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Frequently Asked Questions

What is JSR?

JSR is a new package registry for JavaScript. It is a free alternative to npm, that is designed to work well with all JavaScript tools and runtimes, like Node.js, Deno, Bun, Vite, and more.

Learn more about why we built JSR.

How do I use JSR?

If you want to consume packages, read the Using packages guide.

If you want to publish packages, read the Publishing packages guide.

Is JSR a package manager like npm, yarn, or pnpm?

No. JSR is a package registry (the server storing the packages), not a package manager (the tool that installs packages). You can use existing package managers like npm, yarn, or pnpm with JSR.

A deeper discussion of this can be found here.

Is JSR open source?

Yes. JSR is open source and licensed under the MIT License. You can find the source code on GitHub.

How is JSR different from npm?

JSR is designed to be a superset of npm, allowing existing tools that use npm to seamlessly work with JSR. JSR is designed to be better than npm:

  • Automatic documentation generation
  • Package scoring
  • Native TypeScript support
  • No need for build steps, which leads to better user experience for package publishers
  • Secure, token-less publishing for resistance against supply chain attacks
  • and more… Learn more about why we built JSR.

How is JSR funded? / Do I have to pay for JSR?

JSR is designed to be a public good for the JavaScript community, and will thus always be free to use.

Currently hosting bills for JSR are paid for by the Deno Company. In the future, JSR may be funded by alternative means, like sponsorships, donations, or a foundation. We expect that the Deno Company will be able to continue paying for JSR’s hosting bills for the foreseeable future - JSR is designed to be very cheap to run.

Can I delete a package from JSR?

Source code published to JSR can not be deleted. Learn more about immutability.

You can “yank” a version of a package, which will hide the version from the default view, but it will still be available to users who depend on it. Learn more about yanking.

You may delete a package if it has no published versions. Learn more about deleting empty packages.

Why are there quotas for scopes and package versions on JSR?

To prevent abuse, JSR has quotas for scopes and package versions. These quotas are designed to be generous and should not affect your normal usage. If you need a quota increase, please reach out to us at quotas@jsr.io - we will happily increase your quota if you run into it.

What is JSR’s policy on name squatting?

We disallow name squatting on JSR. We define name squatting as the act of registering a scope / package name with no intention of using it, or to prevent someone with a legitimate use from using it (e.g. to sell it to them).

Learn more about the JSR usage policy.

How do I report a security vulnerability in JSR?

Please follow the Deno Company’s security policy to report security vulnerabilities in JSR infrastructure.

You may also report security vulnerabilities in individual packages to the package’s scope owner. If the scope owner is unresponsive, please reach out to us at security@jsr.io.

How do I report a bug in JSR?

During the open beta, please email us at help@jsr.io, or chat in the #jsr channel on the Deno Discord (https://discord.gg/deno).

Please open an issue on the JSR GitHub repository at jsr-io/jsr.

Why does JSR ask to “Act on your behalf” when I log in with GitHub?

When signing in with GitHub, GitHub presents you with a screen that asks for your permission to authorize JSR. This screen includes a list of resources that JSR can access (only your email addresses and public profile information).

This screen also contains the text “Act on your behalf” which suggests that JSR can perform arbitrary actions on your behalf. This is misleading, and not true. JSR can act on your behalf only to read any resources you have granted it access to (your email addresses and public profile information). It cannot perform arbitrary actions on your behalf.

JSR can not modify your GitHub account, create repositories, create comments, or do anything else that would be considered “acting on your behalf”. GitHub presents this “Act on your behalf” screen to all GitHub Apps, regardless of what permissions they actually request.

You can read more about this in the GitHub documentation and in this discussion thread on the official GitHub Discussions feedback forum.

Yes! You can filter the package search to only return packages that are compatible with one or more runtimes, by using the runtime filter in the search query.

To filter for packages that are compatible with Deno, you can use the query runtime:deno. To filter for packages that are compatible with Node.js, you can use the query runtime:node. You can also combine these filters, for example runtime:deno runtime:browsers will return packages that are compatible with both Deno and web browsers. The possible values for the runtime filter are deno, node, browsers, workerd (Cloudflare Workers), and bun.

Yes! You can specify scope: in the search query to filter packages by scope. To only return packages in the std scope, you can use the query scope:std.

Is “JSR” an initialism for “JavaScript Registry”?

Yes.

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