diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
new file mode 100644
index 0000000..2cd720b
--- /dev/null
+++ b/.github/workflows/tests.yml
@@ -0,0 +1,24 @@
+# file generated with AI assistance: Claude Code - 2026-06-13 23:14:54 UTC
+name: Tests
+
+on:
+  push:
+    branches: [main, master, "feature/**"]
+  pull_request:
+
+jobs:
+  phpunit:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        php: ["8.3", "8.4"]
+    name: PHPUnit (PHP ${{ matrix.php }})
+    steps:
+      - uses: actions/checkout@v4
+      - uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          coverage: none
+      - run: composer install --no-interaction --no-progress
+      - run: vendor/bin/phpunit
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..cff2af8
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+# file generated with AI assistance: Claude Code - 2026-06-13 23:14:54 UTC
+/vendor/
+/composer.lock
+/.phpunit.cache/
diff --git a/composer.json b/composer.json
index 07d5514..fe0e734 100644
--- a/composer.json
+++ b/composer.json
@@ -13,9 +13,13 @@
         "php": ">=8.2",
         "symfony/framework-bundle": "^7.0",
         "symfony/messenger": "^7.0",
+        "symfony/uid": "^7.0",
         "doctrine/orm": "^3.0",
         "doctrine/doctrine-bundle": "^2.0"
     },
+    "require-dev": {
+        "phpunit/phpunit": "^12.0"
+    },
     "autoload": {
         "psr-4": {
             "Dmstr\\SymfonyJobQueue\\": "src/"
diff --git a/docker-compose.yml b/docker-compose.yml
new file mode 100644
index 0000000..8086794
--- /dev/null
+++ b/docker-compose.yml
@@ -0,0 +1,15 @@
+# file generated with AI assistance: Claude Code - 2026-06-13 23:14:54 UTC
+# CLI-only test runner for this bundle — no MySQL/FPM required.
+# Usage (on host):
+#   docker compose run --rm php
+# Runs `composer install` then PHPUnit against tests/.
+services:
+  php:
+    build:
+      dockerfile_inline: |
+        FROM php:8.4-cli-alpine
+        COPY --from=composer:2 /usr/bin/composer /usr/bin/composer
+    working_dir: /repo
+    volumes:
+      - .:/repo
+    command: sh -c "composer install --no-interaction --no-progress && vendor/bin/phpunit"
diff --git a/phpunit.dist.xml b/phpunit.dist.xml
new file mode 100644
index 0000000..9dc4142
--- /dev/null
+++ b/phpunit.dist.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- file generated with AI assistance: Claude Code - 2026-06-13 23:14:54 UTC -->
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
+         bootstrap="vendor/autoload.php"
+         colors="true"
+         cacheDirectory=".phpunit.cache">
+    <testsuites>
+        <testsuite name="default">
+            <directory>tests</directory>
+        </testsuite>
+    </testsuites>
+    <source>
+        <include>
+            <directory>src</directory>
+        </include>
+    </source>
+</phpunit>
diff --git a/tests/Entity/JobTest.php b/tests/Entity/JobTest.php
new file mode 100644
index 0000000..85f610b
--- /dev/null
+++ b/tests/Entity/JobTest.php
@@ -0,0 +1,75 @@
+<?php
+// file generated with AI assistance: Claude Code - 2026-06-13 23:14:54 UTC
+
+declare(strict_types=1);
+
+namespace Dmstr\SymfonyJobQueue\Tests\Entity;
+
+use Dmstr\SymfonyJobQueue\Entity\Job;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Uid\Uuid;
+
+/**
+ * Unit tests for the {@see Job} entity exercised as a plain object — no
+ * Doctrine, no database. Verifies the constructor defaults, fluent setters and
+ * the PreUpdate lifecycle hook.
+ */
+final class JobTest extends TestCase
+{
+    public function testConstructorSetsSaneDefaults(): void
+    {
+        $job = new Job();
+
+        self::assertTrue(Uuid::isValid($job->getId()), 'id must be a valid UUID');
+        self::assertSame('pending', $job->getStatus());
+        self::assertSame(0, $job->getProgress());
+        self::assertSame([], $job->getInputData());
+        self::assertNull($job->getResultData());
+        self::assertNull($job->getErrorMessage());
+        self::assertNull($job->getStartedAt());
+        self::assertNull($job->getCompletedAt());
+        self::assertInstanceOf(\DateTimeImmutable::class, $job->getCreatedAt());
+        self::assertInstanceOf(\DateTimeImmutable::class, $job->getUpdatedAt());
+    }
+
+    public function testEachJobGetsAUniqueId(): void
+    {
+        self::assertNotSame((new Job())->getId(), (new Job())->getId());
+    }
+
+    public function testFluentSettersUpdateState(): void
+    {
+        $job = new Job();
+        $started = new \DateTimeImmutable('2026-01-01 10:00:00');
+        $completed = new \DateTimeImmutable('2026-01-01 10:05:00');
+
+        $result = $job
+            ->setType('ref_project_scan')
+            ->setStatus('completed')
+            ->setInputData(['apiConfiguration' => ['uuid' => '5302d197']])
+            ->setResultData(['imported' => 42])
+            ->setErrorMessage('none')
+            ->setProgress(100)
+            ->setStartedAt($started)
+            ->setCompletedAt($completed);
+
+        self::assertSame($job, $result, 'setters must be fluent');
+        self::assertSame('ref_project_scan', $job->getType());
+        self::assertSame('completed', $job->getStatus());
+        self::assertSame(['apiConfiguration' => ['uuid' => '5302d197']], $job->getInputData());
+        self::assertSame(['imported' => 42], $job->getResultData());
+        self::assertSame('none', $job->getErrorMessage());
+        self::assertSame(100, $job->getProgress());
+        self::assertSame($started, $job->getStartedAt());
+        self::assertSame($completed, $job->getCompletedAt());
+    }
+
+    public function testOnPreUpdateRefreshesUpdatedAt(): void
+    {
+        $job = new Job();
+        $job->onPreUpdate();
+
+        self::assertInstanceOf(\DateTimeImmutable::class, $job->getUpdatedAt());
+        self::assertGreaterThanOrEqual($job->getCreatedAt(), $job->getUpdatedAt());
+    }
+}
diff --git a/tests/Message/JobMessageTest.php b/tests/Message/JobMessageTest.php
new file mode 100644
index 0000000..e80687a
--- /dev/null
+++ b/tests/Message/JobMessageTest.php
@@ -0,0 +1,26 @@
+<?php
+// file generated with AI assistance: Claude Code - 2026-06-13 23:14:54 UTC
+
+declare(strict_types=1);
+
+namespace Dmstr\SymfonyJobQueue\Tests\Message;
+
+use Dmstr\SymfonyJobQueue\Message\JobMessage;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Unit tests for the {@see JobMessage} Messenger envelope payload.
+ */
+final class JobMessageTest extends TestCase
+{
+    public function testCarriesJobId(): void
+    {
+        self::assertSame('job-123', (new JobMessage('job-123'))->getJobId());
+    }
+
+    public function testDistinctMessagesKeepTheirOwnId(): void
+    {
+        self::assertSame('a', (new JobMessage('a'))->getJobId());
+        self::assertSame('b', (new JobMessage('b'))->getJobId());
+    }
+}