Hey guys! Welcome to Part 2 of our Dart Frog series. If you missed Part 1, we set up Dart Frog and built a basic API with hot reload. <a href="https://youtu.be/9rGEQH05x4I" target="_blank" rel="noopener nofollow">Watch it now</a> if you’re new!
Today, we’re leveling up: Building your first real REST API, a full CRUD Todo endpoint, clean, and production-ready backends in pure Dart.
We’ll use dynamic routes, UUIDs, validation, and proper errors. By the end, you’ll have a testable API ready for your Flutter app next video. Let’s jump in!
Watch the full tutorial here: <a href="https://youtu.be/gWkAhCfSsaE" target="_blank" rel="noopener nofollow">https://youtu.be/gWkAhCfSsaE</a>
<h2>Planning &amp; Best Practices</h2>
Quick plan: We’ll create a Todo model with id, title, and completed status. Store them in-memory (Map for fast lookup), perfect for learning, and easy to upgrade to Postgres or Drift later.
Best practices:
<ul>
<li>Dynamic routes with [id].dart</li>
<li>UUID package for unique IDs</li>
<li>Validate JSON bodies</li>
<li>Return correct status: 200, 201, 404, 400.</li>
</ul>
Open your project from Part 1 — or create a new one with <code>dart_frog create todo_api</code>. Run <code>dart_frog dev</code>.
First, add UUID: pubspec.yaml
<pre><code class="language-yaml">dependencies:
 uuid: ^4.5.0 
</code></pre>
<code>flutter pub get</code> (or dart pub get).
Create model: lib/src/todo.dart
<pre><code class="language-dart">///
class Todo {
 ///
 Todo({required this.id, required this.title, this.isCompleted = false});

 /// fromJson
 factory Todo.fromJson(Map&lt;String, dynamic&gt; json) {
 return Todo(
 id: json[&#x27;id&#x27;] as String,
 title: json[&#x27;title&#x27;] as String,
 isCompleted: json[&#x27;isCompleted&#x27;] as bool? ?? false,
 );
 }

 /// id
 final String id;

 /// title
 final String title;

 /// isCompleted
 bool isCompleted;

 /// toJson
 Map&lt;String, dynamic&gt; toJson() {
 return {
 &#x27;id&#x27;: id,
 &#x27;title&#x27;: title,
 &#x27;isCompleted&#x27;: isCompleted,
 };
 }
}
</code></pre>
In-memory store: lib/src/todo_repository.dart
<pre><code class="language-dart">import &#x27;package:my_project/src/todo_model.dart&#x27;;
import &#x27;package:uuid/uuid.dart&#x27;;

const _uuid = Uuid();
final _todos = &lt;String, Todo&gt;{};

/// get all todos
List&lt;Todo&gt; getAllTodos() =&gt; _todos.values.toList();

/// get a tod
Todo? getTodoById(String id) =&gt; _todos[id];

/// create
void createTodo(String title) {
 final id = _uuid.v4();
 _todos[id] = Todo(id: id, title: title);
}

/// update
void updateTodo(String id, {String? title, bool? isCompleted}) {
 final todo = _todos[id];
 if (todo == null) return;
 _todos[id] = Todo(
 id: id,
 title: title ?? todo.title,
 isCompleted: isCompleted ?? todo.isCompleted,
 );
}

/// delete
void deleteTodo(String id) =&gt; _todos.remove(id);
</code></pre>
Now routes!
Collection: routes/todos/index.dart
<pre><code class="language-dart">import &#x27;package:dart_frog/dart_frog.dart&#x27;;
import &#x27;package:my_project/src/todo_repository.dart&#x27;;

Future&lt;Response&gt; onRequest(RequestContext context) async {
 switch (context.request.method) {
 case HttpMethod.get:
 final todos = getAllTodos();
 return Response.json(body: todos.map((e) =&gt; e.toJson()).toList());
 case HttpMethod.post:
 final body = await context.request.json() as Map&lt;String, dynamic&gt;;
 final title = body[&#x27;title&#x27;] as String?;
 if (title == null || title.isEmpty) {
 return Response(statusCode: 400, body: &#x27;Title is required&#x27;);
 }
 createTodo(title);
 return Response(statusCode: 201, body: &#x27;Todo created&#x27;);
 case HttpMethod.delete:
 case HttpMethod.put:
 case HttpMethod.patch:
 case HttpMethod.head:
 case HttpMethod.options:
 return Response(statusCode: 405);
 }
}
</code></pre>
Dynamic item: routes/todos/[id].dart
<pre><code class="language-dart">import &#x27;package:dart_frog/dart_frog.dart&#x27;;
import &#x27;package:my_project/src/todo_repository.dart&#x27;;

Future&lt;Response&gt; onRequest(RequestContext context, String id) async {
 final todo = getTodoById(id);
 if (todo == null) return Response(statusCode: 404);

 switch (context.request.method) {
 case HttpMethod.get:
 return Response.json(body: todo.toJson());
 case HttpMethod.put:
 final body = await context.request.json() as Map&lt;String, dynamic&gt;;
 final title = body[&#x27;title&#x27;] as String?;
 final isCompleted = body[&#x27;isCompleted&#x27;] as bool?;
 updateTodo(id, title: title, isCompleted: isCompleted);
 return Response.json(body: getTodoById(id)!.toJson());
 case HttpMethod.delete:
 deleteTodo(id);
 return Response(statusCode: 204);
 case HttpMethod.post:
 case HttpMethod.patch:
 case HttpMethod.head:
 case HttpMethod.options:
 return Response(statusCode: 405);
 }
}
</code></pre>
<h2>Testing + Wrap (Show curl/Postman)</h2>
Quick tests:
<pre><code>curl http://localhost:8080/todos
curl -X POST http://localhost:8080/todos -H &quot;Content-Type: application/json&quot; -d &#x27;{&quot;title&quot;: &quot;Learn Dart Frog&quot;}&#x27;
curl http://localhost:8080/todos/&lt;generated-id&gt;
</code></pre>
Handles errors gracefully. Production-ready foundation!
Source Code 👇 — Show some ❤️ by starring ⭐ the repo and follow me 😄! <a href="https://github.com/techwithsam/dart_frog_full_course_tutorial" target="_blank" rel="noopener nofollow">https://github.com/techwithsam/dart_frog_full_course_tutorial</a>
This is your first real Dart Frog REST API — congrats! Next: Connect a Flutter app to it.
Samuel Adekunle, Tech With Sam <a href="https://youtube.com/@techwithsam" target="_blank" rel="noopener nofollow">YouTube</a>

Samuel Adekunle

This tutorial walks through building a complete CRUD REST API using Dart Frog. It covers creating a Todo model with UUID-based IDs, implementing in-memory storage with a repository pattern, setting up dynamic routes for collection and individual item endpoints, handling HTTP methods (GET, POST, PUT, DELETE), validating JSON request bodies, and returning appropriate status codes. The guide includes code examples for the data model, repository functions, and route handlers, plus curl commands for testing the API endpoints.

Dart Frog Tutorial Part 2: Building Your First Real REST API (Full CRUD with Todos) 🐸