---
jsApi: true
title: "[T] CadlLibraryDef"

---
```ts
CadlLibraryDef: <T, E> TypeSpecLibraryDef< T, E >
```

## Deprecated

Use TypeSpecLibraryDef

## Type parameters

| Parameter | Default |
| :------ | :------ |
| `T` *extends* \{} | - |
| `E` *extends* `Record`< `string`, `any` \> | `Record`< `string`, `never` \> |
