Doca puts rich text, Markdown, spreadsheets, slides, and an infinite canvas under one login and one permission model, giving individuals and small teams a self-hosted workspace for writing together. Every format supports real-time co-editing with presence, comments, saved history, and manual snapshots, and rich text and Markdown documents can be restored to an earlier version. Documents live in knowledge libraries with tree navigation, invitations, inherited permissions, share links, and trash, while personal files and shared folders sit on local disk or S3-compatible storage. Knowledge books go further: they subscribe to sources, run an editable workflow, keep source evidence, and route results through human review. A personal AI assistant, powered by whichever model you configure, searches authorized documents, reads PDF and Office attachments, edits images, and prepares browser drafts. MCP services let external AI clients such as Codex use those tools under your permissions. Sign in with a password, OIDC, Google, GitHub, WeChat, or QQ, review registrations before they go live, and send webhooks to other systems. A plugin SDK and marketplace add business modules, and a browser extension clips pages into documents. The interface ships in Chinese and English. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.