claude-code-android: Skill for Claude Code

Android / Termux Environment Constraints

Scope and when this applies. These constraints apply when you are executing inside Termux on Android, regardless of how Claude Code itself was packaged. The load-bearing runtime signal is $PREFIX === "/data/data/com.termux/files/usr". If that environment variable points at Termux's prefix, you are in Termux and these constraints apply, even if process.platform reports "linux" (it will report "linux" if Claude Code was installed via this repo's v2.9.0 Path A, which runs the linux-arm64 binary patched via glibc-runner; it will report "android" only on older Path A v2.x installs that used the JS bundle). If $PREFIX is unset or points at /usr, you are inside a chroot-like sandbox (for example, a Linux rootfs running under proot-distro, Path B) or inside a hypervisor-managed Linux VM (Path C), and standard Linux conventions apply; most of this file does not.

If the runtime signals indicate the in-Termux case, the constraints below produce silent failures, not errors. Every suggestion must account for them.

Hard Rules: Never Suggest These

• No sudo. Root does not exist. No su, no doas, no privilege escalation of any kind.
• No systemctl or systemd. Android does not use systemd. No journalctl, no service, no unit files.
• No standard Linux paths. /usr/bin, /etc, /var do not exist or are not writable. Termux paths:
  • Home: /data/data/com.termux/files/home
  • Prefix: /data/data/com.termux/files/usr
  • Binaries: $PREFIX/bin
  • Config: $PREFIX/etc
• No ports below 1024. No root = no binding to 80, 443, etc. Use 1024+.
• Prefer pkg over apt. Both work, but pkg auto-updates the package index before installing.
• No Docker, no containers. The kernel does not support them without root.

Silent Failure Modes

• Node.js is not required by this repo's install.sh. The patched linux-arm64 claude binary is self-contained. If Node is installed separately on native Termux, prefer v25+: v24 had a documented startup hang on ARM64 that was resolved in v25.
• File descriptor limits vary by device. Check with ulimit -n. Avoid spawning many concurrent processes.
• Android can stop background work. Its phantom process controls can kill excess child processes, and battery and background policies can suspend or kill Termux. Keep concurrent subagents and child processes modest. Where Developer options offers "Disable child process restrictions", turning it on helps with the first limit. tmux or nohup keep work running when a terminal window closes, but not after Android kills Termux or the phone reboots.
• process.platform reporting varies by install path. On Path A v2.9.0 (the linux-arm64 binary patched via glibc-runner), Node.js reports process.platform === "linux" even though you are inside Termux. On older Path A v2.x (the JS-bundle npm install) it reports "android". On Path B (proot-distro Ubuntu) and Path C (AVF), it reports "linux" and you are not in Termux. The reliable cross-path signal that you are still in Termux is $PREFIX === "/data/data/com.termux/files/usr".
• #!/usr/bin/env scripts fail under the Path A launcher. When the Bash tool runs a script directly and its first line is #!/usr/bin/env bash (or python3, node), it exits with "bad interpreter": Android has no /usr/bin/env, and Claude Code's subprocesses do not carry Termux's fix for it. Run the interpreter explicitly: bash ./script.sh, python ./script.py. Tools called by name and #!/bin/sh scripts are unaffected.
• Prefer command -v to check command availability. It is a shell builtin. which is available with pkg install which, but this repo's installers do not explicitly install it.