TREK is a full-featured, self-hosted travel planning application built with NestJS (server) and React (client). It enables users to create trips, manage day-by-day itineraries, add places and reservations, track budgets, maintain packing lists, collaborate via real-time chat/notes/polls, and journal memories. The architecture is a monorepo with client, server, shared schemas, and a plugin SDK. Key capabilities include offline-first support via IndexedDB with a mutation queue, real-time WebSocket collaboration, MCP (Model Context Protocol) integration for AI tools, a plugin system with sandboxed RPC host, OAuth 2.1, OIDC SSO, passkeys, and a storage abstraction layer supporting local and S3 backends. The application is production-ready with extensive test coverage (Vitest, Playwright E2E, MSW mocks) and internationalization across 23 locales. The codebase demonstrates strong engineering practices: modular NestJS domains, Zod schema-first validation shared between client and server, idempotent mutation handling, and a well-designed plugin SDK with permission gating and digital signatures.
Logux Server is a framework for building real-time collaborative servers using the Logux protocol. It synchronizes a log of operations between clients, server, and other clients via WebSocket. The server handles authentication, channel subscriptions, action processing (access, resend, process), and supports PostgreSQL for persistent log storage. The architecture is modular, with clear separation of concerns: base server, client management, context, action queues, and logging. It provides a rich API for defining action types and channels with callbacks, and includes test utilities (TestServer, TestClient) for integration testing. The codebase is well-structured, uses modern JavaScript (ESM, Node 22+), and demonstrates high craftsmanship with careful error handling, async patterns, and comprehensive test coverage (100% line coverage target).