Making authenticated requests

In order to fetch data from many web services, you need to provide authorization. There are many ways to do this, but perhaps the most common uses the Authorization HTTP header.

Add Authorization Headers

The http package provides a convenient way to add headers to your requests. You can also take advantage of the dart:io package for common HttpHeaders.

Future<http.Response> fetchPost() {
  return http.get(
    'https://jsonplaceholder.typicode.com/posts/1',
    // Send authorization headers to the backend
    headers: {HttpHeaders.authorizationHeader: "Basic your_api_token_here"},
  );
}

Complete example

This example builds upon the Fetching Data from the Internet recipe.

import 'dart:async';
import 'dart:convert';
import 'dart:io';

import 'package:http/http.dart' as http;

Future<Post> fetchPost() async {
  final response = await http.get(
    'https://jsonplaceholder.typicode.com/posts/1',
    headers: {HttpHeaders.authorizationHeader: "Basic your_api_token_here"},
  );
  final responseJson = json.decode(response.body);

  return Post.fromJson(responseJson);
}

class Post {
  final int userId;
  final int id;
  final String title;
  final String body;

  Post({this.userId, this.id, this.title, this.body});

  factory Post.fromJson(Map<String, dynamic> json) {
    return Post(
      userId: json['userId'],
      id: json['id'],
      title: json['title'],
      body: json['body'],
    );
  }
}