index.js•3.67 kB
#!/usr/bin/env node
/**
* MCP Server for interacting with the BlazeSQL Natural Language Query API.
* Exposes the BlazeSQL query functionality as an MCP tool using McpServer.
*/
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js"; // Reverted import path
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js"; // Reverted import path
import 'dotenv/config'; // Load environment variables from .env file
import { queryBlazeSQL } from './blazesql.js'; // Import the function and types
import { z } from "zod"; // Import Zod for schema validation
// --- API Key Loading ---
const apiKey = process.env.BLAZE_API_KEY;
if (!apiKey) {
console.error("FATAL ERROR: BLAZE_API_KEY environment variable is not set.");
console.error("Please create a .env file based on .env.example and add your API key.");
process.exit(1); // Exit if the key is missing
}
console.error("API Key loaded successfully.");
// --- Server Initialization ---
const server = new McpServer(// Changed to McpServer
{
name: "BlazeSQL MCP Server",
version: "0.2.0", // Updated version
}
// Capabilities are inferred by McpServer when tools are added
);
// --- Register Tool using server.tool() ---
server.tool("blazesql_query", // Tool name
{
db_id: z.string().describe("The ID of the BlazeSQL database connection to query."),
natural_language_request: z.string().describe("The query expressed in natural language (e.g., 'show me total users per city').")
},
// Tool handler function - TS should infer params type from raw shape now
async (params) => {
const { db_id, natural_language_request } = params;
// Input validation is handled by Zod schema above
console.error(`Executing BlazeSQL query for DB ID: ${db_id}`);
console.error(`Natural Language Request: "${natural_language_request}"`);
// Call the BlazeSQL API function - apiKey is guaranteed non-null here
const result = await queryBlazeSQL(db_id, natural_language_request, apiKey);
if (result.success) {
console.error("BlazeSQL query successful. Returning structured results as formatted text.");
// Format the output into a single text block with Markdown
const outputText = `**Agent Response:**\n${result.agent_response}\n\n**Generated SQL:**\n\`\`\`sql\n${result.query ?? "-- No SQL query returned"}\n\`\`\`\n\n**Data Result (JSON):**\n\`\`\`json\n${JSON.stringify(result.data_result ?? {}, null, 2)}\n\`\`\`\n`;
// Return a single text content block
return {
content: [
{
type: "text",
text: outputText
}
]
};
}
else {
// Handle API errors - Throwing an error is standard for tool failures
console.error(`BlazeSQL API Error (Code ${result.error_code}): ${result.error}`);
// Return error message as text content
return {
content: [
{ type: "text", text: `BlazeSQL API Error: ${result.error}` }
],
isError: true // Indicate it's an error response
};
}
});
console.error(`Tool 'blazesql_query' registered using McpServer.`);
// --- Server Startup ---
console.error("BlazeSQL MCP Server configuring...");
/**
* Start the server using stdio transport.
*/
async function main() {
const transport = new StdioServerTransport();
console.error("Connecting transport...");
await server.connect(transport);
console.error("BlazeSQL MCP Server is running and connected via stdio.");
}
main().catch((error) => {
console.error("Server encountered fatal error:", error);
process.exit(1);
});