Bad Request: Mcp-Session-Id header is required in release mode

[andrew-at-v]

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• Protocol Specification
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Your Question

I will create issue if this is real issue

I just deployed mcp server that is running in the project that also use blazor
Suddenly, all my request to blazor and even faveicon get following error

Bad Request: Mcp-Session-Id header is required

which is weird because its only happen when its deployed, works fine during debugging

This is the first time i deploy mcp server with blazor project
Previous deployment mcp server with minimal api project does not have this issue

Investigating...

[andrew-at-v]

ok
in minimal api, i always use /api
in blazor project, this interfere with my normal request

        if (!streamableHttpHandler.HttpServerTransportOptions.Stateless)
        {
            // The GET endpoint is not mapped in Stateless mode since there's no way to send unsolicited messages.
            // Resuming streams via GET is currently not supported in Stateless mode.
            streamableHttpGroup.MapGet("", streamableHttpHandler.HandleGetRequestAsync)
                .WithMetadata(new ProducesResponseTypeMetadata(StatusCodes.Status200OK, contentTypes: ["text/event-stream"]));

now wondering why that option is false in release but true in debug
what's the point of that option anyway

[andrew-at-v]

this is how sdk do mapping

var mcpGroup = endpoints.MapGroup(pattern);
var streamableHttpGroup = mcpGroup.MapGroup("")

this is how i map

MapMcp("{toolCategory?}")

so the fastest workaround is by give prefix when calling MapMcp especially in blazor project or just standarize it everywhere

still wondering why only happen in release mode, dont think i can find the why for now