> For the complete documentation index, see [llms.txt](https://dexiejs.typogram.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dexiejs.typogram.co/dexie/dexie.use.md).

# Dexie.use()

#### Syntax

```javascript
db.use({stack, name?, create})
```

#### Properties of the parameter

| stack : String    | Stack type. Currently, only "dbcore" is supported.                                              |
| ----------------- | ----------------------------------------------------------------------------------------------- |
| name : String     | Optional name of your middleware                                                                |
| create : Function | The middleware itself. It takes a DBCore instance and should return a modified DBCore instance. |

## Remarks

Your provided `create` function takes a DBCore and should return another plain JS object confirming to the DBCore interface.

## Example

```typescript
import Dexie from 'dexie';

const db = new Dexie('dbname');

db.use({
  stack: "dbcore", // The only stack supported so far.
  name: "MyMiddleware", // Optional name of your middleware
  create (downlevelDatabase) {
    // Return your own implementation of DBCore:
    return {
      // Copy default implementation.
      ...downlevelDatabase, 
      // Override table method
      table (tableName) {
        // Call default table method
        const downlevelTable = downlevelDatabase.table(tableName);
        // Derive your own table from it:
        return {
          // Copy default table implementation:
          ...downlevelTable,
          // Override the mutate method:
          mutate: req => {
            // Copy the request object
            const myRequest = {...req};
            // Do things before mutate, then
            // call downlevel mutate:
            return downlevelTable.mutate(myRequest).then(res => {
              // Do things after mutate
              const myResponse = {...res};
              // Then return your response:
              return myResponse;
            });
          }
        }
      }
    };
  }
});

```

In essence, all mutating operations are bulk-oriented. There's only bulkPut(), bulkAdd(), bulkDelete() and deleteRange(). Currently all of these four are reached through a single method mutate().

Interface definitions for DBCore is found [here](https://github.com/dexie/Dexie.js/blob/master/src/public/types/dbcore.d.ts)