feat: robust ML publish with pre-flight, preview, validation, async

- Add /inventory-check endpoint for local pre-flight validation
- Add /listings/validate endpoint using ML /items/validate API
- Add /categories/<id>/attributes endpoint for required attrs
- Add /listings/async + polling for background publishing via Celery
- Editable preview: title (0/60 counter), price, stock per item
- Pre-flight checks: image, stock, price, duplicate detection
- Image upload directly from publish modal (uses existing /items/<id>/image)
- Dynamic required attributes form based on selected ML category
- Frontend: validate button, async polling with progress, detailed error display
- Backend: build_item_payload supports custom_title, extra_attributes

pos/blueprints/marketplace_external_bp.py

@@ -183,6 +183,7 @@ def create_listings():
     category_id = data.get("category_id")
     listing_type = data.get("listing_type", "gold_special")
     shipping_mode = data.get("shipping_mode", "me2")
+    custom_data = data.get("custom_data", {})
 
     if not inventory_ids:
         return jsonify({"error": "inventory_ids required"}), 400
@@ -197,6 +198,7 @@ def create_listings():
             meli_category_id=category_id,
             listing_type_id=listing_type,
             shipping_mode=shipping_mode,
+            custom_data=custom_data,
         )
         return jsonify(result), 201
     except ValueError as e:
@@ -207,6 +209,134 @@ def create_listings():
         conn.close()
 
 
+@marketplace_ext_bp.route("/inventory-check", methods=["POST"])
+@require_auth()
+def inventory_check():
+    """Check local pre-flight status for ML publishing (duplicates, stock, price, image)."""
+    data = request.get_json() or {}
+    inventory_ids = data.get("inventory_ids", [])
+    if not inventory_ids:
+        return jsonify({"error": "inventory_ids required"}), 400
+
+    conn = get_tenant_conn(g.tenant_id)
+    try:
+        result = meli_svc.check_inventory_ml_status(conn, inventory_ids)
+        return jsonify(result)
+    except Exception as e:
+        return jsonify({"error": str(e)}), 500
+    finally:
+        conn.close()
+
+
+@marketplace_ext_bp.route("/categories/<category_id>/attributes", methods=["GET"])
+@require_auth()
+def category_attributes(category_id):
+    """Get required attributes for a MercadoLibre category."""
+    conn = get_tenant_conn(g.tenant_id)
+    try:
+        cfg = meli_svc.get_meli_config(conn)
+        svc = meli_svc._get_meli_service(cfg)
+        if not svc:
+            return jsonify({"error": "MercadoLibre not connected"}), 400
+        attrs = svc.get_category_attributes(category_id)
+        # Filter to required attributes only for the UI
+        required = [a for a in attrs if a.get("tags", {}).get("required")]
+        return jsonify({"attributes": required, "all": attrs})
+    except Exception as e:
+        return jsonify({"error": str(e)}), 500
+    finally:
+        conn.close()
+
+
+@marketplace_ext_bp.route("/listings/validate", methods=["POST"])
+@require_auth()
+def validate_listings():
+    """Validate items payload against ML /items/validate without creating them."""
+    err = _require_meli_manage()
+    if err:
+        return err
+
+    data = request.get_json() or {}
+    inventory_ids = data.get("inventory_ids", [])
+    category_id = data.get("category_id")
+    listing_type = data.get("listing_type", "gold_special")
+    shipping_mode = data.get("shipping_mode", "me2")
+    custom_data = data.get("custom_data", {})
+
+    if not inventory_ids:
+        return jsonify({"error": "inventory_ids required"}), 400
+    if not category_id:
+        return jsonify({"error": "category_id required"}), 400
+
+    conn = get_tenant_conn(g.tenant_id)
+    try:
+        result = meli_svc.validate_items(
+            conn,
+            inventory_ids=inventory_ids,
+            meli_category_id=category_id,
+            listing_type_id=listing_type,
+            shipping_mode=shipping_mode,
+            custom_data=custom_data,
+        )
+        return jsonify(result)
+    except ValueError as e:
+        return jsonify({"error": str(e)}), 400
+    except Exception as e:
+        return jsonify({"error": str(e)}), 500
+    finally:
+        conn.close()
+
+
+@marketplace_ext_bp.route("/listings/async", methods=["POST"])
+@require_auth()
+def create_listings_async():
+    """Enqueue ML publishing as a Celery background task."""
+    err = _require_meli_manage()
+    if err:
+        return err
+
+    data = request.get_json() or {}
+    inventory_ids = data.get("inventory_ids", [])
+    category_id = data.get("category_id")
+    listing_type = data.get("listing_type", "gold_special")
+    shipping_mode = data.get("shipping_mode", "me2")
+    custom_data = data.get("custom_data", {})
+
+    if not inventory_ids:
+        return jsonify({"error": "inventory_ids required"}), 400
+    if not category_id:
+        return jsonify({"error": "category_id required"}), 400
+
+    try:
+        from tasks import publish_meli_items_task
+        task = publish_meli_items_task.delay(
+            g.tenant_id,
+            inventory_ids=inventory_ids,
+            category_id=category_id,
+            listing_type=listing_type,
+            shipping_mode=shipping_mode,
+            custom_data=custom_data,
+        )
+        return jsonify({"task_id": task.id, "status": "queued"}), 202
+    except Exception as e:
+        return jsonify({"error": str(e)}), 500
+
+
+@marketplace_ext_bp.route("/listings/async/<task_id>", methods=["GET"])
+@require_auth()
+def get_async_listing_status(task_id):
+    """Get status of an async ML publishing task."""
+    try:
+        from celery.result import AsyncResult
+        from app import celery as celery_app
+        result = AsyncResult(task_id, app=celery_app)
+        if result.ready():
+            return jsonify({"status": "done", "result": result.result or {}})
+        return jsonify({"status": "pending"})
+    except Exception as e:
+        return jsonify({"error": str(e)}), 500
+
+
 @marketplace_ext_bp.route("/listings/<int:listing_id>/sync", methods=["POST"])
 @require_auth()
 def sync_listing(listing_id):

pos/services/marketplace_external_service.py

@@ -134,9 +134,11 @@ def build_item_payload(
     stock: int,
     shipping_mode: str = "me2",
     listing_type_id: str = "gold_special",
+    custom_title: str = None,
+    extra_attributes: list = None,
 ) -> dict:
     """Convert a Nexus inventory row into a MercadoLibre item payload."""
-    title = f"{inventory_row['name']} {inventory_row['brand'] or ''} {inventory_row['part_number'] or ''}".strip()
+    title = custom_title or f"{inventory_row['name']} {inventory_row['brand'] or ''} {inventory_row['part_number'] or ''}".strip()
     # ML title limit is 60 chars; truncate smartly
     if len(title) > 60:
         title = title[:57] + "..."
@@ -185,6 +187,12 @@ def build_item_payload(
                         {"id": "VEHICLE_MODEL_NAME", "value_name": first["model"]}
                     )
 
+    # Extra attributes from user input (category requirements)
+    if extra_attributes:
+        for attr in extra_attributes:
+            if attr.get("id") and attr.get("value_name"):
+                payload["attributes"].append(attr)
+
     return payload
 
 
@@ -192,12 +200,169 @@ def build_item_payload(
 # LISTINGS CRUD
 # ═══════════════════════════════════════════════════════════════════════════
 
+def check_inventory_ml_status(tenant_conn, inventory_ids: list[int]) -> dict:
+    """Check local pre-flight status for ML publishing.
+
+    Returns per-item dict with checks: has_image, has_stock, has_price,
+    already_published, and the generated title.
+    """
+    cur = tenant_conn.cursor()
+    cur.execute(
+        """
+        SELECT id, part_number, name, brand, price_1, image_url
+        FROM inventory
+        WHERE id = ANY(%s)
+        """,
+        (inventory_ids,),
+    )
+    rows = {r[0]: r for r in cur.fetchall()}
+
+    stock_map = get_stock_bulk(tenant_conn, branch_id=None)
+
+    # Check existing active listings
+    cur.execute(
+        """
+        SELECT inventory_id, external_item_id, external_status, external_permalink
+        FROM marketplace_listings
+        WHERE inventory_id = ANY(%s) AND channel = 'mercadolibre' AND is_active = true
+        """,
+        (inventory_ids,),
+    )
+    listings = {r[0]: {"external_item_id": r[1], "status": r[2], "permalink": r[3]} for r in cur.fetchall()}
+    cur.close()
+
+    results = []
+    for inv_id in inventory_ids:
+        row = rows.get(inv_id)
+        if not row:
+            results.append({"inventory_id": inv_id, "exists": False})
+            continue
+
+        price = float(row[4]) if row[4] else 0
+        stock = stock_map.get(inv_id, 0)
+        image_url = row[5]
+        title = f"{row[2]} {row[3] or ''} {row[1] or ''}".strip()
+        if len(title) > 60:
+            title = title[:57] + "..."
+
+        existing = listings.get(inv_id)
+        results.append({
+            "inventory_id": inv_id,
+            "exists": True,
+            "title": title,
+            "has_image": bool(image_url),
+            "has_stock": stock > 0,
+            "has_price": price > 0,
+            "price": price,
+            "stock": stock,
+            "image_url": image_url,
+            "already_published": existing is not None,
+            "existing_listing": existing,
+        })
+    return {"items": results}
+
+
+def validate_items(
+    tenant_conn,
+    inventory_ids: list[int],
+    meli_category_id: str,
+    listing_type_id: str = "gold_special",
+    shipping_mode: str = "me2",
+    custom_data: dict = None,
+) -> dict:
+    """Validate items against ML /items/validate without creating them.
+
+    Returns per-item validation results with ML error details if any.
+    """
+    cfg = get_meli_config(tenant_conn)
+    svc = _get_meli_service(cfg)
+    if not svc:
+        raise ValueError("MercadoLibre not configured")
+
+    cur = tenant_conn.cursor()
+    cur.execute(
+        """
+        SELECT id, part_number, name, brand, price_1, vehicle_compatibility,
+               image_url, unit, is_active
+        FROM inventory
+        WHERE id = ANY(%s) AND is_active = true
+        """,
+        (inventory_ids,),
+    )
+    rows = {r[0]: r for r in cur.fetchall()}
+    stock_map = get_stock_bulk(tenant_conn, branch_id=None)
+
+    custom_data = custom_data or {}
+    results = {"valid": [], "invalid": []}
+
+    for inv_id in inventory_ids:
+        row = rows.get(inv_id)
+        if not row:
+            results["invalid"].append({"inventory_id": inv_id, "error": "No encontrado o inactivo"})
+            continue
+
+        inv = {
+            "id": row[0],
+            "part_number": row[1],
+            "name": row[2],
+            "brand": row[3],
+            "price_1": float(row[4]) if row[4] else 0,
+            "vehicle_compatibility": row[5],
+            "image_url": row[6],
+            "unit": row[7],
+        }
+
+        stock = stock_map.get(inv_id, 0)
+        if stock <= 0:
+            results["invalid"].append({"inventory_id": inv_id, "error": "Sin stock disponible"})
+            continue
+        if inv["price_1"] <= 0:
+            results["invalid"].append({"inventory_id": inv_id, "error": "El precio debe ser mayor a 0"})
+            continue
+
+        images = []
+        if inv.get("image_url"):
+            images.append(inv["image_url"])
+        if not images:
+            results["invalid"].append({"inventory_id": inv_id, "error": "El producto no tiene imagen"})
+            continue
+
+        title = (custom_data.get("titles") or {}).get(str(inv_id))
+        extra_attrs = (custom_data.get("attributes") or {}).get(str(inv_id))
+        price = (custom_data.get("prices") or {}).get(str(inv_id), inv["price_1"])
+        item_stock = (custom_data.get("stocks") or {}).get(str(inv_id), stock)
+
+        payload = build_item_payload(
+            inv, images, meli_category_id, price, item_stock,
+            shipping_mode=shipping_mode, listing_type_id=listing_type_id,
+            custom_title=title, extra_attributes=extra_attrs,
+        )
+
+        try:
+            validation = svc.validate_item(payload)
+            if validation.get("status") == "valid":
+                results["valid"].append({"inventory_id": inv_id, "validation": validation})
+            else:
+                errors = validation.get("validation_errors", [])
+                error_msgs = [f"{e.get('field', '')}: {e.get('message', '')}" for e in errors]
+                results["invalid"].append({"inventory_id": inv_id, "error": " | ".join(error_msgs) or "Validación fallida", "validation": validation})
+        except MeliError as e:
+            err_msg = _extract_meli_error(e)
+            results["invalid"].append({"inventory_id": inv_id, "error": err_msg})
+        except Exception as e:
+            results["invalid"].append({"inventory_id": inv_id, "error": str(e)})
+
+    cur.close()
+    return results
+
+
 def publish_items(
     tenant_conn,
     inventory_ids: list[int],
     meli_category_id: str,
     listing_type_id: str = "gold_special",
     shipping_mode: str = "me2",
+    custom_data: dict = None,
 ) -> dict:
     """Publish one or more inventory items to MercadoLibre.
 
@@ -225,6 +390,7 @@ def publish_items(
     # Batch fetch stock
     stock_map = get_stock_bulk(tenant_conn, branch_id=None)
 
+    custom_data = custom_data or {}
     results = {"success": [], "failed": []}
 
     for inv_id in inventory_ids:
@@ -257,15 +423,20 @@ def publish_items(
         images = []
         if inv.get("image_url"):
             images.append(inv["image_url"])
-        # TODO: fetch additional images from a separate table if we have gallery support
 
         if not images:
             results["failed"].append({"inventory_id": inv_id, "error": "El producto no tiene imagen. ML requiere imagen para publicar."})
             continue
 
+        title = (custom_data.get("titles") or {}).get(str(inv_id))
+        extra_attrs = (custom_data.get("attributes") or {}).get(str(inv_id))
+        price = (custom_data.get("prices") or {}).get(str(inv_id), inv["price_1"])
+        item_stock = (custom_data.get("stocks") or {}).get(str(inv_id), stock)
+
         payload = build_item_payload(
-            inv, images, meli_category_id, inv["price_1"], stock,
+            inv, images, meli_category_id, price, item_stock,
             shipping_mode=shipping_mode, listing_type_id=listing_type_id,
+            custom_title=title, extra_attributes=extra_attrs,
         )
 
         try:

pos/services/meli_service.py

@@ -145,6 +145,10 @@ class MeliService:
 
     # ─── Items (listings) ────────────────────────────────────────────────
 
+    def validate_item(self, payload: dict) -> dict:
+        """Validate an item payload without creating it."""
+        return self._request("POST", "/items/validate", json_payload=payload)
+
     def create_item(self, payload: dict) -> dict:
         return self._request("POST", "/items", json_payload=payload)
 

pos/static/css/inventory.css

@@ -1333,6 +1333,73 @@
     /* History table inside modal */
     .inv-modal .data-table { width: 100%; }
 
+    /* ─── MercadoLibre Publish Modal Enhancements ────────────────────────── */
+    .meli-preview-card {
+      display: grid;
+      grid-template-columns: 56px 1fr auto auto auto;
+      gap: var(--space-3);
+      align-items: center;
+      padding: var(--space-3);
+      border: 1px solid var(--color-border);
+      border-radius: var(--radius-md);
+      margin-bottom: var(--space-2);
+      background: var(--color-surface-1);
+    }
+    .meli-preview-card img {
+      width: 56px; height: 56px; object-fit: cover; border-radius: var(--radius-sm);
+      background: var(--color-surface-2);
+    }
+    .meli-preview-card .meli-title-input {
+      width: 100%;
+      background: var(--color-surface-2);
+      border: 1px solid var(--color-border);
+      border-radius: var(--radius-sm);
+      color: var(--color-text-primary);
+      padding: 4px 8px;
+      font-size: var(--text-caption);
+    }
+    .meli-preview-card .meli-num-input {
+      width: 80px;
+      background: var(--color-surface-2);
+      border: 1px solid var(--color-border);
+      border-radius: var(--radius-sm);
+      color: var(--color-text-primary);
+      padding: 4px 8px;
+      font-size: var(--text-caption);
+      text-align: right;
+    }
+    .meli-check { font-size: var(--text-caption); display: flex; align-items: center; gap: 4px; }
+    .meli-check.ok { color: var(--color-success); }
+    .meli-check.fail { color: var(--color-error); }
+    .meli-checks-row {
+      display: flex; gap: var(--space-3); flex-wrap: wrap; margin-top: var(--space-1);
+    }
+    .meli-attrs-section {
+      margin-top: var(--space-3);
+      padding: var(--space-3);
+      border: 1px dashed var(--color-border);
+      border-radius: var(--radius-md);
+      background: var(--color-surface-1);
+    }
+    .meli-attrs-grid {
+      display: grid;
+      grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
+      gap: var(--space-3);
+      margin-top: var(--space-2);
+    }
+    .meli-img-upload {
+      border: 2px dashed var(--color-border);
+      border-radius: var(--radius-md);
+      padding: var(--space-3);
+      text-align: center;
+      color: var(--color-text-muted);
+      font-size: var(--text-caption);
+      cursor: pointer;
+      transition: border-color var(--transition-fast);
+    }
+    .meli-img-upload:hover { border-color: var(--color-primary); }
+    .meli-img-upload input { display: none; }
+
     /* ─── MercadoLibre Category Autocomplete ─────────────────────────────── */
     .meli-cat-dropdown {
       position: absolute;

pos/static/js/inventory.js

@@ -784,6 +784,9 @@
 
     // ─── MercadoLibre Bulk Publish Modal ───────────────────────────────────
 
+    var meliPreviewData = {};
+    var meliCategoryAttrs = [];
+
     window.openMeliPublishModal = function() {
         if (selectedItems.size === 0) { showToast('Selecciona al menos un producto', 'warn'); return; }
         document.getElementById('meliPublishModal').classList.add('is-open');
@@ -791,6 +794,9 @@
         document.getElementById('meliCategoryId').value = '';
         document.getElementById('meliCategorySearch').value = '';
         document.getElementById('meliCategoryResults').innerHTML = '';
+        document.getElementById('meliAttrsSection').style.display = 'none';
+        document.getElementById('meliAttrsGrid').innerHTML = '';
+        meliCategoryAttrs = [];
         refreshMeliPublishPreview();
     };
 
@@ -802,17 +808,80 @@
         var container = document.getElementById('meliPublishItemsPreview');
         var countEl = document.getElementById('meliPublishSelectedCount');
         countEl.textContent = selectedItems.size + ' producto(s) seleccionado(s)';
-        if (!inventoryVS || !inventoryVS.data) { container.innerHTML = '<p style="color:var(--color-text-muted);">Sin datos</p>'; return; }
-        var items = inventoryVS.data.filter(function(it) { return selectedItems.has(it.id); });
-        if (!items.length) { container.innerHTML = '<p style="color:var(--color-text-muted);">Ninguno</p>'; return; }
-        var html = '<table class="data-table" style="font-size:var(--text-caption);"><thead><tr><th>ID</th><th>No. Parte</th><th>Nombre</th><th>Stock</th><th style="text-align:right">Precio</th></tr></thead><tbody>';
-        items.forEach(function(it) {
-            html += '<tr><td>' + it.id + '</td><td class="td--mono">' + esc(it.part_number) + '</td><td>' + esc(it.name) + '</td><td>' + it.stock + '</td><td style="text-align:right">$' + fmt(it.price_1) + '</td></tr>';
-        });
-        html += '</tbody></table>';
-        container.innerHTML = html;
+        container.innerHTML = '<p style="color:var(--color-text-muted);font-size:var(--text-caption);">Cargando verificaciones...</p>';
+
+        var ids = Array.from(selectedItems);
+        fetch('/pos/api/marketplace-ext/inventory-check', {
+            method: 'POST',
+            headers: { 'Authorization': 'Bearer ' + token, 'Content-Type': 'application/json' },
+            body: JSON.stringify({ inventory_ids: ids })
+        }).then(function(r){ return r.json(); })
+          .then(function(data) {
+              if (!data.items) { container.innerHTML = '<p style="color:var(--color-error);">Error cargando preview</p>'; return; }
+              var html = '';
+              data.items.forEach(function(it) {
+                  if (!it.exists) {
+                      html += '<div class="meli-preview-card" style="opacity:0.6;"><div style="color:var(--color-error);">Item #' + it.inventory_id + ' no encontrado</div></div>';
+                      return;
+                  }
+                  meliPreviewData[it.inventory_id] = it;
+                  var checks = '';
+                  checks += '<span class="meli-check ' + (it.has_image ? 'ok' : 'fail') + '">' + (it.has_image ? '✅' : '❌') + ' Imagen</span>';
+                  checks += '<span class="meli-check ' + (it.has_stock ? 'ok' : 'fail') + '">' + (it.has_stock ? '✅' : '❌') + ' Stock</span>';
+                  checks += '<span class="meli-check ' + (it.has_price ? 'ok' : 'fail') + '">' + (it.has_price ? '✅' : '❌') + ' Precio</span>';
+                  if (it.already_published) {
+                      checks += '<span class="meli-check ok">✅ <a href="' + esc(it.existing_listing.permalink || '#') + '" target="_blank" style="color:var(--color-success);text-decoration:underline;">Ya publicado (' + esc(it.existing_listing.status) + ')</a></span>';
+                  }
+                  var imgSrc = it.image_url || '';
+                  var imgHtml = imgSrc ? '<img src="' + esc(imgSrc) + '" alt="" onerror="this.style.display=\'none\'">' : '<div style="width:56px;height:56px;background:var(--color-surface-2);border-radius:var(--radius-sm);display:flex;align-items:center;justify-content:center;font-size:10px;color:var(--color-text-muted);">Sin img</div>';
+                  if (!it.has_image) {
+                      imgHtml = '<div class="meli-img-upload" onclick="document.getElementById(\'meliImgUpload-' + it.inventory_id + '\').click()">' +
+                          '<div style="font-size:10px;">+ Subir</div>' +
+                          '<input type="file" id="meliImgUpload-' + it.inventory_id + '" accept="image/*" onchange="handleMeliImageUpload(' + it.inventory_id + ', this)">' +
+                          '</div>';
+                  }
+                  html += '<div class="meli-preview-card" id="meliCard-' + it.inventory_id + '">' +
+                      imgHtml +
+                      '<div>' +
+                          '<input type="text" class="meli-title-input" id="meliTitle-' + it.inventory_id + '" value="' + esc(it.title) + '" maxlength="60" oninput="updateMeliTitleCount(' + it.inventory_id + ')">' +
+                          '<div style="font-size:10px;color:var(--color-text-muted);text-align:right;" id="meliTitleCount-' + it.inventory_id + '">' + it.title.length + '/60</div>' +
+                          '<div class="meli-checks-row">' + checks + '</div>' +
+                      '</div>' +
+                      '<div><label style="font-size:10px;color:var(--color-text-muted);">Precio</label><input type="number" class="meli-num-input" id="meliPrice-' + it.inventory_id + '" value="' + it.price + '"></div>' +
+                      '<div><label style="font-size:10px;color:var(--color-text-muted);">Stock</label><input type="number" class="meli-num-input" id="meliStock-' + it.inventory_id + '" value="' + it.stock + '"></div>' +
+                      '</div>';
+              });
+              container.innerHTML = html;
+          }).catch(function() { container.innerHTML = '<p style="color:var(--color-error);">Error de red</p>'; });
     }
 
+    window.updateMeliTitleCount = function(id) {
+        var el = document.getElementById('meliTitle-' + id);
+        var countEl = document.getElementById('meliTitleCount-' + id);
+        if (el && countEl) countEl.textContent = el.value.length + '/60';
+    };
+
+    window.handleMeliImageUpload = function(itemId, input) {
+        if (!input.files || !input.files[0]) return;
+        var file = input.files[0];
+        var formData = new FormData();
+        formData.append('image', file);
+        fetch('/pos/api/inventory/items/' + itemId + '/image', {
+            method: 'POST',
+            headers: { 'Authorization': 'Bearer ' + token },
+            body: formData
+        }).then(function(r){ return r.json(); })
+          .then(function(data) {
+              if (data.image_url) {
+                  showToast('Imagen subida', 'success');
+                  refreshMeliPublishPreview();
+                  if (inventoryVS) inventoryVS.refresh();
+              } else {
+                  showToast(data.error || 'Error subiendo imagen', 'error');
+              }
+          }).catch(function(){ showToast('Error de red', 'error'); });
+    };
+
     var meliCategorySearchTimeout;
     var meliCatItems = [];
     var meliCatActiveIndex = -1;
@@ -863,6 +932,34 @@
         document.getElementById('meliCategoryResults').innerHTML = '';
         meliCatItems = [];
         meliCatActiveIndex = -1;
+        loadCategoryAttributes(id);
+    };
+
+    window.loadCategoryAttributes = function(categoryId) {
+        var grid = document.getElementById('meliAttrsGrid');
+        var section = document.getElementById('meliAttrsSection');
+        grid.innerHTML = '<p style="color:var(--color-text-muted);font-size:var(--text-caption);">Cargando atributos...</p>';
+        section.style.display = 'block';
+        fetch('/pos/api/marketplace-ext/categories/' + encodeURIComponent(categoryId) + '/attributes', { headers: { 'Authorization': 'Bearer ' + token } })
+            .then(function(r){ return r.json(); })
+            .then(function(data) {
+                meliCategoryAttrs = data.attributes || [];
+                if (!meliCategoryAttrs.length) { grid.innerHTML = '<p style="color:var(--color-text-muted);font-size:var(--text-caption);">No hay atributos obligatorios adicionales.</p>'; return; }
+                var html = '';
+                meliCategoryAttrs.forEach(function(attr) {
+                    var attrId = esc(attr.id);
+                    var attrName = esc(attr.name || attr.id);
+                    var inputHtml = '<input type="text" class="meli-title-input" id="meliAttr-' + attrId + '" placeholder="' + attrName + '">';
+                    if (attr.values && attr.values.length) {
+                        inputHtml = '<select class="meli-title-input" id="meliAttr-' + attrId + '">' +
+                            '<option value="">Selecciona ' + attrName + '</option>' +
+                            attr.values.map(function(v) { return '<option value="' + esc(v.name) + '">' + esc(v.name) + '</option>'; }).join('') +
+                            '</select>';
+                    }
+                    html += '<div class="inv-field"><label>' + attrName + (attr.tags && attr.tags.required ? ' *' : '') + '</label>' + inputHtml + '</div>';
+                });
+                grid.innerHTML = html;
+            }).catch(function() { grid.innerHTML = '<p style="color:var(--color-error);font-size:var(--text-caption);">Error cargando atributos</p>'; });
     };
 
     window.handleMeliCatKeydown = function(e) {
@@ -896,6 +993,114 @@
         }
     });
 
+    function _collectMeliCustomData() {
+        var ids = Array.from(selectedItems);
+        var customData = { titles: {}, prices: {}, stocks: {}, attributes: {} };
+        ids.forEach(function(id) {
+            var titleEl = document.getElementById('meliTitle-' + id);
+            var priceEl = document.getElementById('meliPrice-' + id);
+            var stockEl = document.getElementById('meliStock-' + id);
+            if (titleEl) customData.titles[id] = titleEl.value;
+            if (priceEl) customData.prices[id] = parseFloat(priceEl.value);
+            if (stockEl) customData.stocks[id] = parseInt(stockEl.value);
+            var attrs = [];
+            meliCategoryAttrs.forEach(function(attr) {
+                var el = document.getElementById('meliAttr-' + attr.id);
+                if (el && el.value) {
+                    attrs.push({ id: attr.id, value_name: el.value });
+                }
+            });
+            if (attrs.length) customData.attributes[id] = attrs;
+        });
+        return customData;
+    }
+
+    window.validateMeliPublish = function() {
+        var categoryId = document.getElementById('meliCategoryId').value.trim();
+        if (!categoryId) { document.getElementById('meliPublishResult').innerHTML = '<span style="color:var(--color-error);">Selecciona una categoría de MercadoLibre</span>'; return; }
+        var listingType = document.getElementById('meliListingType').value;
+        var shippingMode = document.getElementById('meliShippingMode').value;
+        var ids = Array.from(selectedItems);
+        var resultEl = document.getElementById('meliPublishResult');
+        var btn = document.getElementById('meliValidateBtn');
+        btn.disabled = true;
+        resultEl.innerHTML = '<span style="color:var(--color-text-muted);">Validando con MercadoLibre...</span>';
+        fetch('/pos/api/marketplace-ext/listings/validate', {
+            method: 'POST',
+            headers: { 'Authorization': 'Bearer ' + token, 'Content-Type': 'application/json' },
+            body: JSON.stringify({
+                inventory_ids: ids,
+                category_id: categoryId,
+                listing_type: listingType,
+                shipping_mode: shippingMode,
+                custom_data: _collectMeliCustomData()
+            })
+        }).then(function(r){ return r.json(); })
+          .then(function(data) {
+              btn.disabled = false;
+              if (data.error) { resultEl.innerHTML = '<span style="color:var(--color-error);">Error: ' + esc(data.error) + '</span>'; return; }
+              var valid = (data.valid || []).length;
+              var invalid = (data.invalid || []);
+              var html = '<div style="margin-bottom:var(--space-2);"><span style="color:var(--color-success);">✅ ' + valid + ' válido(s)</span> · <span style="color:var(--color-error);">❌ ' + invalid.length + ' inválido(s)</span></div>';
+              if (invalid.length) {
+                  html += '<ul style="margin:0;padding-left:var(--space-4);font-size:var(--text-caption);color:var(--color-text-secondary);">';
+                  invalid.forEach(function(f) {
+                      html += '<li>Item #' + esc(f.inventory_id) + ': ' + esc(f.error) + '</li>';
+                  });
+                  html += '</ul>';
+              }
+              resultEl.innerHTML = html;
+          }).catch(function(e) { btn.disabled = false; resultEl.innerHTML = '<span style="color:var(--color-error);">Error: ' + esc(e.message) + '</span>'; });
+    };
+
+    function _renderPublishResult(data, resultEl) {
+        var success = (data.success || []).length;
+        var failedList = data.failed || [];
+        var failed = failedList.length;
+        var html = '<div style="margin-bottom:var(--space-2);"><span style="color:var(--color-success);">✅ ' + success + ' publicado(s)</span> · <span style="color:var(--color-error);">❌ ' + failed + ' fallo(s)</span></div>';
+        if (failedList.length) {
+            html += '<ul style="margin:0;padding-left:var(--space-4);font-size:var(--text-caption);color:var(--color-text-secondary);">';
+            failedList.forEach(function(f) {
+                html += '<li>Item #' + esc(f.inventory_id) + ': ' + esc(f.error) + '</li>';
+            });
+            html += '</ul>';
+        }
+        resultEl.innerHTML = html;
+        if (success > 0) {
+            selectedItems.clear();
+            updateSelectionUI();
+            if (inventoryVS) inventoryVS.refresh();
+        }
+    }
+
+    function _pollMeliAsync(taskId, resultEl, btn) {
+        var attempts = 0;
+        var maxAttempts = 60; // 2 min
+        var interval = setInterval(function() {
+            attempts++;
+            fetch('/pos/api/marketplace-ext/listings/async/' + encodeURIComponent(taskId), { headers: { 'Authorization': 'Bearer ' + token } })
+                .then(function(r){ return r.json(); })
+                .then(function(data) {
+                    if (data.status === 'done') {
+                        clearInterval(interval);
+                        btn.disabled = false;
+                        _renderPublishResult(data.result || {}, resultEl);
+                        setTimeout(function() { closeMeliPublishModal(); }, 3000);
+                    } else if (attempts >= maxAttempts) {
+                        clearInterval(interval);
+                        btn.disabled = false;
+                        resultEl.innerHTML = '<span style="color:var(--color-error);">Timeout esperando resultado. Revisa la pestaña Publicaciones más tarde.</span>';
+                    } else {
+                        resultEl.innerHTML = '<span style="color:var(--color-text-muted);">Publicando en segundo plano... (' + attempts + 's)</span>';
+                    }
+                }).catch(function() {
+                    clearInterval(interval);
+                    btn.disabled = false;
+                    resultEl.innerHTML = '<span style="color:var(--color-error);">Error consultando progreso</span>';
+                });
+        }, 2000);
+    }
+
     window.executeMeliPublish = function() {
         var categoryId = document.getElementById('meliCategoryId').value.trim();
         if (!categoryId) { document.getElementById('meliPublishResult').innerHTML = '<span style="color:var(--color-error);">Selecciona una categoría de MercadoLibre</span>'; return; }
@@ -905,37 +1110,30 @@
         var resultEl = document.getElementById('meliPublishResult');
         var btn = document.getElementById('meliPublishBtn');
         btn.disabled = true;
-        resultEl.innerHTML = '<span style="color:var(--color-text-muted);">Publicando ' + ids.length + ' producto(s)...</span>';
-        fetch('/pos/api/marketplace-ext/listings', {
+        var useAsync = ids.length > 3;
+        var endpoint = useAsync ? '/pos/api/marketplace-ext/listings/async' : '/pos/api/marketplace-ext/listings';
+        resultEl.innerHTML = '<span style="color:var(--color-text-muted);">' + (useAsync ? 'Encolando ' : 'Publicando ') + ids.length + ' producto(s)...</span>';
+        fetch(endpoint, {
             method: 'POST',
             headers: { 'Authorization': 'Bearer ' + token, 'Content-Type': 'application/json' },
             body: JSON.stringify({
                 inventory_ids: ids,
                 category_id: categoryId,
                 listing_type: listingType,
-                shipping_mode: shippingMode
+                shipping_mode: shippingMode,
+                custom_data: _collectMeliCustomData()
             })
         }).then(function(r) { return r.json(); })
           .then(function(data) {
-              btn.disabled = false;
-              if (data.error) { resultEl.innerHTML = '<span style="color:var(--color-error);">Error: ' + esc(data.error) + '</span>'; return; }
-              var success = (data.success || []).length;
-              var failedList = data.failed || [];
-              var failed = failedList.length;
-              var html = '<div style="margin-bottom:var(--space-2);"><span style="color:var(--color-success);">✅ ' + success + ' publicado(s)</span> · <span style="color:var(--color-error);">❌ ' + failed + ' fallo(s)</span></div>';
-              if (failedList.length) {
-                  html += '<ul style="margin:0;padding-left:var(--space-4);font-size:var(--text-caption);color:var(--color-text-secondary);">';
-                  failedList.forEach(function(f) {
-                      html += '<li>Item #' + esc(f.inventory_id) + ': ' + esc(f.error) + '</li>';
-                  });
-                  html += '</ul>';
-              }
-              resultEl.innerHTML = html;
-              if (success > 0) {
-                  selectedItems.clear();
-                  updateSelectionUI();
-                  if (inventoryVS) inventoryVS.refresh();
-                  setTimeout(function() { closeMeliPublishModal(); }, 2500);
+              if (data.error) { btn.disabled = false; resultEl.innerHTML = '<span style="color:var(--color-error);">Error: ' + esc(data.error) + '</span>'; return; }
+              if (useAsync && data.task_id) {
+                  _pollMeliAsync(data.task_id, resultEl, btn);
+              } else {
+                  btn.disabled = false;
+                  _renderPublishResult(data, resultEl);
+                  if ((data.success || []).length > 0) {
+                      setTimeout(function() { closeMeliPublishModal(); }, 2500);
+                  }
               }
           }).catch(function(e) { btn.disabled = false; resultEl.innerHTML = '<span style="color:var(--color-error);">Error: ' + esc(e.message) + '</span>'; });
     };

pos/tasks.py

@@ -267,3 +267,26 @@ def sync_vehicle_compatibility_task(self, tenant_id, item_id, part_number, name,
             tenant_conn.close()
         if master_conn:
             master_conn.close()
+
+
+@celery.task(bind=True)
+def publish_meli_items_task(self, tenant_id: int, inventory_ids: list, category_id: str, listing_type: str = "gold_special", shipping_mode: str = "me2", custom_data: dict = None):
+    """Publish inventory items to MercadoLibre asynchronously."""
+    from services import marketplace_external_service as meli_svc
+    from tenant_db import get_tenant_conn
+
+    conn = get_tenant_conn(tenant_id)
+    try:
+        result = meli_svc.publish_items(
+            conn,
+            inventory_ids=inventory_ids,
+            meli_category_id=category_id,
+            listing_type_id=listing_type,
+            shipping_mode=shipping_mode,
+            custom_data=custom_data or {},
+        )
+        return result
+    except Exception as e:
+        return {"success": [], "failed": [{"inventory_id": "batch", "error": str(e)}]}
+    finally:
+        conn.close()

pos/templates/inventory.html

@@ -13,7 +13,7 @@
   <link rel="manifest" href="/pos/static/pwa/manifest.json" />
   <meta name="theme-color" content="#F5A623" />
 
-  <link rel="stylesheet" href="/pos/static/css/inventory.css?v=4">
+  <link rel="stylesheet" href="/pos/static/css/inventory.css?v=6">
 </head>
 
 <body>
@@ -846,9 +846,12 @@
       </div>
       <div class="inv-modal__body">
         <div id="meliPublishSelectedCount" style="font-size:var(--text-caption);color:var(--color-text-muted);margin-bottom:var(--space-3);">0 productos seleccionados</div>
-        <div id="meliPublishItemsPreview" style="max-height:200px;overflow-y:auto;border:1px solid var(--color-border);border-radius:var(--radius-md);padding:var(--space-3);margin-bottom:var(--space-4);">
-          <p style="color:var(--color-text-muted);font-size:var(--text-caption);">Selecciona productos del inventario para ver el preview.</p>
+
+        <!-- Pre-flight checks & editable preview -->
+        <div id="meliPublishItemsPreview" style="max-height:320px;overflow-y:auto;margin-bottom:var(--space-4);">
+          <p style="color:var(--color-text-muted);font-size:var(--text-caption);">Cargando preview...</p>
         </div>
+
         <div style="display:grid;grid-template-columns:1fr 1fr 1fr;gap:16px;margin-bottom:var(--space-4);">
           <div class="inv-field">
             <label>Categoría ML *</label>
@@ -874,10 +877,20 @@
             <small style="color:var(--color-text-muted);font-size:var(--text-caption);">Tu cuenta requiere ME2 obligatoriamente.</small>
           </div>
         </div>
-        <div id="meliPublishResult" style="min-height:1.5em;"></div>
+
+        <!-- Dynamic required attributes section -->
+        <div id="meliAttrsSection" style="display:none;">
+          <div class="meli-attrs-section">
+            <strong style="font-size:var(--text-body-sm);">Atributos requeridos para esta categoría</strong>
+            <div id="meliAttrsGrid" class="meli-attrs-grid"></div>
+          </div>
+        </div>
+
+        <div id="meliPublishResult" style="min-height:1.5em;margin-top:var(--space-3);"></div>
       </div>
       <div class="inv-modal__footer">
         <button class="btn btn--ghost" onclick="closeMeliPublishModal()">Cancelar</button>
+        <button class="btn btn--secondary" id="meliValidateBtn" onclick="validateMeliPublish()">Validar con ML</button>
         <button class="btn btn--meli" id="meliPublishBtn" onclick="executeMeliPublish()"><svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><rect x="2" y="3" width="20" height="14" rx="2"/><path d="M8 21h8M12 17v4"/></svg> Publicar</button>
       </div>
     </div>
@@ -895,7 +908,7 @@
   <script src="/pos/static/js/pos-utils.js" defer></script>
   <script src="/pos/static/js/sidebar.js" defer></script>
   <script src="/pos/static/js/virtual-scroll.js" defer></script>
-  <script src="/pos/static/js/inventory.js?v=10" defer></script>
+  <script src="/pos/static/js/inventory.js?v=12" defer></script>
   <script src="/pos/static/js/offline-banner.js" defer></script>
   <script src="/pos/static/js/sync-engine.js" defer></script>
   <script>if('serviceWorker' in navigator){navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'});}</script>