Fixes #1829 where MCP servers configured with url parameter instead of command were throwing "Missing required parameter: command" error.

Problem

Previously, GenAIScript only supported stdio-based MCP servers that required command and args parameters:

mcpServers: {
  memory: {
    command: "npx",
    args: ["-y", "@modelcontextprotocol/server-memory"]
  }
}

Attempting to configure URL-based transports resulted in validation errors:

// This would fail with "Missing required parameter: command"
mcpServers: {
  remote: {
    url: "http://localhost:8080/mcp"
  }
}

Solution

This PR adds comprehensive support for URL-based MCP transports while maintaining full backward compatibility:

1. Enhanced Interface Definition

• Made command and args optional in McpServerConfig
• Added url?: string for HTTP/WebSocket/SSE transports
• Added type?: "stdio" | "http" | "sse" for explicit transport specification

2. Multiple Transport Support

• HTTP Transport: Uses StreamableHTTPClientTransport for HTTP-based MCP servers
• SSE Transport: Uses SSEClientTransport for Server-Sent Events
• Stdio Transport: Maintains existing StdioClientTransport functionality

3. Intelligent Configuration Validation

• Auto-detects transport type when type is not specified:
  • url provided → defaults to HTTP transport
  • command provided → defaults to stdio transport
• Validates that appropriate parameters are provided for each transport type
• Prevents invalid configurations (e.g., both command and url)

4. Updated System Scripts

Both system.mcp and system.agent_mcp now support the new parameters with proper validation.

Usage Examples

Stdio Transport (existing - unchanged):

mcpServers: {
  memory: {
    command: "npx",
    args: ["-y", "@modelcontextprotocol/server-memory"]
  }
}

HTTP Transport (new):

mcpServers: {
  remote: {
    url: "http://localhost:8080/mcp",
    type: "http" // optional, inferred from url
  }
}

SSE Transport (new):

mcpServers: {
  events: {
    url: "http://localhost:8080/sse",
    type: "sse"
  }
}

Backward Compatibility

All existing configurations continue to work without any changes. The implementation includes comprehensive validation that provides clear error messages for invalid configurations while automatically detecting the appropriate transport type for valid ones.

This enables GenAIScript to work seamlessly with remote MCP servers over HTTP and SSE protocols, expanding the ecosystem of compatible MCP servers beyond just local stdio-based implementations.

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