For the complete documentation index, see llms.txt. Markdown versions of all docs pages are available by appending .md to any docs URL.

stdio Transport

Connect agentgateway to local process-based MCP servers

The stdio transport connects agentgateway to MCP servers that run as local processes, communicating via standard input/output.

Overview

stdio transport is ideal when:

• MCP servers run as local command-line tools
• You want to manage MCP server lifecycle with agentgateway
• The server is distributed as an npm package or binary

Quick start

# Download the stdio MCP configuration
curl -L https://raw.githubusercontent.com/agentgateway/agentgateway/refs/heads/main/examples/basic/config.yaml -o config.yaml

# Run agentgateway
agentgateway -f config.yaml

Configuration

Configure an stdio MCP backend in your config.yaml:

# yaml-language-server: $schema=https://agentgateway.dev/schema/config
mcp:
  port: 3000
  targets:
  - name: my-mcp-server
    stdio:
      cmd: npx
      args:
        - "-y"
        - "@modelcontextprotocol/server-everything"

Example: MCP test server

The MCP test server (@modelcontextprotocol/server-everything) is useful for testing:

backends:
- mcp:
    targets:
    - name: test-server
      stdio:
        cmd: npx
        args:
          - "-y"
          - "@modelcontextprotocol/server-everything"

Example: Filesystem MCP server

Expose local filesystem access via MCP:

backends:
- mcp:
    targets:
    - name: filesystem
      stdio:
        cmd: npx
        args:
          - "-y"
          - "@modelcontextprotocol/server-filesystem"
          - "/path/to/allowed/directory"

Why use agentgateway?

Verify access

1. Open the agentgateway UI to view your configuration
2. Go to Playground to test tools
3. Click Connect to retrieve available tools
4. Select a tool and click Run Tool to test

Learn more

• MCP Connectivity Guide
• stdio Configuration Reference
• MCP Authentication