cowsay.pw is offline ❌

This is a mirror of the upstream Nix Binary Cache, a service that helps speed up builds for the Nix Package Manager.


Current mirror status:

S3 Backend: offline

ClickHouse: offline


This mirror seems to be malfunctioning. Please contact the administrators.


ClickHouse Status Info: 522 (Origin Connection Time-out)
Minio Status Info: 521 (Origin Down)
Ray ID: 5184cd35998956b5
Worker Version: 1.0.0pre0_0000000

To use this cache, simply set the following lines in your /etc/nix/nix.conf:

substituters = https://cache.nixos.org https://cache.cowsay.pw

Or, set the following lines in your configuration.nix:

nix.binaryCaches = [ "https://cache.nixos.org" "https://cache.cowsay.pw" ]

(You may also use trusted-substituters instead, which will instead allow system users to opt-in to this cache on a per-build basis, rather than globally use it at all times.)

There is no need to include a separate signing key. As this is only a mirror, upstream NAR files are used, and are already signed with the cache.nixos.org private key (so you do not need to trust the operators of this mirror).


This service is hosted and served by CloudFlare, via Workers. It is automatically deployed from GitHub as a "live" service. The underlying storage backend for the binary objects is durable S3-compatible storage, provided by Minio. Updates to this mirror occur upon update the upstream nixpkgs-channels repository, and are checked once every three hours. The services that support this mirror are completely independent of all upstream https://nixos.org infrastructure, and running on completely separate cloud providers, to help avoid SPOFs.

The currently supported set of channels mirrored by this service, polled once every three hours:

Cache requests and responses to this service are logged. Other than the first-party analytics information stored by CloudFlare itself, this information is not shared with any third-party analytics services, is stored on self-hosted servers (using ClickHouse), and is only used to provide information to package maintainers and service operators about package usage, download distribution, and performance metrics of the cache. IP addresses are not logged. To see information about the aggregated analytics collected, as well as further technical details, please visit https://analytics.cowsay.pw


The source code for this application, including this script and the data pipeline, is available at this URL. You may report issues and bugs here.

If you are having trouble, please reach out through one of the support channels with the results of the included diagnostics script which will help us figure out where the issue lies. You can run this script instantly without permanently installing or copying anything:

nix run -f https://github.com/thoughtpolice/nix-mirror/archive/master.tar.gz -c diagnose-cache

Ray ID: 5184cd35998956b5
Visitor IP: 34.231.247.139 (US)
Version: 1.0.0pre0_0000000
Cat fact: Cats get along extremely well with cows, especially talking ones.