The Rust community has outgrown the current policies. This RFC proposes a new “Terms of Use” policy based on prior work by PyPI, npm and GitHub.


Why are we doing this? What use cases does it support? What is the expected outcome? has a “Package Policies” page, which describes the current, organically grown policies. A lot of support requests or questionable uses of however need explicit decisions from the team, since many cases are currently not covered by these policies. Additionally, decisions made by the team may be seen as arbitrary without written guidelines.

The situation around name squatting has lately also reached unsustainable levels, and while namespaces might help with some parts of the problem we would still need policies for name squatting namespaces then.

The main motivation for this RFC is to give the team a fixed set of rules to determine if a project is using in a reasonable way, or if the user should get a warning and the project potentially be removed. It is mostly codifying the existing practices of the team, except for being more strict regarding name squatting.


The following is a proposed new “Terms of Use” policy for, replacing and

Terms of Use

Short version: is a critical resource for the Rust ecosystem, which hosts a variety of packages from a diverse group of users. That resource is only effective when our users are able to work together as part of a community in good faith. While using, you must comply with our Acceptable Use Policies, which include some restrictions on content and conduct on related to user safety, intellectual property, privacy, authenticity, and other limitations. In short, be excellent to each other!

We do not allow content or activity on that:

  • violates the Code of Conduct of the Rust project
  • is unlawful or promotes unlawful activities, incurring legal liability in the countries the Rust Foundation officially operates in
  • is libelous, defamatory, or fraudulent
  • amounts to phishing or attempted phishing
  • infringes any proprietary right of any party, including patent, trademark, trade secret, copyright, right of publicity, or other right
  • unlawfully shares unauthorized product licensing keys, software for generating unauthorized product licensing keys, or software for bypassing checks for product licensing keys, including extension of a free license beyond its trial period
  • contains malicious code, such as computer viruses, computer worms, rootkits, back doors, or spyware, including content submitted for research purposes (tools designed and documented explicitly to assist in security research are acceptable, but exploits and malware that use the registry as a deployment or delivery vector are not)
  • uses obfuscation to hide or mask functionality
  • is discriminatory toward, harasses or abuses another individual or group
  • threatens or incites violence toward any individual or group, especially on the basis of who they are
  • is using as a platform for propagating abuse on other platforms
  • violates the privacy of any third party, such as by posting another person’s personal information without consent
  • gratuitously depicts or glorifies violence, including violent images
  • is sexually obscene or relates to sexual exploitation or abuse, including of minors (see “Sexually Obscene Content” section below)
  • is off-topic, or interacts with platform features in a way that significantly or repeatedly disrupts the experience of other users
  • exists only to reserve a name for a prolonged period of time (often called “name squatting”) without having any genuine functionality, purpose, or significant development activity on the corresponding repository
  • is related to buying, selling, or otherwise trading of package names or any other names on for money or other compensation
  • impersonates any person or entity, including through false association with, or by fraudulently misrepresenting your identity or site’s purpose
  • is related to inauthentic interactions, such as fake accounts and automated inauthentic activity
  • is using our servers for any form of excessive automated bulk activity, to place undue burden on our servers through automated means, or to relay any form of unsolicited advertising or solicitation through our servers, such as get-rich-quick schemes
  • is using our servers for other automated excessive bulk activity or coordinated inauthentic activity, such as
    • spamming
    • cryptocurrency mining
  • is not functionally compatible with the cargo build tool (for example, a “package” cannot simply be a PNG or JPEG image, a movie file, or a text document uploaded directly to the registry)
  • is abusing the package index for purposes it was not intended

You are responsible for using in compliance with all applicable laws, regulations, and all of our policies. These policies may be updated from time to time. We will interpret our policies and resolve disputes in favor of protecting users as a whole. The team reserves the possibility to evaluate each instance on a case-by-case basis.

For issues such as DMCA violations, or trademark and copyright infringements, the team will respect the legal decisions of the Rust Foundation as the official legal entity providing the service.

Package Ownership has a first-come, first-serve policy on crate names. Upon publishing a package, the publisher will be made owner of the package on

If you want to take over a package, we require you to first try and contact the current owner directly. If the current owner agrees, they can add you as an owner of the crate, and you can then remove them, if necessary. If the current owner is not reachable or has not published any contact information the team may reach out to help mediate the process of the ownership transfer.

Crate deletion by their owners is not possible to keep the registry as immutable as possible. If you want to flag your crate as open for transferring ownership to others, you can publish a new version with a message in the README or description communicating to the support team that you consent to transfer the crate to the first person who asks for it:

I consent to the transfer of this crate to the first person who asks for it.

The team may delete crates from the registry that do not comply with the policies on this document. In larger cases of squatting attacks this may happen without prior notification to the author, but in most cases the team will first give the author the chance to justify the purpose of the crate.

Data Access

If you need access to a large subset of the database we recommend first looking at the index repository. This repository is updated live whenever new versions are published and contains all the information needed for cargo to run the dependency resolution algorithm.

In case the index dataset is insufficient for your purposes, we also publish a database dump every 24 hours. This includes the majority of data from our database except for sensitive private information. The latest database dump is available at and information on using the content is contained in the tarball. Please note that while we aim to keep the data structure somewhat stable, we can not give any stability guarantees on the exact database table layouts.

If the index repository and the database dump are insufficient you may also use the API directly, though it is at the discretion of the to block any excessive usage. We require users of the API to limit themselves to a maximum of 1 request per second.

We also require all API users to provide a user-agent header that allows us to uniquely identify your application. This allows us to more accurately monitor any impact your application may have on our service. Providing a user agent that only identifies your HTTP client library (such as reqwest/0.9.1) increases the likelihood that we will block your traffic.

It is recommended, to include contact information in your user-agent header:

  • Bad: User-Agent: reqwest/0.9.1
  • Better: User-Agent: my_bot
  • Best: User-Agent: my_bot ( or User-Agent: my_bot (

This allows us to contact you if we would like a change in your application’s behavior without having to block your traffic.

We reserve the right to block traffic from any client that we determine to be in violation of this policy or causing an impact on the integrity of our service.


Safety is one of the core principles of Rust, and to that end, we would like to ensure that cargo and have secure implementations. To learn more about disclosing security vulnerabilities for these tools, please reference the Rust Security policy for more details.

Note that this policy only applies to official Rust projects like and cargo, and not individual crates. The team and the Security Response working group are not responsible for the disclosure of vulnerabilities to specific crates, and if any issues are found, you should seek guidance from the individual crate owners and their specific policies instead.

Thank you for taking the time to responsibly disclose any issues you find.

Sexually Obscene Content

We do not tolerate content associated with sexual exploitation or abuse of another individual, including where minors are concerned. We do not allow sexually themed or suggestive content that serves little or no purpose other than to solicit an erotic or shocking response, particularly where that content is amplified by its placement in profiles or other social contexts.

This includes:

  • Pornographic content
  • Non-consensual intimate imagery
  • Graphic depictions of sexual acts including photographs, video, animation, drawings, computer-generated images, or text-based content

We recognize that not all nudity or content related to sexuality is obscene. We may allow visual and/or textual depictions in artistic, educational, historical or journalistic contexts, or as it relates to victim advocacy. In some cases a disclaimer can help communicate the context of the project.

Violations and Enforcement retains full discretion to take action in response to a violation of these policies, including account suspension, account termination, or removal of content.

We will however not be proactively monitoring the site for these kinds of violations, but instead relying on the community to draw them to our attention.

While the majority of interactions between individuals in the Rust community falls within our policies, violations of those policies do occur at times. When they do, the team may need to take enforcement action to address the violations. In all cases, content and account deletion is permanent and there is no basis to reverse these moderation actions taken by the team. Account suspension may be lifted at the team’s discretion however, for example in the case of someone’s account being compromised.

Credits & License

This policy is partially based on PyPI’s Acceptable Use Policy and modified from its original form.

Licensed under the Creative Commons Attribution 4.0 International license.

Prior art

As the “Credits & License” says, the main inspiration for the proposed policy is the Acceptable Use Policy of the Python Package Index (PyPI). Their policy in turn is based on the Acceptable Use Policies of GitHub. Both of these policies are licensed under the Creative Commons Attribution 4.0 International license, so we can happily reuse them.

PEP 541 (Python Enhancement Proposal) was also mixed into the document above, specifically the Invalid Projects section.

The third source of material are the “Open-Source Terms” from npm, from which a few more rules on “Acceptable Content” were imported.

RubyGems, Maven Central, Packagist (PHP) and Nuget (C#) were also investigated, but they did not appear to have written rules published in easy-to-find places.

Unresolved questions

  • Is the wording of the “name reservation” clause sufficient to discourage name squatting in the future?
  • Are there any current legitimate uses of that would suddenly be forbidden by these new rules?
  • Should the policies forbid embedding executable binaries in the crate files?

Future possibilities

  • PEP 541 also defines rules for abandoned projects and how people could continue maintenance for them. Introducing something like that would be a large deviation for though, and something that would need a dedicated RFC. Nevertheless, it is worth thinking about if the majority of the Rust community would prefer having such a ruleset.