mcp-client-error-handlin-when-initializing-an-mcp-session-via-streamablehtt-17c834ea

THEN Manually validate the content type of the server response before creating the ClientSession. Wrap the streamablehttp_client call in a function that checks the response headers and raises a meaningful exception if the content type is not 'application/json' or similar. Alternatively, use a custom read stream that raises an error on unexpected content.

async def checked_streamablehttp_client(url):
    async with streamablehttp_client(url) as (read, write, _):
        # Assuming read is a StreamReader; actual implementation may vary
        # Check the underlying response object if accessible, or read a chunk.
        # Simplified: raise if first bytes indicate non-JSON.
        yield read, write