# PHP on Apache (mod\_php)

This guide will walk you through installing and setting up Zen Firewall by Aikido for your application. Follow the steps below to protect your application.

If you encounter any issues or problems, don't hesitate reach out on support chat or Github issues

<https://github.com/AikidoSec/firewall-php>

## Requirements

* PHP 7.2+ (tested up to PHP 8.5).
* Apache `mod_php` runtime.
* [Aikido account](https://help.aikido.dev/getting-started/setting-up-your-account) & [Zen Firewall token](https://help.aikido.dev/zen-firewall/zen-installation-instructions/creating-an-aikido-zen-firewall-token)

## Installation & Configuration

{% stepper %}
{% step %}
**Install Zen Firewall by Aikido**

Zen for PHP is installed as a system package.

Prerequisites:

* Ensure you have `sudo` privileges.
* Use a supported PHP version (7.2+).

For Red Hat-based systems (RHEL, CentOS, Fedora):

```bash
rpm -Uvh --oldpackage https://github.com/AikidoSec/firewall-php/releases/latest/download/aikido-php-firewall.x86_64.rpm
```

For Red Hat-based arm64 / aarch64:

```bash
rpm -Uvh --oldpackage https://github.com/AikidoSec/firewall-php/releases/latest/download/aikido-php-firewall.aarch64.rpm
```

For Debian-based systems (Debian, Ubuntu):

```bash
curl -L -O https://github.com/AikidoSec/firewall-php/releases/latest/download/aikido-php-firewall.x86_64.deb
dpkg -i -E ./aikido-php-firewall.x86_64.deb
```

For Debian-based arm64 / aarch64:

```bash
curl -L -O https://github.com/AikidoSec/firewall-php/releases/latest/download/aikido-php-firewall.aarch64.deb
dpkg -i -E ./aikido-php-firewall.aarch64.deb
```

Set environment variables in your Apache vhost:

{% @aikido-custom-code/code-highlight language="apache" content="\<VirtualHost \*:80>

* SetEnv AIKIDO\_TOKEN "AIK\_RUNTIME\_..."
* SetEnv AIKIDO\_BLOCK "false" </VirtualHost>" %}

Then restart Apache:

```bash
service apache2 restart
```

{% endstep %}

{% step %}
**Enable Request Blocking and User Identification**

Use this middleware to enable rate limiting, user identification, and blocking features.

Zen Firewall does not require this middleware to block attacks. Core attack protection works without it. The middleware provides additional request context that Zen uses for protections such as [rate limiting](https://help.aikido.dev/zen-firewall/zen-features/setting-up-rate-limiting-for-routes), [user blocking](https://help.aikido.dev/zen-firewall/zen-features/blocking-users-with-zen-firewall), [bot blocking](https://help.aikido.dev/zen-firewall/zen-features/blocking-bot-traffic-with-zen-firewall), [country blocking](https://help.aikido.dev/zen-firewall/zen-features/blocking-traffic-by-country-with-zen-firewall), and [threat actor](https://help.aikido.dev/zen-firewall/zen-features/blocking-known-threat-actors-with-zen-firewall) blocking.

Adapt the example to fit how your application identifies users and handles requests.

Use `set_user` and `should_block_request` in your request pipeline:

{% @aikido-custom-code/code-highlight language="php" content="+if (extension\_loaded('aikido')) {

* \aikido\set\_user('123', 'John Doe');
*
* $decision = \aikido\should\_block\_request();
*
* if ($decision->block && $decision->type === 'blocked') {
* ```
    http_response_code(403);
  ```
* ```
    exit('You are blocked by Zen.');
  ```
* }
*
* if ($decision->block && $decision->type === 'ratelimited') {
* ```
    http_response_code(429);
  ```
* ```
    exit('You are rate limited by Zen.');
  ```
* }
  +}" %}
  {% endstep %}

{% step %}
**Test your app**

Browse to your application and perform a couple of actions or open a couple of pages. Zen will automatically discover the routes in your application.

{% hint style="info" %}
Zen sends data back to Aikido every 10 minutes
{% endhint %}

You can verify a working agent by looking at the following pages of your Zen application:

* **Events**: Should show an "Application started" event.
* **Routes**: After some time your application routes will start showing here with the method, route and requests.
* **Instances**: Should show the number of active instances for your application where Zen is installed.

<figure><img src="https://3149773201-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FyKbzcQGrx7UtrG0nPZZ7%2Fuploads%2FcBVQ6hPTYOWgbnRaVIZI%2FScreenshot%202025-06-23%20at%2010.08.35.png?alt=media&#x26;token=eae8f436-01b9-478e-872e-b3813232196b" alt=""><figcaption></figcaption></figure>
{% endstep %}

{% step %}
**Setup rate limiting in the dashboard**

When you've added the Zen Firewall middleware you can test protecting a route from brute force attacks, you do this by setting up rate limit in the Aikido Dashboard:

1. Click on the created app.
2. Go to the **Routes** tab.
3. Find the route you would like to limit and click **Setup rate limiting**.
4. Follow the instructions to configure the rate limit (e.g., 5 requests per minute).

![API route management interface showing authentication routes with protection and rate limiting options.](https://3149773201-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FyKbzcQGrx7UtrG0nPZZ7%2Fuploads%2FuLKgJLpyKEIZhfq0dEEi%2FScreenshot%202025-10-30%20at%2010.38.17.png?alt=media\&token=db7263f6-b9ec-4da2-94ac-180a295eb535)

![Set rate limiting for POST /auth/login to 5 requests per minute.](https://3149773201-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FyKbzcQGrx7UtrG0nPZZ7%2Fuploads%2Fgit-blob-2633dcea71b485b0257ecf6b607323a9646dae06%2Fucarecdn-34b1af76-facb-4b6d-9c87-155236236b8f.png?alt=media)

**Verify Rate Limiting**

Start your app and try to access the route you've rate limited 5 times within a minute. After the fifth attempt, you should receive a rate limit error:

```
You are rate limited by Aikido firewall. (Your IP: 1.2.3.4)
```

{% endstep %}

{% step %}
**Next steps**

Congrats you've successfully installed Zen Firewall. If you encountered any problems, have concerns or feature requests, don't hesitate to reach out to support.

You can now go and explore the many features that Zen Firewall provides:

* [blocking-bot-traffic-with-zen-firewall](https://help.aikido.dev/zen-firewall/zen-features/blocking-bot-traffic-with-zen-firewall "mention")
* [blocking-tor-traffic-with-zen-firewall](https://help.aikido.dev/zen-firewall/zen-features/blocking-tor-traffic-with-zen-firewall "mention")
* [blocking-users-with-zen-firewall](https://help.aikido.dev/zen-firewall/zen-features/blocking-users-with-zen-firewall "mention")
* [blocking-known-threat-actors-with-zen-firewall](https://help.aikido.dev/zen-firewall/zen-features/blocking-known-threat-actors-with-zen-firewall "mention")
* [blocking-traffic-by-country-with-zen-firewall](https://help.aikido.dev/zen-firewall/zen-features/blocking-traffic-by-country-with-zen-firewall "mention")
* [setting-up-rate-limiting-for-routes](https://help.aikido.dev/zen-firewall/zen-features/setting-up-rate-limiting-for-routes "mention")
* [monitor-outbound-domains](https://help.aikido.dev/zen-firewall/zen-features/monitor-outbound-domains "mention")

Additional information:

* [how-zen-works-performance-reliability](https://help.aikido.dev/zen-firewall/miscellaneous/how-zen-works-performance-reliability "mention")
* [blocking-vs-detection-mode-in-zen-firewall](https://help.aikido.dev/zen-firewall/zen-features/blocking-vs-detection-mode-in-zen-firewall "mention")
* [understanding-your-zen-statistics](https://help.aikido.dev/zen-firewall/zen-features/understanding-your-zen-statistics "mention")
  {% endstep %}
  {% endstepper %}