# Falcon File Transfer (fft)

> Peer-to-peer bulk file transfer that fills long, lossy, high-bandwidth networks at the speed of the link. Encrypted by default (AES-256-GCM, forward-secret Noise handshake), end-to-end BLAKE3 verified, zero-configuration NAT traversal over the BitTorrent DHT. Linux, macOS, Windows. By Makai Systems LLC; early access.

## Measured performance (Google Cloud c3-standard-8 pair, tc netem, 10 GiB, encrypted)
- Clean cloud link: 15.9 Gbps
- 100 ms RTT, 1% loss: 12.2 Gbps (default TCP CUBIC: 0.019 Gbps)
- 300 ms RTT, 2% loss: 8.4 Gbps (tuned TCP BBR, 8 streams: 0.74 Gbps; CUBIC: 0.006 Gbps)
- 1 Gbps bottleneck at 100 ms: 0.90 Gbps, 0.01% retransmitted
- NAT-to-NAT (no open ports), 8 paths: 14.9 Gbps
- 100 GiB disk to disk at 100 ms / 1% loss: 4 min 25 s (SSD-bound), ~310 MB memory throughout

## Key capabilities
- Paces to the path's measured capacity; tolerates random loss (stays fast at 10-20% random loss)
- Loss recovery within about a round trip while transferring; adaptive forward error correction
- Serverless peer discovery (public BitTorrent DHT) or an optional private rendezvous service that never sees file data; NAT hole punching; direct mode for LAN / VPC / private links
- AES-256-GCM per packet; whole-file BLAKE3 verification computed while streaming
- Resume interrupted transfers; recursive directories; receiver daemon mode
- Constant memory regardless of file size; disk-aware pacing; kernel and NIC offloads

## Links
- Home: https://falconfft.com/
- Full context: https://falconfft.com/llms-full.txt
- Contact: earlyaccess@falconfft.com