client/Services/Grpc/GrpcMetadataFactory.cs

using CloudPrint.Client.Models;
using Grpc.Core;

namespace CloudPrint.Client.Services.Grpc;

public static class GrpcMetadataFactory
{
    public static Metadata Create(string apiKey, string printerToken, AdminSession adminSession)
    {
        var metadata = new Metadata();

        AddIfNotEmpty(metadata, "x-api-key", apiKey);
        AddIfNotEmpty(metadata, "x-printer-token", printerToken);

        if (adminSession.IsAuthenticated)
        {
            metadata.Add("authorization", $"Bearer {adminSession.AccessToken}");
        }

        return metadata;
    }

    private static void AddIfNotEmpty(Metadata metadata, string key, string value)
    {
        if (!string.IsNullOrWhiteSpace(value))
        {
            metadata.Add(key, value);
        }
    }
}