---
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)
