Private feeds

Sleet writes static files, and NuGet reads them with plain HTTP requests. To keep a feed private, keep the storage private and put something in front of it that checks who is asking. This page explains why, and lists the options.

Why NuGet can't use storage credentials

NuGet can send a user name and password to a package source, using basic or Windows authentication. Azure Storage and Amazon S3 don't accept those. They need Entra ID tokens, shared access signatures, or request signatures that NuGet can't create.

A shared access signature (SAS) in the source URL doesn't help either. NuGet reads index.json with it, but every other request uses the URLs written in the feed files, which don't include the signature.

The credentials in sleet.json are only used by Sleet to write the feed. They don't control who can read it.

Options

Option	Storage	How it works
Proxy with basic authentication	Any	A small web app or reverse proxy checks a user name and password, then returns files from private storage.
CloudFront with Lambda@Edge	Amazon S3	CloudFront reads a private bucket, and a Lambda@Edge function checks basic authentication. See private feed on AWS.
Web server with authentication	Local folder	IIS, nginx, or Apache serves the folder and requires basic or Windows authentication. See web servers and static hosting.
Network restrictions	Azure, Amazon S3	Storage only accepts reads from your network, for example with the Azure Storage firewall or private endpoints, or with an S3 bucket policy that checks aws:SourceIp or aws:SourceVpce. Clients don't need credentials.

For the proxy and CloudFront options, clients add credentials to their NuGet.Config. See sources that need credentials.

Point baseURI at the front end

Sleet writes absolute URLs into the feed files, using baseURI. Set baseURI to the URL of the proxy or CDN, so that all NuGet requests go through it. Sleet still writes to storage through path.

{
  "sources": [
    {
      "name": "feed",
      "type": "azure",
      "container": "feed",
      "path": "https://myaccount.blob.core.windows.net/feed/",
      "baseURI": "https://packages.example.com/"
    }
  ]
}

Set baseURI before the first push. To change it on an existing feed, see change baseURI or path in place.

Keep the storage private

When Sleet creates a container or bucket on the first push, it makes it public. Create it yourself first:

• Azure: create the container before the first push. New containers are private by default. Sleet doesn't change the access level of a container that already exists.

az storage container create --name feed --account-name myaccount --auth-mode login

• Amazon S3: create the bucket before the first push and leave Block Public Access on. Sleet doesn't change the policy or public access settings of a bucket that already exists. See create the bucket yourself for the commands, and skip the public policy.
• Local folder: make sure the web server only serves the feed folder to signed-in users.

Features that need anonymous access

• Badges are fetched by shields.io, which can't sign in. They only work if the badges/ files are public.
• The symbol server must be reachable by your debugger. Check that your debugger can sign in to the front end.
• An external search service must be reachable by clients, with the same kind of authentication as the feed.