--- name: knowledge-base-management description: Guide for working with the Knowledge Base system in DEVS. Use this when asked to add knowledge management features, file handling, or document processing. --- # Knowledge Base Management for DEVS The Knowledge Base system allows users to store and manage files, documents, and other knowledge items that agents can reference during conversations. ## Core Concepts ### KnowledgeItem Interface ```typescript interface KnowledgeItem { id: string name: string type: 'file' | 'folder' fileType?: 'document' | 'image' | 'text' content?: string // Text content or base64 for files contentHash?: string // SHA-256 hash for deduplication mimeType?: string size?: number path: string // Virtual path in knowledge base parentId?: string // Parent folder ID lastModified: Date createdAt: Date tags?: string[] description?: string syncSource?: 'manual' | 'filesystem_api' | 'connector' fileSystemHandle?: string // For File System API sync watchId?: string lastSyncCheck?: Date } ``` ## File Type Detection Supported file types in `src/lib/knowledge-utils.ts`: ```typescript const TEXT_EXTENSIONS = [ '.txt', '.md', '.js', '.ts', '.jsx', '.tsx', '.css', '.html', '.xml', '.csv', '.yaml', '.yml', '.log', ] const IMAGE_EXTENSIONS = [ '.jpg', '.jpeg', '.png', '.gif', '.bmp', '.webp', '.svg', '.ico', '.tiff', '.tif', ] const DOCUMENT_EXTENSIONS = [ '.pdf', '.doc', '.docx', '.xls', '.xlsx', '.ppt', '.pptx', '.rtf', '.epub', ] function getFileType( filename: string, ): 'text' | 'image' | 'document' | 'unknown' { const ext = filename.toLowerCase().split('.').pop() if (TEXT_EXTENSIONS.includes(`.${ext}`)) return 'text' if (IMAGE_EXTENSIONS.includes(`.${ext}`)) return 'image' if (DOCUMENT_EXTENSIONS.includes(`.${ext}`)) return 'document' return 'unknown' } ``` ## Database Operations ```typescript import { db } from '@/lib/db' // Create knowledge item async function createKnowledgeItem( item: Omit, ): Promise { const id = crypto.randomUUID() await db.knowledge.add({ ...item, id }) return id } // Get items by path async function getItemsByPath(path: string): Promise { return db.knowledge.where('path').startsWith(path).toArray() } // Get folder contents async function getFolderContents(folderId?: string): Promise { if (folderId) { return db.knowledge.where('parentId').equals(folderId).toArray() } return db.knowledge.filter((item) => !item.parentId).toArray() } // Search by content hash (deduplication) async function findDuplicate( contentHash: string, ): Promise { return db.knowledge.where('contentHash').equals(contentHash).first() } ``` ## Content Hashing for Deduplication ```typescript async function generateContentHash( content: string | ArrayBuffer, ): Promise { const data = typeof content === 'string' ? new TextEncoder().encode(content) : new Uint8Array(content) const hashBuffer = await crypto.subtle.digest('SHA-256', data) const hashArray = Array.from(new Uint8Array(hashBuffer)) return hashArray.map((b) => b.toString(16).padStart(2, '0')).join('') } ``` ## File Upload Handling ```typescript async function handleFileUpload( file: File, parentId?: string, ): Promise { const content = await readFileContent(file) const contentHash = await generateContentHash(content) // Check for duplicates const existing = await findDuplicate(contentHash) if (existing) { toast.info('File already exists in knowledge base') return existing } const item: KnowledgeItem = { id: crypto.randomUUID(), name: file.name, type: 'file', fileType: getFileType(file.name), content: typeof content === 'string' ? content : btoa(content), contentHash, mimeType: file.type, size: file.size, path: parentId ? `${getPath(parentId)}/${file.name}` : `/${file.name}`, parentId, lastModified: new Date(file.lastModified), createdAt: new Date(), syncSource: 'manual', } await db.knowledge.add(item) return item } async function readFileContent(file: File): Promise { return new Promise((resolve, reject) => { const reader = new FileReader() if (file.type.startsWith('text/') || getFileType(file.name) === 'text') { reader.onload = () => resolve(reader.result as string) reader.onerror = reject reader.readAsText(file) } else { reader.onload = () => resolve(reader.result as ArrayBuffer) reader.onerror = reject reader.readAsArrayBuffer(file) } }) } ``` ## Folder Watching (File System API) ```typescript import { db } from '@/lib/db' async function watchFolder(handle: FileSystemDirectoryHandle): Promise { // Request permission const permission = await handle.requestPermission({ mode: 'read' }) if (permission !== 'granted') { throw new Error('Permission denied') } // Scan and sync folder await syncFolder(handle, undefined) // Store handle for persistence await db.knowledge.add({ id: crypto.randomUUID(), name: handle.name, type: 'folder', path: `/${handle.name}`, createdAt: new Date(), lastModified: new Date(), syncSource: 'filesystem_api', fileSystemHandle: handle.name, }) } async function syncFolder( handle: FileSystemDirectoryHandle, parentId?: string, ): Promise { for await (const entry of handle.values()) { if (entry.kind === 'file') { const file = await entry.getFile() await handleFileUpload(file, parentId) } else if (entry.kind === 'directory') { // Create folder and recurse const folderId = await createFolder(entry.name, parentId) await syncFolder(entry, folderId) } } } ``` ## Context Injection for Agents When agents need knowledge context: ```typescript import { db } from '@/lib/db' async function getRelevantKnowledge( query: string, agentId: string, ): Promise { // Get agent's assigned knowledge items const agentKnowledge = await getAgentKnowledge(agentId) // Search for relevant items const searchTerms = query.toLowerCase().split(' ') return agentKnowledge.filter((item) => { const searchText = `${item.name} ${item.description || ''} ${item.tags?.join(' ') || ''}`.toLowerCase() return searchTerms.some((term) => searchText.includes(term)) }) } function formatKnowledgeForContext(items: KnowledgeItem[]): string { return items .map((item) => { return `## ${item.name} ${item.description || ''} ${item.content || '[Binary content]'} ---` }) .join('\n\n') } ``` ## Document Processing For processing different document types: ```typescript // src/lib/document-processor.ts export async function processDocument(item: KnowledgeItem): Promise { switch (item.fileType) { case 'text': return item.content || '' case 'document': return await extractTextFromDocument(item) case 'image': // Could use OCR or image description return `[Image: ${item.name}]` default: return `[Unsupported file type: ${item.mimeType}]` } } ``` ## Component Integration ```tsx import { useCallback, useState } from 'react' import { Button, Card, Progress } from '@heroui/react' import { Icon } from '@/components/Icon' import { toast } from '@/lib/toast' function KnowledgeUploader() { const [isUploading, setIsUploading] = useState(false) const [progress, setProgress] = useState(0) const handleDrop = useCallback(async (e: React.DragEvent) => { e.preventDefault() const files = Array.from(e.dataTransfer.files) setIsUploading(true) setProgress(0) for (let i = 0; i < files.length; i++) { await handleFileUpload(files[i]) setProgress(((i + 1) / files.length) * 100) } setIsUploading(false) toast.success(`Uploaded ${files.length} files`) }, []) return ( e.preventDefault()} className="border-dashed border-2 p-8 text-center" >

Drop files here to upload

{isUploading && } ) } ``` ## Testing ```typescript import { describe, it, expect, beforeEach, vi } from 'vitest' import { db } from '@/lib/db' vi.mock('@/lib/db') describe('Knowledge Base', () => { beforeEach(() => { vi.clearAllMocks() }) it('should detect file types correctly', () => { expect(getFileType('document.md')).toBe('text') expect(getFileType('image.png')).toBe('image') expect(getFileType('file.pdf')).toBe('document') expect(getFileType('data.bin')).toBe('unknown') }) it('should generate consistent content hashes', async () => { const content = 'test content' const hash1 = await generateContentHash(content) const hash2 = await generateContentHash(content) expect(hash1).toBe(hash2) }) it('should detect duplicates', async () => { const hash = 'abc123' vi.mocked(db.knowledge.where).mockReturnValue({ equals: vi.fn().mockReturnValue({ first: vi.fn().mockResolvedValue({ id: 'existing' }), }), } as any) const result = await findDuplicate(hash) expect(result).toEqual({ id: 'existing' }) }) }) ```

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