[BUG] GetContainerFileAsync throws InvalidOperationException

[didrh]

Describe the bug

When calling GetContainerFileAsync with a valid container id and file id i get this Error:

System.InvalidOperationException: 'The requested operation requires an element of type 'Number', but the target element has type 'Null'.' at System.Text.Json.ThrowHelper.ThrowJsonElementWrongTypeException(JsonTokenType expectedType, JsonTokenType actualType) at System.Text.Json.JsonElement.GetInt32() at OpenAI.Containers.ContainerFileResource.DeserializeContainerFileResource(JsonElement element, ModelReaderWriterOptions options) at OpenAI.Containers.ContainerFileResource.op_Explicit(ClientResult result) at OpenAI.Containers.ContainerClient.<GetContainerFileAsync>d__38.MoveNext()

Steps to reproduce

1. Call Code Intepreter to Generate a File
2. Wait for the StreamingResponseTextAnnotationAddedUpdate
3. Try to get the File form the Container (Getting FileContent works fine)

Code snippets

OpenAIResponseClient client = new(model: "gpt-4.1", apiKey: "[API KEY]");
ContainerClient containerClient = new(apiKey: "[API KEY]");


var rco = new ResponseCreationOptions()
{
    Tools = { CodeInterpreterTool.CreateCodeInterpreterTool(new CodeInterpreterToolContainer(CodeInterpreterToolContainerConfiguration.CreateAutomaticContainerConfiguration(new List<string>()))) }
};

await foreach (StreamingResponseUpdate update in client.CreateResponseStreamingAsync("Generate an Excel with 3 columns. Ue generic data", rco))
{
    if (update is StreamingResponseOutputTextDeltaUpdate delta)
    {
        Console.Write(delta.Delta);
    }
    else if(update is StreamingResponseTextAnnotationAddedUpdate textAnnotationUpdate)
    {
        var annotation = JsonSerializer.Deserialize<ContainerFileCitation>(textAnnotationUpdate.Annotation, new JsonSerializerOptions() { PropertyNameCaseInsensitive = true });
        if (annotation.Type != "container_file_citation")
        {
            continue;
        }

        var containerdata = await containerClient.GetContainerFileContentAsync(annotation.ContainerId, annotation.FileId); //this works
        var containerfile = await containerClient.GetContainerFileAsync(annotation.ContainerId, annotation.FileId); //this throws error
    }
}

OS

Windows

.NET version

.NET 8

Library version

2.5.0

[jsquire]

Hi @didrh. Thank you for reaching out and we regret that you're experiencing difficulties. I was able to reproduce the behavior using your snippet and have traced the root cause back to the OpenAI service violating their contract. The response for GetContainerFileAsync is a container file object and is coming back as:

{
  "id": "cfile_68e00d3f00548191beee5ba13bdf0522",
  "object": "container.file",
  "created_at": 1759513919,
  "bytes": null,
  "container_id": "cntr_68e00d3053c08190a78e0fd376348c120fa7328683a3e27b",
  "path": "/mnt/data/generic_data.xlsx",
  "source": "assistant"
}

The problem comes from the bytes field being null rather than valid integer value, as the platform docs and the REST API spec define. Because the response is controlled by the OpenAI service, the client has no insight nor influence over it. The maintainers of the OpenAI client library are unable to assist.

Unfortunately, OpenAI does not offer service support from this repository. The most reliable and direct way to get support is by reaching out to the OpenAI Support Team. You can either email support@openai.com or start a new chat session via the Help Center. The OpenAI support team is available 24/7 and is equipped to assist with the full range of requests.

I'm going to close this out; if I've misunderstood what you're describing, please let us know in a comment and we'd be happy to assist as we're able.

[jsquire]

//cc: @trrwilson, for awareness.