Cobalt is a privacy-focused media downloader web application with a SvelteKit frontend and Node.js/Express API backend. Users paste a URL from supported platforms (YouTube, TikTok, Instagram, Twitter/X, Vimeo, Reddit, SoundCloud, Twitch, Bilibili, and 15+ others) and receive a downloadable media file. The architecture is a monorepo with three packages: @imput/cobalt-web (static frontend), @imput/cobalt-api (processing backend), and @imput/version-info (build-time version helper). The API acts as a fancy proxy - it fetches media streams from source platforms, optionally remuxes/transcodes via FFmpeg (server-side or client-side via libav.js WebAssembly), and streams results back without ever writing to disk. The frontend handles URL input, settings management (localStorage with migration), a processing queue with Web Workers for client-side FFmpeg, i18n (EN/RU), and PWA features. Key data flows: user submits URL → API validates/matches service → extracts stream URLs → returns tunnel/redirect/picker response → frontend either streams directly, proxies via API, or processes locally via Web Workers. External dependencies: FFmpeg (via ffmpeg-static), youtubei.js for YouTube, hls-parser, undici for HTTP, Redis (optional for rate limiting), Cloudflare Turnstile (optional bot protection).
vkbottle is an asynchronous Python framework for building VK (VKontakte) bots and interacting with the VK API. It provides both high-level abstractions (Bot, User, labelers, rules, middlewares, state dispensers) and low-level API clients with pluggable request/response validation, token rotation, and error handling. The framework is fully async, built on asyncio and aiohttp, and supports long polling, callback API, and dual mode (simultaneous polling and callback). It includes extensive tooling for keyboards, templates, uploaders, markdown-to-VK-format conversion, VKScript generation, event deduplication, and a waiter machine for awaiting future events. The architecture is modular with abstract base classes for nearly every component, enabling custom implementations. The codebase is well-structured with clear separation of concerns, extensive test coverage, and CI/CD pipelines. Deprecated components (LoopWrapper, Blueprints) are clearly marked, and the library is actively maintained with a mature version 4.11.0.