How to use APPIUM_HOME for Appium extensions

Project test suites can load the wrong Appium driver when every install goes into the default user extension directory. APPIUM_HOME points Appium at a separate driver and plugin directory, so a project or CI job can install the extensions it needs without changing another suite.

Appium stores managed drivers and plugins outside the server package. If APPIUM_HOME is unset, Appium uses ~/.appium; when it is set, the extension CLI and Appium server read extension metadata and packages from that directory instead.

Use the same APPIUM_HOME value when installing extensions, listing extensions, and starting the server. Keep project-local homes out of source control because they contain installed npm packages and cache metadata, and recreate or cache them as part of the local or CI setup.

Steps to use APPIUM_HOME for Appium extensions:

Open a terminal in the project root.
Create a project-local Appium home directory.
```
$ mkdir -p .appium-home/android
```

Install the Android driver into that home.

$ APPIUM_HOME="$PWD/.appium-home/android" appium driver install uiautomator2
- Checking if 'appium-uiautomator2-driver' is compatible
- Installing 'uiautomator2'
- Validating 'uiautomator2'
Driver uiautomator2@7.6.1 successfully installed
- automationName: UiAutomator2
- platformNames: ["Android"]

Use the driver or plugin name required by the project. The selected APPIUM_HOME receives the npm package and Appium extension metadata for this install.

List installed drivers from the same home.

$ APPIUM_HOME="$PWD/.appium-home/android" appium driver list --installed
- Listing installed drivers (rerun with --verbose for more info)
- uiautomator2@7.6.1 [installed (npm)]

List a different Appium home before using it.
```
$ APPIUM_HOME="$PWD/.appium-home/web" appium driver list --installed
- Listing installed drivers (rerun with --verbose for more info)
```
No driver row below the listing line means Appium is reading a separate home with no installed drivers yet.
Start Appium with the same home used for the project.
```
$ APPIUM_HOME="$PWD/.appium-home/android" appium --address 0.0.0.0 --port 4723
```
Starting Appium without this environment variable makes the server fall back to the default ~/.appium directory and can hide drivers installed only in the project home.

Related: How to start the Appium server
Keep the project-local Appium home out of source control.
```
.appium-home/
```

Author: Mohd Shakir Zakaria
Mohd Shakir Zakaria is a cloud architect with deep roots in software development and open-source advocacy. Certified in AWS, Red Hat, VMware, ITIL, and Linux, he specializes in designing and managing robust cloud and on-premises infrastructures.