PHP client library for xrDebug

2.0.2 2024-06-23 14:05 UTC


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PHP client library for xrDebug. This library provides a set of functions to dump variables, send raw messages, and interact with the inspector.

VarDump functionality is provided by the VarDump package and throwable handling by the ThrowableHandler package.

Quick start

Install using Composer.

composer require --dev xrdebug/php

Make sure to load the Composer autoload.php file in your project's entry point file, usually at index.php.

require_once __DIR__ . '/vendor/autoload.php';

Use xr() directly in your code to dump any variable. For example for a WordPress plugin:

add_action('plugins_loaded', function () {
    $userCanManageOptions = current_user_can('manage_options');


There's a interactive demo of this library in the ./demo directory. To use the demo execute xrdebug server with default settings.

Execute the following command to start the demo, it sends messages to the xrDebug server explaining you the debugger user interface.

php demo/welcome.php

Execute the following command to see how xrDebug handles errors.

php demo/error-handling.php

Debug Helpers

This xrDebug PHP client provides the following helper functions in the root namespace. Use these anywhere in your code.


Use function xr($var1, $var2,...) to dump one or more variable(s).

xr($var, 'Hola, mundo!');

Pass a topic using t:.

xr($var, t: 'Epic win');

Pass an emote using e:.

xr($var, e: '😎');

Pass bitwise flags to trigger special behavior.

  • f: XR_BACKTRACE to include debug backtrace.
xr($var, f: XR_BACKTRACE);


Use function xrr() to send a raw message.

xrr('<h1>Hola, mundo!</h1>');
xrr('<span>Test</span>', t: 'Epic win');
xrr('<b>test</b>', e: '😎');
xrr('some string<br>', f: XR_BACKTRACE);


Use function xri() to interact with the inspector.

Use pause to pause code execution.


Use memory to send memory usage information.



Function vd is a drop-in replacement for var_dump, it is provided by the VarDump package. It prints information about one or more variables to the output stream.

vd($var1, $var2,);
// more code


Function vdd does same as vd, but with die(0) which halts further execution.

// does exit();


Code-based configuration

Use xrConfig() to configure the xrDebug server connection.

    isEnabled: true,
    isHttps: false,
    host: 'localhost',
    port: 27420,
    key: file_get_contents('private.key')

File-based configuration

Configure the client by placing a xr.php file in project's root directory.

We recommend adding xr.php to your .gitignore.


return [
    'isEnabled' => true,
    'isHttps' => false,
    'host' => 'localhost',
    'port' => 27420,
    'key' => file_get_contents('private.key'),

Error handling

To handle errors with xrDebug you will require to configure your project to handle errors as exceptions and register a shutdown function:

use Chevere\ThrowableHandler\ThrowableHandler;


Exception handling

The PHP client provides a throwable handler that can hook or replace existing exception handler logic thanks to the ThrowableHandler package.

Register handler

Use registerThrowableHandler to enable xrDebug throwable handling.

use Chevere\xrDebug\PHP\registerThrowableHandler;

// True append xrDebug to your existing handler
// False use only xrDebug handler

Triggered handler

Use throwableHandler in any existing exception handler logic:

use Chevere\xrDebug\PHP\throwableHandler;

    function(Throwable $throwable) {
        // ...
        try {
        } catch(Throwable) {
            // Don't panic

Custom inspectors

Extra inspectors can be defined to provide more context aware debug information. To create a custom inspector use XrInspectorTrait to implement the XrInspectorInterface and use sendCommand method.

For code below, myDump defines a method that will stream data from your application logic and myPause sends a pause with debug backtrace by default.


use Chevere\xrDebug\PHP\Traits\XrInspectorTrait;
use Chevere\xrDebug\PHP\Interfaces\XrInspectorInterface;

class MyInspector implements XrInspectorInterface
    use XrInspectorTrait;

    public function myDump(
        string $t = '',
        string $e = '',
        int $f = 0,
    ): void {
        $data = 'my queries from somewhere...';
            command: 'message',
            body: $data,
            topic: $t,
            emote: $e,
            flags: $f,

    public function myPause(
        int $f = XR_DEBUG_BACKTRACE,
    ): void {
            command: 'pause',
            flags: $f,

The method sendCommand enables to interact with the existing xrDebug instance.

private function sendCommand(
    string $command,
    string $body = '',
    string $topic = '',
    string $emote = '',
    int $flags = 0

Null inspector

A null inspector is required to void any inspection call if xrDebug is disabled. The null inspector should implement the same methods as the real inspector, but without carrying any action.

💡 Use XrInspectorNullTrait to implement the XrInspectorInterface when providing null inspector.


use Chevere\xrDebug\PHP\Traits\XrInspectorNullTrait;
use Chevere\xrDebug\PHP\Interfaces\XrInspectorInterface;

class MyInspectorNull implements XrInspectorInterface
    use XrInspectorNullTrait;

    public function myDump(
        string $t = '',
        string $e = '',
        int $f = 0,
    ): void {

    public function myPause(
        int $f = XR_DEBUG_BACKTRACE,
    ): void {

Helper function for custom inspector

use Chevere\xrDebug\PHP\XrInspectorInstance;
use Chevere\xrDebug\PHP\Interfaces\XrInspectorInterface;
use LogicException;
use MyInspector;
use MyInspectorNull;

function my_inspector(): MyInspector
    try {
        return XrInspectorInstance::get();
    } catch (LogicException) {
        $inspector = getXr()->enable()
            ? MyInspector::class
            : MyInspectorNull::class;
        $client = getXr()->client();
        $inspector = new $inspector($client);
        $instance = new XrInspectorInstance($inspector);

        return $instance::get();

To use your custom helper:



Documentation available at docs.xrdebug.com.


Copyright Rodolfo Berrios A.

xrDebug is licensed under the Apache License, Version 2.0. See LICENSE for the full license text.

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.