MCP Config

MCP Configuration Management

Overview

This skill helps you properly configure MCP servers in Claude Code. It ensures MCP servers are configured in the right location and scope to avoid unnecessary context pollution across all sessions.

Critical Concepts

Two Valid Configuration Locations

ONLY these two locations are valid for MCP configuration:

1. User/Local scope: ~/.claude.json

   • In the mcpServers field (global for all projects)
   • Or under specific project paths (project-specific in user config)

2. Project scope: .mcp.json in your project root

   • Checked into source control
   • Only affects the current project

⚠️ Important Rules

• DO NOT configure MCPs in ~/.claude.json global mcpServers - This loads MCPs in ALL sessions and wastes context space
• DO configure MCPs in project-level .mcp.json - This only loads MCPs when working in that specific project
• Avoid settings.json for MCP control - The permissions.allow field can override disabled settings and cause confusion

When to Use This Skill

Invoke this skill when:

• Adding a new MCP server to a project
• Removing/disabling an MCP server
• MCP servers are loading when they shouldn't be
• Need to clean up MCP configuration
• Want to understand why an MCP is or isn't loading

Quick Start

Configuration Workflow

1. Check Current MCP Status

First, understand what MCPs are currently loaded:

# Check user-level configuration
cat ~/.claude.json | grep -A 20 '"mcpServers"' | head -25

# Check project-level configuration
cat .mcp.json 2>/dev/null || echo "No project .mcp.json found"

# Check settings.json (should NOT have MCP config)
cat ~/.claude/settings.json | grep -A 5 '"permissions"'

2. Add MCP to Current Project

Best Practice: Always add MCPs at project level

Create or edit .mcp.json in your project root:

{
  "mcpServers": {
    "server-name": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "package-name"],
      "env": {
        "API_KEY": "your-key-here"
      }
    }
  }
}

3. Remove MCP Configuration

From global config (~/.claude.json):

import json

with open('/Users/likai/.claude.json', 'r') as f:
    data = json.load(f)

# Remove from global mcpServers
if 'mcpServers' in data and 'server-name' in data['mcpServers']:
    del data['mcpServers']['server-name']
    print(f"Removed server-name from global config")

with open('/Users/likai/.claude.json', 'w') as f:
    json.dump(data, f, indent=2)

From project config (.mcp.json):

import json

try:
    with open('.mcp.json', 'r') as f:
        data = json.load(f)

    if 'mcpServers' in data and 'server-name' in data['mcpServers']:
        del data['mcpServers']['server-name']

    with open('.mcp.json', 'w') as f:
        json.dump(data, f, indent=2)
    print("Removed server-name from project config")
except FileNotFoundError:
    print("No .mcp.json found in project")

4. Clean Up settings.json

Remove any MCP-related permissions that might override configuration:

import json

with open('/Users/likai/.claude/settings.json', 'r') as f:
    data = json.load(f)

# Remove permissions block if it contains MCP references
if 'permissions' in data:
    if 'allow' in data['permissions']:
        data['permissions']['allow'] = [
            item for item in data['permissions']['allow']
            if not item.startswith('mcp__')
        ]
        if not data['permissions']['allow']:
            del data['permissions']

with open('/Users/likai/.claude/settings.json', 'w') as f:
    json.dump(data, f, indent=2)

Common MCP Servers

Pencil (Design Tool)

{
  "mcpServers": {
    "pencil": {
      "command": "/Users/likai/.vscode/extensions/highagency.pencildev-0.6.29/out/mcp-server-darwin-arm64",
      "args": ["--app", "visual_studio_code"],
      "env": {},
      "type": "stdio"
    }
  }
}

Shadcn Studio

{
  "mcpServers": {
    "shadcn-studio-mcp": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "shadcn-studio-mcp",
        "API_KEY=your-api-key",
        "EMAIL=your-email"
      ],
      "env": {}
    }
  }
}

Unsplash

{
  "mcpServers": {
    "unsplash": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@microlee666/unsplash-mcp-server"],
      "env": {
        "UNSPLASH_ACCESS_KEY": "your-access-key"
      }
    }
  }
}

Troubleshooting

Problem: MCP loads in all sessions

Cause: MCP is configured in ~/.claude.json global mcpServers

Solution:

1. Remove from ~/.claude.json global config
2. Add to project-level .mcp.json instead
3. Restart Claude Code session

Problem: MCP won't disable despite "disabled": true

Cause: permissions.allow in settings.json overrides disabled setting

Solution:

1. Remove MCP from settings.json permissions
2. Remove the entire permissions block if empty
3. Restart Claude Code session

Problem: MCP configuration conflicts

Cause: MCP configured in multiple locations with different settings

Solution:

1. Check all three locations: ~/.claude.json, .mcp.json, settings.json
2. Keep configuration in ONE place only (prefer .mcp.json)
3. Remove from other locations

Problem: Can't find where MCP is configured

Diagnostic commands:

# Search all possible locations
echo "=== Global Config ==="
grep -A 10 '"mcpServers"' ~/.claude.json | head -15

echo "=== Project Config ==="
cat .mcp.json 2>/dev/null || echo "No .mcp.json"

echo "=== Settings ==="
grep -A 5 '"permissions"' ~/.claude/settings.json 2>/dev/null || echo "No permissions"

echo "=== Project Settings ==="
grep -A 5 '"permissions"' .claude/settings.json 2>/dev/null || echo "No project settings"

Best Practices

1. ✅ Always use project-level .mcp.json for project-specific MCPs
2. ✅ Keep ~/.claude.json global mcpServers empty to avoid context pollution
3. ✅ Avoid MCP configuration in settings.json - use it only for permissions if needed
4. ✅ Restart Claude Code after configuration changes to ensure they take effect
5. ✅ Check into source control - Commit .mcp.json so team members get the same MCPs
6. ❌ Never use disabled: true - Just remove the MCP configuration entirely
7. ❌ Don't mix configuration locations - Pick one place and stick to it

Configuration Priority

When Claude Code loads MCPs, it follows this priority:

1. Project-level .mcp.json (highest priority)
2. User-level ~/.claude.json project-specific config
3. User-level ~/.claude.json global mcpServers
4. settings.json permissions can override all of the above

Recommendation: Use only project-level .mcp.json to avoid confusion.

Example: Complete Cleanup and Reconfiguration

# 1. Clean up global config
python3 << 'EOF'
import json
with open('/Users/likai/.claude.json', 'r') as f:
    data = json.load(f)
data['mcpServers'] = {}
with open('/Users/likai/.claude.json', 'w') as f:
    json.dump(data, f, indent=2)
print("✓ Cleaned global mcpServers")
EOF

# 2. Clean up settings.json
python3 << 'EOF'
import json
with open('/Users/likai/.claude/settings.json', 'r') as f:
    data = json.load(f)
if 'permissions' in data:
    del data['permissions']
with open('/Users/likai/.claude/settings.json', 'w') as f:
    json.dump(data, f, indent=2)
print("✓ Cleaned settings.json permissions")
EOF

# 3. Create project-level config
cat > .mcp.json << 'EOF'
{
  "mcpServers": {
    "your-mcp-name": {
      "type": "stdio",
      "command": "your-command",
      "args": [],
      "env": {}
    }
  }
}
EOF
echo "✓ Created project .mcp.json"

# 4. Restart Claude Code
echo "⚠️  Please restart Claude Code for changes to take effect"

Summary

• Two valid locations: ~/.claude.json and .mcp.json
• Best practice: Use project-level .mcp.json only
• Avoid: Global mcpServers in ~/.claude.json (wastes context)
• Avoid: MCP config in settings.json (causes conflicts)
• Always restart Claude Code after configuration changes

Source: libukai/awesome-agent-skills → plugins/claude-code-setting/skills/mcp-config/SKILL.md