philiprehberger_api_client

Declarative API client with typed responses, retries, and interceptors

Requirements

• Dart >= 3.6

Installation

Add to your pubspec.yaml:

dependencies:
  philiprehberger_api_client: ^0.1.0

Then run:

dart pub get

Usage

import 'package:philiprehberger_api_client/api_client.dart';

final client = ApiClient(baseUrl: 'https://api.example.com');
final response = await client.get('/users');
print(response.jsonList);
client.close();

GET Requests

// Simple GET
final response = await client.get('/users');

// GET with query parameters
final filtered = await client.get('/users', query: {'role': 'admin'});

// Access typed response data
final users = response.jsonList;
final user = response.jsonMap;

POST, PUT, PATCH Requests

// POST with JSON body (automatically serialized)
final created = await client.post('/users', body: {
  'name': 'Alice',
  'email': 'alice@example.com',
});

// PUT request
await client.put('/users/1', body: {'name': 'Updated'});

// PATCH request
await client.patch('/users/1', body: {'email': 'new@example.com'});

// DELETE request
await client.delete('/users/1');

Interceptors

// Add headers to every request
client.addInterceptor(HeaderInterceptor({
  'Authorization': 'Bearer token',
  'Accept': 'application/json',
}));

// Log requests and responses
client.addInterceptor(LogInterceptor(print));

// Custom interceptor
class AuthRefreshInterceptor extends Interceptor {
  @override
  ApiRequest onRequest(ApiRequest request) {
    return request.withHeaders({'Authorization': 'Bearer $token'});
  }

  @override
  void onError(Object error) {
    if (error is HttpError && error.statusCode == 401) {
      // Handle token refresh
    }
    throw error;
  }
}

Retry Configuration

final client = ApiClient(
  baseUrl: 'https://api.example.com',
  retryConfig: const RetryConfig(
    maxAttempts: 3,
    initialDelay: Duration(milliseconds: 500),
    backoffMultiplier: 2.0,
    retryableStatuses: {408, 429, 500, 502, 503, 504},
  ),
);

Error Handling

try {
  final response = await client.get('/users');
} on HttpError catch (e) {
  print('HTTP ${e.statusCode}');
} on TimeoutError catch (e) {
  print('Request timed out: ${e.message}');
} on RetryExhaustedError catch (e) {
  print('Failed after ${e.attempts} attempts');
} on ApiError catch (e) {
  print('API error: ${e.message}');
}

Response Inspection

final response = await client.get('/users/1');

// Status helpers
response.isSuccess;     // true for 2xx
response.isClientError; // true for 4xx
response.isServerError; // true for 5xx

// Typed JSON access
response.json;     // dynamic
response.jsonMap;  // Map<String, dynamic>
response.jsonList; // List<dynamic>

// Metadata
response.statusCode; // 200
response.headers;    // Map<String, String>
response.duration;   // Duration

API

ApiClient

Method / Property	Description
ApiClient({required String baseUrl, Duration timeout, RetryConfig? retryConfig, http.Client? httpClient})	Create an API client
get(String path, {Map<String, String>? query, Map<String, String>? headers})	Send a GET request
post(String path, {Object? body, Map<String, String>? headers})	Send a POST request
put(String path, {Object? body, Map<String, String>? headers})	Send a PUT request
patch(String path, {Object? body, Map<String, String>? headers})	Send a PATCH request
delete(String path, {Map<String, String>? headers})	Send a DELETE request
addInterceptor(Interceptor interceptor)	Add a request/response interceptor
removeInterceptor(Interceptor interceptor)	Remove an interceptor
close()	Close the underlying HTTP client

ApiRequest

Method / Property	Description
ApiRequest({required String method, required Uri uri, Map<String, String> headers, String? body})	Create an API request
method	The HTTP method
uri	The fully resolved URI
headers	The request headers
body	The request body
withHeaders(Map<String, String> extra)	Create a copy with merged headers

ApiResponse

Method / Property	Description
statusCode	The HTTP status code
headers	The response headers
body	The response body as a string
duration	The time taken to complete the request
isSuccess	Whether the status code is 2xx
isClientError	Whether the status code is 4xx
isServerError	Whether the status code is 5xx
json	Decode the body as JSON (dynamic)
jsonMap	Decode the body as a JSON map
jsonList	Decode the body as a JSON list

Error Types

Class	Description
ApiError	Base error for API operations
HttpError	Thrown for non-2xx status codes; exposes statusCode
TimeoutError	Thrown when a request exceeds the timeout
RetryExhaustedError	Thrown when all retry attempts fail; exposes attempts and lastError

Interceptor

Method	Description
onRequest(ApiRequest request)	Called before a request is sent; return a modified or same request
onResponse(ApiResponse response)	Called after a response is received; return a modified or same response
onError(Object error)	Called on error; can throw or handle

Built-in Interceptors

Class	Description
HeaderInterceptor(Map<String, String> headers)	Adds headers to every request
LogInterceptor(void Function(String) log)	Logs requests and responses to a callback

RetryConfig

Method / Property	Description
RetryConfig({int maxAttempts, Duration initialDelay, double backoffMultiplier, Set<int> retryableStatuses})	Create retry configuration
maxAttempts	Maximum number of retry attempts (default: 3)
initialDelay	Initial delay before the first retry (default: 500ms)
backoffMultiplier	Multiplier for each subsequent retry (default: 2.0)
retryableStatuses	Status codes that trigger a retry (default: 408, 429, 500, 502, 503, 504)
delayForAttempt(int attempt)	Calculate delay for a given attempt number
shouldRetry(int statusCode)	Whether a status code should trigger a retry

Development

dart pub get
dart analyze --fatal-infos
dart test

Support

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License

MIT