diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..26c0390
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,31 @@
+name: PHPUnit Test
+
+on:
+  push:
+    branches:
+      - '**'
+
+jobs:
+  phpunit:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        php-version: ['8.0', '8.1', '8.2', '8.3']
+    steps:
+      # Checkout the code
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      # Set up PHP with matrix version
+      - name: Set up PHP ${{ matrix.php-version }}
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-version }}
+
+      # Install dependencies via Composer
+      - name: Install dependencies
+        uses: php-actions/composer@v6
+
+      # Run PHPUnit tests
+      - name: Run PHPUnit
+        run: ./vendor/bin/phpunit
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..2976ea6
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+/vendor/
+/composer.lock
+/.phpunit.result.cache
+/.idea
diff --git a/LICENSE b/LICENSE
index 1349250..fd46c23 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2024 belka-car
+Copyright (c) 2024 BelkaCar
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..89870ec
--- /dev/null
+++ b/README.md
@@ -0,0 +1,22 @@
+# Gauge Exporter PHP Client
+
+PHP Client for [Gague Exporter](https://github.com/belka-car/gague-exporter). 
+
+
+## Usage example
+```php
+<?php
+
+use Belkacar\GaugeExporterClient\GaugeExporterClient;
+use Belkacar\GaugeExporterClient\MetricBag;
+use GuzzleHttp\Client;
+
+require_once "vendor/autoload.php";
+
+$bag = new MetricBag('metric-name');
+$bag->increment(['a' => 'b'], 100);
+$bag->increment(['a' => 'b', 'c' => 'd'], 500);
+
+$client = new GaugeExporterClient(new Client(), 'https://127.0.0.1:8181', ['env' => 'prod']);
+$client->send($bag, 150);
+```
diff --git a/composer.json b/composer.json
new file mode 100755
index 0000000..3b24166
--- /dev/null
+++ b/composer.json
@@ -0,0 +1,32 @@
+{
+    "name": "belkacar/gauge-exporter-client",
+    "description": "Gauge Exporter PHP client",
+    "type": "library",
+    "license": "MIT",
+    "require": {
+        "php": "^8.0",
+        "ext-json": "*",
+        "guzzlehttp/psr7": "^2.6",
+        "psr/http-client": "^1.0",
+        "webmozart/assert": "^1.11"
+    },
+    "autoload": {
+        "psr-4": {
+            "Belkacar\\GaugeExporterClient\\": "src/"
+        }
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "Belkacar\\GaugeExporterClient\\Tests\\": "tests/"
+        }
+    },
+    "config": {
+        "allow-plugins": {
+            "php-http/discovery": true
+        }
+    },
+    "require-dev": {
+        "phpunit/phpunit": "^9.6",
+        "php-http/mock-client": "^1.6"
+    }
+}
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
new file mode 100644
index 0000000..7d24a86
--- /dev/null
+++ b/phpunit.xml.dist
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit bootstrap="vendor/autoload.php"
+         backupGlobals="false"
+         backupStaticAttributes="false"
+         colors="true"
+         verbose="true"
+         convertErrorsToExceptions="true"
+         convertNoticesToExceptions="true"
+         convertWarningsToExceptions="true"
+         processIsolation="false"
+         stopOnFailure="false">
+    <testsuites>
+        <testsuite name="Unit Tests">
+            <directory>tests</directory>
+        </testsuite>
+    </testsuites>
+</phpunit>
diff --git a/src/Exception/BadResponseException.php b/src/Exception/BadResponseException.php
new file mode 100644
index 0000000..35aa595
--- /dev/null
+++ b/src/Exception/BadResponseException.php
@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Belkacar\GaugeExporterClient\Exception;
+
+use Psr\Http\Client\ClientExceptionInterface;
+use Psr\Http\Message\ResponseInterface;
+
+final class BadResponseException extends \RuntimeException implements ClientExceptionInterface
+{
+    private ResponseInterface $response;
+
+    public function __construct(ResponseInterface $response)
+    {
+        $this->response = $response;
+        parent::__construct('');
+    }
+
+    public function getResponse(): ResponseInterface
+    {
+        return $this->response;
+    }
+}
diff --git a/src/GaugeExporterClient.php b/src/GaugeExporterClient.php
new file mode 100644
index 0000000..24437a9
--- /dev/null
+++ b/src/GaugeExporterClient.php
@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Belkacar\GaugeExporterClient;
+
+use Belkacar\GaugeExporterClient\Exception\BadResponseException;
+use Psr\Http\Client\ClientExceptionInterface;
+use Psr\Http\Client\ClientInterface;
+use GuzzleHttp\Psr7\Request;
+use stdClass;
+
+final class GaugeExporterClient
+{
+    private string $apiDomain;
+    private ClientInterface $client;
+    private array $defaultLabels;
+
+    public function __construct(ClientInterface $client, string $apiDomain, array $defaultLabels = [])
+    {
+        $this->client = $client;
+        $this->apiDomain = trim($apiDomain, " \n\r\t\v\0/");
+        $this->defaultLabels = MetricLine::normalizeLabels($defaultLabels);
+    }
+
+    /**
+     * @throws BadResponseException
+     * @throws ClientExceptionInterface
+     */
+    public function send(MetricBag $metricBag, int $ttlSec): void
+    {
+        $body = [
+            'ttl' => $ttlSec,
+            'data' => $this->generateData($metricBag),
+        ];
+        $request = new Request(
+            'PUT',
+            sprintf('%s/gauge/%s', $this->apiDomain, $metricBag->getMetricName()),
+            ['Content-Type' => 'application/json'],
+            json_encode($body),
+        );
+
+        $response = $this->client->sendRequest($request);
+        if ($response->getStatusCode() !== 200) {
+            throw new BadResponseException($response);
+        }
+    }
+
+    private function generateData(MetricBag $metricBag): array
+    {
+        $result = [];
+        foreach ($metricBag->getLogLines() as $logLine) {
+            $labels = array_merge($this->defaultLabels, $logLine->getLabels());
+            $result[] = [
+                'labels' => !empty($labels) ? $labels : new stdClass(),
+                'value' => $logLine->getValue()
+            ];
+        }
+        return $result;
+    }
+}
diff --git a/src/MetricBag.php b/src/MetricBag.php
new file mode 100644
index 0000000..6633bc8
--- /dev/null
+++ b/src/MetricBag.php
@@ -0,0 +1,63 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Belkacar\GaugeExporterClient;
+
+use InvalidArgumentException;
+
+final class MetricBag
+{
+    private const METRIC_NAME_PATTERN = '/^[a-zA-Z_:][a-zA-Z0-9_:.]*$/';
+
+    private string $metric;
+
+    /**
+     * @var array<string, float>
+     */
+    private array $labelsToValuePair;
+
+    public function __construct(string $metricName)
+    {
+        if (!preg_match(self::METRIC_NAME_PATTERN, $metricName)) {
+            throw new InvalidArgumentException('Metric name "' . $metricName . '" does not match ' . self::METRIC_NAME_PATTERN);
+        }
+        $this->metric = $metricName;
+        $this->labelsToValuePair = [];
+    }
+
+    public function set(array $labels, float $value): void
+    {
+        $labels = MetricLine::normalizeLabels($labels);
+
+        $this->labelsToValuePair[json_encode($labels)] = $value;
+    }
+
+    public function increment(array $labels, float $value = 1): void
+    {
+        $labels = MetricLine::normalizeLabels($labels);
+
+        $key = json_encode($labels);
+        if (!array_key_exists($key, $this->labelsToValuePair)) {
+            $this->labelsToValuePair[$key] = 0;
+        }
+        $this->labelsToValuePair[$key] += $value;
+    }
+
+    public function getMetricName(): string
+    {
+        return $this->metric;
+    }
+
+    /**
+     * @return list<MetricLine>
+     */
+    public function getLogLines(): array
+    {
+        $result = [];
+        foreach ($this->labelsToValuePair as $labels => $value) {
+            $result[] = new MetricLine(json_decode($labels, true), $value);
+        }
+        return $result;
+    }
+}
diff --git a/src/MetricLine.php b/src/MetricLine.php
new file mode 100644
index 0000000..e4a2024
--- /dev/null
+++ b/src/MetricLine.php
@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Belkacar\GaugeExporterClient;
+
+use InvalidArgumentException;
+
+final class MetricLine
+{
+    private array $labels;
+    private float $value;
+
+    public function __construct(array $labels, float $value)
+    {
+        $this->labels = self::normalizeLabels($labels);
+        $this->value = $value;
+    }
+
+    public function getValue(): float
+    {
+        return $this->value;
+    }
+
+    public function getLabels(): array
+    {
+        return $this->labels;
+    }
+
+    public static function normalizeLabels(array $labels): array
+    {
+        if (count(array_filter(array_keys($labels), 'is_int')) > 0) {
+            throw new InvalidArgumentException('Labels must be specified as associative array');
+        }
+        asort($labels);
+
+        return $labels;
+    }
+}
diff --git a/tests/GaugeExporterClientTest.php b/tests/GaugeExporterClientTest.php
new file mode 100755
index 0000000..03bb76a
--- /dev/null
+++ b/tests/GaugeExporterClientTest.php
@@ -0,0 +1,192 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Belkacar\GaugeExporterClient\Tests;
+
+use Belkacar\GaugeExporterClient\Exception\BadResponseException;
+use Belkacar\GaugeExporterClient\GaugeExporterClient;
+use Belkacar\GaugeExporterClient\MetricBag;
+use GuzzleHttp\Psr7\Response;
+use Http\Message\RequestMatcher\RequestMatcher;
+use Http\Mock\Client as MockClient;
+use PHPUnit\Framework\TestCase;
+use Psr\Http\Message\RequestInterface;
+
+class GaugeExporterClientTest extends TestCase
+{
+    public function testGaugeExporterClientHostTrailingSlashTrimmed(): void
+    {
+        // Arrange
+        $psrClientMock = new MockClient();
+        $exporterClient = new GaugeExporterClient($psrClientMock, 'https://example.com///');
+
+        // Act
+        $exporterClient->send(new MetricBag('metric.name'), 100);
+
+        // Assert
+        $expected = 'https://example.com/gauge/metric.name';
+        $actual = (string)$psrClientMock->getLastRequest()->getUri();
+        $this->assertSame($expected, $actual);
+    }
+
+    public function testWholeRequest(): void
+    {
+        // Arrange
+        $psrClientMock = new MockClient();
+        $exporterClient = new GaugeExporterClient($psrClientMock, 'https://example.com');
+
+        // Act
+        $metricBag = new MetricBag('metric.name');
+        $metricBag->set(['key1' => 'b', 'key2' => 'd'], 10);
+        $metricBag->set(['key1' => 'b', 'key2' => 'e'], 10);
+        $exporterClient->send($metricBag, 100);
+
+        // Assert
+        $this->assertSame(
+            [
+                'method' => 'PUT',
+                'url'  => 'https://example.com/gauge/metric.name',
+                'data' => '{"ttl":100,"data":[{"labels":{"key1":"b","key2":"d"},"value":10},{"labels":{"key1":"b","key2":"e"},"value":10}]}',
+            ],
+            $this->simplifyRequest($psrClientMock->getLastRequest()),
+        );
+    }
+
+    public function testWholeRequestWithEmptyLabelsMetric(): void
+    {
+        // Arrange
+        $psrClientMock = new MockClient();
+        $exporterClient = new GaugeExporterClient($psrClientMock, 'https://example.com');
+
+        // Act
+        $metricBag = new MetricBag('metric.name');
+        $metricBag->set([], 10);
+        $exporterClient->send($metricBag, 100);
+
+        // Assert
+        $this->assertSame(
+            [
+                'method' => 'PUT',
+                'url'  => 'https://example.com/gauge/metric.name',
+                'data' => '{"ttl":100,"data":[{"labels":{},"value":10}]}',
+            ],
+            $this->simplifyRequest($psrClientMock->getLastRequest()),
+        );
+    }
+
+    public function testWholeRequestWithEmptyBag(): void
+    {
+        // Arrange
+        $psrClientMock = new MockClient();
+        $exporterClient = new GaugeExporterClient($psrClientMock, 'https://example.com');
+
+        // Act
+        $metricBag = new MetricBag('metric.name');
+        $exporterClient->send($metricBag, 100);
+
+        // Assert
+        $this->assertSame(
+            [
+                'method' => 'PUT',
+                'url'  => 'https://example.com/gauge/metric.name',
+                'data' => '{"ttl":100,"data":[]}',
+            ],
+            $this->simplifyRequest($psrClientMock->getLastRequest()),
+        );
+    }
+
+    public function testWholeRequestWithDefaultLabels(): void
+    {
+        // Arrange
+        $psrClientMock = new MockClient();
+        $exporterClient = new GaugeExporterClient(
+            $psrClientMock,
+            'https://example.com',
+            [
+                'key2' => 'default_key2',
+                'key3' => 'default_key3',
+            ]
+        );
+
+        // Act
+        $metricBag = new MetricBag('metric.name');
+        $metricBag->set(['key1' => 'b', 'key2' => 'd'], 10);
+        $metricBag->set(['key1' => 'b'], 12);
+        $exporterClient->send($metricBag, 100);
+
+        // Assert
+        $expectedData = [
+            ['labels' => ['key2' => 'd', 'key3' => 'default_key3', 'key1' => 'b'], 'value' => 10],
+            ['labels' => ['key2' => 'default_key2', 'key3' => 'default_key3', 'key1' => 'b'], 'value' => 12],
+        ];
+        $this->assertSame(
+            [
+                'method' => 'PUT',
+                'url'  => 'https://example.com/gauge/metric.name',
+                'data' => '{"ttl":100,"data":' . json_encode($expectedData) . '}',
+            ],
+            $this->simplifyRequest($psrClientMock->getLastRequest()),
+        );
+    }
+
+    public function testWholeRequestWithEmptyBagAndDefaultLabels(): void
+    {
+        // Arrange
+        $psrClientMock = new MockClient();
+        $exporterClient = new GaugeExporterClient(
+            $psrClientMock,
+            'https://example.com',
+            [
+                'key2' => 'default_key2',
+                'key3' => 'default_key3',
+            ]
+        );
+
+        // Act
+        $metricBag = new MetricBag('metric.name');
+        $exporterClient->send($metricBag, 100);
+
+        // Assert
+        $this->assertSame(
+            [
+                'method' => 'PUT',
+                'url'  => 'https://example.com/gauge/metric.name',
+                'data' => '{"ttl":100,"data":[]}',
+            ],
+            $this->simplifyRequest($psrClientMock->getLastRequest()),
+        );
+    }
+
+    public function testGaugeExporterClientThrowsExceptionWhenResponseCodeOtherThan200(): void
+    {
+        // Arrange
+        $psrClientMock = new MockClient();
+        $psrClientMock->on(
+            new RequestMatcher('gauge/metric.name', 'example.com', ['PUT'], ['https']),
+            new Response(500, ['Content-Type' => 'application/json'], '{"error": "Unexpected error"}')
+        );
+        $exporterClient = new GaugeExporterClient($psrClientMock, 'https://example.com');
+
+        // Act
+        $exception = null;
+        try {
+            $exporterClient->send(new MetricBag('metric.name'), 100);
+        } catch (BadResponseException $e) {
+            $exception = $e;
+        }
+
+        // Assert
+        $this->assertSame(BadResponseException::class, get_class($exception));
+        $this->assertSame($exception->getResponse()->getBody()->getContents(), '{"error": "Unexpected error"}');
+    }
+
+    private function simplifyRequest(RequestInterface $request): array
+    {
+        return [
+            'method' => $request->getMethod(),
+            'url' => (string)$request->getUri(),
+            'data' => $request->getBody()->getContents(),
+        ];
+    }
+}
diff --git a/tests/MetricBagTest.php b/tests/MetricBagTest.php
new file mode 100644
index 0000000..dd7057d
--- /dev/null
+++ b/tests/MetricBagTest.php
@@ -0,0 +1,234 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Belkacar\GaugeExporterClient\Tests;
+
+use Belkacar\GaugeExporterClient\MetricBag;
+use Exception;
+use InvalidArgumentException;
+use PHPUnit\Framework\TestCase;
+
+class MetricBagTest extends TestCase
+{
+    public function testCannotCreateMetricWithEmptyName(): void
+    {
+        // Arrange, Act
+        $exceptionClass = null;
+        try {
+            new MetricBag('');
+        } catch (Exception $e) {
+            $exceptionClass = get_class($e);
+        }
+
+        // Assert
+        $this->assertSame(InvalidArgumentException::class, $exceptionClass);
+    }
+
+    /**
+     * @dataProvider invalidMetricsNamesProvider
+     */
+    public function testCannotCreateMetricWithWrongName(string $metricName): void
+    {
+        // Arrange, Act
+        $exceptionClass = null;
+        try {
+            new MetricBag($metricName);
+        } catch (Exception $e) {
+            $exceptionClass = get_class($e);
+        }
+
+        // Assert
+        $this->assertSame(InvalidArgumentException::class, $exceptionClass);
+    }
+
+    public function invalidMetricsNamesProvider(): array
+    {
+        return [
+            ['123abc'],
+            ['/abc/'],
+            ['-abc'],
+            ['abc!'],
+        ];
+    }
+
+    public function testEmptyMetricWithNoValuesIsValid(): void
+    {
+        // Arrange, Act
+        $metricBag = new MetricBag('metric.name');
+
+        // Assert
+        $actual = $this->convertMetricBagToArray($metricBag);
+        $this->assertSame([], $actual);
+    }
+
+    public function testSetCorrectlyAddsNewMetricValues(): void
+    {
+        // Arrange
+        $metricBag = new MetricBag('metric.name');
+
+        // Act
+        $metricBag->set(['label1' => 'value1', 'label2' => 'value2'], 123);
+        $metricBag->set(['label1' => 'value3', 'label2' => 'value4'], 123.4);
+
+        // Assert
+        $expected = [
+            ['labels' => ['label1' => 'value1', 'label2' => 'value2'], 'value' => 123.0],
+            ['labels' => ['label1' => 'value3', 'label2' => 'value4'], 'value' => 123.4],
+        ];
+        $actual = $this->convertMetricBagToArray($metricBag);
+        $this->assertSame($expected, $actual);
+    }
+
+    public function testSetCorrectlyOverwritesExistingMetricValue(): void
+    {
+        // Arrange
+        $metricBag = new MetricBag('metric.name');
+        $metricBag->set(['label1' => 'value1', 'label2' => 'value2'], 123);
+        $metricBag->set(['label1' => 'value3', 'label2' => 'value4'], 123.4);
+
+        // Act
+        $metricBag->set(['label1' => 'value3', 'label2' => 'value4'], 789);
+
+        // Assert
+        $expected = [
+            ['labels' => ['label1' => 'value1', 'label2' => 'value2'], 'value' => 123.0],
+            ['labels' => ['label1' => 'value3', 'label2' => 'value4'], 'value' => 789.0],
+        ];
+        $actual = $this->convertMetricBagToArray($metricBag);
+        $this->assertSame($expected, $actual);
+    }
+
+    public function testIncrementCorrectlyChangesMetricValue(): void
+    {
+        // Arrange
+        $metricBag = new MetricBag('metric.name');
+        $metricBag->set(['label1' => 'value1', 'label2' => 'value2'], 123);
+        $metricBag->set(['label1' => 'value3', 'label2' => 'value4'], 123.4);
+        $metricBag->set(['label1' => 'value5', 'label2' => 'value6'], 123);
+
+        // Act
+        $metricBag->increment(['label1' => 'value3', 'label2' => 'value4'], 123.4);
+
+        // Assert
+        $expected = [
+            ['labels' => ['label1' => 'value1', 'label2' => 'value2'], 'value' => 123.0],
+            ['labels' => ['label1' => 'value3', 'label2' => 'value4'], 'value' => 246.8],
+            ['labels' => ['label1' => 'value5', 'label2' => 'value6'], 'value' => 123.0],
+        ];
+        $actual = $this->convertMetricBagToArray($metricBag);
+        $this->assertSame($expected, $actual);
+    }
+
+    public function testIncrementCorrectlyChangesMissingMetricValue(): void
+    {
+        // Arrange
+        $metricBag = new MetricBag('metric.name');
+
+        // Act
+        $metricBag->increment(['label1' => 'value3', 'label2' => 'value4'], 123.4);
+
+        // Assert
+        $expected = [
+            ['labels' => ['label1' => 'value3', 'label2' => 'value4'], 'value' => 123.4],
+        ];
+        $actual = $this->convertMetricBagToArray($metricBag);
+        $this->assertSame($expected, $actual);
+    }
+
+    public function testOnlyAssocLabelsAreAllowedWithinSet(): void
+    {
+        // Arrange
+        $metricBag = new MetricBag('metric.name');
+        $exceptionClassForSet = null;
+        $exceptionClassForInc = null;
+
+        // Act
+        try {
+            $metricBag->set(['label1:value1', 'label2:value2'], 123.4);
+        } catch (Exception $e) {
+            $exceptionClassForSet = get_class($e);
+        }
+        try {
+            $metricBag->increment(['label1:value1', 'label2:value2'], 123.4);
+        } catch (Exception $e) {
+            $exceptionClassForInc = get_class($e);
+        }
+
+        // Assert
+        $this->assertSame(InvalidArgumentException::class, $exceptionClassForSet);
+        $this->assertSame(InvalidArgumentException::class, $exceptionClassForInc);
+    }
+
+    public function testDifferentSortForLabelsAreTreatedTheSame(): void
+    {
+        // Arrange
+        $metricBag = new MetricBag('metric.name');
+
+        // Act
+        $metricBag->increment(['label1' => 'value3', 'label2' => 'value4'], 123.4);
+        $metricBag->increment(['label2' => 'value4', 'label1' => 'value3'], 123.4);
+
+        $metricBag->set(['label3' => 'value3', 'label4' => 'value4'], 123.4);
+        $metricBag->set(['label4' => 'value4', 'label3' => 'value3'], 200);
+
+        // Assert
+        $expected = [
+            ['labels' => ['label1' => 'value3', 'label2' => 'value4'], 'value' => 246.8],
+            ['labels' => ['label3' => 'value3', 'label4' => 'value4'], 'value' => 200.0],
+        ];
+        $actual = $this->convertMetricBagToArray($metricBag);
+        $this->assertSame($expected, $actual);
+    }
+
+    public function testEmptyLabelsAreAllowed(): void
+    {
+        // Arrange
+        $metricBag = new MetricBag('metric.name');
+        $exceptionClassForSet = null;
+        $exceptionClassForInc = null;
+
+        // Act
+        $metricBag->set([], 123.4);
+        $metricBag->increment([], 123.4);
+
+        // Assert
+        $expected = [
+            ['labels' => [], 'value' => 246.8],
+        ];
+        $actual = $this->convertMetricBagToArray($metricBag);
+        $this->assertSame($expected, $actual);
+    }
+
+    public function testDifferentLabelsCardinalityWithinSameMetricBagIsAllowed(): void
+    {
+        // Arrange
+        $metricBag = new MetricBag('metric.name');
+
+        // Act
+        $metricBag->increment(['label1' => 'value3', 'label2' => 'value4'], 123.4);
+        $metricBag->increment(['label1' => 'value3', 'label2' => 'value4', 'label3' => 'value5'], 123.4);
+
+        $metricBag->set(['label3' => 'value3', 'label4' => 'value4'], 123.4);
+        $metricBag->set(['label3' => 'value3', 'label4' => 'value4', 'label5' => 'value5'], 123.4);
+
+        // Assert
+        $expected = [
+            ['labels' => ['label1' => 'value3', 'label2' => 'value4'], 'value' => 123.4],
+            ['labels' => ['label1' => 'value3', 'label2' => 'value4', 'label3' => 'value5'], 'value' => 123.4],
+            ['labels' => ['label3' => 'value3', 'label4' => 'value4'], 'value' => 123.4],
+            ['labels' => ['label3' => 'value3', 'label4' => 'value4', 'label5' => 'value5'], 'value' => 123.4],
+        ];
+        $actual = $this->convertMetricBagToArray($metricBag);
+        $this->assertSame($expected, $actual);
+    }
+
+    private function convertMetricBagToArray(MetricBag $metricBag): array
+    {
+        $result = [];
+        foreach ($metricBag->getLogLines() as $logLine) {
+            $result[] = ['labels' => $logLine->getLabels(), 'value' => $logLine->getValue()];
+        }
+        return $result;
+    }
+}