MCP Datastore Server

import { Datastore } from '@google-cloud/datastore'; export class DatastoreClient { datastore; constructor() { this.datastore = new Datastore({ projectId: process.env.GOOGLE_CLOUD_PROJECT, keyFilename: process.env.GOOGLE_APPLICATION_CREDENTIALS, }); } async listKinds() { try { const query = this.datastore.createQuery('__kind__').select('__key__'); const [entities] = await this.datastore.runQuery(query); return entities.map(entity => entity[this.datastore.KEY].name).filter(Boolean); } catch (error) { throw new Error(`Failed to list kinds: ${error instanceof Error ? error.message : 'Unknown error'}`); } } async getEntity(kind, key, parent) { try { let entityKey; if (parent) { const parentKeyValue = isNaN(Number(parent)) ? parent : parseInt(parent); const keyValue = isNaN(Number(key)) ? key : parseInt(key); entityKey = this.datastore.key([kind, parentKeyValue, kind, keyValue]); } else { entityKey = this.datastore.key([kind, isNaN(Number(key)) ? key : parseInt(key)]); } const [entity] = await this.datastore.get(entityKey); if (!entity) { return null; } return { key: entity[this.datastore.KEY], ...entity, }; } catch (error) { throw new Error(`Failed to get entity: ${error instanceof Error ? error.message : 'Unknown error'}`); } } async queryEntities(kind, limit = 100, offset = 0) { try { const query = this.datastore.createQuery(kind) .limit(limit) .offset(offset); const [entities] = await this.datastore.runQuery(query); return entities.map(entity => ({ key: entity[this.datastore.KEY], ...entity, })); } catch (error) { throw new Error(`Failed to query entities: ${error instanceof Error ? error.message : 'Unknown error'}`); } } async filterEntities(kind, field, value, limit = 100) { try { let query = this.datastore.createQuery(kind); if (field === '__key__' || field === 'key') { const keyValue = isNaN(Number(value)) ? value : parseInt(value); const entityKey = this.datastore.key([kind, keyValue]); query = query.filter('__key__', '=', entityKey); } else { const convertedValue = this.convertValue(value); query = query.filter(field, '=', convertedValue); } query = query.limit(limit); const [entities] = await this.datastore.runQuery(query); return entities.map(entity => ({ key: entity[this.datastore.KEY], ...entity, })); } catch (error) { throw new Error(`Failed to filter entities: ${error instanceof Error ? error.message : 'Unknown error'}`); } } async countEntities(kind, field, value) { try { let query = this.datastore.createQuery(kind).select('__key__'); if (field && value !== undefined) { if (field === '__key__' || field === 'key') { const keyValue = isNaN(Number(value)) ? value : parseInt(value); const entityKey = this.datastore.key([kind, keyValue]); query = query.filter('__key__', '=', entityKey); } else { const convertedValue = this.convertValue(value); query = query.filter(field, '=', convertedValue); } } const [entities] = await this.datastore.runQuery(query); return entities.length; } catch (error) { throw new Error(`Failed to count entities: ${error instanceof Error ? error.message : 'Unknown error'}`); } } convertValue(value) { if (value.toLowerCase() === 'true') return true; if (value.toLowerCase() === 'false') return false; if (value.toLowerCase() === 'null') return null; const numValue = Number(value); if (!isNaN(numValue)) return numValue; return value; } }