DynamoVisualProgramming.DynamoServices by Autodesk

<PackageReference Include="DynamoVisualProgramming.DynamoServices" Version="3.4.0-beta6130" />

 IExternalCodeCompletionData

This interface is essentially the same as ICompletionData from AvalonEdit except it does not include any references to WPF.
namespace Autodesk.DesignScript.Interfaces { internal interface IExternalCodeCompletionData { ExternalCodeCompletionType CompletionType { get; } string Text { get; } object Content { get; } string Description { get; } double Priority { get; } } }