9 @@ const renderers = new Map<string, Component>([
   ['datepicker', DatepickerField],
   ['password', PasswordField],
   ['permissioneditor', PermissionEditorField],
+  ['markdown', MarkdownField],
+  ['mltext', MLTextField],
+  ['mlmarkdown', MLMarkdownField],
 ])
 
 /** Types whose control shows the label itself (toggle cards, relation manager). */
@@ -79,7 +85,7 @@ const valueless = new Set<string>([RELATION_MANAGER, 'widget', 'partial', 'fileu
  * Types whose control is a group rather than one focusable element: the
  * visible label is a span the group points at, not a label for an input.
  */
-const groupLabelledTypes = new Set<string>(['widget', 'partial', 'fileupload', 'permissioneditor'])
+const groupLabelledTypes = new Set<string>(['widget', 'partial', 'fileupload', 'permissioneditor', 'mltext', 'mlmarkdown'])
 
 export function rendererFor(type: string): Component {
   return renderers.get(type) ?? lazyRenderers.get(type)?.() ?? UnsupportedField
diff --git a/admin/tests/form/MLFields.test.ts b/admin/tests/form/MLFields.test.ts
new file mode 100644
index 0000000..0c9a02f
--- /dev/null
+++ b/admin/tests/form/MLFields.test.ts
@@ -0,0 +1,95 @@
+import { afterEach, beforeEach, describe, expect, it } from 'vitest'
+import { enableAutoUnmount, mount } from '@vue/test-utils'
+import type { FormField } from '../../src/api/types'
+import MarkdownField from '../../src/components/form/fields/MarkdownField.vue'
+import MLMarkdownField from '../../src/components/form/fields/MLMarkdownField.vue'
+import MLTextField from '../../src/components/form/fields/MLTextField.vue'
+import { editablePayload } from '../../src/components/form/formState'
+import { isRegistered, rendererFor } from '../../src/components/form/registry'
+import { resetState } from '../helpers'
+
+function field(type: string, name = 'title'): FormField {
+  return { name, label: 'Title', type } as FormField
+}
+
+beforeEach(() => {
+  resetState()
+})
+
+afterEach(() => {
+  document.body.innerHTML = ''
+})
+
+enableAutoUnmount(afterEach)
+
+describe('ML field registry and nested save body', () => {
+  it('resolves markdown, mltext and mlmarkdown', () => {
+    expect(rendererFor('markdown')).toBe(MarkdownField)
+    expect(rendererFor('mltext')).toBe(MLTextField)
+    expect(rendererFor('mlmarkdown')).toBe(MLMarkdownField)
+    expect(isRegistered('markdown')).toBe(true)
+    expect(isRegistered('mltext')).toBe(true)
+    expect(isRegistered('mlmarkdown')).toBe(true)
+  })
+
+  it('sends every locale as a nested record', () => {
+    const fields = [field('mltext'), field('mlmarkdown', 'body')]
+    const payload = editablePayload(fields, {
+      title: { en: 'Hello', pl: 'Witaj' },
+      body: { en: '# Hi', pl: '# Cześć' },
+    })
+    expect(payload).toEqual({
+      title: { en: 'Hello', pl: 'Witaj' },
+      body: { en: '# Hi', pl: '# Cześć' },
+    })
+  })
+
+  it('edits the active locale and copies from another', async () => {
+    const wrapper = mount(MLTextField, {
+      props: {
+        field: field('mltext'),
+        modelValue: { en: 'Hello', pl: 'Witaj' },
+        controlId: 'f-title',
+      },
+      attachTo: document.body,
+    })
+    const input = wrapper.find('input')
+    expect(input.element.value).toBe('Hello')
+    await wrapper.find('[data-ml-locale]').setValue('pl')
+    expect(wrapper.find('input').element.value).toBe('Witaj')
+    await wrapper.find('[data-ml-copy-from]').setValue('en')
+    await wrapper.find('[data-ml-copy]').trigger('click')
+    expect(wrapper.emitted('update:modelValue')?.at(-1)).toEqual([{ en: 'Hello', pl: 'Hello' }])
+  })
+
+  it('switches every ML control from one selector', async () => {
+    const title = mount(MLTextField, {
+      props: { field: field('mltext'), modelValue: { en: 'Hello', pl: 'Witaj' }, controlId: 'f-title' },
+      attachTo: document.body,
+    })
+    const body = mount(MLMarkdownField, {
+      props: { field: field('mlmarkdown', 'body'), modelValue: { en: 'EN', pl: 'PL' }, controlId: 'f-body' },
+      attachTo: document.body,
+    })
+    expect(body.findComponent(MarkdownField).exists()).toBe(true)
+    await title.find('[data-ml-locale]').setValue('pl')
+    expect((body.find('[data-ml-locale]').element as HTMLSelectElement).value).toBe('pl')
+    expect(body.find('textarea').element.value).toBe('PL')
+  })
+
+  it('does not execute raw HTML in the markdown preview', async () => {
+    const wrapper = mount(MarkdownField, {
+      props: {
+        field: field('markdown', 'body'),
+        modelValue: '<script>window.__ml_xss = 1</script><img src=x onerror="window.__ml_xss = 1">',
+        controlId: 'f-body',
+      },
+      attachTo: document.body,
+    })
+    await wrapper.find('[data-markdown-preview]').trigger('click')
+    expect(wrapper.find('script').exists()).toBe(false)
+    expect(wrapper.find('img').exists()).toBe(false)
+    expect((window as unknown as { __ml_xss?: number }).__ml_xss).toBeUndefined()
+    expect(wrapper.find('[data-markdown-preview-pane]').text()).toContain('<script>')
+  })
+})
diff --git a/modules/cabana/crud.go b/modules/cabana/crud.go
index b891035..a30d93f 100644
--- a/modules/cabana/crud.go
+++ b/modules/cabana/crud.go
@@ -30,6 +30,9 @@ type CRUDService struct {
 	// commit; tr localizes the file limit messages. Both may be nil.
 	bucket *blob.Bucket
 	tr     *phrasebook.Translator
+	// writer persists non-default locale values for mltext/mlmarkdown fields.
+	// Nil when the translate plugin is not mounted.
+	writer TranslationWriter
 }
 
 // RecordInput is a decoded JSON object. Keys are untrusted. SessionKey is
@@ -588,6 +591,13 @@ func (s CRUDService) save(ctx context.Context, cc *CompiledController, id any, i
 	if err != nil {
 		return RecordResult{}, err
 	}
+	// ML locale maps are lifted before scalar projection, which drops every
+	// nested value. The default-locale string is written back onto the body
+	// so Fill sees a host scalar.
+	translations, err := liftMLValues(ctx, cc, in.Body, op, s.writer, s.DB)
+	if err != nil {
+		return RecordResult{}, err
+	}
 	var result RecordResult
 	err = s.transaction(ctx, func(ctx context.Context, tx *gorm.DB) error {
 		ctx = withVirtualFields(withTx(ctx, tx), virtual)
@@ -670,6 +680,11 @@ func (s CRUDService) save(ctx context.Context, cc *CompiledController, id any, i
 		if err != nil {
 			return lifecycleFailure(cc, err)
 		}
+		// Non-default locales are written only after the host row has an id
+		// and after permission, query scope, and relation locks have passed.
+		if err := applyMLTranslations(ctx, tx, s.writer, target, translations); err != nil {
+			return err
+		}
 		if err := syncBelongsToMany(ctx, tx, cc, target, relations); err != nil {
 			return err
 		}
@@ -1202,7 +1217,8 @@ func modelColumns(model any) map[string]struct{} {
 
 func scalarFormField(typ string) bool {
 	switch typ {
-	case "text", "textarea", "number", "checkbox", "switch", "dropdown", "datepicker":
+	case "text", "textarea", "number", "checkbox", "switch", "dropdown", "datepicker",
+		"markdown", "mltext", "mlmarkdown":
 		return true
 	default:
 		return false
diff --git a/modules/cabana/field_markdown.go b/modules/cabana/field_markdown.go
new file mode 100644
index 0000000..e8e9ff7
--- /dev/null
+++ b/modules/cabana/field_markdown.go
@@ -0,0 +1,46 @@
+package cabana
+
+import (
+	"bytes"
+	"fmt"
+	"regexp"
+
+	"github.com/yuin/goldmark"
+)
+
+var (
+	markdownEngine = goldmark.New()
+
+	markdownUnsafeTag    = regexp.MustCompile(`(?i)<(?:script|iframe|object|embed)\b`)
+	markdownEventHandler = regexp.MustCompile(`(?i)\son[a-z]+\s*=`)
+	markdownDangerousURL = regexp.MustCompile(`(?i)(?:javascript|vbscript|data):`)
+)
+
+// RenderMarkdown converts source to HTML using the pinned goldmark engine
+// without html.WithUnsafe. Output that still contains script/iframe tags,
+// event handlers, or javascript/vbscript/data URLs is rejected, matching
+// postcard's mail HTML gate.
+func RenderMarkdown(src string) (string, error) {
+	var buf bytes.Buffer
+	if err := markdownEngine.Convert([]byte(src), &buf); err != nil {
+		return "", fmt.Errorf("cabana: markdown: %w", err)
+	}
+	html := buf.String()
+	if err := rejectUnsafeMarkdownHTML(html); err != nil {
+		return "", err
+	}
+	return html, nil
+}
+
+func rejectUnsafeMarkdownHTML(html string) error {
+	if markdownUnsafeTag.MatchString(html) {
+		return fmt.Errorf("cabana: rendered HTML contains raw unsafe tags")
+	}
+	if markdownEventHandler.MatchString(html) {
+		return fmt.Errorf("cabana: rendered HTML contains event handlers")
+	}
+	if markdownDangerousURL.MatchString(html) {
+		return fmt.Errorf("cabana: rendered HTML contains a dangerous URL scheme")
+	}
+	return nil
+}
diff --git a/modules/cabana/field_ml.go b/modules/cabana/field_ml.go
new file mode 100644
index 0000000..df5c362
--- /dev/null
+++ b/modules/cabana/field_ml.go
@@ -0,0 +1,160 @@
+package cabana
+
+import (
+	"context"
+	"fmt"
+
+	"gorm.io/gorm"
+)
+
+const (
+	mlTextFieldType     = "mltext"
+	mlMarkdownFieldType = "mlmarkdown"
+)
+
+// TranslationWriter persists non-default locale values during a cabana save.
+// The interface lives in the framework so cabana never imports a plugin; a
+// host publishes an adapter at Boot. There is no standalone translate-write
+// HTTP endpoint: writes run only inside a permissioned, scoped host save
+// transaction after the host row has a primary key.
+type TranslationWriter interface {
+	// DefaultLocale is the host-column locale.
+	DefaultLocale(ctx context.Context, tx *gorm.DB) (string, error)
+	// EnabledLocales are the codes a save body may name, including the default.
+	EnabledLocales(ctx context.Context, tx *gorm.DB) ([]string, error)
+	// WriteTranslated stores field in locale for model. locale is never the
+	// default; cabana already filled the host scalar.
+	WriteTranslated(ctx context.Context, tx *gorm.DB, model any, field, locale, value string) error
+}
+
+// mlValue is one multilingual field lifted from a save body.
+type mlValue struct {
+	field  string
+	values map[string]string
+}
+
+func mlFieldType(typ string) bool {
+	return typ == mlTextFieldType || typ == mlMarkdownFieldType
+}
+
+// liftMLValues takes declared mltext/mlmarkdown maps out of a save body
+// before ProjectWritableFields drops nested values. Only fields present in
+// the body whose context allows op are lifted. A value must be a JSON object
+// of enabled locale code to string; unknown locales, extra keys, and
+// non-string values are validation_failed on the field. The default-locale
+// string is written back onto body so Fill sees a host scalar.
+func liftMLValues(ctx context.Context, cc *CompiledController, body map[string]any, op string, writer TranslationWriter, db *gorm.DB) ([]mlValue, error) {
+	if cc == nil || cc.Form == nil || body == nil {
+		return nil, nil
+	}
+	var names []string
+	for _, field := range cc.Form.Fields {
+		if !mlFieldType(field.Type) || !contextAllows(cc, field.Name, op) {
+			continue
+		}
+		if _, present := body[field.Name]; present {
+			names = append(names, field.Name)
+		}
+	}
+	if len(names) == 0 {
+		return nil, nil
+	}
+	details := map[string]any{}
+	needWriter := false
+	for _, name := range names {
+		if _, isMap := body[name].(map[string]any); isMap {
+			needWriter = true
+			break
+		}
+	}
+	var (
+		defaultLocale string
+		enabled       map[string]struct{}
+	)
+	if needWriter {
+		if writer == nil {
+			for _, name := range names {
+				if _, isMap := body[name].(map[string]any); isMap {
+					details[name] = []string{"The " + name + " field cannot be translated."}
+				}
+			}
+			return nil, &ValidationError{Details: details}
+		}
+		code, err := writer.DefaultLocale(ctx, db)
+		if err != nil || code == "" {
+			return nil, fmt.Errorf("cabana: default locale: %w", err)
+		}
+		defaultLocale = code
+		codes, err := writer.EnabledLocales(ctx, db)
+		if err != nil {
+			return nil, fmt.Errorf("cabana: enabled locales: %w", err)
+		}
+		enabled = make(map[string]struct{}, len(codes))
+		for _, loc := range codes {
+			enabled[loc] = struct{}{}
+		}
+	}
+	var out []mlValue
+	for _, name := range names {
+		raw := body[name]
+		object, isMap := raw.(map[string]any)
+		if !isMap {
+			if nestedValue(raw) {
+				details[name] = []string{"The " + name + " field must be an object of locale codes to text."}
+			}
+			continue
+		}
+		values := make(map[string]string, len(object))
+		ok := true
+		for locale, item := range object {
+			if _, known := enabled[locale]; !known {
+				ok = false
+				break
+			}
+			text, isString := item.(string)
+			if !isString {
+				ok = false
+				break
+			}
+			values[locale] = text
+		}
+		if !ok {
+			details[name] = []string{"The " + name + " field must be an object of locale codes to text."}
+			continue
+		}
+		if _, hasDefault := values[defaultLocale]; !hasDefault {
+			details[name] = []string{"The " + name + " field must include the default locale."}
+			continue
+		}
+		body[name] = values[defaultLocale]
+		out = append(out, mlValue{field: name, values: values})
+	}
+	if len(details) > 0 {
+		return nil, &ValidationError{Details: details}
+	}
+	return out, nil
+}
+
+// applyMLTranslations writes non-default locale values through the published
+// TranslationWriter. It runs after the host row write so the model has a
+// primary key, and only with the tx of the host save.
+func applyMLTranslations(ctx context.Context, tx *gorm.DB, writer TranslationWriter, model any, translations []mlValue) error {
+	if writer == nil || len(translations) == 0 {
+		return nil
+	}
+	defaultLocale, err := writer.DefaultLocale(ctx, tx)
+	if err != nil {
+		return fmt.Errorf("cabana: default locale: %w", err)
+	}
+	for _, item := range translations {
+		for locale, value := range item.values {
+			if locale == defaultLocale {
+				continue
+			}
+			if err := writer.WriteTranslated(ctx, tx, model, item.field, locale, value); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
diff --git a/modules/cabana/form_schema.go b/modules/cabana/form_schema.go
index fd812f1..f6798e9 100644
--- a/modules/cabana/form_schema.go
+++ b/modules/cabana/form_schema.go
@@ -26,6 +26,7 @@ var (
 		"switch": {}, "dropdown": {}, "relation": {}, "relation-manager": {},
 		"widget": {}, "partial": {}, "fileupload": {}, "datepicker": {},
 		"password": {}, "permissioneditor": {},
+		"markdown": {}, "mltext": {}, "mlmarkdown": {},
 	}
 	formSpans = map[string]struct{}{
 		"left": {}, "right": {}, "full": {}, "auto": {}, "row": {},
diff --git a/modules/cabana/http.go b/modules/cabana/http.go
index b6fea84..bb068b5 100644
--- a/modules/cabana/http.go
+++ b/modules/cabana/http.go
@@ -930,7 +930,13 @@ func (s *service) crud() (CRUDService, error) {
 	if err != nil {
 		return CRUDService{}, err
 	}
-	return CRUDService{DB: db, bucket: s.bucket(), tr: s.translator()}, nil
+	svc := CRUDService{DB: db, bucket: s.bucket(), tr: s.translator()}
+	if s.app != nil {
+		if w, ok := s.app.Lookup[TranslationWriter](); ok {
+			svc.writer = w
+		}
+	}
+	return svc, nil
 }
 
 func (s *service) list(w http.ResponseWriter, r *http.Request) {
diff --git a/modules/cabana/ml_smoke_test.go b/modules/cabana/ml_smoke_test.go
new file mode 100644
index 0000000..3fdccb9
--- /dev/null
+++ b/modules/cabana/ml_smoke_test.go
@@ -0,0 +1,261 @@
+package cabana
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"strings"
+	"testing"
+	"testing/fstest"
+
+	"git.golem15.com/golem15/summercms/modules/pact"
+	"gorm.io/gorm"
+)
+
+const mlFormConfig = `name: posts
+form: ~/plugins/acme/demo/models/post/fields.yaml
+modelClass: Post
+`
+
+const mlListConfig = `modelClass: Post
+list: ~/plugins/acme/demo/models/post/columns.yaml
+recordsPerPage: 20
+toolbar:
+    buttons: [create]
+`
+
+const mlFields = `fields:
+    title:
+        label: Title
+        type: mltext
+        required: true
+`
+
+const mlColumns = `columns:
+    title:
+        label: Title
+        searchable: true
+`
+
+type mlPost struct {
+	ID    uint   `gorm:"column:id;primaryKey"`
+	Title string `gorm:"column:title"`
+}
+
+func (mlPost) TableName() string        { return "cabana_ml_posts" }
+func (mlPost) Fillable() []string       { return []string{"title"} }
+func (mlPost) Rules() map[string]string { return map[string]string{"title": "required"} }
+
+type mlController struct{}
+
+func (mlController) ID() string        { return "acme.demo.posts" }
+func (mlController) ModelName() string { return "Post" }
+func (mlController) ConfigDir() string { return "controllers/posts" }
+func (mlController) NewRecord() any    { return &mlPost{} }
+
+func (mlController) FormExtendQuery(ctx context.Context, q *gorm.DB) *gorm.DB {
+	return q
+}
+
+var (
+	_ pact.AdminController   = mlController{}
+	_ pact.AdminRecordSource = mlController{}
+	_ pact.FormExtendQuery   = mlController{}
+)
+
+type recordingWriter struct {
+	defaultLocale string
+	enabled       []string
+	attrs         map[string]map[string]string
+	ids           []uint
+}
+
+func (w *recordingWriter) DefaultLocale(context.Context, *gorm.DB) (string, error) {
+	return w.defaultLocale, nil
+}
+
+func (w *recordingWriter) EnabledLocales(context.Context, *gorm.DB) ([]string, error) {
+	return append([]string(nil), w.enabled...), nil
+}
+
+func (w *recordingWriter) WriteTranslated(_ context.Context, _ *gorm.DB, model any, field, locale, value string) error {
+	post, _ := model.(*mlPost)
+	if post == nil || post.ID == 0 {
+		return &ValidationError{Details: map[string]any{field: []string{"translation writer ran before the host row had an id"}}}
+	}
+	w.ids = append(w.ids, post.ID)
+	if w.attrs == nil {
+		w.attrs = map[string]map[string]string{}
+	}
+	if w.attrs[locale] == nil {
+		w.attrs[locale] = map[string]string{}
+	}
+	w.attrs[locale][field] = value
+	return nil
+}
+
+func mlFS() fstest.MapFS {
+	return fstest.MapFS{
+		"controllers/posts/config_list.yaml": &fstest.MapFile{Data: []byte(mlListConfig)},
+		"controllers/posts/config_form.yaml": &fstest.MapFile{Data: []byte(mlFormConfig)},
+		"models/post/columns.yaml":           &fstest.MapFile{Data: []byte(mlColumns)},
+		"models/post/fields.yaml":            &fstest.MapFile{Data: []byte(mlFields)},
+	}
+}
+
+func mlCompiled(t *testing.T) *CompiledController {
+	t.Helper()
+	reg, err := compileRegistry([]controllerRef{{
+		plugin: formPlugin{fsys: mlFS()},
+		ctl:    mlController{},
+	}})
+	if err != nil {
+		t.Fatalf("registry: %v", err)
+	}
+	cc, ok := reg.Get("acme.demo.posts")
+	if !ok || cc.Form == nil {
+		t.Fatalf("compiled controller missing form: %+v", cc)
+	}
+	return cc
+}
+
+func TestMLNestedSaveSmoke(t *testing.T) {
+	t.Run("schema accepts markdown mltext mlmarkdown and rejects unknown", func(t *testing.T) {
+		accepted := `fields:
+    title:
+        type: mltext
+        label: Title
+    excerpt:
+        type: markdown
+        label: Excerpt
+    body:
+        type: mlmarkdown
+        label: Body
+`
+		schema, err := CompileForm("acme.demo", schemaController{model: "Widget"}, formFS(formConfig, accepted))
+		if err != nil {
+			t.Fatalf("compile accepted types: %v", err)
+		}
+		got := map[string]string{}
+		for _, field := range schema.Fields {
+			got[field.Name] = field.Type
+		}
+		if got["title"] != "mltext" || got["excerpt"] != "markdown" || got["body"] != "mlmarkdown" {
+			t.Fatalf("types = %v", got)
+		}
+		_, err = CompileForm("acme.demo", schemaController{model: "Widget"}, formFS(formConfig, "fields:\n    title:\n        type: mlunknown\n        label: Title\n"))
+		if err == nil || !strings.Contains(err.Error(), "unsupported type mlunknown") {
+			t.Fatalf("unknown type err = %v", err)
+		}
+	})
+
+	t.Run("ProjectWritableFields still drops generic nested maps", func(t *testing.T) {
+		cc := mlCompiled(t)
+		projected := ProjectWritableFields(cc, map[string]any{
+			"title": map[string]any{"en": "Hello", "pl": "Witaj"},
+			"extra": map[string]any{"nested": true},
+		})
+		if len(projected) != 0 {
+			t.Fatalf("unlifted nested maps reached projection: %#v", projected)
+		}
+	})
+
+	t.Run("save lifts locales, fills English, writes Polish", func(t *testing.T) {
+		_, shared := newListService(t)
+		db := shared
+		if err := db.Migrator().DropTable(&mlPost{}); err != nil {
+			t.Fatal(err)
+		}
+		if err := db.AutoMigrate(&mlPost{}); err != nil {
+			t.Fatal(err)
+		}
+		writer := &recordingWriter{defaultLocale: "en", enabled: []string{"en", "pl"}}
+		svc := CRUDService{DB: db, writer: writer}
+		cc := mlCompiled(t)
+
+		rec, err := svc.Create(context.Background(), cc, RecordInput{Body: map[string]any{
+			"title": map[string]any{"en": "Hello", "pl": "Witaj"},
+			"extra": map[string]any{"nested": true},
+		}})
+		if err != nil {
+			t.Fatalf("create: %v", err)
+		}
+		if rec["title"] != "Hello" {
+			t.Fatalf("projected title = %#v, want Hello", rec["title"])
+		}
+		var row mlPost
+		if err := db.First(&row).Error; err != nil {
+			t.Fatal(err)
+		}
+		if row.Title != "Hello" {
+			t.Fatalf("host title = %q, want Hello", row.Title)
+		}
+		if writer.attrs["en"] != nil {
+			t.Fatalf("default locale duplicated in attributes: %#v", writer.attrs["en"])
+		}
+		if writer.attrs["pl"]["title"] != "Witaj" {
+			t.Fatalf("Polish attributes = %#v", writer.attrs)
+		}
+		raw, err := json.Marshal(writer.attrs["pl"])
+		if err != nil || string(raw) != `{"title":"Witaj"}` {
+			t.Fatalf("attribute JSON = %s err=%v", raw, err)
+		}
+		if len(writer.ids) != 1 || writer.ids[0] != row.ID || row.ID == 0 {
+			t.Fatalf("writer ids = %v host id = %d", writer.ids, row.ID)
+		}
+
+		_, err = svc.Create(context.Background(), cc, RecordInput{Body: map[string]any{
+			"title": map[string]any{"en": "Hello", "de": "Hallo"},
+		}})
+		if err == nil {
+			t.Fatal("undeclared locale succeeded")
+		}
+		var ve *ValidationError
+		if !asValidation(err, &ve) || ve.Details["title"] == nil {
+			t.Fatalf("undeclared locale err = %v", err)
+		}
+	})
+
+	t.Run("unsafe markdown cannot become executable HTML", func(t *testing.T) {
+		if _, err := RenderMarkdown("<script>alert(1)</script>"); err == nil || !strings.Contains(err.Error(), "raw unsafe tags") {
+			// goldmark without WithUnsafe drops the raw tag; leftover HTML
+			// must still be rejected if a later renderer change lets it through.
+			html, convErr := renderMarkdownUnchecked("<script>alert(1)</script>")
+			if convErr != nil {
+				t.Fatal(convErr)
+			}
+			if strings.Contains(strings.ToLower(html), "<script") {
+				if err == nil {
+					t.Fatalf("RenderMarkdown accepted script HTML: %s", html)
+				}
+			}
+		}
+		if html, err := RenderMarkdown("[x](javascript:alert(1))"); err == nil && strings.Contains(strings.ToLower(html), "javascript:") {
+			t.Fatalf("javascript URL survived: %s", html)
+		} else if err == nil && strings.Contains(strings.ToLower(html), "<script") {
+			t.Fatalf("script tag survived: %s", html)
+		}
+		if _, err := RenderMarkdown(`<img src=x onerror="alert(1)">`); err == nil {
+			html, _ := renderMarkdownUnchecked(`<img src=x onerror="alert(1)">`)
+			if strings.Contains(strings.ToLower(html), "onerror") {
+				t.Fatalf("event handler survived: %s", html)
+			}
+		}
+		if html, err := RenderMarkdown("# Hello"); err != nil || !strings.Contains(html, "<h1>") {
+			t.Fatalf("safe markdown: html=%s err=%v", html, err)
+		}
+	})
+}
+
+func asValidation(err error, dest **ValidationError) bool {
+	return errors.As(err, dest)
+}
+
+func renderMarkdownUnchecked(src string) (string, error) {
+	var buf bytes.Buffer
+	if err := markdownEngine.Convert([]byte(src), &buf); err != nil {
+		return "", err
+	}
+	return buf.String(), nil
+}