NuGet packages

Last reviewed Jun 1, 2026 Content v20260601

Track mode: server_compiled
Means: Compiled runner
Reading: ~1 min
Level: intermediate

This lesson

This lesson teaches NuGet packages: the syntax, patterns, and safety habits you need before advancing in C#.

Teams still ship NuGet packages in C# codebases—skipping it leaves gaps in debugging and code reviews.

You will apply NuGet packages in contexts like: Internal libraries, CLI tools, and microservices versioned with NuGet.

Write C# with Console.WriteLine (top-level or Program), click Run on server—the dev runner uses dotnet build/run on a temp net8 project (requires .NET SDK; LEARNING_RUNNER_ENABLED=true).

Toward the end of the track—consolidate before capstone-style review lessons.

NuGet is the .NET package manager—libraries ship as versioned packages referenced in .csproj, similar to Maven Central for Java. Restore downloads dependencies into a local cache.

Adding packages

dotnet add package Newtonsoft.Json
dotnet restore

Pin versions in CI; audit transitive dependencies for security advisories.

PackageReference

<PackageReference Include="Newtonsoft.Json" Version="13.0.3" />

Important interview questions and answers

Q: dotnet restore?
A: Downloads NuGet packages declared in project files before build.
Q: Transitive dependencies?
A: NuGet pulls dependent packages automatically—review lock files in teams.

Self-check

What command adds a package to a project?
Where do PackageReference entries live?

Pitfall: Pin package versions in CI—dotnet add package without version constraints can pull breaking updates on restore.

Interview prep

What is NuGet?: The .NET package manager—restore downloads dependencies listed in the csproj to a local cache before build.
PackageReference vs packages.config?: Modern SDK projects use PackageReference in the csproj; legacy projects used separate packages.config files.

Interview tip Lesson completion confidence

Can you explain this lesson in 30 seconds without reading notes?

Self-reflection (saved on this device)

Not saved yet.

Playground

Runs on the configured server runner (dev: npm run runner with LEARNING_RUNNER_ENABLED=true). Output appears below the editor.

Code runner not available

Server runner is disabled. Set LEARNING_RUNNER_ENABLED=true and LEARNING_RUNNER_URL in .env (see .env.example).

Check yourself

Multiple choice — immediate feedback.

Discussion

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Starter discussion topics

PackageReference?
Transitive deps?

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