import { FastMCP } from "fastmcp";
import { z } from "zod";
import { registerToolsWithServer, initializeTools } from './tools/index.js';
import pg from 'pg';
const { Pool } = pg;
import dotenv from 'dotenv';
import logger from './utils/logger.js';
// Load environment variables from .env file
dotenv.config();
// Database configuration
const dbConfig = {
connectionString: process.env.POSTGRESQL_ADDON_URI,
// Additional database configuration options can be added here
max: 20, // Maximum number of clients in the pool
idleTimeoutMillis: 30000, // How long a client is allowed to remain idle before being closed
};
/**
* Initialize the PostgreSQL connection pool
*/
export const initializeDbPool = () => {
try {
const pool = new Pool(dbConfig);
console.log('PostgreSQL connection pool initialized');
return pool;
} catch (error) {
console.error('Failed to initialize PostgreSQL connection pool:', error);
throw error;
}
};
/**
* Create and configure the MCP server
* @param {Object} dbPool - PostgreSQL connection pool
* @returns {Server} Configured MCP server instance
*/
export const createMCPServer = (dbPool) => {
// Create a new MCP server instance
const server = new FastMCP({
name: 'RAGmonsters MCP Server',
version: '0.1.0',
description: 'A domain-specific MCP server for the RAGmonsters dataset',
});
// Initialize the monsters module with the database pool
initializeTools(dbPool);
logger.info('Initialized monsters module with database pool');
// Register all tools from our tools module
registerToolsWithServer(server);
server.addTool({
name: "add",
description: "Add two numbers",
parameters: z.object({
a: z.number(),
b: z.number(),
}),
execute: async (args) => {
return String(args.a + args.b);
},
});
// Resource: Database Schema (Principle 2)
server.addResource({
uri: "ragmonsters://schema",
name: "RAGmonsters Database Schema",
mimeType: "text/plain",
description: "Schema definition for the monsters database, describing available columns and types.",
load: async () => {
return {
text: `
Monster {
id: ID!
name: String!
category: Enum(Aquatic, Elemental, Spirit/Ethereal, ...)
rarity: Enum(Common, Rare, Very Rare, ...)
habitat: String
biome: String
powers: {
primary: String
secondary: String
special: String
}
}
`
};
}
});
// Prompt: Answering Style (Principle 3 - Guidance)
server.addPrompt({
name: "answering-style",
description: "Guidelines for how to answer questions about monsters",
load: async () => {
return {
messages: [
{
role: "user",
content: {
type: "text",
text: "How should I answer questions about RAGmonsters?"
}
},
{
role: "assistant",
content: {
type: "text",
text: "When discussing monsters:\n1. Always cite the monster's Name and ID.\n2. Mention the source policy if available.\n3. Be concise but descriptive about their powers.\n4. If the category is 'Extremely Rare', emphasize the danger."
}
}
]
};
}
});
// Resource: Query Tips (Method 2: Documentation)
server.addResource({
uri: "ragmonsters://docs/query-tips",
name: "Query Tips",
mimeType: "text/plain",
description: "A compact note on how to query effectively.",
load: async () => {
return {
text: "Tips for querying RAGmonsters:\n" +
"1. Use getMonsters for discovery (searching by habitat, category, etc.).\n" +
"2. Use getMonsterById for detailed stats, powers, and weaknesses.\n" +
"3. Use getHabitats/getCategories to see available filter values first.\n" +
"4. When comparing monsters, retrieve their details separately if needed."
};
}
});
// Resource: Images (Method 2: Assets - Placeholder)
server.addResourceTemplate({
uriTemplate: "ragmonsters://images/{monsterId}",
name: "Monster Image",
mimeType: "image/png",
description: "Read-only access to monster artwork (placeholder).",
arguments: [
{ name: "monsterId", description: "ID of the monster" }
],
load: async (params) => {
const monsterId = params.monsterId;
return {
text: `[Image Placeholder for Monster ID ${monsterId}]\n(Visual: A terrifying creature lurks here...)`
};
}
});
// Prompt: Disambiguation (Method 3: Guidance)
server.addPrompt({
name: "disambiguation",
description: "Instructions for handling ambiguity when multiple monsters match",
load: async () => {
return {
messages: [
{
role: "user",
content: {
type: "text",
text: "What if my search matches multiple monsters?"
}
},
{
role: "assistant",
content: {
type: "text",
text: "If multiple monsters match the user's query:\n" +
"1. Do NOT guess.\n" +
"2. List the matching options with their IDs and Categories.\n" +
"3. Ask the user to clarify which one they mean.\n" +
"4. Example: 'Did you mean the Aquatic Abyssalurk (ID 1) or the Construct Abyssal-Droid (ID 99)?'"
}
}
]
};
}
});
logger.info('MCP server created and configured');
return server;
};
/**
* Initialize and start the MCP server
*/
export const initializeAndStartServer = async () => {
const dbPool = initializeDbPool();
const server = createMCPServer(dbPool);
logger.info('Starting MCP server with STDIO transport');
server.start({
transportType: "stdio",
});
};
initializeAndStartServer();
