Android (Termux)

Synchi can sync files between a Linux machine and an Android device using Termux, a terminal emulator that provides a Linux environment on your phone.

The sync is bidirectional, the only question is where you run Synchi from:

Run Synchi from Linux (recommended): Your Linux machine runs Synchi and connects to Android over SSH. Synchi does not need to be installed on Android. You only need Termux with SSH and storage access. Follow the Termux SSH setup below, then see the example configuration.
Run Synchi from Android: Synchi runs inside Termux and connects to your Linux machine over SSH. This requires building Synchi from source on the phone.

Termux SSH setup

Regardless of where you run Synchi, the Android device needs Termux with SSH and storage access. All of the following steps are done inside Termux on the Android device.

Install OpenSSH

pkg install openssh

Grant storage access

To access Android’s shared storage (photos, downloads, etc.):

termux-setup-storage

This creates ~/storage/shared which maps to Android’s internal storage (/sdcard).

Start the SSH server

sshd

Termux runs sshd on port 8022 (not 22), because Android restricts ports below 1024.

Authentication

Set up key-based authentication or password authentication:

# On your Android device (Termux):
mkdir -p ~/.ssh

# On your Linux machine, copy your public key:
ssh-copy-id -p 8022 USERNAME@ANDROID_IP

Or manually paste your public key into ~/.ssh/authorized_keys on the Termux side.

If you prefer password auth for initial setup:

passwd

This sets a Termux-specific password. Use it with ssh -p 8022 USERNAME@ANDROID_IP.

Find your username and IP

whoami

Termux usernames look like u0_a123 — this is normal on Android.

ifconfig

Look for the wlan0 inet address (e.g., 192.168.1.105). This is your phone’s local IP.

Test the connection from your Linux machine:

ssh -p 8022 u0_a123@192.168.1.105

Networking options

Same Wi-Fi network: Use the IP from ifconfig. Simple, but the IP may change.

Tailscale (recommended for reliability): Install Tailscale on both devices. It assigns stable IPs that work across networks.

Android: Install from Play Store
Linux: tailscale.com/download

With Tailscale, use the Tailscale IP instead of the local one. No port forwarding or firewall configuration needed.

Run from Linux

Synchi runs on your Linux machine and connects to the Android device over SSH. Nothing needs to be installed on Android besides Termux with SSH.

Example configuration (on your Linux machine):

root_a = "/home/user/photos"
root_b = "ssh://u0_a123@192.168.1.105:8022/data/data/com.termux/files/home/storage/shared/DCIM"

include = ["**"]
ignore = ["**/cache/**", "**/.thumbnails/**"]

preserve_owner = false
preserve_permissions = false

synchi sync

Run from Android

If you want to run Synchi from your phone, you need to build it from source inside Termux.

Install Synchi inside Termux

pkg install rust git openssh
cargo install synchi

Add the cargo bin directory to your PATH:

echo 'export PATH="$PATH:$HOME/.cargo/bin"' >> ~/.bashrc
source ~/.bashrc

Verify:

synchi --version

Note: The Linux ARM64 binary from GitHub Releases does not work in Termux (different C library). You must build from source.

Example configuration

root_a = "/data/data/com.termux/files/home/storage/shared/Documents"
root_b = "ssh://user@192.168.1.100/home/user/Documents"

include = ["**"]

preserve_owner = false
preserve_permissions = false

Root A must be local, so when running from Termux, the Android path is root A.

Android-specific notes

Disable ownership and permissions: Android storage does not support POSIX ownership or permissions. Always set preserve_owner = false and preserve_permissions = false.
Keep Termux awake: Long syncs may fail if Android suspends Termux. Run termux-wake-lock before syncing, or acquire a wake lock in Termux settings.
Port 8022: Termux sshd uses port 8022 by default. Include :8022 in your SSH root spec.