René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"SSE does not work on nested routes","articleBody":"**Describe the bug**\nURL parts are being omitted on SSE client session connect.\n\nINFO:mcp.client.sse:Connecting to SSE endpoint: https://url-part1.url-part2.com/route1/route2/sse\nINFO:httpx:HTTP Request: GET https://url-part1.url-part2.com/route1/route2/sse \"HTTP/1.1 200 OK\"\nINFO:mcp.client.sse:Received endpoint URL: https://url-part1.url-part2.com/route2/messages/?session_id=a2bd62740b69466c8b27043ccda2513f\nINFO:mcp.client.sse:Starting post writer with endpoint URL: https://url-part1.url-part2.com/route2/messages/?session_id=a2bd62740b69466c8b27043ccda2513f\n\n**To Reproduce**\n```\nimport asyncio\nimport logging\nfrom fastmcp import Client\nfrom fastmcp.client.transports import (\n    SSETransport\n)\n\n\nsse_url = \"https://url-part1.url-part2.com/route1/route2/sse\"\nasync def main():\n    # Connect to a server over SSE (common for web-based MCP servers)\n    async with Client(SSETransport(url=sse_url)) as client:\n        # Send a message to the server\n        result = await client.list_tools()\n        print(result)\n\n\nif __name__ == \"__main__\":\n    logging.basicConfig(level=logging.INFO)\n    asyncio.run(main())\n```\n**Expected behavior**\nroute1 is not omitted\n\n**Desktop (please complete the following information):**\n - OS: Ubuntu\n - Version 1.9.0\n\n**Additional context**\nissue stems from:\n.venv/lib/python3.12/site-packages/mcp/client/sse.py line 66\n","author":{"url":"https://github.com/kocsszi","@type":"Person","name":"kocsszi"},"datePublished":"2025-05-16T10:42:04.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":4},"url":"https://github.com/733/python-sdk/issues/733"}