> This page is for Home.

> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://developers.webflow.com/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://developers.webflow.com/_mcp/server.

# Breaking changes in JavaScript SDK: December 17, 2024 release

> Important breaking changes in the December 17, 2024 release of the Webflow Data API and SDK that require updates to your implementation.

This document outlines the breaking changes introduced in the [December 17, 2024 release](/data/changelog/121724) of the Webflow Data API and JavaScript SDK. Review these changes carefully as they may require updates to your existing implementations.

## Breaking changes in JavaScript SDK

> **Note**
>
> These changes require updates to existing code if you're using the JavaScript SDK. Review and update your implementation to ensure compatibility.

### Collection management

* **Changed method name for deleting collections**

  ```typescript
  // Old
  client.collections.deleteCollection()

  // New
  client.collections.delete(collectionId)
  ```

* **New method for deleting collection fields**

  ```typescript
  client.collections.deleteField(collectionId, fieldId)
  ```

### CMS item creation

* **Changed:** `client.collections.createItems()` replaces previous methods
* **Removed:** `client.collections.createItemForMultipleLocales()`

### Pages localization

* **Changed parameter name:** The `locale` query parameter is now `localeId`

## Migration guide

### Deleting collection items

If you're using the existing collection deletion method, update your code to use the new method name:

**`Delete collection item`**

```typescript title="Delete collection item"
// Before
await client.collections.deleteCollection(collectionId);

// After
await client.collections.delete(collectionId);
```

### Collection item creation

Replace any usage of the deprecated methods with the new unified method:

**`Create collection item`**

```typescript title="Create collection item"
// Before (deprecated)
await client.collections.createItemForMultipleLocales(collectionId, {
  localeIds: [primaryCmsLocaleId, secondaryCmsLocaleId],
  // other params
});

// After
await client.collections.items.createItems(collectionId, {
  cmsLocaleIds: [primaryCmsLocaleId, secondaryCmsLocaleId],
  isArchived: false,
  isDraft: false,
  fieldData: {
    // your fields here
  },
});
```

### Page localization

Update any code that queries localized pages to use the new parameter name:

**`Page localization`**

```typescript title="Page localization"
// Before
const pages = await client.pages.list({ locale: "507f1f77bcf86cd799439011" });

// After
const pages = await client.pages.list({ localeId: "507f1f77bcf86cd799439011" });
```

If you encounter any issues with these changes, please [contact our support team](https://webflow.com/dashboard/support) for assistance.

## SDK improvements

* **Type improvements**
  * Removed requirement for `id` in request payloads when creating resources
  * `fieldData` type in CMS Items now allows arbitrary key/value pairs, supporting custom fields

* **Flexible CMS item creation**
  The SDK now allows creation of CMS items with custom fields without requiring type updates