# AbstractHttpAdapter

**Kind:** Class

**Source:** [`packages/core/adapters/http-adapter.ts`](https://github.com/nestjs/nest/blob/master/packages/core/adapters/http-adapter.ts#L8)

**Part of:** [Core](subsystem-packages-core)

`AbstractHttpAdapter` defines the common HTTP server adapter contract used by NestJS platform integrations. It delegates middleware and route registration methods such as `use()`, `get()`, `post()`, and `head()` to the underlying HTTP framework instance, allowing Nest applications to work with different server implementations.

**Implements:** `HttpServer`

## Methods

| Method | Signature | Returns |
|---|---|---|
| `init` | `init()` | `void` |
| `use` | `use(args: any[])` | `void` |
| `get` | `get(handler: RequestHandler)` | `void` |
| `get` | `get(path: any, handler: RequestHandler)` | `void` |
| `get` | `get(args: any[])` | `void` |
| `post` | `post(handler: RequestHandler)` | `void` |
| `post` | `post(path: any, handler: RequestHandler)` | `void` |
| `post` | `post(args: any[])` | `void` |
| `head` | `head(handler: RequestHandler)` | `void` |
| `head` | `head(path: any, handler: RequestHandler)` | `void` |
| `head` | `head(args: any[])` | `void` |
| `delete` | `delete(handler: RequestHandler)` | `void` |
| `delete` | `delete(path: any, handler: RequestHandler)` | `void` |
| `delete` | `delete(args: any[])` | `void` |
| `put` | `put(handler: RequestHandler)` | `void` |
| `put` | `put(path: any, handler: RequestHandler)` | `void` |
| `put` | `put(args: any[])` | `void` |
| `patch` | `patch(handler: RequestHandler)` | `void` |
| `patch` | `patch(path: any, handler: RequestHandler)` | `void` |
| `patch` | `patch(args: any[])` | `void` |
| `propfind` | `propfind(handler: RequestHandler)` | `void` |
| `propfind` | `propfind(path: any, handler: RequestHandler)` | `void` |
| `propfind` | `propfind(args: any[])` | `void` |
| `proppatch` | `proppatch(handler: RequestHandler)` | `void` |
| `proppatch` | `proppatch(path: any, handler: RequestHandler)` | `void` |
| `proppatch` | `proppatch(args: any[])` | `void` |
| `mkcol` | `mkcol(handler: RequestHandler)` | `void` |
| `mkcol` | `mkcol(path: any, handler: RequestHandler)` | `void` |
| `mkcol` | `mkcol(args: any[])` | `void` |
| `copy` | `copy(handler: RequestHandler)` | `void` |
| `copy` | `copy(path: any, handler: RequestHandler)` | `void` |
| `copy` | `copy(args: any[])` | `void` |
| `move` | `move(handler: RequestHandler)` | `void` |
| `move` | `move(path: any, handler: RequestHandler)` | `void` |
| `move` | `move(args: any[])` | `void` |
| `lock` | `lock(handler: RequestHandler)` | `void` |
| `lock` | `lock(path: any, handler: RequestHandler)` | `void` |
| `lock` | `lock(args: any[])` | `void` |
| `unlock` | `unlock(handler: RequestHandler)` | `void` |
| `unlock` | `unlock(path: any, handler: RequestHandler)` | `void` |
| `unlock` | `unlock(args: any[])` | `void` |
| `all` | `all(handler: RequestHandler)` | `void` |
| `all` | `all(path: any, handler: RequestHandler)` | `void` |
| `all` | `all(args: any[])` | `void` |
| `search` | `search(handler: RequestHandler)` | `void` |
| `search` | `search(path: any, handler: RequestHandler)` | `void` |
| `search` | `search(args: any[])` | `void` |
| `options` | `options(handler: RequestHandler)` | `void` |
| `options` | `options(path: any, handler: RequestHandler)` | `void` |
| `options` | `options(args: any[])` | `void` |

## Properties

| Property | Type |
|---|---|
| `httpServer` | `TServer` |
| `onRouteTriggered` | `| ((requestMethod: RequestMethod, path: string) => void) | undefined` |

## Diagram

```mermaid
graph LR
  Nest[Nest Application] --> Adapter[AbstractHttpAdapter]
  Adapter --> Instance[Underlying HTTP Framework Instance]
  Adapter --> Init[init()]
  Adapter --> Middleware[use()]
  Adapter --> Routes[get() / post() / head()]
  Middleware --> Instance
  Routes --> Instance
  Instance --> Server[HTTP Server]
```

## Usage

```ts
import * as express from 'express';
import { NestFactory } from '@nestjs/core';
import { ExpressAdapter } from '@nestjs/platform-express';
import { AppModule } from './app.module';

async function bootstrap() {
  const expressApp = express();
  const httpAdapter = new ExpressAdapter(expressApp);

  // Register framework-native middleware through the adapter.
  httpAdapter.use((req, res, next) => {
    console.log(`${req.method} ${req.url}`);
    next();
  });

  // Register routes directly on the underlying platform.
  httpAdapter.get('/health', (_req, res) => {
    res.status(200).json({ status: 'ok' });
  });

  httpAdapter.head('/health', (_req, res) => {
    res.status(200).end();
  });

  const app = await NestFactory.create(AppModule, httpAdapter);
  await app.listen(3000);
}

bootstrap();
```

## AI Coding Instructions

- Extend `AbstractHttpAdapter` only when integrating a new HTTP platform; use concrete adapters such as `ExpressAdapter` or `FastifyAdapter` in application code.
- Delegate route and middleware methods to the underlying framework instance so native platform behavior is preserved.
- Keep `get()`, `post()`, and `head()` overload behavior compatible with the target framework’s route-registration API.
- Use `use()` for platform middleware registration, but prefer Nest middleware, guards, interceptors, and controllers for application-level concerns.
- Ensure the adapter is initialized and passed to `NestFactory.create()` when configuring a custom HTTP server instance.

## How it works

`AbstractHttpAdapter<TServer, TRequest, TResponse>` is a public abstract base class for HTTP platform adapters. It implements the `HttpServer<TRequest, TResponse>` contract and stores both a platform instance and, separately, an HTTP server value. Its type parameters default to `any`. [`packages/core/adapters/http-adapter.ts:5-18`](packages/core/adapters/http-adapter.ts#L5-L18)

## Relationships

- IMPORTS → `HttpServer`
- IMPORTS → `RequestMethod`
- IMPORTS → `VersioningOptions`
- IMPORTS → `RequestHandler`
- IMPORTS → `VersionValue`
- IMPORTS → `NestApplicationOptions`

## Used by

3 references from 3 files. Each is a place in this repository where the symbol is actually used — go read one rather than trusting an example.

### Imported by (3)

- `ExpressAdapter` — `packages/platform-express/adapters/express-adapter.ts`:51
- `FastifyAdapter` — `packages/platform-fastify/adapters/fastify-adapter.ts`:124
- `TestingModule` — `packages/testing/testing-module.ts`:26