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# tools.devServer

- **Type:** `Object`
- **Default:** `{}`

The config of DevServer can be modified through `tools.devServer`.

### Options

#### compress

:::warning
**Deprecated**: This configuration is deprecated, please use [dev.server.compress](https://modernjs.dev/en/configure/app/dev/server) instead.
:::

- **Type:** `boolean`
- **Default:** `true`

Whether to enable gzip compression for served static assets.

If you want to disable the gzip compression, you can set `compress` to `false`:

```ts
export default {
  tools: {
    devServer: {
      compress: false,
    },
  },
};
```

#### headers

:::warning
**Deprecated**: This configuration is deprecated, please use [dev.server.headers](https://modernjs.dev/en/configure/app/dev/server) instead.
:::

- **Type:** `Record<string, string>`
- **Default:** `undefined`

Adds headers to all responses.

```js
export default {
  tools: {
    devServer: {
      headers: {
        'X-Custom-Foo': 'bar',
      },
    },
  },
};
```

#### historyApiFallback

:::warning
**Deprecated**: This configuration is deprecated, please use [dev.server.historyApiFallback](https://modernjs.dev/en/configure/app/dev/server) instead.
:::

- **Type:** `boolean | ConnectHistoryApiFallbackOptions`
- **Default:** `false`

The index.html page will likely have to be served in place of any 404 responses. Enable `devServer.historyApiFallback` by setting it to `true`:

```js
export default {
  tools: {
    devServer: {
      historyApiFallback: true,
    },
  },
};
```

For more options and information, see the [connect-history-api-fallback](https://github.com/bripkens/connect-history-api-fallback) documentation.

#### proxy

:::warning
**Deprecated**: This configuration is deprecated, use [dev.server.proxy](https://modernjs.dev/en/configure/app/dev/server) instead.
:::

- **Type:** `ProxyOptions[] | Record<string, string | ProxyOptions>`
- **Default:** `undefined`

Configure proxy rules for the dev server, and forward requests to the specified service.

```js
export default {
  tools: {
    devServer: {
      proxy: {
        // http://localhost:8080/api -> https://example.com/api
        // http://localhost:8080/api/foo -> https://example.com/api/foo
        '/api': 'https://example.com',
      },
    },
  },
};
```

#### watch

:::warning
**Deprecated**: This configuration is deprecated, please use [dev.server.watch](https://modernjs.dev/en/configure/app/dev/server) instead.
:::

- **Type:** `boolean`
- **Default:** `true`

Whether to watch files change in directories such as `mock/`, `server/`, `api/`.