MCP Gateway Configuration Skill

Purpose

This skill provides guidance for configuring MCP (Model Context Protocol) gateways for the Riksdagsmonitor platform. It covers multi-server integration, tool routing, security configuration, and access control to enable secure and efficient AI-assisted development workflows.

When to Use This Skill

Apply this skill when:

• ✅ Setting up or modifying .github/copilot-mcp-config.json

• ✅ Adding new MCP servers to the gateway

• ✅ Configuring tool routing between MCP servers

• ✅ Setting up access control for MCP tools

• ✅ Troubleshooting MCP connectivity issues

• ✅ Reviewing MCP configuration for security

• ✅ Integrating new data sources via MCP

Do NOT use for:

• ❌ MCP security hardening (use mcp-gateway-security)

• ❌ General API gateway configuration (different pattern)

• ❌ Application-level API design (use service layer patterns)

MCP Architecture Overview

┌─────────────────────────────────────────────┐ │ GitHub Copilot │ │ (AI Assistant Client) │ └──────────────────┬──────────────────────────┘ │ ▼ ┌─────────────────────────────────────────────┐ │ MCP Gateway Layer │ │ ┌─────────────────────────────────────┐ │ │ │ copilot-mcp-config.json │ │ │ │ - Server definitions │ │ │ │ - Tool routing rules │ │ │ │ - Access control policies │ │ │ └─────────────────────────────────────┘ │ └──────┬──────────┬──────────┬────────────────┘ │ │ │ ▼ ▼ ▼ ┌──────────┐ ┌──────────┐ ┌──────────┐ │ GitHub │ │ Filesystem│ │ Playwright│ │ MCP │ │ MCP │ │ MCP │ │ Server │ │ Server │ │ Server │ └──────────┘ └──────────┘ └──────────┘

Configuration Structure

Base Configuration (copilot-mcp-config.json )

{ "mcpServers": { "server-name": { "type": "stdio", "command": "command-to-run", "args": ["arg1", "arg2"], "env": { "ENV_VAR": "value" } } } }

Server Type Patterns

stdio Servers (Local Process):

{ "filesystem": { "type": "stdio", "command": "npx", "args": ["-y", "@modelcontextprotocol/server-filesystem", "/path/to/allowed"], "env": {} } }

SSE Servers (Remote HTTP):

{ "remote-server": { "type": "sse", "url": "https://mcp-server.example.com/sse", "headers": { "Authorization": "Bearer ${MCP_TOKEN}" } } }

CIA Platform MCP Servers

Required Servers

Server Purpose Tools Provided

github Repository operations Issues, PRs, code search, Actions

filesystem Local file operations Read, write, search files

playwright Browser automation UI testing, screenshots

Configuration Best Practices

1. Minimize Filesystem Access:

{ "filesystem": { "type": "stdio", "command": "npx", "args": [ "-y", "@modelcontextprotocol/server-filesystem", "/home/runner/work/cia/cia" ] } }

Only expose the project root — never expose / , /home , or parent directories.

2. Use Environment Variables for Secrets:

{ "github": { "type": "stdio", "command": "github-mcp-server", "env": { "GITHUB_TOKEN": "${GITHUB_TOKEN}" } } }

Never hardcode tokens in configuration files.

3. Specify Exact Package Versions:

{ "args": ["-y", "@modelcontextprotocol/server-filesystem@1.2.3"] }

Pin versions to prevent supply chain attacks.

Tool Routing

Routing Principles

• Least Privilege — Each server should only expose tools needed for its purpose

• Separation of Concerns — Different servers for different capabilities

• Fail-Safe Defaults — Tools should default to read-only when possible

• Audit Trail — All tool invocations should be logged

Tool Categories

Category Server Example Tools

Code Management github create_pull_request, push_files

Code Analysis github search_code, get_file_contents

File Operations filesystem read_file, write_file, search

UI Testing playwright navigate, click, screenshot

Issue Management github create_issue, list_issues

CI/CD github list_workflows, get_job_logs

Access Control Configuration

Server-Level Access Control

{ "mcpServers": { "filesystem": { "type": "stdio", "command": "npx", "args": [ "-y", "@modelcontextprotocol/server-filesystem", "/home/runner/work/cia/cia" ], "env": { "ALLOWED_OPERATIONS": "read,write,search" } } } }

Directory Restrictions

Allowed directories should follow the principle of least privilege:

✅ /home/runner/work/cia/cia — Project root ✅ /home/runner/work/cia/cia/src — Source code ✅ /home/runner/work/cia/cia/.github — CI/CD configuration

❌ /home/runner — Too broad ❌ /etc — System configuration ❌ /tmp — Temporary files (security risk)

Troubleshooting

Common Issues

Issue Symptom Resolution

Server not starting "Failed to connect" error Check command path and args

Permission denied Tool call fails Verify filesystem paths and permissions

Token expired Authentication errors Refresh environment variables

Version mismatch Unexpected tool behavior Pin and update package versions

Timeout Tool call hangs Check network connectivity for SSE servers

Diagnostic Commands

Verify MCP config syntax

cat .github/copilot-mcp-config.json | python3 -m json.tool

Check if MCP server binary is available

which github-mcp-server

Test filesystem server

npx -y @modelcontextprotocol/server-filesystem --help

Check environment variables

env | grep -i mcp env | grep -i github_token

Configuration Validation Checklist

□ JSON syntax is valid □ All server commands exist and are executable □ Environment variables are properly referenced (not hardcoded) □ Filesystem paths follow least privilege □ Package versions are pinned □ No secrets in configuration file □ Configuration is committed to repository □ Server definitions match documented architecture □ Access control rules are documented

ISMS Alignment

Configuration Area ISO 27001 NIST CSF CIS Controls

Access Control A.8.3 PR.AC-4 CIS 6.1

Secret Management A.8.24 PR.DS-1 CIS 3.11

Configuration Mgmt A.8.9 PR.IP-1 CIS 4.1

Audit Logging A.8.15 DE.AE-3 CIS 8.2

Change Control A.8.32 PR.IP-3 CIS 4.2

References

• Model Context Protocol Specification

• GitHub Copilot MCP Configuration

• CIA .github/copilot-mcp-config.json