[FromHeader] Guid id

public IModelBinder GetBinder(ModelBinderProviderContext context)
{
    if (context == null)
    {
        throw new ArgumentNullException(nameof(context));
    }

    if (context.BindingInfo.BindingSource != null &&
            context.BindingInfo.BindingSource.CanAcceptDataFrom(BindingSource.Header))
    {
        // We only support strings and collections of strings. Some cases can fail
        // at runtime due to collections we can't modify.
        if (context.Metadata.ModelType == typeof(string) ||
            context.Metadata.ElementType == typeof(string))
        {
            return new HeaderModelBinder();
        }
    }

    return null;
}

public class GuidHeaderModelBinder : IModelBinder
{
    public Task BindModelAsync(ModelBindingContext bindingContext)
    {
        if (bindingContext.ModelType != typeof(Guid)) return Task.CompletedTask;
        if (!bindingContext.BindingSource.CanAcceptDataFrom(BindingSource.Header)) return Task.CompletedTask;

        var headerName = bindingContext.ModelName;
        var stringValue = bindingContext.HttpContext.Request.Headers[headerName];
        bindingContext.ModelState.SetModelValue(bindingContext.ModelName, stringValue, stringValue);

        // Attempt to parse the guid
        if (Guid.TryParse(stringValue, out var valueAsGuid))
        {
            bindingContext.Result = ModelBindingResult.Success(valueAsGuid);
        }

        return Task.CompletedTask;
    }
}

public IActionResult SampleAction(
    [FromHeader(Name = "my-guid")][ModelBinder(BinderType = typeof(GuidHeaderModelBinder))]Guid foo)
{
    return Json(new { foo });
}

$.ajax({
  method: 'GET',
  headers: { 'my-guid': '70e9dfda-4982-4b88-96f9-d7d284a10cb4' },
  url: '/home/sampleaction'
});

public async Task BindModelAsync(ModelBindingContext BindingContext)
{
    // Read HTTP header.
    string headerName = BindingContext.FieldName;
    if (BindingContext.HttpContext.Request.Headers.ContainsKey(headerName))
    {
        StringValues headerValues = BindingContext.HttpContext.Request.Headers[headerName];
        if (headerValues == StringValues.Empty)
        {
            // Value not found in HTTP header.  Substitute empty GUID.
            BindingContext.ModelState.SetModelValue(BindingContext.FieldName, headerValues, Guid.Empty.ToString());
            BindingContext.Result = ModelBindingResult.Success(Guid.Empty);
        }
        else
        {
            // Value found in HTTP header.
            string correlationIdText = headerValues[0];
            BindingContext.ModelState.SetModelValue(BindingContext.FieldName, headerValues, correlationIdText);
            // Parse GUID.
            BindingContext.Result = Guid.TryParse(correlationIdText, out Guid correlationId)
                ? ModelBindingResult.Success(correlationId)
                : ModelBindingResult.Failed();
        }
    }
    else
    {
        // HTTP header not found.
        BindingContext.Result = ModelBindingResult.Failed();
    }
    await Task.FromResult(default(object));
}

public class GuidHeaderModelBinderProvider : IModelBinderProvider
{
    public IModelBinder GetBinder(ModelBinderProviderContext Context)
    {
        if (Context.Metadata.ModelType == typeof(Guid))
        {
            if (Context.BindingInfo.BindingSource == BindingSource.Header)
            {
                return new BinderTypeModelBinder(typeof(GuidHeaderModelBinder));
            }
        }
        return null;
    }
}

[HttpGet("getbars")]
public async Task<string> GetBarsAsync([FromHeader] Guid CorrelationId, int Count)
{
    Logger.Log(CorrelationId, $"Creating {Count} foo bars.");
    StringBuilder stringBuilder = new StringBuilder();
    for (int count = 0; count < Count; count++)
    {
        stringBuilder.Append("Bar! ");
    }
    return await Task.FromResult(stringBuilder.ToString());
}

// Add MVC and configure model binding.
Services.AddMvc(Options =>
{
    Options.ModelBinderProviders.Insert(0, new GuidHeaderModelBinderProvider());
});