---
url: /api/symbols/workbox-build/build/customchunkcallback.md
---

# CustomChunkCallback

Type Alias @vite-pwa/workbox-build/build

Defines a custom code chunk group.
Receives the module ID (file path) and returns the desired chunk name
or undefined if the module should stay in the default bundle.

```ts
type CustomChunkCallback = B
```