Telepathy

Private, low-latency peer-to-peer voice chat for desktop, mobile, and the web.

Telepathy is an open-source communication app built with Flutter, Rust, and iroh. It combines real-time audio, video, and text chat in a lightweight cross-platform application.

Download Telepathy from GitHub Releases for the native experience, or try Telepathy in the browser.

Features

• Flutter UI with Windows, Linux, macOS, iOS, Android, and web support.
• iroh networking, direct p2p connectivity with QUIC, TLS 1.3, and post-quantum cryptography by default.
• Lossless 16 bit raw audio and SEA codec support.
• nnnoiseless noise suppression.
• Built-in text chat with media and file attachments.
• Efficient use of CPU and memory resources, more than 10x lower than Discord.
• Low end-to-end latency enabled by direct connectivity and low processing delay.

Work in Progress

• ffmpeg based screensharing for Windows, macOS, and Linux.
• Game overlay for Windows.
• Telepathy rooms (group calls).

Planned

• Lossless audio codec support.
• Built in update pipeline with version checking and patching.
• Echo cancellation.
• Automatic input gain.
• Webcam, camera, and screenshare support for desktop, mobile, and web.
• Signed desktop builds, App Store and Android Playstore downloads.
• Standalone Telepathy Audio and Telepathy Video crates.

Local Development

• Flutter, Dart, and Cargo are required for building the project.
• For development, use flutter run -d <device> or flutter build <device> --debug.
• Live reload is supported in JetBrains and other IDEs with the Flutter plugin.
• For release builds, use flutter build <device>.

Additional Requirements

• Android development requires Android Studio.
• macOS and iOS development requires Xcode.
• Web development requires the latest wasm-pack and wasm-opt & the nightly Rust toolchain.

Verifying Release Artifacts

Every artifact published to a GitHub Release is signed with a Sigstore build-provenance attestation that binds it to the workflow run and commit that produced it. Verify any downloaded asset before installing:

gh attestation verify <downloaded-file> --repo chanderlud/telepathy

Example:

gh attestation verify telepathy-1.2.3-windows-installer-x86_64.exe --repo chanderlud/telepathy

A passing check confirms the file was built from the chanderlud/telepathy repository on GitHub Actions and has not been modified since. Requires the GitHub CLI (gh) to be installed and authenticated.

Note: attestation is provenance, not code signing. It does not satisfy macOS Gatekeeper or Windows SmartScreen, and the macOS/iOS builds remain unsigned.

Architecture

High Level Design

• Flutter to Rust (and back) is enabled by Flutter Rust Bridge.
• This design enables the same codebase to target desktop, mobile, and the web.

Audio Processing

• Telepathy's real-time audio processing is implemented in the Telepathy Audio crate.
• A simple, high level API is exposed for creating input & output streams, along with device enumeration, and sound effect playback.
• Platform specific SIMD optimizations, a zero-allocation design, and the internal use of rtrb enables high quality real-time performance on any device with remarkably low resource utilization.

Classic Call Design

• Telepathy Audio provides the audio processing while iroh handles networking.
• Denoising runs on the sending side; each participant in a call decides if they want to use their compute resources to denoise their audio input.
• Every participant in a call must agree on the same audio codec options for sending & receiving.
• If a frame's RMS is below the input sensitivity threshold, no audio is sent (keep-alive packets are used during silence). The output stream gracefully transitions between speech and silence using cross-fade.
• In a classic two-way call, each client runs an input and output stream.

Project History

• Telepathy started as "Audio Chat," a Python Tkinter application with simple UDP networking and AES cryptography.
• After proving the concept with Python and Tkinter, the project was rewritten in Rust with Flutter for cross-platform support.
• The networking layer was upgraded from a custom approach to libp2p to gain enterprise-grade security primitives and more capable P2P connectivity.
• libp2p was replaced with iroh for more robust real-time networking & simpler session logic.

Media

Main Screen

Settings

Direct Call

Learn More

• Article: chanchan.dev
• Contact: me@chanchan.dev