32600 error code when trying to connect to mcp with openai responses API

Author: aflam745Created Oct 16, 2025Updated Sep 14, 2026
Labelsbugstale

Describe the bug

I have been trying to use the githup-mcp as tool in the openai responses API and I seem to be connecting but keep getting

"error": { "type": "mcp_protocol_error", "code": 32600, "message": "Session terminated" },

even with simple calls such as return 5 most recent issue from a particular repo

Current code running

    const resp = await client.responses.create({
      model: session.model,
      temperature: 0,
      parallel_tool_calls: false,
      input: [
        { role: "system", content: [{ type: "input_text", text: "Exactly one MCP tool call; no optional fields." }] },
        { role: "user", content: [{ type: "input_text", text:
          'Call "list_issues" and return the 5 most recent issues with exactly: {"query":"repo:github/github-mcp-server"}'  
        }] },
      ],
      tools: [
        {
          type: "mcp",
          server_label: "github",
          server_url: "https://api.githubcopilot.com/mcp/",
          headers: {
            Authorization: `Bearer ${process.env.GITHUB_READ_ONLY_API_KEY}`,
          },
          require_approval: "never",
          allowed_tools: [
            "search_repositories",
            "search_issues",
            "get_issue",
            "list_issues",
          ],
        }
      ],
      max_output_tokens: 200,
    });

Any tips or help would be greatly appreciated have been trying all kinds of types of inputs and nothing is working. Thanks.

Source: github/github-mcp-server