Tor Project releases Arti 2.0 with major improvements to relay and directory authority

The Tor Project has announced the release of Arti 2.0, introducing some updates to its next-generation implementation of the Tor anonymity protocol using the Rust programming language. This version drops support for the long-deprecated proxy.socks_port and proxy.dns_port configuration options, as well as the old syntax for designating directory authorities. All public APIs in the arti crate are now explicitly marked as experimental, guiding developers to expect changes as the platform evolves.

Building on these removals, Arti 2.0 introduces the inet-auto socket type, allowing the RPC server to select an available TCP port automatically. This feature helps simplify automated deployments or containerized setups. Behind the scenes, significant technical work continues on relay and directory authority support, although users cannot yet run Arti as a relay or authority.

For relays, this update brings a modular circuit reactor architecture, options to launch relay channels, handshake response mechanisms, and preparations for relays to act as the server in Transport Layer Security (TLS) connections. Regarding directory authorities, the release advances management, validation, and storage of authority certificates. These efforts move Arti closer to supporting full relay and directory authority functionality in the future.