> Be aware npm configurations are valid on the classic version
The classic version is able to regonize the `.npmrc` file, but also provides their own configuration file named `.yarnrc`.
To set up a registry, create a file and define a registry.
```
// .yarnrc
registry "http://localhost:4873"
```
By using this version you should enable `always-auth` in your configuration running:
```
npm config set always-auth true
```
`yarn@1.x` does not send the authorization header on `yarn install` if your packages requires authentication, by enabling `always-auth` will force yarn do it on each request.
#### Yarn Berry (>=2.x) {#yarn-berry-2x}
> Yarn berry does not recognize `--registry` or `.npmrc` file anymore.
For defining a registry you must use the `.yarnrc.yml` located in the root of your project or global configuration.
When you publish a package the `npmRegistryServer` must be used. Keep in mind the `publishConfig.registry` in the `package.json` will override this configuration.
```yaml
// .yarnrc.yml
npmRegistryServer: "http://localhost:4873"
unsafeHttpWhitelist:
- localhost
```
> `unsafeHttpWhitelist` is only need it if you don't use `https` with a valid certificate.
Using scopes is also possible and more segmented, you can define a token peer scope if is required.
