Joris Obert

Posted on Jan 8

How to Add Comments to a Flutter App Without a Backend

#flutter #dart #mobile #saas

Adding a comments section to a mobile app sounds simple at first.

In practice, it usually means dealing with backend infrastructure:

authentication, database schemas, security rules, pagination, moderation, spam protection…

For many Flutter apps, this quickly becomes overkill.

In this article, I’ll show a backend-less approach to adding comments to a Flutter app, using a production-ready comments SDK with a built-in UI.

No Firebase project.

No Supabase setup.

No custom backend code.

The usual approaches (and their cost)

When Flutter developers need comments, they usually go down one of these paths:

Firebase / Firestore

Design collections and indexes
Write Firestore security rules
Handle pagination manually
Implement moderation logic
Manage abuse and rate limiting

Supabase / custom backend

Design a Postgres schema
Configure Row-Level Security (RLS)
Maintain API endpoints
Handle auth, caching, and scaling

These solutions are powerful — but expensive in time and maintenance, especially if comments are not the core feature of your product.

A backend-less alternative

Instead of building and maintaining a backend, you can use a managed comments service with a Flutter SDK that handles:

authentication
data storage
moderation
pagination
abuse protection
UI rendering

From the Flutter app’s perspective, you only:

initialize the SDK
provide a thread identifier
pass the current user

Everything else runs in managed infrastructure.

Example: adding comments to a Flutter app

Below is a minimal example using GVL Comments, a Flutter comments UI SDK backed by a managed comments cloud.

1. Install the package
flutter pub add gvl_comments

2. Initialize the SDK
An install key is created once from the dashboard (no backend setup required).

import 'package:flutter/material.dart';
import 'package:gvl_comments/gvl_comments.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  const installKey = String.fromEnvironment('GVL_INSTALL_KEY');
  assert(installKey.isNotEmpty);

  await CommentsKit.initialize(installKey: installKey);

  runApp(const MyApp());
}

3. Render the comments UI

Scaffold(
  body: GvlCommentsList(
    threadKey: 'post:5YqL4w8bQm9ZkF3R7sN2D',
    user: UserProfile(
      id: 'user_1',
      name: 'John Doe',
      avatarUrl: 'https://example.com/avatar.png',
    ),
  ),
);

That’s it.

You now have:

a comment list
a composer
reactions
moderation states
pagination

All without writing backend code.

How threads work

Each comment thread is identified by a deterministic threadKey.

Examples:

post:<id>
article:<id>
video:<uuid>

Security and moderation (handled for you)
A backend-less approach does not mean less security.

The platform enforces:

tenant-isolated data (strict RLS)
scoped authentication tokens
multi-level rate limiting
moderation states (pending, approved, rejected, reported)

From the Flutter app, these states are surfaced directly in the UI.

Why not Firebase or Supabase?

Firebase and Supabase are excellent tools.

But if your goal is simply to:

add comments
keep your app simple
avoid backend maintenance

Then trading low-level flexibility for speed and safety is often the right decision.

Live demo

I recorded a short demo showing the full integration from a fresh Flutter project to comments running on screen:

🎥 Flutter comments without backend (5-minute demo)
👉 Live Demo

Conclusion

Adding comments to a Flutter app does not necessarily require building a backend.

If comments are not your core business, a managed solution can save weeks of development time and long-term maintenance.

Sometimes, a few lines of Flutter code are enough.

Resources

Project site
Flutter package

I’m Joris, founder of GoodVibesLab. I build apps & developer tools for Flutter teams.
Originally published on Medium.

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