Free Objective-C Exchange Rate API

Welcome to the UnirateAPI Objective-C documentation! Our free exchange rate API provides real-time currency conversion capabilities that you can easily integrate into your iOS and macOS applications. Whether you're building a financial app, travel utility, or any application that needs currency conversion, our API has you covered.

UnirateAPI is designed to be developer-friendly and reliable, with a focus on simplicity and performance. This guide will show you how to integrate currency conversion functionality into your Objective-C applications.

With UnirateAPI, you get:

Real-time exchange rates from reliable sources
Simple RESTful API endpoints
Support for 590+ currencies
Completely free with no credit card required
99.9% uptime guarantee
Fast response times (avg. 50ms)
Automatic currency updates every hour

Using our API with Objective-C is:

Perfect for iOS and macOS native applications
Easy to implement with NSURLSession
Compatible with modern JSON parsing
Great for creating financial and travel apps
Supports both synchronous and asynchronous calls

For more detailed information about our API endpoints, rate limits, and advanced features, please check our main API documentation.

Below you'll find examples showing how to use our API with Objective-C.

Getting Started with objc

You can use our API in Objective-C by making HTTP requests using NSURLSession. The following examples demonstrate how to implement currency conversion in your iOS or macOS applications.


// UnirateAPIClient.h
#import 

@interface UnirateAPIClient : NSObject

@property (nonatomic, strong, readonly) NSString *apiKey;

- (instancetype)initWithAPIKey:(NSString *)apiKey;

// Convert currency
- (void)convertAmount:(double)amount
          fromCurrency:(NSString *)fromCurrency
            toCurrency:(NSString *)toCurrency
           completion:(void (^)(NSDictionary *result, NSError *error))completion;

// Get exchange rate
- (void)getExchangeRateFromCurrency:(NSString *)fromCurrency
                        toCurrency:(NSString *)toCurrency
                        completion:(void (^)(double rate, NSError *error))completion;

// Get supported currencies
- (void)getSupportedCurrenciesWithCompletion:(void (^)(NSDictionary *currencies, NSError *error))completion;

@end


// UnirateAPIClient.m
#import "UnirateAPIClient.h"

@interface UnirateAPIClient ()
@property (nonatomic, strong, readwrite) NSString *apiKey;
@property (nonatomic, strong) NSURLSession *session;
@property (nonatomic, strong) NSString *baseURL;
@end

@implementation UnirateAPIClient

- (instancetype)initWithAPIKey:(NSString *)apiKey {
    self = [super init];
    if (self) {
        _apiKey = apiKey;
        _baseURL = @"https://api.unirateapi.com/api";
        
        NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration];
        _session = [NSURLSession sessionWithConfiguration:config];
    }
    return self;
}

- (void)convertAmount:(double)amount
        fromCurrency:(NSString *)fromCurrency
          toCurrency:(NSString *)toCurrency
          completion:(void (^)(NSDictionary *result, NSError *error))completion {
    
    NSString *endpoint = @"/convert";
    NSDictionary *params = @{
        @"api_key": self.apiKey,
        @"from": fromCurrency,
        @"to": toCurrency,
        @"amount": [NSString stringWithFormat:@"%f", amount]
    };
    
    [self performRequestWithEndpoint:endpoint parameters:params completion:^(id responseObject, NSError *error) {
        if (error) {
            completion(nil, error);
            return;
        }
        completion(responseObject, nil);
    }];
}

- (void)getExchangeRateFromCurrency:(NSString *)fromCurrency
                        toCurrency:(NSString *)toCurrency
                        completion:(void (^)(double rate, NSError *error))completion {
    
    NSString *endpoint = @"/rates";
    NSDictionary *params = @{
        @"api_key": self.apiKey,
        @"base": fromCurrency,
        @"symbols": toCurrency
    };
    
    [self performRequestWithEndpoint:endpoint parameters:params completion:^(id responseObject, NSError *error) {
        if (error) {
            completion(0, error);
            return;
        }
        
        NSDictionary *rates = responseObject[@"rates"];
        double rate = [rates[toCurrency] doubleValue];
        completion(rate, nil);
    }];
}

- (void)getSupportedCurrenciesWithCompletion:(void (^)(NSDictionary *currencies, NSError *error))completion {
    NSString *endpoint = @"/currencies";
    NSDictionary *params = @{
        @"api_key": self.apiKey
    };
    
    [self performRequestWithEndpoint:endpoint parameters:params completion:^(id responseObject, NSError *error) {
        if (error) {
            completion(nil, error);
            return;
        }
        
        completion(responseObject, nil);
    }];
}

- (void)performRequestWithEndpoint:(NSString *)endpoint
                       parameters:(NSDictionary *)parameters
                       completion:(void (^)(id responseObject, NSError *error))completion {
    
    NSURLComponents *components = [NSURLComponents componentsWithString:[self.baseURL stringByAppendingString:endpoint]];
    NSMutableArray *queryItems = [NSMutableArray array];
    
    [parameters enumerateKeysAndObjectsUsingBlock:^(NSString *key, NSString *value, BOOL *stop) {
        [queryItems addObject:[NSURLQueryItem queryItemWithName:key value:value]];
    }];
    
    components.queryItems = queryItems;
    
    NSURLRequest *request = [NSURLRequest requestWithURL:components.URL];
    
    NSURLSessionDataTask *task = [self.session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
        if (error) {
            dispatch_async(dispatch_get_main_queue(), ^{
                completion(nil, error);
            });
            return;
        }
        
        NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)response;
        if (httpResponse.statusCode != 200) {
            NSError *statusError = [NSError errorWithDomain:@"UnirateAPIErrorDomain" 
                                                     code:httpResponse.statusCode 
                                                 userInfo:@{NSLocalizedDescriptionKey: @"API request failed"}];
            dispatch_async(dispatch_get_main_queue(), ^{
                completion(nil, statusError);
            });
            return;
        }
        
        NSError *jsonError;
        id jsonObject = [NSJSONSerialization JSONObjectWithData:data options:0 error:&jsonError];
        
        if (jsonError) {
            dispatch_async(dispatch_get_main_queue(), ^{
                completion(nil, jsonError);
            });
            return;
        }
        
        dispatch_async(dispatch_get_main_queue(), ^{
            completion(jsonObject, nil);
        });
    }];
    
    [task resume];
}

@end


// Example usage in a view controller
#import "ViewController.h"
#import "UnirateAPIClient.h"

@interface ViewController ()
@property (nonatomic, strong) UnirateAPIClient *apiClient;
@property (nonatomic, strong) IBOutlet UITextField *amountTextField;
@property (nonatomic, strong) IBOutlet UILabel *resultLabel;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    // Initialize the API client with your API key
    self.apiClient = [[UnirateAPIClient alloc] initWithAPIKey:@"YOUR_API_KEY"];
}

- (IBAction)convertButtonTapped:(id)sender {
    double amount = [self.amountTextField.text doubleValue];
    
    [self.apiClient convertAmount:amount 
                   fromCurrency:@"USD" 
                     toCurrency:@"EUR" 
                     completion:^(NSDictionary *result, NSError *error) {
        
        if (error) {
            NSLog(@"Error: %@", error.localizedDescription);
            self.resultLabel.text = @"Conversion failed";
            return;
        }
        
        NSString *formattedResult = [NSString stringWithFormat:@"%.2f %@ = %.2f %@",
                                    amount,
                                    result[@"from"],
                                    [result[@"result"] doubleValue],
                                    result[@"to"]];
        
        self.resultLabel.text = formattedResult;
    }];
}

@end

Response Example


// API Response:
{
  "from": "USD",
  "to": "EUR",
  "amount": 100,
  "result": 92.45
}

// Console Output:
100.00 USD = 92.45 EUR

Important Notes

Replace 'YOUR_API_KEY' with your actual API key
Use NSURLSession for making HTTP requests in modern applications
For better security, store your API key in the Keychain or as an environment variable
Consider using a caching mechanism to reduce API calls in production
Implement proper error handling for network failures
For iOS apps, add the 'NSAppTransportSecurity' exception if needed
Consider supporting offline mode by saving the last known conversion rates

Ready to Get Started?

Get Your API Key