Please improve the integration with MEAI and C# MCP SDK.

[rwoodley]

Confirm this is a feature request for the .NET library and not the underlying OpenAI API

• This is a feature request for the .NET library

Describe the feature or improvement you are requesting

In order to get the "The official .NET library for the OpenAI API" to talk to the "official C# SDK for the Model Context Protocol" we have to write ~60 lines of code to convert from OpenAI's ChatToolCall to the argument dictionary expected by the MCP SDK.

It appears this was discussed internally at Microsoft in this PR: #422, and a decision was made there not to better integrate the 2 SDKs. I am requesting to restart this discussion and revisit the decisions made there.

The examples for the MCP SDK indicate that you can use the OpenAI SDK with MEAI, but in fact that is not the case.

The MCP SDK has a nice annotation-driven implementation that eliminates so much boiler plate. But the incompatibility discussed in the above PR basically destroys much of the concise-ness of the MCP SDK's implementation. Perhaps this is not a concern of the authors of the OpenAI SDK, but since both are from Microsoft, smoother integration would be hoped for.

Additional context

No response

[jsquire]

@KrzysztofCwalina, @achandmsft: Would you be so kind as to offer your thoughts on whether further discussion on the conclusions from #422 may lead to a different outcome?

[jsquire]

@rwoodley: Thank you for reaching out and we regret that you're experiencing difficulties. I've looped in the stakeholders for this decision to see if they're willing to restart discussions.

[KrzysztofCwalina]

@rwoodley, I have been looking into improving the integration here. We are thinking about adding a helper that would convert the arguments returned by OpenAI (as JSON bytes) to a dictionary (based on JSON Schema). I just need to think a bit abut the best location or such helper: OpenAI package, Microsoft.Extensions.AI.OpenAI package, directly on BinaryData.

[KrzysztofCwalina]

@rwoodley, I did some more digging here. It seems like the objects in the dictionary passed to the MCP client tool call can be boxed JsonElement values. Given that, the following one line seems to be doing the conversion necessary:

BinaryData arguments = ...
var mcpArguments = JsonSerializer.Deserialize<Dictionary<string, object>>(arguments.ToMemory().Span);

// or even;
// var mcpArguments = arguments.FunctionArguments.ToObjectFromJson<Dictionary<string, object>>();

Would you mind trying if that works for you?

[rwoodley]

@KrzysztofCwalina - My code wasn't quite as succinct as yours, but yes something like this works:

   private Dictionary<string, object?> ConvertToMCPSDKToolCall(ChatToolCall toolCall) {
        return JsonSerializer.Deserialize<Dictionary<string, object>>(
            toolCall.FunctionArguments.ToMemory().Span);
    }

But we also need something like this:

    private ChatTool ConvertToOpenAIChatTool(McpClientTool mcpTool)
    {
        var mcpToolSchema = mcpTool.JsonSchema.ToString();

        return ChatTool.CreateFunctionTool(
          mcpTool.Name,
          mcpTool.Description,
          BinaryData.FromString(enhancedSchema)
        );
    }

But my larger point which I tried to make in my initial post was whether MEAI was deprecated or not. If "The official .NET library for the OpenAI API" doesn't work with MEAI, then MEAI is basically just an Ollama wrapper. Many articles and examples would need to be deleted. And developers who want the flexibility to swap models will have to end of writing something like MEAI anyhow.

Unless Microsoft is expecting the community to build the integration?

[stephentoub]

MEAI was deprecated or not

Absolutely not. From the .NET team's perspective and investments, it is the basis for the AI and .NET ecosystem.

[KrzysztofCwalina]

@rwoodley, if your question is about using MEAI with OpenAI, and not strictly just the MCP client, then you can use Microsoft.Extensions.AI.OpenAI package to expose OpenAI ChatClient as IChatClient. If you then use IChatClient for the completion calls, you don't need any conversions while calling IMcpClient

ChatClient openai = ..
IChatCLient chat = openai.AsIChatClient();

[KrzysztofCwalina]

But we also need something like this

Yeah, for the conversion from McpClientTool to ChatTool a conversion helper would be best. @stephentoub , what do you think about adding something like the following to Microsoft.Extensions.AI.OpenAI:

// existing type
public static class OpenAIClientExtensions {
    // new method
    public static ChatTool AsOpenAIChatTool(this AIFunction aiFunction)
}

[KrzysztofCwalina]

I opened a PR: dotnet/extensions#6539

[rwoodley]

Thank you for your prompt responses! I am ok with closing this ticket.

[KrzysztofCwalina]

@rwoodley, thank you for raising this issue!

[KrzysztofCwalina]

@rwoodley, BTW, I opened a PR to add the converters: dotnet/extensions#6539