With over 1,200 GitHub stars, 12,000+ commits, and more than a decade of active development distributed under the AGPL-3.0 license, Cozy Cloud operates as a comprehensive personal data hub that goes far beyond file storage by connecting your documents, contacts, calendars, banking transactions, energy bills, and productivity tools into a single self-hosted platform where no third party profiles you. The cozy-stack Go binary handles file storage, CouchDB document management, job scheduling, app serving, and the REST API in a single process consuming approximately 150MB of RAM idle. Sandboxed konnectors import data from 50+ external services — banks, utility providers, telecom operators, cloud drives — running as isolated jobs via nsjail to prevent untrusted code from accessing other user data. The built-in app store serves web applications in subdomain-isolated environments with Content Security Policy headers, each app communicating exclusively through the documented REST API. Real-time synchronization via PouchDB replication and WebSocket keeps files, contacts, and documents consistent across desktop clients, mobile apps for iOS and Android with automatic photo backup, and the web interface. Security features include automatic Let's Encrypt TLS certificates, Argon2id password hashing, optional TOTP two-factor authentication, and GDPR-compliant data export via the CLI. Each user receives their own isolated instance with independent storage, database, and application configuration. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.