AdGuard has open-sourced its proprietary VPN protocol, now named TrustTunnel. This release provides the full specification and reference implementation for its server and clients, which are designed to mimic standard HTTPS traffic to evade network detection and throttling. The move fulfills a long-standing promise to its user community.

Traditional VPN protocols like OpenVPN and WireGuard can be easily identified and blocked by deep-packet inspection. TrustTunnel addresses this by using TLS encryption and HTTP/2 or HTTP/3 transport, allowing VPN traffic to blend seamlessly with regular web traffic. This design aims to maintain strong privacy and security without sacrificing connection speed, especially on mobile networks.

By releasing TrustTunnel under a permissive license, AdGuard hopes to foster broader adoption and community contribution, not just auditability. Clients are available for Linux, Windows, macOS, iOS, and Android, offering features like flexible routing rules and real-time traffic logs. This positions TrustTunnel as a potential open alternative to existing VPN protocols.