Postgres MCP Server

Instructions

Implementation Reference

• src/index.ts:1374-1406 (handler)

  Primary handler function for the 'connections' tool. Dispatches based on 'action' parameter to return pool status, operational stats, or test connection using DatabaseConnectionManager methods.
  private async handleConnections(args: any) { const { action } = args; switch (action) { case 'status': return { content: [{ type: 'text', text: JSON.stringify(this.dbManager.getPoolStats(), null, 2) }] }; case 'stats': return { content: [{ type: 'text', text: JSON.stringify(this.dbManager.getOperationalStats(), null, 2) }] }; case 'test': const isHealthy = await this.dbManager.testConnection(); return { content: [{ type: 'text', text: JSON.stringify({ connected: isHealthy, timestamp: new Date().toISOString() }, null, 2) }] }; default: throw new Error(`Unknown connections action: ${action}`); } }
• src/index.ts:392-405 (schema)

  Input schema and metadata definition for the 'connections' MCP tool, specifying the required 'action' parameter with supported values.
  name: 'connections', description: 'Connection pool management: status, statistics, configuration', inputSchema: { type: 'object', properties: { action: { type: 'string', enum: ['status', 'stats', 'test', 'reset'], description: 'Action: status (pool status), stats (detailed statistics), test (test connection), reset (reset pool)' } }, required: ['action'] } },
• src/index.ts:634-636 (registration)

  Registration of the 'connections' tool schema via the ListToolsRequestSchema handler, which returns the full toolDefinitions array including 'connections'.
  this.server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: toolDefinitions, }));
• src/index.ts:668-669 (registration)

  Handler dispatch registration for 'connections' tool in the MCP CallToolRequestSchema switch statement.
  return await this.handleConnections(args);
• src/database/connection-manager.ts:281-292 (helper)

  Helper method returning current connection pool statistics (total, idle, waiting connections, config), used by 'status' action in connections tool.
  getPoolStats(): ConnectionPoolStats { return { totalConnections: this.pool.totalCount, idleConnections: this.pool.idleCount, waitingCount: this.pool.waitingCount, config: { min: this.config.get().pool.min, max: this.config.get().pool.max, idleTimeoutMillis: this.config.get().pool.idleTimeoutMillis, } }; }