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MCPs Node (Model Context Protocol)

MCPs connect your agent to external tools, databases, and services.

Overview

Purpose: Integrate external systems (databases, APIs, documentation) Connection: Top-right handle of main agent card Color: Blue Icon: 🔌 Required: Optional (0 to many)

What are MCPs?

Model Context Protocol (MCP) servers provide external tool access:
  • Documentation lookup (Context7)
  • Database connections (PostgreSQL, MongoDB)
  • File systems
  • Custom APIs
Think: Like plugins for your agent.

MCP Structure

MCPs are configured with command + arguments:
{
  "context7": {
    "command": "npx",
    "args": ["-y", "@context7/mcp-server"],
    "env": {
      "CONTEXT7_API_KEY": "your-key"
    }
  }
}
Stored in .mcp.json at project root.

Built-in MCPs

Context7 (Documentation Lookup)

Purpose: Retrieve up-to-date library documentation Configuration:
{
  "context7": {
    "command": "npx",
    "args": ["-y", "@context7/mcp-server"],
    "env": {
      "CONTEXT7_API_KEY": "your-api-key"
    }
  }
}
Use case: Agent looks up React/Vue/Python docs

File System MCP

Purpose: Access local file system Configuration:
{
  "filesystem": {
    "command": "npx",
    "args": ["-y", "@modelcontextprotocol/server-filesystem", "/allowed/path"]
  }
}
Use case: Read/write files outside project directory

Database MCPs

PostgreSQL:
{
  "postgresql": {
    "command": "npx",
    "args": ["-y", "@modelcontextprotocol/server-postgres"],
    "env": {
      "DATABASE_URL": "postgresql://user:pass@localhost/db"
    }
  }
}
Use case: Query customer database, analytics

Creating Custom MCPs

Via Settings → Node Managers → MCPs:
  1. Click “Add New MCP”
  2. Enter name (e.g., “Internal API”)
  3. Define command: node server.js
  4. Add arguments: ["--port", "3000"]
  5. Set environment variables (API keys, URLs)
  6. Save to workspace library
MCP appears in sidebar → drag to canvas.

Configuration

When clicked on canvas:
  • Edit command and args
  • Set environment variables
  • Configure connection settings
  • Test connectivity

Real-World Examples

Example 1: Slack Integration

{
  "slack": {
    "command": "node",
    "args": ["slack-mcp-server.js"],
    "env": {
      "SLACK_TOKEN": "xoxb-your-token",
      "SLACK_CHANNEL": "#general"
    }
  }
}
Agent can:
  • Send Slack messages
  • Read channel history
  • Search conversations

Example 2: Redis Cache

{
  "redis": {
    "command": "node",
    "args": ["redis-mcp.js"],
    "env": {
      "REDIS_URL": "redis://localhost:6379"
    }
  }
}
Agent can:
  • Cache frequently-used data
  • Store session information
  • Implement rate limiting

Example 3: AWS Services

{
  "aws": {
    "command": "node",
    "args": ["aws-mcp-server.js"],
    "env": {
      "AWS_REGION": "us-east-1",
      "AWS_ACCESS_KEY_ID": "your-key",
      "AWS_SECRET_ACCESS_KEY": "your-secret"
    }
  }
}
Agent can:
  • Upload files to S3
  • Query DynamoDB
  • Invoke Lambda functions

Security Considerations

⚠️ Important:
  • MCPs have full system access based on their permissions
  • Store credentials in environment variables (not hardcoded)
  • Use read-only database accounts when possible
  • Audit MCP server code before use
  • Restrict network access via firewalls
Best practice: Test MCPs in sandbox before production use.

MCP vs. Skills

FeatureMCPsSkills
PurposeExternal systemsAgent capabilities
ScopeSystem-wideProject-specific
LanguageAny (runs as separate process)Python/JS/shell
ExampleDatabase connectionData processing
Use both: MCPs connect to external systems, skills process data.

Troubleshooting

MCP won’t connect

Check:
  1. Command path is correct
  2. Dependencies installed (npx can find package)
  3. Environment variables set correctly
  4. Network connectivity (for remote services)
  5. Authentication credentials valid

MCP is slow

Solutions:
  • Add caching layer
  • Use connection pooling
  • Implement rate limiting
  • Choose geographically-close servers

Next Steps