KnowledgeGraph MCP Server

#!/usr/bin/env node import { KnowledgeGraphManager, Entity, Relation } from '../index.js'; import { StorageConfig, StorageType } from '../storage/types.js'; import path from 'path'; const __dirname = path.join(process.cwd(), 'examples'); // Sample entities with tags for demonstration const sampleEntities: Entity[] = [ { name: 'React', entityType: 'JavaScript Library', observations: [ 'Component-based architecture', 'Virtual DOM for performance', 'Developed by Meta (Facebook)', 'Declarative programming model' ], tags: ['frontend', 'javascript', 'ui', 'popular', 'meta'] }, { name: 'Vue.js', entityType: 'JavaScript Framework', observations: [ 'Progressive framework', 'Easy learning curve', 'Excellent documentation', 'Template-based syntax' ], tags: ['frontend', 'javascript', 'ui', 'progressive', 'beginner-friendly'] }, { name: 'Django', entityType: 'Python Framework', observations: [ 'Batteries-included philosophy', 'ORM for database operations', 'Admin interface out of the box', 'MTV (Model-Template-View) pattern' ], tags: ['backend', 'python', 'web', 'orm', 'admin'] }, { name: 'Express.js', entityType: 'Node.js Framework', observations: [ 'Minimal and flexible', 'Middleware-based architecture', 'Fast and unopinionated', 'Large ecosystem' ], tags: ['backend', 'javascript', 'nodejs', 'minimal', 'middleware'] }, { name: 'PostgreSQL', entityType: 'Database', observations: [ 'ACID compliant', 'Advanced SQL features', 'Extensible with custom functions', 'Strong consistency guarantees' ], tags: ['database', 'sql', 'relational', 'acid', 'enterprise'] }, { name: 'MongoDB', entityType: 'Database', observations: [ 'Document-oriented storage', 'Flexible schema', 'Horizontal scaling', 'JSON-like documents' ], tags: ['database', 'nosql', 'document', 'scalable', 'json'] } ]; const sampleRelations: Relation[] = [ { from: 'React', to: 'Vue.js', relationType: 'competes_with' }, { from: 'Express.js', to: 'Django', relationType: 'alternative_to' }, { from: 'React', to: 'Express.js', relationType: 'often_used_with' }, { from: 'Django', to: 'PostgreSQL', relationType: 'commonly_uses' }, { from: 'Express.js', to: 'MongoDB', relationType: 'frequently_paired_with' } ]; async function demonstrateTagSystem() { console.log('🏷️ Knowledge Graph MCP Server - Tag System Demonstration'); console.log('========================================================\n'); const config: StorageConfig = { type: StorageType.POSTGRESQL, connectionString: 'postgresql://postgres:password@localhost:5432/knowledgegraph_tag_demo' }; const manager = new KnowledgeGraphManager(config); try { // 1. Create entities with tags console.log('1️⃣ Creating entities with tags...'); await manager.createEntities(sampleEntities, 'tag_demo'); await manager.createRelations(sampleRelations, 'tag_demo'); console.log(`✅ Created ${sampleEntities.length} entities and ${sampleRelations.length} relations\n`); // 2. Demonstrate tag search - exact matching console.log('2️⃣ Searching by tags (exact matching)...'); // Search for frontend technologies const frontendResults = await manager.searchNodes('', { exactTags: ['frontend'], tagMatchMode: 'any' }, 'tag_demo'); console.log(`🔍 Frontend technologies (${frontendResults.entities.length} found):`); frontendResults.entities.forEach(entity => { console.log(` • ${entity.name} (${entity.entityType}) - Tags: [${entity.tags?.join(', ') || 'none'}]`); }); console.log(); // Search for JavaScript technologies const jsResults = await manager.searchNodes('', { exactTags: ['javascript'], tagMatchMode: 'any' }, 'tag_demo'); console.log(`🔍 JavaScript technologies (${jsResults.entities.length} found):`); jsResults.entities.forEach(entity => { console.log(` • ${entity.name} (${entity.entityType}) - Tags: [${entity.tags?.join(', ') || 'none'}]`); }); console.log(); // Search for databases const dbResults = await manager.searchNodes('', { exactTags: ['database'], tagMatchMode: 'any' }, 'tag_demo'); console.log(`🔍 Database technologies (${dbResults.entities.length} found):`); dbResults.entities.forEach(entity => { console.log(` • ${entity.name} (${entity.entityType}) - Tags: [${entity.tags?.join(', ') || 'none'}]`); }); console.log(); // 3. Demonstrate "all" mode search console.log('3️⃣ Searching with "all" mode (must have ALL specified tags)...'); const frontendJsResults = await manager.searchNodes('', { exactTags: ['frontend', 'javascript'], tagMatchMode: 'all' }, 'tag_demo'); console.log(`🔍 Frontend + JavaScript technologies (${frontendJsResults.entities.length} found):`); frontendJsResults.entities.forEach(entity => { console.log(` • ${entity.name} - Tags: [${entity.tags?.join(', ') || 'none'}]`); }); console.log(); // 4. Demonstrate adding tags console.log('4️⃣ Adding new tags to existing entities...'); const addTagsResult = await manager.addTags([ { entityName: 'React', tags: ['hooks', 'jsx'] }, { entityName: 'Vue.js', tags: ['composition-api', 'reactive'] }, { entityName: 'PostgreSQL', tags: ['open-source'] } ], 'tag_demo'); addTagsResult.forEach(result => { console.log(`✅ Added tags to ${result.entityName}: [${result.addedTags.join(', ')}]`); }); console.log(); // 5. Show updated entities console.log('5️⃣ Updated entities after adding tags...'); const updatedGraph = await manager.readGraph('tag_demo'); const reactEntity = updatedGraph.entities.find(e => e.name === 'React'); const vueEntity = updatedGraph.entities.find(e => e.name === 'Vue.js'); const pgEntity = updatedGraph.entities.find(e => e.name === 'PostgreSQL'); console.log(`📝 React tags: [${reactEntity?.tags?.join(', ') || 'none'}]`); console.log(`📝 Vue.js tags: [${vueEntity?.tags?.join(', ') || 'none'}]`); console.log(`📝 PostgreSQL tags: [${pgEntity?.tags?.join(', ') || 'none'}]`); console.log(); // 6. Demonstrate removing tags console.log('6️⃣ Removing tags from entities...'); const removeTagsResult = await manager.removeTags([ { entityName: 'React', tags: ['meta'] }, { entityName: 'MongoDB', tags: ['json'] } ], 'tag_demo'); removeTagsResult.forEach(result => { console.log(`🗑️ Removed tags from ${result.entityName}: [${result.removedTags.join(', ')}]`); }); console.log(); // 7. Demonstrate enhanced search (includes tags in general search) console.log('7️⃣ Enhanced search (includes tags in general text search)...'); const enhancedResults = await manager.searchNodes('nosql', 'tag_demo'); console.log(`🔍 Search for "nosql" (${enhancedResults.entities.length} found):`); enhancedResults.entities.forEach(entity => { console.log(` • ${entity.name} - Found via tags: [${entity.tags?.join(', ') || 'none'}]`); }); console.log(); // 8. Demonstrate case sensitivity console.log('8️⃣ Demonstrating case sensitivity in tag search...'); const caseSensitiveResults = await manager.searchNodes('', { exactTags: ['Frontend'], tagMatchMode: 'any' }, 'tag_demo'); // Capital F console.log(`🔍 Search for "Frontend" (capital F): ${caseSensitiveResults.entities.length} found`); console.log(' (Tags are case-sensitive for exact matching)\n'); // 9. Show final state console.log('9️⃣ Final knowledge graph state...'); const finalGraph = await manager.readGraph('tag_demo'); console.log(`📊 Total entities: ${finalGraph.entities.length}`); console.log(`📊 Total relations: ${finalGraph.relations.length}`); console.log(`📊 Total unique tags: ${[...new Set(finalGraph.entities.flatMap(e => e.tags))].length}`); const allTags = [...new Set(finalGraph.entities.flatMap(e => e.tags))].sort(); console.log(`🏷️ All tags: [${allTags.join(', ')}]`); } catch (error) { console.error('❌ Demo failed:', error); process.exit(1); } finally { await manager.close(); } console.log('\n🎉 Tag system demonstration completed successfully!'); console.log('\nKey Features Demonstrated:'); console.log('• ✅ Exact-match tag searching (case-sensitive)'); console.log('• ✅ "Any" and "All" search modes'); console.log('• ✅ Adding and removing tags from existing entities'); console.log('• ✅ Enhanced general search that includes tags'); console.log('• ✅ Backward compatibility with entities without tags'); console.log('• ✅ Duplicate tag prevention'); console.log('• ✅ Relation preservation in filtered results'); } // Run the demonstration demonstrateTagSystem().catch(console.error);