Describe the bug

I'm using OpenAI Responses API and the remote GitHub MCP server with PAT authentication. Starting a few days ago I noticed that the first interaction works fine, but then every subsequent tool call fails. This used to work fine.

Some users report setting stateless_http=True in the MCP server itself seems to fix this issue (Source).

    "name": "list_pull_requests",
    "server_label": "github",
    "type": "mcp_call",
    "error": {
      "type": "mcp_protocol_error",
      "code": 32600,
      "message": "Session terminated"
    },

Affected version

latest

Steps to reproduce the behavior

response = await llm.responses.create(
    model="gpt-4.1",
    tools=[
        Mcp(
            server_label="github",
            server_url="https://api.githubcopilot.com/mcp/",
            type="mcp",
            headers={
                "Authorization": f"Bearer {GITHUB_PAT}",
            },
            require_approval="never",
        )
    ],
    input="what is my github username? how many issues do i have open?"
)
print(response.model_dump_json(indent=2))

Expected vs actual behavior

The session should persist for multiple tool calls.