# First contact: ADB from your host to your phone

> The first bench build — enable Developer options, turn on USB debugging, install the platform-tools, approve the pairing, and run your first read-only inspection. Risk level: one toggle, fully reversible.

Source: https://androidharness.com/guides/2026-11-09-first-contact-adb/
Author: The Android Harness desk

Published: 2026-11-09

This is the first build on the bench: by the end, your host machine can
talk to your Android device over **ADB** (Android Debug Bridge), and you
will have run your first read-only inspection command. Everything here is
reversible — the only device change is one settings toggle.

> **Risk level: low.** One toggle (USB debugging), which you can switch
> back off at any time, plus a pairing you can revoke. No data is touched.

**Sources for this guide (named, not linked — this site carries no
external links):** the Android Developers documentation pages *Enable
on-device developer options*
(developer.android.com/studio/debug/dev-options),
*Android Debug Bridge (adb)* (developer.android.com/tools/adb), and the
*SDK Platform-Tools release page*
(developer.android.com/tools/releases/platform-tools) — all retrieved
2026-11-09. Where our own bench notes add detail, they say so.

## What you need

- An **Android device** — a spare is ideal, a daily driver works.
- A **USB cable that carries data.** If the host never sees the device at
  any step below, suspect the cable first (bench note: charge-only cables
  are a real and common dead end).
- A **host computer** — Windows, macOS, or Linux.

## Step 1 — Enable Developer options

On the device: **Settings → About phone**, then tap **Build number**
**seven times**. The device confirms with a "You are now a developer!"
message, and a **Developer options** entry appears in Settings.

Bench note: device makers move and rename these menus (the exact label of
the build-number row varies by maker and Android version). If the path
above doesn't match what you see, check your device maker's own support
documentation — the Android documentation linked above describes the
general procedure.

## Step 2 — Turn on USB debugging

In **Settings → Developer options**, enable **USB debugging** and confirm
the prompt. Per the Android documentation, this is what allows the device
to be "seen" by a host running adb. It stays on until you toggle it off —
and toggling it off is the full undo for this entire guide.

## Step 3 — Install the platform-tools on the host

Download the official **SDK Platform-Tools** zip for your host OS from
the release page linked above (it contains `adb`), unpack it, and run the
commands below from that directory (or add the directory to your PATH).
The official zip is the only download this guide recommends — third-party
"adb installers" are unnecessary.

## Step 4 — Connect and approve the pairing

Connect the device by cable, unlock its screen, then on the host run:

```
adb devices
```

On first contact the device is listed as **unauthorized**, and the device
shows an **"Allow USB debugging?"** dialog carrying the host computer's
**RSA key fingerprint**. Confirm the fingerprint is the pairing you just
started, then tap **Allow** (tick "Always allow from this computer" if
this is your own bench host). Run `adb devices` again — the device now
reads **device**. This is the documented pairing flow; the fingerprint is
the security model: you are approving *that specific host*.

Bench note: to undo a pairing, **Developer options → Revoke USB debugging
authorizations** clears every approved host (documented behavior).

## Step 5 — First read-only inspection

Two read-only commands — they change nothing on the device:

```
adb shell getprop ro.build.version.release
adb shell getprop ro.product.model
```

The first prints the device's Android version; the second prints its
model name. Write both down in your bench log — a harness starts with
knowing exactly what is strapped into it.

## What's next

Your harness is live: host, cable, device, approved pairing, first
inspection done. The [Harness Starter Package](/package/) carries the
command reference card and the follow-up guides as they publish — read
the [full guide archive](/guides/) here anytime, free.