// use the DataContract attribute to link your model to a layout
[DataContract(Name="NameOfYourLayout")]
public class Model
{
    [DataMember]
    public string Name { get; set; }

    // if your model name does not match use DataMember
    [DataMember(Name="overrideFieldName")] // the filemaker field to use
    public string Address { get; set; }

    [DataMember]
    public string SomeContainerField { get; set; }

    // use the ContainerDataFor attribute to map container data to a byte[]
    [ContainerDataFor("SomeContainerField")] // use the name in your C# model
    public byte[] DataForSomeContainerField { get; set; }

    // if your model has properties you don't want mapped use
    [IgnoreDataMember] // to skip mapping of the field
    public string NotNeededField { get; set; }
}

services.AddSingleton<FMData.ConnectionInfo>(ci => new FMData.ConnectionInfo
{
    FmsUri = "https://example.com",
    Username = "user",
    Password = "password",
    Database = "FILEMAKERFILE"
});
services.AddHttpClient<IFileMakerApiClient, FileMakerRestClient>();

services.AddHttpClient(); // setup IHttpClientFactory in the DI container
services.AddSingleton<FMData.ConnectionInfo>(ci => new FMData.ConnectionInfo
{
    FmsUri = "https://example.com",
    Username = "user",
    Password = "password",
    Database = "FILEMAKERFILE"
});
// Keep the FileMaker client as a singleton for speed
services.AddSingleton<IFileMakerApiClient, FileMakerRestClient>(s => {
    var hcf = s.GetRequiredService<IHttpClientFactory>();
    var ci = s.GetRequiredService<ConnectionInfo>();
    return new FileMakerRestClient(hcf.CreateClient(), ci);
});

var client = new FileMakerRestClient("server", "fileName", "user", "pass"); // without .fmp12
var toFind = new Model { Name = "someName" };
var results = await client.FindAsync(toFind);
// results = IEnumerable<Model> matching with Name field matching "someName" as a FileMaker Findrequest.

var client = new FileMakerRestClient("server", "fileName", "user", "pass"); // without .fmp12
var toCreate = new Model { Name = "someName", Address = "123 Main Street" };
var results  = await client.CreateAsync(toCreate);
//  results is an ICreateResponse which indicates success (0/OK or Failure with FMS code/message)

var client = new FileMakerRestClient("server", "fileName", "user", "pass"); // without .fmp12
var fileMakerRecordId = 1; // this is the value from the calculation: Get(RecordID)
var toUpdate = new Model { Name = "someName", Address = "123 Main Street" };
var results = await client.EditAsync(fileMakerRecordId, toCreate);
//  results is an IEditResponse which indicates success (0/OK or Failure with FMS code/message)

Func<Model, int, object> FMRecordIdMapper = (o, id) => o.FileMakerRecordId = id;
var client = new FileMakerRestClient("server", "fileName", "user", "pass"); // without .fmp12
var toFind = new Model { Name = "someName" };
var results = await client.FindAsync(toFind, FMRecordIdMapper);
// results is IEnumerable<Model> matching with Name field matching "someName" as a FileMaker Findrequest.

var client = new FileMakerRestClient("server", "fileName", "user", "pass"); // without .fmp12
var toFind = new Model { Name = "someName" };
var results = await client.FindAsync(toFind);
await client.ProcessContainers(results);
// results = IEnumerable<Model> matching with Name field matching "someName" as a FileMaker Findrequest.

// assume recordId = a FileMaker RecordId mapped using FMIdMapper
// assume containerDataByteArray is a byte array with file contents of some sort
var client = new FileMakerRestClient("server", "fileName", "user", "pass"); // without .fmp12
_client.UpdateContainerAsync(
    "layout",
    recordId,
    "containerFieldName",
    "filename.jpg/png/pdf/etc",
    containerDataByteArray);