Architecture

Transplant Pipeline

The core innovation: graft OpenCode's JavaScript module graph into the official Android Bun ELF, then run a "revive surgery" to produce a single Bionic executable.

Official Bun ELF → Extract → Module graph insertion → Patch → Assemble → Revive → Working binary

Key insight: the original failure ("zero glibc is impossible") was caused by assemble never patching BUN_COMPILED.size in the .bun section. Fixed in the transplant pipeline.

Seccomp SIGSYS Shim

Dual-layer protection:

• Handler: Inline syscall interception + DT_NEEDED[0] interposer
• PLT interposer: Catches syscalls from child processes

This ensures the binary can handle Android's seccomp restrictions gracefully.

TUI (libopentui.so)

A self-built bionic libopentui.so (compiled with NDK) provides terminal UI rendering. Swapped into the binary via tools/transplant/swap_tui.py at equal length.

• W10a deep smoke test: 5/5 pass (real chat, resize, clean exit, 5min soak)
• RSS actually drops during idle (proven stable)

Native Watcher

tools/watcher/ provides a standalone file watching daemon:

• watcher.c — NDK inotify recursive watching
• shim.js — Plugin-side interface
• E2E: all three event types <100ms, self-heal ≤612ms

Package Format

• bin/opencode is a real executable ELF (no bash wrapper)
• Three-way mutual exclusion: opencode ↔︎ opencode-glibc ↔︎ opencode-compressed
• Standalone variant: bin/opencode-glibc entry, coexists with native