diff --git a/src/Domain/Article/Article.php b/src/Domain/Article/Article.php
new file mode 100644
index 0000000..91243af
--- /dev/null
+++ b/src/Domain/Article/Article.php
@@ -0,0 +1,142 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Domain\Article;
+
+use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
+use Doctrine\ORM\Mapping as ORM;
+use Symfony\Component\Uid\Uuid;
+
+#[ORM\Entity]
+#[ORM\Table(name: 'articles', schema: 'app')]
+class Article
+{
+    #[ORM\Id]
+    #[ORM\Column(type: 'uuid')]
+    private Uuid $id;
+
+    #[ORM\ManyToOne(targetEntity: ArticleType::class)]
+    #[ORM\JoinColumn(nullable: false)]
+    private ArticleType $articleType;
+
+    #[ORM\Column(type: 'string', length: 255, unique: true)]
+    private string $sku;
+
+    #[ORM\Column(type: 'string', length: 100, unique: true)]
+    private string $inventoryNumber;
+
+    #[ORM\Column(type: 'string', enumType: ArticleStatus::class)]
+    private ArticleStatus $status;
+
+    #[ORM\Column(type: 'integer')]
+    private int $stock;
+
+    #[ORM\Column(type: 'string', enumType: ArticleCondition::class)]
+    private ArticleCondition $condition;
+
+    #[ORM\Column(type: 'text', nullable: true)]
+    private ?string $conditionNotes = null;
+
+    #[ORM\Column(type: 'decimal', precision: 10, scale: 2, nullable: true)]
+    private ?string $listingPrice = null;
+
+    #[ORM\Column(type: 'string', length: 255, nullable: true)]
+    private ?string $serialNumber = null;
+
+    #[ORM\Column(type: 'string', length: 255, nullable: true)]
+    private ?string $ebayListingId = null;
+
+    #[ORM\Column(type: 'text', nullable: true)]
+    private ?string $ebayTitle = null;
+
+    #[ORM\Column(type: 'text', nullable: true)]
+    private ?string $ebayDescription = null;
+
+    /** @var Collection<int, AttributeValue> */
+    #[ORM\OneToMany(mappedBy: 'article', targetEntity: AttributeValue::class, cascade: ['persist', 'remove'])]
+    private Collection $attributeValues;
+
+    /** @var Collection<int, ArticlePhoto> */
+    #[ORM\OneToMany(mappedBy: 'article', targetEntity: ArticlePhoto::class, cascade: ['persist', 'remove'], orderBy: ['sortOrder' => 'ASC'])]
+    private Collection $photos;
+
+    public function __construct(
+        ArticleType $articleType,
+        string $sku,
+        string $inventoryNumber,
+        int $stock,
+        ArticleCondition $condition,
+    ) {
+        $this->id = Uuid::v7();
+        $this->articleType = $articleType;
+        $this->sku = $sku;
+        $this->inventoryNumber = $inventoryNumber;
+        $this->status = ArticleStatus::Ingesting;
+        $this->stock = $stock;
+        $this->condition = $condition;
+        $this->attributeValues = new ArrayCollection();
+        $this->photos = new ArrayCollection();
+    }
+
+    public function transitionTo(ArticleStatus $newStatus): void
+    {
+        if (!$this->status->canTransitionTo($newStatus)) {
+            throw new \DomainException(\sprintf(
+                'Cannot transition from %s to %s',
+                $this->status->value,
+                $newStatus->value,
+            ));
+        }
+        $this->status = $newStatus;
+    }
+
+    public function decrementStock(): void
+    {
+        if ($this->stock <= 0) {
+            throw new \DomainException('Stock cannot go below zero');
+        }
+        --$this->stock;
+    }
+
+    public function isOutOfStock(): bool { return 0 === $this->stock; }
+
+    public function getMainPhoto(): ?ArticlePhoto
+    {
+        foreach ($this->photos as $photo) {
+            if ($photo->isMain()) {
+                return $photo;
+            }
+        }
+
+        return null;
+    }
+
+    public function getId(): Uuid { return $this->id; }
+    public function getArticleType(): ArticleType { return $this->articleType; }
+    public function getSku(): string { return $this->sku; }
+    public function getInventoryNumber(): string { return $this->inventoryNumber; }
+    public function getStatus(): ArticleStatus { return $this->status; }
+    public function getStock(): int { return $this->stock; }
+    public function getCondition(): ArticleCondition { return $this->condition; }
+    public function getConditionNotes(): ?string { return $this->conditionNotes; }
+    public function getListingPrice(): ?string { return $this->listingPrice; }
+    public function getSerialNumber(): ?string { return $this->serialNumber; }
+    public function getEbayListingId(): ?string { return $this->ebayListingId; }
+    public function getEbayTitle(): ?string { return $this->ebayTitle; }
+    public function getEbayDescription(): ?string { return $this->ebayDescription; }
+
+    /** @return Collection<int, AttributeValue> */
+    public function getAttributeValues(): Collection { return $this->attributeValues; }
+
+    /** @return Collection<int, ArticlePhoto> */
+    public function getPhotos(): Collection { return $this->photos; }
+
+    public function setConditionNotes(?string $notes): void { $this->conditionNotes = $notes; }
+    public function setListingPrice(?string $price): void { $this->listingPrice = $price; }
+    public function setSerialNumber(?string $sn): void { $this->serialNumber = $sn; }
+    public function setEbayListingId(?string $id): void { $this->ebayListingId = $id; }
+    public function setEbayTitle(?string $title): void { $this->ebayTitle = $title; }
+    public function setEbayDescription(?string $desc): void { $this->ebayDescription = $desc; }
+}
diff --git a/src/Domain/Article/ArticlePhoto.php b/src/Domain/Article/ArticlePhoto.php
new file mode 100644
index 0000000..38f814b
--- /dev/null
+++ b/src/Domain/Article/ArticlePhoto.php
@@ -0,0 +1,62 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Domain\Article;
+
+use App\Domain\Storage\StoragePath;
+use Doctrine\ORM\Mapping as ORM;
+use Symfony\Component\Uid\Uuid;
+
+#[ORM\Entity]
+#[ORM\Table(name: 'article_photos', schema: 'app')]
+class ArticlePhoto
+{
+    #[ORM\Id]
+    #[ORM\Column(type: 'uuid')]
+    private Uuid $id;
+
+    #[ORM\ManyToOne(targetEntity: Article::class, inversedBy: 'photos')]
+    #[ORM\JoinColumn(nullable: false, onDelete: 'CASCADE')]
+    private Article $article;
+
+    #[ORM\ManyToOne(targetEntity: StoragePath::class)]
+    #[ORM\JoinColumn(nullable: false)]
+    private StoragePath $storagePath;
+
+    #[ORM\Column(type: 'string', length: 500)]
+    private string $filename;
+
+    #[ORM\Column(type: 'boolean')]
+    private bool $isMain;
+
+    #[ORM\Column(type: 'integer')]
+    private int $sortOrder;
+
+    public function __construct(
+        Article $article,
+        StoragePath $storagePath,
+        string $filename,
+        bool $isMain,
+        int $sortOrder,
+    ) {
+        $this->id = Uuid::v7();
+        $this->article = $article;
+        $this->storagePath = $storagePath;
+        $this->filename = $filename;
+        $this->isMain = $isMain;
+        $this->sortOrder = $sortOrder;
+    }
+
+    public function getId(): Uuid { return $this->id; }
+    public function getStoragePath(): StoragePath { return $this->storagePath; }
+    public function getFilename(): string { return $this->filename; }
+    public function isMain(): bool { return $this->isMain; }
+    public function getSortOrder(): int { return $this->sortOrder; }
+    public function setSortOrder(int $sortOrder): void { $this->sortOrder = $sortOrder; }
+
+    public function getFullPath(): string
+    {
+        return $this->storagePath->resolveFilePath($this->filename);
+    }
+}
diff --git a/src/Domain/Article/ArticleType.php b/src/Domain/Article/ArticleType.php
new file mode 100644
index 0000000..dbbe57f
--- /dev/null
+++ b/src/Domain/Article/ArticleType.php
@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Domain\Article;
+
+use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
+use Doctrine\ORM\Mapping as ORM;
+use Symfony\Component\Uid\Uuid;
+
+#[ORM\Entity]
+#[ORM\Table(name: 'article_types', schema: 'app')]
+class ArticleType
+{
+    #[ORM\Id]
+    #[ORM\Column(type: 'uuid')]
+    private Uuid $id;
+
+    #[ORM\Column(type: 'string', length: 255, unique: true)]
+    private string $name;
+
+    /** @var Collection<int, AttributeDefinition> */
+    #[ORM\ManyToMany(targetEntity: AttributeDefinition::class)]
+    #[ORM\JoinTable(name: 'article_type_attributes', schema: 'app')]
+    private Collection $attributeDefinitions;
+
+    public function __construct(string $name)
+    {
+        $this->id = Uuid::v7();
+        $this->name = $name;
+        $this->attributeDefinitions = new ArrayCollection();
+    }
+
+    public function getId(): Uuid { return $this->id; }
+    public function getName(): string { return $this->name; }
+    public function setName(string $name): void { $this->name = $name; }
+
+    /** @return Collection<int, AttributeDefinition> */
+    public function getAttributeDefinitions(): Collection { return $this->attributeDefinitions; }
+
+    public function addAttributeDefinition(AttributeDefinition $def): void
+    {
+        if (!$this->attributeDefinitions->contains($def)) {
+            $this->attributeDefinitions->add($def);
+        }
+    }
+
+    public function removeAttributeDefinition(AttributeDefinition $def): void
+    {
+        $this->attributeDefinitions->removeElement($def);
+    }
+}
diff --git a/src/Domain/Article/AttributeDefinition.php b/src/Domain/Article/AttributeDefinition.php
new file mode 100644
index 0000000..3f74345
--- /dev/null
+++ b/src/Domain/Article/AttributeDefinition.php
@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Domain\Article;
+
+use Doctrine\ORM\Mapping as ORM;
+use Symfony\Component\Uid\Uuid;
+
+#[ORM\Entity]
+#[ORM\Table(name: 'attribute_definitions', schema: 'app')]
+class AttributeDefinition
+{
+    #[ORM\Id]
+    #[ORM\Column(type: 'uuid')]
+    private Uuid $id;
+
+    #[ORM\Column(type: 'string', length: 255)]
+    private string $name;
+
+    #[ORM\Column(type: 'string', enumType: AttributeType::class)]
+    private AttributeType $type;
+
+    #[ORM\Column(type: 'string', length: 50, nullable: true)]
+    private ?string $unit = null;
+
+    /** @var list<string>|null */
+    #[ORM\Column(type: 'json', nullable: true)]
+    private ?array $options = null;
+
+    public function __construct(string $name, AttributeType $type)
+    {
+        $this->id = Uuid::v7();
+        $this->name = $name;
+        $this->type = $type;
+    }
+
+    public function getId(): Uuid { return $this->id; }
+    public function getName(): string { return $this->name; }
+    public function setName(string $name): void { $this->name = $name; }
+    public function getType(): AttributeType { return $this->type; }
+    public function getUnit(): ?string { return $this->unit; }
+    public function setUnit(?string $unit): void { $this->unit = $unit; }
+
+    /** @return list<string>|null */
+    public function getOptions(): ?array { return $this->options; }
+
+    /** @param list<string>|null $options */
+    public function setOptions(?array $options): void { $this->options = $options; }
+}
diff --git a/src/Domain/Article/AttributeValue.php b/src/Domain/Article/AttributeValue.php
new file mode 100644
index 0000000..07b6eb5
--- /dev/null
+++ b/src/Domain/Article/AttributeValue.php
@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Domain\Article;
+
+use Doctrine\ORM\Mapping as ORM;
+use Symfony\Component\Uid\Uuid;
+
+#[ORM\Entity]
+#[ORM\Table(name: 'attribute_values', schema: 'app')]
+#[ORM\UniqueConstraint(columns: ['article_id', 'attribute_definition_id'])]
+class AttributeValue
+{
+    #[ORM\Id]
+    #[ORM\Column(type: 'uuid')]
+    private Uuid $id;
+
+    #[ORM\ManyToOne(targetEntity: Article::class, inversedBy: 'attributeValues')]
+    #[ORM\JoinColumn(nullable: false, onDelete: 'CASCADE')]
+    private Article $article;
+
+    #[ORM\ManyToOne(targetEntity: AttributeDefinition::class)]
+    #[ORM\JoinColumn(nullable: false)]
+    private AttributeDefinition $attributeDefinition;
+
+    #[ORM\Column(type: 'text')]
+    private string $value;
+
+    public function __construct(
+        Article $article,
+        AttributeDefinition $attributeDefinition,
+        string $value,
+    ) {
+        $this->id = Uuid::v7();
+        $this->article = $article;
+        $this->attributeDefinition = $attributeDefinition;
+        $this->value = $value;
+    }
+
+    public function getId(): Uuid { return $this->id; }
+    public function getAttributeDefinition(): AttributeDefinition { return $this->attributeDefinition; }
+    public function getValue(): string { return $this->value; }
+    public function setValue(string $value): void { $this->value = $value; }
+
+    public function getCastValue(): mixed
+    {
+        return match ($this->attributeDefinition->getType()) {
+            AttributeType::Int => (int) $this->value,
+            AttributeType::Float => (float) $this->value,
+            AttributeType::Bool => filter_var($this->value, \FILTER_VALIDATE_BOOLEAN),
+            AttributeType::MultiSelect => \json_decode($this->value, true),
+            default => $this->value,
+        };
+    }
+}
diff --git a/src/Domain/Storage/StoragePath.php b/src/Domain/Storage/StoragePath.php
new file mode 100644
index 0000000..df082aa
--- /dev/null
+++ b/src/Domain/Storage/StoragePath.php
@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Domain\Storage;
+
+use Doctrine\ORM\Mapping as ORM;
+use Symfony\Component\Uid\Uuid;
+
+#[ORM\Entity]
+#[ORM\Table(name: 'storage_paths', schema: 'app')]
+class StoragePath
+{
+    #[ORM\Id]
+    #[ORM\Column(type: 'uuid')]
+    private Uuid $id;
+
+    #[ORM\Column(type: 'string', length: 255)]
+    private string $label;
+
+    #[ORM\Column(type: 'string', length: 500)]
+    private string $basePath;
+
+    #[ORM\Column(type: 'bigint')]
+    private int $quotaBytes;
+
+    #[ORM\Column(type: 'integer')]
+    private int $priority;
+
+    #[ORM\Column(type: 'boolean')]
+    private bool $isActive;
+
+    public function __construct(
+        string $label,
+        string $basePath,
+        int $quotaBytes,
+        int $priority,
+        bool $isActive = true,
+    ) {
+        $this->id = Uuid::v7();
+        $this->label = $label;
+        $this->basePath = $basePath;
+        $this->quotaBytes = $quotaBytes;
+        $this->priority = $priority;
+        $this->isActive = $isActive;
+    }
+
+    public function getId(): Uuid { return $this->id; }
+    public function getLabel(): string { return $this->label; }
+    public function getBasePath(): string { return $this->basePath; }
+    public function setBasePath(string $basePath): void { $this->basePath = $basePath; }
+    public function getQuotaBytes(): int { return $this->quotaBytes; }
+    public function getPriority(): int { return $this->priority; }
+    public function isActive(): bool { return $this->isActive; }
+    public function setIsActive(bool $isActive): void { $this->isActive = $isActive; }
+
+    public function resolveFilePath(string $filename): string
+    {
+        return \rtrim($this->basePath, '/').'/'.$filename;
+    }
+}
diff --git a/tests/Unit/Domain/Article/ArticleTest.php b/tests/Unit/Domain/Article/ArticleTest.php
new file mode 100644
index 0000000..2af6303
--- /dev/null
+++ b/tests/Unit/Domain/Article/ArticleTest.php
@@ -0,0 +1,70 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Domain\Article;
+
+use App\Domain\Article\Article;
+use App\Domain\Article\ArticleCondition;
+use App\Domain\Article\ArticleStatus;
+use App\Domain\Article\ArticleType;
+use PHPUnit\Framework\TestCase;
+
+final class ArticleTest extends TestCase
+{
+    private ArticleType $type;
+
+    protected function setUp(): void
+    {
+        $this->type = new ArticleType('Notebook');
+    }
+
+    public function test_new_article_has_ingesting_status(): void
+    {
+        $article = new Article($this->type, 'NB-001', 'INV-001', 1, ArticleCondition::Good);
+
+        $this->assertSame(ArticleStatus::Ingesting, $article->getStatus());
+        $this->assertSame(1, $article->getStock());
+    }
+
+    public function test_valid_status_transition(): void
+    {
+        $article = new Article($this->type, 'NB-001', 'INV-001', 1, ArticleCondition::Good);
+        $article->transitionTo(ArticleStatus::Draft);
+
+        $this->assertSame(ArticleStatus::Draft, $article->getStatus());
+    }
+
+    public function test_invalid_status_transition_throws(): void
+    {
+        $article = new Article($this->type, 'NB-001', 'INV-001', 1, ArticleCondition::Good);
+
+        $this->expectException(\DomainException::class);
+        $article->transitionTo(ArticleStatus::Sold);
+    }
+
+    public function test_decrement_stock(): void
+    {
+        $article = new Article($this->type, 'NB-001', 'INV-001', 3, ArticleCondition::Good);
+        $article->decrementStock();
+
+        $this->assertSame(2, $article->getStock());
+        $this->assertFalse($article->isOutOfStock());
+    }
+
+    public function test_decrement_to_zero_marks_out_of_stock(): void
+    {
+        $article = new Article($this->type, 'NB-001', 'INV-001', 1, ArticleCondition::Good);
+        $article->decrementStock();
+
+        $this->assertTrue($article->isOutOfStock());
+    }
+
+    public function test_decrement_below_zero_throws(): void
+    {
+        $article = new Article($this->type, 'NB-001', 'INV-001', 0, ArticleCondition::Good);
+
+        $this->expectException(\DomainException::class);
+        $article->decrementStock();
+    }
+}