Uploading packages

Upload and publish a package permanently

Uploading a package puts it in the main package index so that anyone can download it and view information about it. You can only upload a package version once and this cannot be undone, so try to get it right the first time! To reduce the risk of mistakes it's recommended to use the package candidates feature described below.

Packages must be in the form produced by Cabal's sdist command: a gzipped tar file package-version.tar.gz comprising a directory package-version containing a package of that name and version, including package.cabal. See the notes at the bottom of the page.

Package versioning

In order to ensure the integrity and well-functioning of the Hackage/Cabal ecosystem, all packages should follow Haskell's Package Versioning Policy (PVP).

In particular, be aware that although the PVP and SemVer are based on the same concepts they differ significantly in structure and consequently are not compatible with each other. Please consult the PVP/SemVer FAQ section for more details about the differences and related issues.

Open source licenses

The code and other material you upload and distribute via this site must be under an open source license. This is a service operated for the benefit of the community and that is our policy. It is also so that we can operate the service in compliance with copyright laws.

The Hackage operators do not want to be in the business of making judgements on what is and is not a valid open source license, but we retain the right to remove packages that are not under licenses that are open source in spirit, or that conflict with our ability to operate this service. (If you want advice, see the ones Cabal recommends.)

The Hackage operators do not need and are not asking for any rights beyond those granted by the open source license you choose to use. All normal open source licenses grant enough rights to be able to operate this service.

In particular, we expect as a consequence of the license that:

  1. we have the right to distribute what you have uploaded to other people
  2. we have the right to distribute certain derivatives and format conversions, including but not limited to:
    • documentation derived from the package
    • alternative presentations and formats of code (e.g. html markup)
    • excerpts and presentation of package metadata
    • modified versions of package metadata

Please make sure that you comply with the license of all code and other material that you upload. For example, check that your tarball includes the license files of any 3rd party code that you include.


To upload a package, you'll need a Hackage username and password.

If you upload a package or package candidate and no other versions exist in the package database, you become part of the maintainer group for that package, and you can add other maintainers if you wish. If a maintainer group exists for a package, only its members can upload new versions of that package.

If there is no maintainer, the uploader can remove themselves from the group, and a package trustee can add anyone who wishes to assume the responsibility. The Maintainer field of the Cabal file should be None in this case. If a package is being maintained, any release not approved and supported by the maintainer should use a different package name. Then use the Maintainer field as above either to commit to supporting the fork yourself or to mark it as unsupported.

Package Candidates (Tech Preview)

Package candidates are a way to preview the package page, view any warnings or possible errors you might encounter, and let others install it before publishing it to the main index. (Note: you can view these warnings with 'cabal check'.) You can have multiple candidates for each package at the same time so long as they each have different versions. Finally, you can publish a candidate to the main index if it's not there already.

Package candidates have not yet been fully implemented and are still being improved; see Package Candidates Project Dashboard for an overview of what still needs to be done.

Upload a package candidate