Langfuse is an open-source LLM observability and evaluation platform. It provides tracing, prompt management, evaluations, datasets, experiments, monitors, and a public API for integrating with AI applications. The architecture is a monorepo with pnpm workspaces and Turborepo, consisting of a Next.js frontend (web), a background worker (Express + BullMQ), a shared package with types and server utilities, and an enterprise edition. Data flows from ingestion (REST API, OpenTelemetry, SDKs) into ClickHouse for high-volume analytics and PostgreSQL for relational metadata. Background jobs handle evaluations, batch exports, cloud billing, and integrations. The codebase is well-structured with extensive testing, a custom ESLint plugin, and reusable UI components. It is actively maintained with frequent migrations and feature additions.
FastGPT is a production-grade AI Agent building platform that enables users to create, deploy, and manage AI applications through a visual workflow editor. The system provides a full-stack solution including a Next.js frontend with Chakra UI, a comprehensive REST API layer, and a modular backend architecture. Core capabilities include a workflow engine with agent loops, tool calling, dataset (knowledge base) management with vector search, sandboxed code execution (JS/Python), multi-tenant team management with fine-grained permissions, billing and usage tracking, and integration with external platforms (WeChat, Feishu, Dingtalk, MCP). The platform is designed for both open-source community and commercial deployments, with feature gating via license activation. The codebase is organized as a monorepo with clear separation of concerns: shared types and constants in `packages/global`, business logic in `packages/service`, UI components in `packages/web`, data access layer in `packages/dal`, and separate services for sandbox execution and volume management. It relies on MongoDB, Redis, BullMQ, S3-compatible storage, and multiple vector database backends (PG, Milvus, OceanBase, SeekDB, OpenGauss). The architecture is predominantly monolithic with the main application as a Next.js app, but sandbox and volume manager run as independent services, indicating a hybrid monolith/microservices pattern.
This is a NestJS boilerplate for building RESTful APIs with TypeScript, PostgreSQL, TypeORM, and modern DevOps practices. The system provides a modular backend architecture with authentication (JWT), user management, post management, email verification via BullMQ queues, health checks, Swagger API documentation, and comprehensive testing setup. It follows NestJS best practices with clear separation of concerns across modules for auth, users, posts, health, and background jobs. Key features include cursor-based and offset-based pagination, internationalization (i18n), Redis caching, security headers via Helmet, and environment-based configuration management. The codebase demonstrates strong engineering practices with reusable utilities for password handling, configuration validation, and sophisticated cursor pagination that could be extracted to other projects with minimal modification.