MCP Datastore Server

#!/usr/bin/env node import { Server } from '@modelcontextprotocol/sdk/server/index.js'; import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js'; import { CallToolRequestSchema, ListToolsRequestSchema, } from '@modelcontextprotocol/sdk/types.js'; import { DatastoreClient } from './datastore.js'; const server = new Server( { name: 'mcp-datastore-server', version: '1.0.0', }, { capabilities: { tools: {}, }, } ); const datastoreClient = new DatastoreClient(); server.setRequestHandler(ListToolsRequestSchema, async () => { return { tools: [ { name: 'datastore_list_kinds', description: 'List all available entity kinds (tables) in the Datastore', inputSchema: { type: 'object', properties: {}, }, }, { name: 'datastore_get', description: 'Get an entity by its key', inputSchema: { type: 'object', properties: { kind: { type: 'string', description: 'The entity kind', }, key: { type: 'string', description: 'The entity key (name or ID)', }, parent: { type: 'string', description: 'Parent key if the entity has a parent (optional)', }, }, required: ['kind', 'key'], }, }, { name: 'datastore_query', description: 'Execute a query on entities with optional filters', inputSchema: { type: 'object', properties: { kind: { type: 'string', description: 'The entity kind to query', }, limit: { type: 'number', description: 'Maximum number of results to return (default: 100)', }, offset: { type: 'number', description: 'Number of results to skip (default: 0)', }, }, required: ['kind'], }, }, { name: 'datastore_filter', description: 'Query entities with a simple equality filter on any field', inputSchema: { type: 'object', properties: { kind: { type: 'string', description: 'The entity kind to query', }, field: { type: 'string', description: 'The field name to filter on (can be key field or property)', }, value: { type: 'string', description: 'The value to match exactly', }, limit: { type: 'number', description: 'Maximum number of results to return (default: 100)', }, }, required: ['kind', 'field', 'value'], }, }, { name: 'datastore_count', description: 'Count entities in a kind, optionally with a filter', inputSchema: { type: 'object', properties: { kind: { type: 'string', description: 'The entity kind to count', }, field: { type: 'string', description: 'The field name to filter on (optional)', }, value: { type: 'string', description: 'The value to match exactly (required if field is provided)', }, }, required: ['kind'], }, }, ], }; }); server.setRequestHandler(CallToolRequestSchema, async (request) => { try { const { name, arguments: args } = request.params; if (!args) { throw new Error('No arguments provided'); } switch (name) { case 'datastore_list_kinds': const kinds = await datastoreClient.listKinds(); return { content: [ { type: 'text', text: `Available entity kinds:\n${kinds.map((k: string) => `- ${k}`).join('\n')}`, }, ], }; case 'datastore_get': const entity = await datastoreClient.getEntity( args.kind as string, args.key as string, args.parent as string | undefined ); return { content: [ { type: 'text', text: entity ? JSON.stringify(entity, null, 2) : 'Entity not found', }, ], }; case 'datastore_query': const results = await datastoreClient.queryEntities( args.kind as string, args.limit as number | undefined, args.offset as number | undefined ); return { content: [ { type: 'text', text: JSON.stringify(results, null, 2), }, ], }; case 'datastore_filter': const filteredResults = await datastoreClient.filterEntities( args.kind as string, args.field as string, args.value as string, args.limit as number | undefined ); return { content: [ { type: 'text', text: JSON.stringify(filteredResults, null, 2), }, ], }; case 'datastore_count': const count = await datastoreClient.countEntities( args.kind as string, args.field as string | undefined, args.value as string | undefined ); return { content: [ { type: 'text', text: `Count: ${count}`, }, ], }; default: throw new Error(`Unknown tool: ${name}`); } } catch (error) { return { content: [ { type: 'text', text: `Error: ${error instanceof Error ? error.message : 'Unknown error'}`, }, ], isError: true, }; } }); async function main() { const transport = new StdioServerTransport(); await server.connect(transport); console.error('MCP Datastore server running on stdio'); } main().catch((error) => { console.error('Server error:', error); process.exit(1); });