Introduction to vMCP
Overview
Virtual MCP Server (vMCP) is a feature of the ToolHive Kubernetes Operator that acts as an aggregation proxy, consolidating multiple backend MCP servers into a single unified interface. Instead of configuring clients to connect to each MCP server individually, you connect once to vMCP and access all backend tools through a single endpoint.
Core capabilities
- Multi-server aggregation: Connect to one endpoint instead of many
- Tool conflict resolution: Automatic namespacing when backend MCP servers have overlapping tool names
- Centralized authentication: Single sign-on with per-backend token exchange
- Composite workflows: Multi-step operations across backend MCP servers with parallel execution, approval gates, and error handling
When to use vMCP
Good fit
- You manage 5+ MCP servers
- You need cross-system workflows requiring coordination
- You have centralized authentication and authorization requirements
- You need reusable workflow definitions
Not needed
- You use a single MCP server
- You have simple, one-step operations
- You have no orchestration requirements
Architecture overview
How it works
- You define an MCPGroup (a resource that organizes related MCP servers) containing your backend MCPServer resources
- You create a VirtualMCPServer that references the group
- The operator discovers all backend MCP servers in the group and aggregates their capabilities
- Clients connect to the VirtualMCPServer endpoint and see a unified view of all tools