curl -H 'Authorization: Token token="replace-with-token"' http://domain.com/books

NSURL *url = [NSURL URLWithString:@"http://domain.com/books"];
    config = [NSURLSessionConfiguration defaultSessionConfiguration];
    [config setHTTPAdditionalHeaders:@{@"token":@"4959a0bc00a15e335fb6"}];
    NSURLSession *session = [NSURLSession sessionWithConfiguration:config];
    [[session dataTaskWithURL:url completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
        NSLog(@"%@", [NSJSONSerialization JSONObjectWithData:data options:0 error:nil]);
    }] resume];