---
url: /reference/api/TypeAlias.ChunkAddonFunction.md
---
# Type Alias: ChunkAddonFunction

```ts
type ChunkAddonFunction = (ctx) => ChunkAddonObject | string | undefined
```

Defined in: [src/features/output.ts:97](https://github.com/rolldown/tsdown/blob/9f98be3c9c6627ed1c4e5bdec3d8a18e5463c4c8/src/features/output.ts#L97)

## Parameters

### ctx

#### fileName

`string`

#### format

[`Format`](TypeAlias.Format.md)

## Returns

[`ChunkAddonObject`](Interface.ChunkAddonObject.md) | `string` | `undefined`