Type: "http" MCP servers silently ignored when passed via mcp_servers parameter in Python SDK

[sanchar10]

Bug

When passing type: "http" (or type: "sse") MCP servers via the mcp_servers parameter in create_session(), the CLI subprocess silently ignores them. Only stdio/local type servers are connected.
No error is raised — the HTTP servers simply don't appear as tools.

The same HTTP MCP servers work correctly in interactive CLI mode (where the CLI reads ~/.copilot/mcp-config.json directly) and via enableConfigDiscovery=True.

Versions

• Python SDK: github-copilot-sdk 0.2.2
• CLI: GitHub Copilot CLI 1.0.32-1
• Python: 3.14.0
• OS: Windows 11

Expected Behavior

HTTP MCP servers passed via mcp_servers should be connected and their tools made available to the model, matching the behavior documented in
mcp.md.

Actual Behavior

HTTP MCP servers are silently ignored. The model only sees CLI built-in tools. No error or warning is raised.

Repro Code

import asyncio
from copilot import CopilotClient
from copilot.session import PermissionHandler

async def main():
    client = CopilotClient()
    await client.start()

    session = await client.create_session(
        on_permission_request=PermissionHandler.approve_all,
        model="gpt-4.1",
        mcp_servers={
            "github": {
                "type": "http",
                "url": "https://api.githubcopilot.com/mcp/",
                "tools": ["*"],
            },
        },
    )

    response = await session.send_and_wait(
        "List every tool name you have access to. Output ONLY a comma-separated list.",
        timeout=120.0,
    )
    print(response.data.content)
    # Output: powershell, write_powershell, read_powershell, stop_powershell,
    #         list_powershell, view, create, edit, web_fetch, report_intent,
    #         show_file, skill, sql, task, read_agent, list_agents, write_agent, grep, glob
    # ^^^ No github MCP tools appear

    await client.stop()

asyncio.run(main())

What We Tested

Approach	Result
mcp_servers with type: "http"	❌ Silently ignored, 0 MCP tools
mcp_servers with type: "sse"	❌ Silently ignored, 0 MCP tools
mcp_servers with stdio server	✅ Works correctly
enableConfigDiscovery=True (same HTTP servers in global config)	✅ HTTP servers load, tools appear
Interactive CLI (reads config directly)	✅ HTTP servers work

Additional Context

• enableConfigDiscovery=True proves the CLI CAN connect to HTTP MCP servers — it just doesn't when they're passed via the SDK's mcp_servers RPC parameter.
• The SDK correctly serializes HTTP server configs into the mcpServers payload (verified via logging in client.py line ~1251).
• Tested with multiple HTTP MCP servers (GitHub MCP, ServiceTree, bluebird-mcp) — none work via mcp_servers.
• enableConfigDiscovery is not a viable workaround because it loads ALL servers from global config, easily exceeding the 128 tool limit.