1---
2title: registry
3section: 7
4description: The JavaScript Package Registry
5---
6
7### Description
8
9To resolve packages by name and version, npm talks to a registry website
10that implements the CommonJS Package Registry specification for reading
11package info.
12
13npm is configured to use the **npm public registry** at
14<https://registry.npmjs.org> by default. Use of the npm public registry is
15subject to terms of use available at <https://docs.npmjs.com/policies/terms>.
16
17You can configure npm to use any compatible registry you like, and even run
18your own registry. Use of someone else's registry may be governed by their
19terms of use.
20
21npm's package registry implementation supports several
22write APIs as well, to allow for publishing packages and managing user
23account information.
24
25The npm public registry is powered by a CouchDB database,
26of which there is a public mirror at <https://skimdb.npmjs.com/registry>.
27
28The registry URL used is determined by the scope of the package (see
29[`scope`](/using-npm/scope). If no scope is specified, the default registry is
30used, which is supplied by the [`registry` config](/using-npm/config#registry)
31parameter.  See [`npm config`](/commands/npm-config),
32[`npmrc`](/configuring-npm/npmrc), and [`config`](/using-npm/config) for more on
33managing npm's configuration.
34Authentication configuration such as auth tokens and certificates are configured
35specifically scoped to an individual registry. See
36[Auth Related Configuration](/configuring-npm/npmrc#auth-related-configuration)
37
38When the default registry is used in a package-lock or shrinkwrap it has the
39special meaning of "the currently configured registry". If you create a lock
40file while using the default registry you can switch to another registry and
41npm will install packages from the new registry, but if you create a lock
42file while using a custom registry packages will be installed from that
43registry even after you change to another registry.
44
45### Does npm send any information about me back to the registry?
46
47Yes.
48
49When making requests of the registry npm adds two headers with information
50about your environment:
51
52* `Npm-Scope` – If your project is scoped, this header will contain its
53  scope. In the future npm hopes to build registry features that use this
54  information to allow you to customize your experience for your
55  organization.
56* `Npm-In-CI` – Set to "true" if npm believes this install is running in a
57  continuous integration environment, "false" otherwise. This is detected by
58  looking for the following environment variables: `CI`, `TDDIUM`,
59  `JENKINS_URL`, `bamboo.buildKey`. If you'd like to learn more you may find
60  the [original PR](https://github.com/npm/npm-registry-client/pull/129)
61  interesting.
62  This is used to gather better metrics on how npm is used by humans, versus
63  build farms.
64
65The npm registry does not try to correlate the information in these headers
66with any authenticated accounts that may be used in the same requests.
67
68### How can I prevent my package from being published in the official registry?
69
70Set `"private": true` in your `package.json` to prevent it from being
71published at all, or
72`"publishConfig":{"registry":"http://my-internal-registry.local"}`
73to force it to be published only to your internal/private registry.
74
75See [`package.json`](/configuring-npm/package-json) for more info on what goes in the package.json file.
76
77### Where can I find my (and others') published packages?
78
79<https://www.npmjs.com/>
80
81### See also
82
83* [npm config](/commands/npm-config)
84* [config](/using-npm/config)
85* [npmrc](/configuring-npm/npmrc)
86* [npm developers](/using-npm/developers)
87