diff --git a/packages/blog/src/entities/article.test.ts b/packages/blog/src/entities/article.test.ts
new file mode 100644
index 0000000..e5e9727
--- /dev/null
+++ b/packages/blog/src/entities/article.test.ts
@@ -0,0 +1,85 @@
+import { describe, expect, it } from "vitest";
+import { articleSchema, articleStatusSchema, type Article } from "./article";
+
+describe("articleSchema", () => {
+  it("accepts a minimal valid article with default status", () => {
+    const result = articleSchema.parse({
+      id: "abc",
+      title: "Hello",
+      slug: "hello",
+      content: { type: "doc", children: [] },
+      authorId: "u1",
+      createdAt: new Date(),
+      updatedAt: new Date(),
+    });
+    expect(result.status).toBe("draft");
+  });
+
+  it("accepts unknown rich-text content", () => {
+    const result = articleSchema.parse({
+      id: "abc",
+      title: "Hello",
+      slug: "hello",
+      content: "any string is also fine",
+      authorId: "u1",
+      createdAt: new Date(),
+      updatedAt: new Date(),
+    });
+    expect(result.content).toBe("any string is also fine");
+  });
+
+  it("rejects empty title", () => {
+    expect(() =>
+      articleSchema.parse({
+        id: "a",
+        title: "",
+        slug: "s",
+        content: null,
+        authorId: "u",
+        createdAt: new Date(),
+        updatedAt: new Date(),
+      }),
+    ).toThrow();
+  });
+
+  it("rejects title over 255 chars", () => {
+    expect(() =>
+      articleSchema.parse({
+        id: "a",
+        title: "x".repeat(256),
+        slug: "s",
+        content: null,
+        authorId: "u",
+        createdAt: new Date(),
+        updatedAt: new Date(),
+      }),
+    ).toThrow();
+  });
+});
+
+describe("articleStatusSchema", () => {
+  it("accepts 'draft' and 'published'", () => {
+    expect(articleStatusSchema.parse("draft")).toBe("draft");
+    expect(articleStatusSchema.parse("published")).toBe("published");
+  });
+
+  it("rejects unknown status", () => {
+    expect(() => articleStatusSchema.parse("archived")).toThrow();
+  });
+});
+
+describe("Article type", () => {
+  it("widens content to unknown", () => {
+    const _example: Article = {
+      id: "x",
+      title: "t",
+      slug: "s",
+      content: { whatever: true },
+      status: "draft",
+      authorId: "u",
+      createdAt: new Date(),
+      updatedAt: new Date(),
+    };
+    expect(_example).toBeDefined();
+  });
+});
diff --git a/packages/blog/src/entities/article.ts b/packages/blog/src/entities/article.ts
new file mode 100644
index 0000000..9f3354b
--- /dev/null
+++ b/packages/blog/src/entities/article.ts
@@ -0,0 +1,17 @@
+import { z } from "zod";
+
+export const articleStatusSchema = z.enum(["draft", "published"]);
+
+export const articleSchema = z.object({
+  id: z.string(),
+  title: z.string().min(1).max(255),
+  slug: z.string().min(1).max(255),
+  content: z.unknown(),
+  status: articleStatusSchema.default("draft"),
+  authorId: z.string(),
+  createdAt: z.date(),
+  updatedAt: z.date(),
+});
+
+export type Article = z.infer<typeof articleSchema>;
+export type ArticleStatus = z.infer<typeof articleStatusSchema>;
diff --git a/packages/blog/src/entities/errors.ts b/packages/blog/src/entities/errors.ts
new file mode 100644
index 0000000..628de66
--- /dev/null
+++ b/packages/blog/src/entities/errors.ts
@@ -0,0 +1,11 @@
+export class ArticleNotFoundError extends Error {
+  constructor(message = "Article not found", options?: ErrorOptions) {
+    super(message, options);
+  }
+}
+
+export class InputParseError extends Error {
+  constructor(message: string, options?: ErrorOptions) {
+    super(message, options);
+  }
+}