langflow-ai/langflow · error · HTTPException

MCP configuration can only be installed from a local connect

Error message

MCP configuration can only be installed from a local connection

What it means

Error "MCP configuration can only be installed from a local connection" thrown in langflow-ai/langflow.

Source

Thrown at src/backend/base/langflow/api/v1/mcp_projects.py:832

    if request.client:
        return request.client.host

    # Fallback if we can't determine the IP - use a non-local IP
    return "255.255.255.255"  # Non-routable IP that will never be local


@router.post("/{project_id}/install")
async def install_mcp_config(
    project_id: UUID,
    body: MCPInstallRequest,
    request: Request,
    current_user: CurrentActiveMCPUser,
):
    """Install MCP server configuration for Cursor, Windsurf, or Claude."""
    # Check if the request is coming from a local IP address
    client_ip = get_client_ip(request)
    if not is_local_ip(client_ip):
        raise HTTPException(status_code=500, detail="MCP configuration can only be installed from a local connection")

    removed_servers: list[str] = []  # Track removed servers for reinstallation
    try:
        project = await verify_project_access(project_id, current_user)

        # Check if project requires API key authentication and generate if needed
        generated_api_key = None

        # Determine if we need to generate an API key
        should_generate_api_key = False
        if not get_settings_service().settings.mcp_composer_enabled:
            # When MCP_COMPOSER is disabled, check auth settings or fallback to auto_login setting
            settings_service = get_settings_service()
            if project.auth_settings:
                # Project has auth settings - check if it requires API key
                if project.auth_settings.get("auth_type") == "apikey":
                    should_generate_api_key = True
            elif not settings_service.auth_settings.AUTO_LOGIN:

View on GitHub (pinned to 976ec789d2)

Solutions

1. Run the MCP configuration install from the same machine that hosts the Langflow server (local connection).

When it happens

Trigger: Occurs when an MCP configuration install is attempted from a non-local (remote) client connection.

Common situations: See trigger scenarios.

AI-assisted analysis of langflow-ai/langflow@976ec789d2 (2026-08-14). Data as JSON: /api/errors/663f2636d8f96924. Report an issue: GitHub.