# Assembly metadata and compilation details

> Define metadata for your assemblies.

You can define additional metadata for your assemblies and retrieve information on the assemblies included in a [project build](/engine/6000.0/manual/building-and-publishing/building-introduction.md).

## Setting assembly attributes

You can use assembly attributes to set metadata properties for your assemblies. Although not a requirement, it's good practice to define these attributes in a separate file named `AssemblyInfo.cs` alongside your Assembly Defintion.

For example, the following assembly attributes specify several .NET assembly metadata values and the Unity-defined [`Preserve`](/engine/6000.0/script-reference/unityengine/scripting/preserveattribute.md) attribute, which affects how unused code is removed from an assembly when you build your project:

```lang-cs
[assembly: System.Reflection.AssemblyCompany("Bee Corp.")]
[assembly: System.Reflection.AssemblyTitle("Bee's Assembly")]
[assembly: System.Reflection.AssemblyCopyright("Copyright 2020.")]
[assembly: UnityEngine.Scripting.Preserve]
```

## Getting assembly information in build scripts

Use the [`CompilationPipeline`](/engine/6000.0/script-reference/unityeditor/compilation/compilationpipeline.md) class to retrieve information about all assemblies built by Unity for a project, including those created based on Assembly Definition assets.

For example, the following script uses the `CompilationPipeline` class to list all the current Player assemblies in a project:

```lang-cs
using UnityEditor;
using UnityEditor.Compilation;
public static class AssemblyLister
{
    [MenuItem("Tools/List Player Assemblies in Console")]
    public static void PrintAssemblyNames()
    {
        UnityEngine.Debug.Log("== Player Assemblies ==");
        Assembly[] playerAssemblies =
            CompilationPipeline.GetAssemblies(AssembliesType.Player);

        foreach (var assembly in playerAssemblies)
        {
            UnityEngine.Debug.Log(assembly.name);
        }
    }
}
```

## Additional resources

* [Creating assembly definitions](/engine/6000.0/manual/scripting/compilation-and-code-reload/script-compilation/assembly-definition-files/assembly-definitions-creating.md)
* [Referencing assemblies](/engine/6000.0/manual/scripting/compilation-and-code-reload/script-compilation/assembly-definition-files/assembly-definitions-referencing.md)
* [Assembly Definition properties](/engine/6000.0/manual/scripting/compilation-and-code-reload/script-compilation/assembly-definition-files/class-assembly-definition-importer.md)
* [Assembly Definition Reference properties](/engine/6000.0/manual/scripting/compilation-and-code-reload/script-compilation/assembly-definition-files/class-assembly-definition-reference-importer.md)
* [Assembly Definition File Format](/engine/6000.0/manual/scripting/compilation-and-code-reload/script-compilation/assembly-definition-files/file-format.md)