NixOS Logo provides prebuilt binaries for Nixpkgs and NixOS. It is used automatically by the Nix package manager to speed up builds.

Heads up: This service is IN BETA, and you must opt into it explicitly before it will be deployed to To use, change your default substituter to

For more information, see the Wiki for how to configure and use this service, as well as the current limitations. Check the ChangeLog for what's new.

Help, troubleshooting, and about this service

If you are having trouble, please reach out with the results of this diagnostics script, which will help us figure out where the issue lies. You can copy the above script and run it from a file, or you can run it immediately using Nix:

nix run -f -c diagnose-cache

An accompanying Wiki describes how this service operates, how to get in touch with the developers, report bugs, get the source code, understand the configuration, and much more. There is also a ChangeLog describing major updates made to this service.

General support for Nix and the Nix community can be found on the NixOS website. The source code for our CDN setup, this landing page content, and configuration details are available at this URL.

© Stichting NixOS Foundation, 2019. Support NixOS! π
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