Claude Code MCP Expert Skill

Claude Code MCP Expert

Connect Claude Code to external tools, databases, and services using Model Context Protocol (MCP).

When to Use

User wants to connect external services (GitHub, Jira, Sentry)
User needs database access (PostgreSQL, MongoDB)
User asks about MCP configuration or .mcp.json
User has MCP connection or authentication issues

What is MCP?

Model Context Protocol (MCP) is an open standard that connects AI agents to:

External APIs (GitHub, Jira, Notion, Slack)
Databases (PostgreSQL, MongoDB, MySQL)
File systems (local, Google Drive)
Custom integrations

Quick Start

# Add an HTTP server
claude mcp add --transport http sentry https://mcp.sentry.dev/mcp

# Add an SSE server
claude mcp add --transport sse atlassian https://mcp.atlassian.com/v1/sse

# Add a stdio server (npm package)
claude mcp add --transport stdio github -- npx -y @modelcontextprotocol/server-github

# Manage servers interactively
/mcp

Transport Types

HTTP (Most Common)

For cloud services with REST-like endpoints.

claude mcp add --transport http sentry https://mcp.sentry.dev/mcp
claude mcp add --transport http github https://api.github.com/mcp
claude mcp add --transport http notion https://mcp.notion.com/mcp

SSE (Server-Sent Events)

For streaming services.

claude mcp add --transport sse atlassian https://mcp.atlassian.com/v1/sse
claude mcp add --transport sse asana https://mcp.asana.com/sse

stdio (Local/NPM Packages)

For local tools or npm packages.

claude mcp add --transport stdio postgres \
  --env POSTGRES_CONNECTION_STRING="postgresql://user:pass@localhost:5432/db" \
  -- npx -y @modelcontextprotocol/server-postgres

claude mcp add --transport stdio filesystem \
  --env ALLOWED_DIRECTORIES="/path/to/dir" \
  -- npx -y @modelcontextprotocol/server-filesystem

Popular Integrations

Development Tools

| Service | Command | |---------|---------| | Sentry | claude mcp add --transport http sentry https://mcp.sentry.dev/mcp | | GitHub | claude mcp add --transport http github https://api.github.com/mcp | | Socket | claude mcp add --transport http socket https://mcp.socket.dev/ |

Project Management

| Service | Command | |---------|---------| | Jira | claude mcp add --transport sse atlassian https://mcp.atlassian.com/v1/sse | | Linear | claude mcp add --transport http linear https://mcp.linear.app/mcp | | Notion | claude mcp add --transport http notion https://mcp.notion.com/mcp | | Asana | claude mcp add --transport sse asana https://mcp.asana.com/sse |

Databases

# PostgreSQL
claude mcp add --transport stdio postgres \
  --env POSTGRES_CONNECTION_STRING="postgresql://localhost:5432/mydb" \
  -- npx -y @modelcontextprotocol/server-postgres

# MongoDB
claude mcp add --transport stdio mongodb \
  --env MONGODB_URI="mongodb://localhost:27017/mydb" \
  -- npx -y @modelcontextprotocol/server-mongodb

Communication

# Slack
claude mcp add --transport stdio slack \
  --env SLACK_BOT_TOKEN=xoxb-your-token \
  --env SLACK_TEAM_ID=T1234567 \
  -- npx -y @modelcontextprotocol/server-slack

# Gmail
claude mcp add --transport stdio gmail \
  -- npx -y @modelcontextprotocol/server-gmail

Configuration Files

.mcp.json Structure

{
  "mcpServers": {
    "server-name": {
      "transport": "http",
      "url": "https://mcp.service.com/mcp"
    },
    "database": {
      "transport": "stdio",
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-postgres"],
      "env": {
        "POSTGRES_CONNECTION_STRING": "postgresql://localhost/db"
      }
    }
  }
}

Configuration Scopes

| Scope | Location | Use Case | |-------|----------|----------| | User | ~/.claude/.mcp.json | Personal tools, global | | Project | .claude/.mcp.json | Team-shared, git committed | | Local | .claude/.mcp.local.json | Personal overrides, not committed |

Add with Scope

claude mcp add --transport http sentry https://mcp.sentry.dev/mcp --user     # Global
claude mcp add --transport http linear https://mcp.linear.app/mcp --project  # Team
claude mcp add --transport http notion https://mcp.notion.com/mcp --local    # Personal override

Authentication

OAuth (Recommended)

# Install server
claude mcp add --transport http github https://api.github.com/mcp

# Authenticate via /mcp command
/mcp
# Select: Authenticate with server
# Browser opens → authorize → done

API Keys (Environment Variables)

claude mcp add --transport stdio server-name \
  --env API_KEY=your_api_key \
  -- npx -y package-name

Via settings.json

{
  "env": {
    "GITHUB_TOKEN": "ghp_xxxxx",
    "SENTRY_AUTH_TOKEN": "sntrys_xxxxx"
  }
}

Using MCP Features

MCP Tools

Once connected, use naturally:

"Check Sentry for errors in the last 24 hours"
"Create a PR for this feature on GitHub"
"List my assigned Jira tickets"
"Query the users table for active accounts"

MCP Resources

Reference MCP-provided files:

Review @mcp://github/README.md and suggest improvements

MCP Prompts as Commands

MCP prompts become slash commands:

/mcp__github__create_issue "Bug in login" high
/mcp__jira__update_status PROJ-123 "In Progress"

Managing Servers

Interactive Management

/mcp
# Options:
# - View all servers
# - Add new server
# - Remove server
# - Authenticate
# - View tools/prompts/resources

Command Line

claude mcp list                    # List servers
claude mcp add ...                 # Add server
claude mcp remove server-name      # Remove server

Troubleshooting

Server Not Connecting

Verify URL/command - check for typos
Check auth - run /mcp → Authenticate
Test network - can you reach the URL?
Debug mode - run claude --debug

Authentication Failing

Re-authenticate: /mcp → Clear auth → Re-authenticate
Check API key validity
Verify OAuth tokens not expired
Check permissions/scopes

stdio Server Errors

# Test command manually
npx -y @modelcontextprotocol/server-postgres

# Check environment variables are set
echo $POSTGRES_CONNECTION_STRING

# Verify npm package exists
npm info @modelcontextprotocol/server-postgres

Tools Not Available

Confirm server is connected: /mcp
Check authentication completed
Restart Claude Code
Verify server provides expected tools

Security Best Practices

DO:

Use OAuth when available
Store secrets in settings.json, not .mcp.json
Use project scope for team configs
Review server permissions regularly

DON'T:

Commit API keys to git
Install untrusted servers
Share OAuth tokens
Use broad permissions unnecessarily

Example Workflows

Issue to PR

# Setup
claude mcp add --transport http github https://api.github.com/mcp
claude mcp add --transport sse atlassian https://mcp.atlassian.com/v1/sse

# Usage
"Read JIRA ticket ENG-123, implement the feature, and create a PR on GitHub"

Error Investigation

# Setup
claude mcp add --transport http sentry https://mcp.sentry.dev/mcp

# Usage
"Check Sentry for errors in the last hour and fix them"

Database Query to Report

# Setup
claude mcp add --transport stdio postgres \
  --env POSTGRES_CONNECTION_STRING="postgresql://localhost/analytics" \
  -- npx -y @modelcontextprotocol/server-postgres

# Usage
"Find users who signed up this month and summarize their activity"

Resources

MCP Website: https://modelcontextprotocol.io/
MCP Servers List: https://github.com/modelcontextprotocol/servers
Claude Code MCP Docs: https://docs.anthropic.com/en/docs/claude-code/mcp

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