spoofdpi is a cross-platform proxy tool that bypasses Deep Packet Inspection (DPI) by fragmenting and desynchronizing TLS handshakes. It operates in three modes: HTTP proxy, SOCKS5 proxy, or TUN interface (transparent proxy). In production, it intercepts outgoing connections, reads the TLS ClientHello, splits it into segments using configurable strategies (SNI-split, random, chunk, first-byte, or custom plans), optionally sends fake packets before the real data, and may disorder segments by manipulating the TTL field so that DPI middleboxes misparse the connection while the destination server reassembles it correctly. It also includes a built-in DNS resolver with UDP, HTTPS (DoH), and system backends, and a rule system for per-domain/per-IP configuration. The architecture is a single Go binary with modular internal packages: config (TOML+CLI loading), desync (TLS/UDP desynchronization), dns (multi-backend resolver), netutil (connection management, dialing, TTL setting), packet (raw packet capture/injection via pcap or Linux raw sockets), proto (HTTP, SOCKS5, TLS parsing), rule (domain and CIDR matching), server (HTTP, SOCKS5, TUN server implementations), session (context-based tracing), trie (generic trie structures), cache (sharded LRU and TTL caches), and logging (zerolog-based structured logging). The TUI mode uses bubbletea for a terminal interface showing real-time speed and logs. Key entry points are cmd/spoofdpi/main.go (main function) which parses CLI flags, loads configuration, and starts the selected server. External dependencies include gopacket for packet manipulation, wireguard-tun for TUN device support, gvisor for TCP/IP stack in TUN mode, and various Go packages for CLI, TOML, DNS, and logging. The code is well-structured with extensive use of interfaces, generics, and concurrency primitives (context, channels, goroutines).