Can you use multiple MCP servers in one Claude session?

How it works

When you start a session in Claude Desktop or Claude.ai with multiple active servers, the client queries each MCP server for its list of capabilities (using the tools/list protocol). It registers all available tools globally. When processing prompts, Claude automatically selects the correct tool by matches with the schemas provided by the respective servers.

Example Multi-Server configuration in Claude Desktop

Here is how you define three concurrent servers in one local setup:

{
  "mcpServers": {
    "postgres-db": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-postgres", "--conn", "postgresql://localhost/dev"]
    },
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": { "GITHUB_PERSONAL_ACCESS_TOKEN": "ghp_123" }
    },
    "local-fs": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/Users/dev/project"]
    }
  }
}