Skip to main content

Server Types

MCP Gateway supports three transport modes for connecting to MCP servers. Choose based on your server's capabilities and your deployment requirements.

Comparison​

TransportMemoryStartupBest For
HTTP~60 MB~1.5sServers with native HTTP support
Stdio~100 MB~2.5sTraditional npm MCP packages
Docker~70 MB~4sIsolation, complex dependencies

HTTP Mode​

The most efficient mode. The server runs as an HTTP service and the gateway communicates via JSON-RPC over HTTP.

{
  "playwright": {
    "command": "npx",
    "args": ["-y", "@playwright/mcp-server", "--port", "9001"],
    "transport": "http",
    "url": "http://localhost:9001/mcp"
  }
}

When to use HTTP​

  • Server supports native HTTP mode (Playwright, Context7)
  • You need the lowest overhead
  • You want direct port control

Pros​

  • No wrapper overhead
  • Fastest startup
  • Direct HTTP communication

Cons​

  • Not all servers support it
  • Manual port management

Stdio Mode (Default)​

The gateway spawns the server as a child process and communicates via stdin/stdout. A thin HTTP wrapper is automatically generated.

{
  "github": {
    "command": "npx",
    "args": ["-y", "@modelcontextprotocol/server-github"],
    "transport": "stdio"
  }
}
info

"transport": "stdio" is the default and can be omitted.

When to use Stdio​

  • Traditional MCP servers from npm
  • Servers without native HTTP support
  • No Docker available

Pros​

  • Works with any stdio-based server
  • Auto-generated HTTP wrapper
  • No Docker required

Cons​

  • Wrapper adds overhead (~50MB)
  • Slightly slower startup

Docker Mode​

Runs the MCP server inside a Docker container. Best for servers with complex dependencies or when you need isolation.

{
  "fetch": {
    "command": "docker",
    "args": [
      "run", "--rm", "-i",
      "-p", "9002:8080",
      "mcp/fetch:latest"
    ],
    "transport": "docker",
    "url": "http://localhost:9002/mcp"
  }
}

When to use Docker​

  • Server has complex dependencies (Python, system libs)
  • You need sandboxed execution
  • Consistent environment across machines

Pros​

  • Isolated environment
  • Consistent dependencies
  • Security sandbox

Cons​

  • Requires Docker installed
  • Slowest startup (image pull)
  • Container overhead

Choosing a Transport​

Does server support native HTTP?
├─ YES → Use HTTP mode
└─ NO
   └─ Need isolation or Docker?
      ├─ YES → Use Docker mode
      └─ NO → Use Stdio mode

Mixed Configuration​

You can mix transport types in a single configuration:

{
  "mcpServers": {
    "playwright": {
      "transport": "http",
      "command": "npx",
      "args": ["-y", "@playwright/mcp-server", "--port", "9001"],
      "url": "http://localhost:9001/mcp"
    },
    "github": {
      "transport": "stdio",
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"]
    },
    "fetch": {
      "transport": "docker",
      "command": "docker",
      "args": ["run", "--rm", "-p", "9002:8080", "mcp/fetch:latest"],
      "url": "http://localhost:9002/mcp"
    }
  }
}