diff --git a/openapi_first/templates/model_app/data.py b/openapi_first/templates/model_app/data.py
new file mode 100644
index 0000000..51cb18e
--- /dev/null
+++ b/openapi_first/templates/model_app/data.py
@@ -0,0 +1,44 @@
+"""
+In-memory data store using Pydantic models.
+
+This module is NOT thread-safe and is intended for demos and scaffolds only.
+"""
+
+from typing import Dict
+
+from models import Item, ItemCreate
+
+_items: Dict[int, Item] = {
+    1: Item(id=1, name="Apple", price=0.5),
+    2: Item(id=2, name="Banana", price=0.3),
+}
+
+_next_id = 3
+
+
+def list_items() -> list[Item]:
+    return list(_items.values())
+
+
+def get_item(item_id: int) -> Item:
+    return _items[item_id]
+
+
+def create_item(payload: ItemCreate) -> Item:
+    global _next_id
+    item = Item(id=_next_id, **payload.model_dump())
+    _items[_next_id] = item
+    _next_id += 1
+    return item
+
+
+def update_item(item_id: int, payload: ItemCreate) -> Item:
+    if item_id not in _items:
+        raise KeyError(item_id)
+    item = Item(id=item_id, **payload.model_dump())
+    _items[item_id] = item
+    return item
+
+
+def delete_item(item_id: int) -> None:
+    del _items[item_id]
diff --git a/openapi_first/templates/model_app/main.py b/openapi_first/templates/model_app/main.py
new file mode 100644
index 0000000..c0b50a2
--- /dev/null
+++ b/openapi_first/templates/model_app/main.py
@@ -0,0 +1,8 @@
+from openapi_first.app import OpenAPIFirstApp
+import routes
+
+app = OpenAPIFirstApp(
+    openapi_path="openapi.yaml",
+    routes_module=routes,
+    title="Model CRUD Example Service",
+)
diff --git a/openapi_first/templates/model_app/models.py b/openapi_first/templates/model_app/models.py
new file mode 100644
index 0000000..f5b9402
--- /dev/null
+++ b/openapi_first/templates/model_app/models.py
@@ -0,0 +1,18 @@
+"""
+Pydantic domain models for the CRUD example.
+"""
+
+from pydantic import BaseModel
+
+
+class ItemBase(BaseModel):
+    name: str
+    price: float
+
+
+class ItemCreate(ItemBase):
+    pass
+
+
+class Item(ItemBase):
+    id: int
diff --git a/openapi_first/templates/model_app/openapi.yaml b/openapi_first/templates/model_app/openapi.yaml
new file mode 100644
index 0000000..f34debb
--- /dev/null
+++ b/openapi_first/templates/model_app/openapi.yaml
@@ -0,0 +1,116 @@
+openapi: 3.0.3
+info:
+  title: Model CRUD Example Service
+  version: "1.0.0"
+  description: OpenAPI-first CRUD service with Pydantic models.
+
+paths:
+  /items:
+    get:
+      operationId: list_items
+      responses:
+        "200":
+          description: List of items
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: "#/components/schemas/Item"
+
+    post:
+      operationId: create_item
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/ItemCreate"
+      responses:
+        "201":
+          description: Item created
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Item"
+
+  /items/{item_id}:
+    get:
+      operationId: get_item
+      parameters:
+        - name: item_id
+          in: path
+          required: true
+          schema:
+            type: integer
+      responses:
+        "200":
+          description: Item found
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Item"
+        "404":
+          description: Item not found
+
+    put:
+      operationId: update_item
+      parameters:
+        - name: item_id
+          in: path
+          required: true
+          schema:
+            type: integer
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/ItemCreate"
+      responses:
+        "200":
+          description: Item updated
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Item"
+        "404":
+          description: Item not found
+
+    delete:
+      operationId: delete_item
+      parameters:
+        - name: item_id
+          in: path
+          required: true
+          schema:
+            type: integer
+      responses:
+        "204":
+          description: Item deleted
+        "404":
+          description: Item not found
+
+components:
+  schemas:
+    Item:
+      type: object
+      required: [id, name, price]
+      properties:
+        id:
+          type: integer
+        name:
+          type: string
+        price:
+          type: number
+          format: float
+
+    ItemCreate:
+      type: object
+      required: [name, price]
+      properties:
+        name:
+          type: string
+        price:
+          type: number
+          format: float
diff --git a/openapi_first/templates/model_app/routes.py b/openapi_first/templates/model_app/routes.py
new file mode 100644
index 0000000..82d6d23
--- /dev/null
+++ b/openapi_first/templates/model_app/routes.py
@@ -0,0 +1,48 @@
+"""
+CRUD route handlers bound via OpenAPI operationId.
+"""
+
+from fastapi import Response, HTTPException
+
+from models import ItemCreate
+from data import (
+    list_items as _list_items,
+    get_item as _get_item,
+    create_item as _create_item,
+    update_item as _update_item,
+    delete_item as _delete_item,
+)
+
+
+def list_items():
+    return _list_items()
+
+
+def get_item(item_id: int):
+    try:
+        return _get_item(item_id)
+    except KeyError:
+        raise HTTPException(status_code=404, detail="Item not found")
+
+
+def create_item(payload: ItemCreate, response: Response):
+    item = _create_item(payload)
+    response.status_code = 201
+    return item
+
+
+def update_item(item_id: int, payload: ItemCreate):
+    try:
+        return _update_item(item_id, payload)
+    except KeyError:
+        raise HTTPException(status_code=404, detail="Item not found")
+
+
+def delete_item(item_id: int, response: Response):
+    try:
+        _delete_item(item_id)
+    except KeyError:
+        raise HTTPException(status_code=404, detail="Item not found")
+
+    response.status_code = 204
+    return None
diff --git a/openapi_first/templates/model_app/test_model_app.py b/openapi_first/templates/model_app/test_model_app.py
new file mode 100644
index 0000000..c93da53
--- /dev/null
+++ b/openapi_first/templates/model_app/test_model_app.py
@@ -0,0 +1,98 @@
+"""
+End-to-end tests for the OpenAPI-first model CRUD example app.
+
+These tests validate that all CRUD operations behave correctly
+against the in-memory mock data store using Pydantic models.
+
+The tests assume:
+- OpenAPI-first route binding
+- Pydantic model validation
+- In-memory storage (no persistence guarantees)
+- Deterministic behavior in a single process
+"""
+
+from fastapi.testclient import TestClient
+
+from main import app
+
+
+client = TestClient(app)
+
+
+def test_list_items_initial():
+    """Initial items should be present."""
+    response = client.get("/items")
+    assert response.status_code == 200
+
+    data = response.json()
+    assert isinstance(data, list)
+    assert len(data) >= 2
+
+    ids = {item["id"] for item in data}
+    assert 1 in ids
+    assert 2 in ids
+
+
+def test_get_item():
+    """Existing item should be retrievable by ID."""
+    response = client.get("/items/1")
+    assert response.status_code == 200
+
+    item = response.json()
+    assert item["id"] == 1
+    assert isinstance(item["name"], str)
+    assert isinstance(item["price"], float)
+
+
+def test_create_item():
+    """Creating a new item should return the created entity."""
+    payload = {
+        "name": "Orange",
+        "price": 0.8,
+    }
+
+    response = client.post("/items", json=payload)
+    assert response.status_code == 201
+
+    item = response.json()
+    assert "id" in item
+    assert item["name"] == payload["name"]
+    assert item["price"] == payload["price"]
+
+    # Verify it appears in list
+    list_response = client.get("/items")
+    ids = {i["id"] for i in list_response.json()}
+    assert item["id"] in ids
+
+
+def test_update_item():
+    """Updating an item should replace its values."""
+    payload = {
+        "name": "Green Apple",
+        "price": 0.6,
+    }
+
+    response = client.put("/items/1", json=payload)
+    assert response.status_code == 200
+
+    item = response.json()
+    assert item["id"] == 1
+    assert item["name"] == payload["name"]
+    assert item["price"] == payload["price"]
+
+    # Verify persisted update
+    get_response = client.get("/items/1")
+    updated = get_response.json()
+    assert updated["name"] == payload["name"]
+    assert updated["price"] == payload["price"]
+
+
+def test_delete_item():
+    """Deleting an item should remove it from the store."""
+    response = client.delete("/items/2")
+    assert response.status_code == 204
+
+    # Verify deletion
+    list_response = client.get("/items")
+    ids = {item["id"] for item in list_response.json()}
+    assert 2 not in ids