Skill v1.0.0
Automated scan100/100version: "1.0.0" name: flutter-networking description: Comprehensive Flutter networking guidance including HTTP CRUD operations, WebSocket connections, authentication, error handling, and performance optimization. Use when Claude needs to implement HTTP requests GET POST PUT DELETE, WebSocket real-time communication, authenticated requests with headers and tokens, background parsing with isolates, REST API integration with proper error handling, or any network-related functionality in Flutter applications. metadata: author: Stanislav [MADTeacher] Chernyshev version: "1.0"
Flutter Networking
Quick Start
Add HTTP dependency to pubspec.yaml:
dependencies:http: ^1.6.0
Basic GET request:
import 'package:http/http.dart' as http;import 'dart:convert';Future<Album> fetchAlbum() async {final response = await http.get(Uri.parse('https://api.example.com/albums/1'),);if (response.statusCode == 200) {return Album.fromJson(jsonDecode(response.body));} else {throw Exception('Failed to load album');}}
Use in UI with FutureBuilder:
FutureBuilder<Album>(future: futureAlbum,builder: (context, snapshot) {if (snapshot.hasData) {return Text(snapshot.data!.title);} else if (snapshot.hasError) {return Text('${snapshot.error}');}return const CircularProgressIndicator();},)
HTTP Methods
GET - Fetch Data
Use for retrieving data. See http-basics.md for complete examples.
POST - Create Data
Use for creating new resources. Requires Content-Type: application/json header.
final response = await http.post(Uri.parse('https://api.example.com/albums'),headers: <String, String>{'Content-Type': 'application/json; charset=UTF-8',},body: jsonEncode(<String, String>{'title': title}),);
See http-basics.md for POST examples.
PUT - Update Data
Use for updating existing resources.
final response = await http.put(Uri.parse('https://api.example.com/albums/1'),headers: <String, String>{'Content-Type': 'application/json; charset=UTF-8',},body: jsonEncode(<String, String>{'title': title}),);
DELETE - Remove Data
Use for deleting resources.
final response = await http.delete(Uri.parse('https://api.example.com/albums/1'),headers: <String, String>{'Content-Type': 'application/json; charset=UTF-8',},);
WebSocket
Add WebSocket dependency:
dependencies:web_socket_channel: ^3.0.3
Basic WebSocket connection:
import 'package:web_socket_channel/web_socket_channel.dart';final _channel = WebSocketChannel.connect(Uri.parse('wss://echo.websocket.events'),);// Listen for messagesStreamBuilder(stream: _channel.stream,builder: (context, snapshot) {return Text(snapshot.hasData ? '${snapshot.data}' : '');},)// Send message_channel.sink.add('Hello');// Close connection_channel.sink.close();
See websockets.md for complete WebSocket implementation.
Authentication
Add authorization headers to requests:
import 'dart:io';final response = await http.get(Uri.parse('https://api.example.com/data'),headers: {HttpHeaders.authorizationHeader: 'Bearer $token'},);
Common authentication patterns:
- Bearer Token:
Authorization: Bearer <token> - Basic Auth:
Authorization: Basic <base64_credentials> - API Key:
X-API-Key: <key>
See authentication.md for detailed authentication strategies.
Error Handling
Handle HTTP errors appropriately:
if (response.statusCode >= 200 && response.statusCode < 300) {return Data.fromJson(jsonDecode(response.body));} else if (response.statusCode == 401) {throw UnauthorizedException();} else if (response.statusCode == 404) {throw NotFoundException();} else {throw ServerException();}
See error-handling.md for comprehensive error handling strategies.
Performance
Background Parsing with Isolates
For large JSON responses, use compute() to parse in background isolate:
import 'package:flutter/foundation.dart';Future<List<Photo>> fetchPhotos(http.Client client) async {final response = await client.get(Uri.parse('https://api.example.com/photos'),);return compute(parsePhotos, response.body);}List<Photo> parsePhotos(String responseBody) {final parsed = (jsonDecode(responseBody) as List).cast<Map<String, dynamic>>();return parsed.map<Photo>((json) => Photo.fromJson(json)).toList();}
See performance.md for optimization techniques.
Integration with Architecture
When using MVVM architecture (see flutter-architecture):
- Service Layer: Create HTTP service for API endpoints
- Repository Layer: Aggregate data from services, handle caching
- ViewModel Layer: Transform repository data for UI
Example service:
class AlbumService {final http.Client _client;AlbumService(this._client);Future<Album> fetchAlbum(int id) async {final response = await _client.get(Uri.parse('https://api.example.com/albums/$id'),);if (response.statusCode == 200) {return Album.fromJson(jsonDecode(response.body));} else {throw Exception('Failed to load album');}}}
Common Patterns
Repository Pattern
Single source of truth for data type:
class AlbumRepository {final AlbumService _service;final LocalStorage _cache;Future<Album> getAlbum(int id) async {try {return await _cache.getAlbum(id) ??await _service.fetchAlbum(id);} catch (e) {throw AlbumFetchException();}}}
Retry Logic
Implement exponential backoff for failed requests:
Future<T> fetchWithRetry<T>(Future<T> Function() fetch, {int maxRetries = 3,}) async {for (int i = 0; i < maxRetries; i++) {try {return await fetch();} catch (e) {if (i == maxRetries - 1) rethrow;await Future.delayed(Duration(seconds: 2 << i));}}throw StateError('Unreachable');}
Best Practices
DO
- Use type-safe model classes with
fromJsonfactories - Handle all HTTP status codes appropriately
- Parse JSON in background isolates for large responses
- Implement retry logic for transient failures
- Cache responses when appropriate
- Use proper timeouts
- Secure tokens and credentials
DON'T
- Parse JSON on main thread for large responses
- Ignore error states in UI
- Store tokens in source code or public repositories
- Make requests without timeout configuration
- Block UI thread with network operations
- Throw generic exceptions without context
Resources
references/
- http-basics.md - Complete HTTP CRUD operations examples
- websockets.md - WebSocket implementation patterns
- authentication.md - Authentication strategies and token management
- error-handling.md - Comprehensive error handling patterns
- performance.md - Optimization techniques and best practices
assets/examples/
fetch_example.dart- Complete GET request with FutureBuilderpost_example.dart- POST request implementationwebsocket_example.dart- WebSocket client with stream handlingauth_example.dart- Authenticated request examplebackground_parsing.dart- compute() for JSON parsing
assets/code-templates/
http_service.dart- Reusable HTTP service templaterepository_template.dart- Repository pattern template