PaperPhonePlus

Overview

PaperPhone Plus is a full-featured, open-source instant messaging platform that delivers the familiar, polished experience of WeChat — private and group messaging, social feeds, voice and video calls — while putting privacy first through real end-to-end encryption. The entire stack is designed to be self-hosted, giving individuals and organizations complete sovereignty over their communication data.

Security & Encryption

At the heart of PaperPhone Plus is a zero-knowledge architecture. Every private message is encrypted on-device using a stateless Elliptic-Curve Diffie–Hellman (ECDH) key exchange combined with XSalsa20-Poly1305 authenticated encryption. A fresh ephemeral keypair is generated for every single message, providing forward secrecy — even if a key is compromised, past remain messages unreadable. The server handles only opaque ciphertext and routing metadata; private keys are stored exclusively on-device across a four-tier persistence layer (memory → localStorage → sessionStorage → IndexedDB) and are never transmitted. Signal-style safety number verification allows users to independently confirm the integrity of their encrypted sessions.

Communication Features

Rich Messaging — Text, images, video, documents (with file-type icons for PDF, DOCX, XLSX, etc.), voice messages, an emoji panel with 200+ emoji across 8 categories, and Telegram sticker pack integration. Messages support delivery receipts, read status, and typing indicators.

Video & Voice Calls — 1:1 calls use peer-to-peer WebRTC with Cloudflare TURN (or Metered.ca) for NAT traversal. Group calls use a WebRTC Mesh topology supporting up to 6 participants.

Group Chat — Groups support up to 2,000 members with plain-text messaging, Do Not Disturb mode, member management, and QR-code-based invitations with configurable expiry.

Friend System — Friend requests require approval with up to 512-character verification messages. Users can set custom nicknames and organize contacts with a multi-tag system using a 12-color palette.

Auto-Delete Messages — Five configurable tiers (never / 1 day / 3 days / 1 week / 1 month). In private chats, either party can set the timer; in groups, only the owner can.

File Upload — Single files up to 500 MB, stored on Cloudflare R2 (S3-compatible) or locally, with real-time progress animation.

Social Features

Moments — A WeChat-style social feed where users can post text with up to 9 photos or a single video (≤ 10 minutes). Supports likes (showing friend avatars), comments, and tag-based visibility control. Bidirectional privacy settings allow users to hide another person's Moments or block them from viewing their own.

Timeline — A Xiaohongshu (Little Red Book)-style public posting area with a dual-column masonry layout. Supports up to 50 media items and 2,000 characters per post, anonymous posting, likes, and comments.