Backend

Comprehensive guide for Cloudflare Durable Objects - globally unique, stateful objects for coordination, real-time communication, and persistent state management.Use when: building real-time applications, creating WebSocket servers with hibernation, implementing chat rooms or multiplayer games, coordinating between multiple clients, managing per-user or per-room state, implementing rate limiting or session management, scheduling tasks with alarms, building queues or workflows, or encountering "do class export", "new_sqlite_classes", "migrations required", "websocket hibernation", "alarm api error", or "global uniqueness" errors.Prevents 15+ documented issues: class not exported, missing migrations, wrong migration type, constructor overhead blocking hibernation, setTimeout breaking hibernation, in-memory state lost on hibernation, outgoing WebSocket not hibernating, global uniqueness confusion, partial deleteAll on KV backend, binding name mismatches, state size limits exceeded, non-atomic migrations, loc

High-performance web scraping API with Chrome TLS fingerprint and JS rendering

Node.js/TypeScript backend expert. Handles Express/Fastify API routes, TypeScript strict mode, Prisma ORM, Zod validation, error handling, configuration management. Use when project is Node.js backend (package.json + TypeScript server).

Backend AI functionality with Vercel AI SDK v5 - text generation, structured output with Zod,tool calling, and agents. Multi-provider support for OpenAI, Anthropic, Google, and Cloudflare Workers AI.Use when: implementing server-side AI features, generating text/chat completions, creating structuredAI outputs with Zod schemas, building AI agents with tools, streaming AI responses, integratingOpenAI/Anthropic/Google/Cloudflare providers, or encountering AI SDK errors like AI_APICallError,AI_NoObjectGeneratedError, streaming failures, or worker startup limits.Keywords: ai sdk core, vercel ai sdk, generateText, streamText, generateObject, streamObject,ai sdk node, ai sdk server, zod ai schema, ai tools calling, ai agent class, openai sdk, anthropic sdk,google gemini sdk, workers-ai-provider, ai streaming backend, multi-provider ai, ai sdk errors,AI_APICallError, AI_NoObjectGeneratedError, streamText fails, worker startup limit ai

Complete guide for OpenAI's Assistants API v2: stateful conversational AI with built-in tools(Code Interpreter, File Search, Function Calling), vector stores for RAG (up to 10,000 files),thread/run lifecycle management, and streaming patterns. Both Node.js SDK and fetch approaches.⚠️ DEPRECATION NOTICE: OpenAI plans to sunset Assistants API in H1 2026 in favor of Responses API.This skill remains valuable for existing apps and migration planning.Use when: building stateful chatbots with OpenAI, implementing RAG with vector stores, executingPython code with Code Interpreter, using file search for document Q&A, managing conversation threads,streaming assistant responses, or encountering errors like "thread already has active run", vectorstore indexing delays, run polling timeouts, or file upload issues.Keywords: openai assistants, assistants api, openai threads, openai runs, code interpreter assistant,file search openai, vector store openai, openai rag, assistant streaming, thread persistence,state

Git workflow patterns for agents. Invoke at session start when working in a git repository, before any git operations (status, add, commit, push, rebase), when making code changes, or when the user asks to commit, create PRs, or manage branches. Covers atomic commits, intentional staging, history restructuring, and safe parallel work patterns.

Perform automated security analysis on code changes to identify common vulnerabilities including SQL injection, path traversal, hardcoded secrets, XSS, and insecure API usage. Reviews Python code for OWASP Top 10 vulnerabilities.

Production-grade authentication & authorization covering JWT, cookies, sessions, hashing, MFA, OAuth2, RBAC, and permissions across all frameworks (Next.js, Express.js, FastAPI, Django, Spring, etc.). Includes intelligent pattern selection, Better Auth integration, email verification, social login, token revocation, permission management, and 10+ years security expertise. Use when implementing authentication, authorization, user management, MFA, OAuth integration, or securing APIs in any framework.

Implement PostHog analytics for PhotoVault with dual tracking (client + server). Use when working with event tracking, funnel analysis, user identification, TypeScript event schemas, ad-blocker-proof server-side tracking, or debugging missing analytics data. Includes PhotoVault event definitions and privacy defaults.

Model system responsibilities across clients, servers, and optional peer-to-peer nodes.

Use this skill when implementing real-time features with WebSockets, including connection lifecycle management, pub/sub event patterns, state synchronization between client and server, event broadcasting, and integration with frontend state management (React Query, SWR, etc.). Covers FastAPI/Node.js/Express backends and React/Next.js/Vue frontends with fallback strategies and error recovery.

Complete Supabase setup for Mem0 OSS including PostgreSQL schema with pgvector for embeddings, memory_relationships tables for graph memory, RLS policies for user/tenant isolation, performance indexes, connection pooling, and backup/migration strategies. Use when setting up Mem0 with Supabase, configuring OSS memory backend, implementing memory persistence, migrating from Platform to OSS, or when user mentions Mem0 Supabase, memory database, pgvector for Mem0, memory isolation, or Mem0 backup.

Implementing Supabase realtime subscriptions and live updates for StickerNest. Use when the user asks to add realtime, live updates, presence, subscriptions, postgres_changes, broadcast channels, or sync data across tabs/devices. Covers Supabase Realtime, EventBus integration, and subscription lifecycle.

General-purpose browser automation skill for Playwright. Use this skill when the user wants to automate browser tasks like testing login flows, scraping data, taking screenshots, filling forms, clicking elements, or any interactive web automation. This skill provides smart utilities for session management, error handling, and development server detection. NOT for scheduled monitoring (use web-monitor-bot instead).

Manage Node.js dependencies including adding, updating, auditing, and resolving conflicts. Use when updating dependencies or resolving version conflicts.

Analyzes a codebase to generate comprehensive architectural documentation including technologies used, data flows, functional components, APIs, external dependencies, commit history analysis, and complexity hotspots.

Supabase backend development: database, RLS, Edge Functions, queries.USE WHEN: creating tables, migrations, RPC functions, Edge Functions,RLS policies, query optimization, Supabase infrastructure.NOT FOR: Flutter UI (use flutter-developer), tests (use testing-agent).Examples:<example>Context: The user needs to create a new database table.user: "Create a table for customer reviews with ratings and comments"assistant: "I'll use the backend-dev skill to design the reviews table with RLS policies."<commentary>Database table creation requires backend-dev.</commentary></example><example>Context: The user needs server-side business logic.user: "Create an Edge Function to calculate dynamic pricing"assistant: "I'll use backend-dev to develop the Edge Function for pricing."<commentary>Edge Functions are a core backend-dev responsibility.</commentary></example>

Expert SuperClaude prompt engineering assistant that analyzes user needs and crafts optimal prompts using the full SuperClaude framework - commands, flags, personas, MCP servers, wave orchestration, parallel execution patterns, continuous execution directives, and the new PM Agent orchestration system with PDCA cycles and Serena memory integration.

SQLAlchemy Python SQL toolkit and ORM with powerful query builder, relationship mapping, and database migrations via Alembic. Use when building Python applications with complex database requirements, using FastAPI/Flask/Django, or needing type-safe SQL queries.

Optimizes and transforms images with Imgix CDN using URL-based API. Use when serving responsive images, applying real-time transformations, and optimizing delivery without processing overhead.