---
lang: en
title: 'API docs: core.application.interceptor'
keywords: LoopBack 4.0, LoopBack 4, Node.js, TypeScript, OpenAPI
sidebar: lb4_sidebar
editurl: https://github.com/loopbackio/loopback-next/tree/master/packages/core
permalink: /doc/en/lb4/apidocs.core.application.interceptor.html
---

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[Home](./index.md) &gt; [@loopback/core](./core.md) &gt; [Application](./core.application.md) &gt; [interceptor](./core.application.interceptor.md)

## Application.interceptor() method

Register an interceptor

**Signature:**

```typescript
interceptor(interceptor: Interceptor | Constructor<Provider<Interceptor>>, nameOrOptions?: string | InterceptorBindingOptions): Binding<Interceptor>;
```

## Parameters

|  Parameter | Type | Description |
|  --- | --- | --- |
|  interceptor | [Interceptor](./context.interceptor.md) \| [Constructor](./context.constructor.md)<!-- -->&lt;[Provider](./context.provider.md)<!-- -->&lt;[Interceptor](./context.interceptor.md)<!-- -->&gt;&gt; | An interceptor function or provider class |
|  nameOrOptions | string \| [InterceptorBindingOptions](./context.interceptorbindingoptions.md) | _(Optional)_ Binding name or options |

**Returns:**

[Binding](./context.binding.md)<!-- -->&lt;[Interceptor](./context.interceptor.md)<!-- -->&gt;