---
id: uplinks
title: "Uplinks"
---
An *uplink* is a link with an external registry that provides acccess to external packages.

![Uplinks](/img/uplinks.png)

### Usage

```yaml
uplinks:
  npmjs:
   url: https://registry.npmjs.org/
  server2:
    url: http://mirror.local.net/
    timeout: 100ms
  server3:
    url: http://mirror2.local.net:9000/
  baduplink:
    url: http://localhost:55666/
```

### Configuration

You can define mutiple uplinks and each of them must have an unique name (key). They can have two properties:

| Property     | Type    | Required | Example                                                                       | Support | Description                                                                                                        | Default    |
| ------------ | ------- | -------- | ----------------------------------------------------------------------------- | ------- | ------------------------------------------------------------------------------------------------------------------ | ---------- |
| url          | string  | Yes      | https://registry.npmjs.org/                                                   | all     | The registry url                                                                                                   | npmjs      |
| ca           | string  | No       | ~./ssl/client.crt'                                                            | all     | SSL path certificate                                                                                               | No default |
| timeout      | string  | No       | 100ms                                                                         | all     | set new timeout for the request                                                                                    | 30s        |
| maxage       | string  | No       | 10m                                                                           | all     | limit maximun failure request                                                                                      | 2m         |
| fail_timeout | string  | No       | 10m                                                                           | all     | defines max time when a request becomes a failure                                                                  | 5m         |
| max_fails    | number  | No       | 2                                                                             | all     | limit maximun failure request                                                                                      | 2          |
| cache        | boolean | No       | [true,false]                                                                  | >= 2.1  | avoid cache tarballs                                                                                               | true       |
| auth         | list    | No       | type: [bearer], [token: "token",token_env: [true,\<get name process.env\>]] | >= 2.5  | assigns the header 'Authorization' see: http://blog.npmjs.org/post/118393368555/deploying-with-npm-private-modules | disabled   |
| headers      | list    | No       | authorization: "Bearer SecretJWToken=="                                       | all     | list of custom headers for the uplink                                                                              | disabled   |
| strict_ssl   | boolean | No       | [true,false]                                                                  | >= 3.0  | If true, requires SSL certificates be valid.                                                                       | true       |

> The `auth` property allows you to use a auth token via an environment variable, [clik here for an example](https://github.com/verdaccio/verdaccio/releases/tag/v2.5.0).

### You Must know

* Verdaccio does not use Basic Authentication since version `v2.3.0`. All tokens generated by verdaccio are based on JWT ([JSON Web Token](https://jwt.io/))
* Uplinks must be registries compatible with the `npm` endpoints. Eg: *verdaccio*, `sinopia@1.4.0`, *npmjs registry*, *yarn registry*, *JFrog*, *Nexus* and more.
* Setting `cache` to false will help to save space in your hard drive. This will avoid store `tarballs` but [it will keep metadata in folders](https://github.com/verdaccio/verdaccio/issues/391).
* Exceed with multiple uplinks might slow down the lookup of your packages due for each request a npm client does, verdaccio does 1 call for each uplink.
* The (timeout, maxage and fail_timeout) format follow the [NGINX measurement units](http://nginx.org/en/docs/syntax.html)