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
MCP Structure
MCPs are configured with command + arguments:.mcp.json at project root.
Built-in MCPs
Context7 (Documentation Lookup)
Purpose: Retrieve up-to-date library documentation Configuration:File System MCP
Purpose: Access local file system Configuration:Database MCPs
PostgreSQL:Creating Custom MCPs
Via Settings → Node Managers → MCPs:- Click “Add New MCP”
- Enter name (e.g., “Internal API”)
- Define command:
node server.js - Add arguments:
["--port", "3000"] - Set environment variables (API keys, URLs)
- Save to workspace library
Configuration
When clicked on canvas:- Edit command and args
- Set environment variables
- Configure connection settings
- Test connectivity
Real-World Examples
Example 1: Slack Integration
- Send Slack messages
- Read channel history
- Search conversations
Example 2: Redis Cache
- Cache frequently-used data
- Store session information
- Implement rate limiting
Example 3: AWS Services
- 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
MCP vs. Skills
| Feature | MCPs | Skills |
|---|---|---|
| Purpose | External systems | Agent capabilities |
| Scope | System-wide | Project-specific |
| Language | Any (runs as separate process) | Python/JS/shell |
| Example | Database connection | Data processing |
Troubleshooting
MCP won’t connect
Check:- Command path is correct
- Dependencies installed (
npxcan find package) - Environment variables set correctly
- Network connectivity (for remote services)
- Authentication credentials valid
MCP is slow
Solutions:- Add caching layer
- Use connection pooling
- Implement rate limiting
- Choose geographically-close servers
Next Steps
- Hooks Node - Lifecycle events
- Sub-agents Node - Specialized agents