Add artifact to release

addartifact.cs

var endpoint = new Octopus.Client.OctopusServerEndpoint(baseUri, apiKey);
var repository = new Octopus.Client.OctopusRepository(endpoint);

var project = repository.Projects.FindByName(projectName);
var release = repository.Projects.GetReleaseByVersion(project, releaseVersion);
var artifact = new Octopus.Client.Model.ArtifactResource
{
    Filename = fileName,
    RelatedDocumentIds = new Octopus.Platform.Model.ReferenceCollection(new [] { project.Id, release.Id })
};

var createdArtifact = repository.Artifacts.Create(artifact);
createdArtifact.Dump();

using(var file = File.OpenRead(filePath))
{
    repository.Artifacts.PutContent(createdArtifact, file);
}