HttpContextAccessor has empty HttpContext for HTTP Streaming but not for SSE

[ouvreboite]

Describe the bug
How/when the dependencies are injected is inconsistent between SSE and HttpStreaming.

Mainly, the dependencies for HTTP streaming (non-stateless) are derived from StreamableHttpHandler.ApplicationServices and this handler is registered as a singleton. So the HttpContextAccessor has an empty HttpContext.
On the other hand, the dependencies for SSE are derived from the HttpContext.RequestServices (in SseHandler), so the HttpContextAccessor has a filled HttpContext

To Reproduce

builder.Services.AddHttpContextAccessor();
builder.Services.AddMcpServer()
    .WithHttpTransport()
    .WithTools<EchoTool>()

[McpServerToolType]
public sealed class EchoTool(IHttpContextAccessor accessor)
{
    [McpServerTool]
    public bool HasContext() => accessor.HttpContext != null;
}

• Connect with SSE: HasContext returns "true" ✅
• Connect with non-stateless HttpStreaming: HasContext returns "false" 🔴

Naive question: why can't we use HttpContext.RequestServices in both?

[halter73]

Which version of the ModelContextProtocol.AspNetCore package are you using? This looks like #365 which was fixed in 0.3.0-preview.3.

[ouvreboite]

0.3.0-preview.1

So that may be indeed fixed. Thanks!

(I'll check monday and close the issue if that's the case)