In Flutter, you can paginate REST API results by sending page numbers and page sizes as parameters with each request and retrieve a limited number of records per request. Here’s an example of how you can implement pagination in a Flutter application.

Here’s an example of how we can implement pagination in a Flutter application using the https://jsonplaceholder.typicode.com/posts API:

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'],
    );
  }
}

First, define a method that makes the API request, passing the page number and page size as parameters:

1. First, define a method that makes the API request, passing the page number and page size as parameters:

Future<List<Post>> getPosts(int page, int pageSize) async {
  final response = await http.get(
      'https://jsonplaceholder.typicode.com/posts?_page=$page&_limit=$pageSize');

  if (response.statusCode == 200) {
    var posts = (json.decode(response.body) as List)
        .map((p) => Post.fromJson(p))
        .toList();
    return posts;
  } else {
    throw Exception('Failed to load posts');
  }
}

In your widget, initialize the variables for the current page number and page size:

3. Then, in the build method, make the API call using the getPosts method and update the UI accordingly:

@override
Widget build(BuildContext context) {
  return Scaffold(
    body: FutureBuilder<List<Post>>(
      future: getPosts(_currentPage, _pageSize),
      builder: (context, snapshot) {
        if (snapshot.hasData) {
          return ListView.builder(
            itemCount: snapshot.data.length + 1,
            itemBuilder: (context, index) {
              if (index == snapshot.data.length) {
                return Container(
                  padding: EdgeInsets.all(10.0),
                  child: RaisedButton(
                    child: Text('Load more'),
                    onPressed: () {
                      setState(() {
                        _currentPage++;
                      });
                    },
                  ),
                );
              }
              // Show the post items
              return ListTile(
                title: Text(snapshot.data[index].title),
                subtitle: Text(snapshot.data[index].body),
              );
            },
          );
        } else if (snapshot.hasError) {
          return Text("${snapshot.error}");
        }
        return CircularProgressIndicator();
      },
    ),
  );
}

This is just a simple example, you may need to make adjustments based on your API structure and requirements.