Newsdata.io Dart / Flutter Client

Official Dart/Flutter client for the Newsdata.io News API. Pure Dart — works in Flutter (iOS, Android, Web, Desktop) and standalone Dart (CLI, server, AngularDart). Typed named-parameter methods for all eight endpoints with client-side validation, retries with exponential backoff, Stream-based pagination, and a typed exception hierarchy.

Zero Flutter dependencies; only runtime deps are package:http and package:meta.

Installation

flutter pub add newsdataapi
# or for pure Dart projects:
dart pub add newsdataapi

Quickstart

import 'package:newsdataapi/newsdataapi.dart';

Future<void> main() async {
  final client = NewsDataApiClient(apiKey: 'YOUR_API_KEY');

  try {
    final resp = await client.latest(
      q: 'bitcoin',
      country: ['us', 'gb'],
      language: ['en'],
    );
    for (final article in resp.articles) {
      print('${article.title} — ${article.link}');
    }
  } on NewsdataRateLimitException catch (e) {
    print('rate limited, retry after ${e.retryAfter} seconds');
  } on NewsdataException catch (e) {
    print('failed: $e');
  } finally {
    client.close();
  }
}

Endpoints

Method	Endpoint	Notes
client.latest(...)	/1/latest	Real-time news
client.archive(...)	/1/archive	Historical news
client.sources(...)	/1/sources	Available sources (single page)
client.crypto(...)	/1/crypto	Cryptocurrency news
client.market(...)	/1/market	Market / financial news
client.count({required fromDate, required toDate, ...})	/1/count	Aggregate counts
client.cryptoCount({required fromDate, required toDate, ...})	/1/crypto/count	Aggregate crypto counts
client.marketCount({required fromDate, required toDate, ...})	/1/market/count	Aggregate market counts

Every endpoint method has typed named parameters for every accepted field — the Dart compiler enforces that only valid parameters for that endpoint compile. The count endpoints' fromDate / toDate are required, so forgetting them is a compile error, not a runtime one.

Multi-value params accept List<String> (sent comma-joined). Booleans become 1/0. Names like qInTitle/fromDate are camelCase Dart-side — the SDK maps them to the API's lowercase form (qintitle, from_date).

Pagination

Two helpers — both work for every endpoint except sources:

// 1) scrollAll: follow nextPage and return one merged response.
final all = await client.scrollAll(
  endpoint: Endpoint.latest,
  params: {'q': 'news'},
  maxResults: 200,
);
print(all.articles.length); // up to 200 articles

// 2) paginate: idiomatic Stream<NewsdataResponse>.
await for (final page in client.paginate(
  endpoint: Endpoint.latest,
  params: {'q': 'news'},
  maxPages: 5,
)) {
  process(page.articles);
}

paginate returns a Stream, so you can use everything Dart streams give you — take, where, transform, cancellation via await for break.

Raw query

await client.latest(rawQuery: 'q=bitcoin&country=us&language=en');

rawQuery is mutually exclusive with every other parameter and is parsed and validated against the endpoint's allowed keys before the request leaves.

Client-side validation

A NewsdataValidationException is thrown — before any HTTP request — when:

• a parameter is not accepted by that endpoint;
• mutually-exclusive parameters are set together — q/qInTitle/qInMeta, country/excludeCountry, category/excludeCategory, language/excludeLanguage, domain/domainUrl/excludeDomain;
• size is outside 1–50;
• sentimentScore is set without sentiment.

Plus the count endpoints' fromDate/toDate are required at the type level — no runtime check needed.

Error handling

try {
  final resp = await client.latest(q: 'news');
} on NewsdataValidationException catch (e) {
  // bad parameter — e.param, e.message
} on NewsdataAuthException catch (e) {
  // 401 / 403
} on NewsdataRateLimitException catch (e) {
  // 429 — e.retryAfter (seconds)
} on NewsdataServerException catch (e) {
  // 5xx
} on NewsdataApiException catch (e) {
  // other API errors — e.statusCode, e.responseBody
} on NewsdataNetworkException catch (e) {
  // socket / TLS / timeout — e.cause
}

Hierarchy:

NewsdataException                       (catch-all base)
├── NewsdataValidationException         (.param, .message)
├── NewsdataApiException                (.statusCode, .responseBody)
│   ├── NewsdataAuthException           (401 / 403)
│   ├── NewsdataRateLimitException      (429; .retryAfter)
│   └── NewsdataServerException         (5xx)
└── NewsdataNetworkException            (.cause)

Configuration

final client = NewsDataApiClient(
  apiKey: apiKey,
  timeout: const Duration(seconds: 30),
  maxRetries: 5,
  retryBackoff: const Duration(seconds: 2),     // base, exponential
  retryBackoffMax: const Duration(seconds: 60), // cap on a single sleep
  paginationDelay: const Duration(seconds: 1),
  includeHeaders: true,                          // attach response headers
  httpClient: myCustomClient,                    // proxies, mTLS, etc.
  logger: (level, msg) => print('[$level] $msg'),// API key is redacted in URLs
);

httpClient is the standard http.Client — inject http_test_handler, http_logger, dio_http_client, or any package that provides one, and the SDK uses it transparently. The SDK does not close the injected client (the caller owns it); it does close a client it created itself when client.close() is called.

Retries cover network errors, HTTP 429, and 5xx responses. 429 honors the Retry-After header (integer seconds or HTTP-date); otherwise backoff is exponential. Auth and other 4xx errors are never retried.

Where it works

Platform	Supported
Flutter — iOS	✅
Flutter — Android	✅
Flutter — Web	✅ (CORS rules on the API apply)
Flutter — macOS / Windows / Linux	✅
Pure Dart — CLI / server	✅

This is a pure Dart package, not a plugin — no platform channels, no Swift or Kotlin to compile.

Development

dart pub get
dart analyze --fatal-infos
dart format --output=none --set-exit-if-changed lib test example
dart test                                       # 34 tests; no network needed

The test suite uses package:http/testing's MockClient to mock the API end-to-end. No API key required.

License

MIT