InstapaperKit lets you access the full Instapaper API. It is written in Objective-C and works on both platforms, Mac OS X and iOS. InstapaperKit is licensed under the MIT license.

InstapaperKit uses a git submodule. To get the source code and the submodule, do the following:

git clone git://github.com/matthiasplappert/InstapaperKit.git /some/path/InstapaperKit
cd /some/path/InstapaperKit/
git submodule update --init --recursive

The easiest way to use InstapaperKit is top add all classes from the Xcode InstapaperKit group to your own project. The included Xcode project also includes a framework build target, which you can use on Mac OS X. You should now be able to #import "InstapaperKit.h" (if you use the framework you have to #import <InstapaperKit/InstapaperKit.h>).

Instapaper requires a Subscription account for most methods. Exceptions are requesting an auth token, verifying credentials, adding a bookmark, and listing folders. Fore more information, please read the Instapaper API documentation.

The Instapaper API uses xAuth. InstapaperKit takes care of signing your requests and all that nasty stuff. However, you have to configure InstapaperKit properly before you can use it.

Start by setting your OAuth consumer key and secret. If you don’t have those yet, you have to request them.

[IKEngine setOAuthConsumerKey:@"your application's consumer key"
            andConsumerSecret:@"your application's consumer secret"];

The values you provided are used globally, so every IKEngine instance uses them. It is therefore highly recommended that you do this configuration as soon as your application did finish launching. Make sure that you keep your OAuth consumer secret, well, secret!

xAuth (just like OAuth) doesn’t authenticate users by their username and password but a token and secret. You therefore should never store a user’s password but only the token and secret. You typically request a token as soon as the user enters his username and password.

// Assuming that your class has an instance variable _engine
_engine = [[IKEngine alloc] initWithDelegate:self];
[_engine authTokenForUsername:@"user@domain.com" password:@"shh, secret!" userInfo:nil];

Once the request is complete, your delegate’s engine:connection:didReceiveAuthToken:andTokenSecret: method will get called:

- (void)engine:(IKEngine *)engine connection:(IKURLConnection *)connection didReceiveAuthToken:(NSString *)token andTokenSecret:(NSString *)secret
{
    // Assign token and secret
    engine.OAuthToken  = token;
    engine.OAuthTokenSecret = secret;

    // Save token and secret in keychain (do not use NSUserDefaults for the secret!)
}

Make sure to store your token and secret, you don’t want to request the token and secret every time the application starts. Also make sure to store the secret in a safe place like the keychain.

Once you have properly configured InstapaperKit, you can start using the API. As InstapaperKit uses asynchronous connections, it makes heavy use of IKEngineDelegate.

IKEngineDelegate defines 4 general methods: engine:willStartConnection:, engine:didFinishConnection:, engine:didFailConnection:error:, and engine:didCancelConnection:. Those methods get called every time a connection starts, finishes, fails or is cancelled. You can use IKURLConnections type property to figure out which type of connection you’re dealing with.

IKEngineDelegate also defines a couple of delegate method which gets called on a successful request. Those methods pass the parsed return value of the respective request. Please note that the engine:didFinishConnection: method will always get called, no matter if you implement a specific success method or not.

The InstapaperKit Xcode project includes the Test target that builds a simple Mac OS X app which implements all delegate methods and logs the results. Go ahead, give the framework a try!

• InstapaperKit uses the names, error codes and defaults introduced by the Instapaper API
• JSONKit by John Engelhart is used to parse JSON
• NSData+Base64 by Matt Gallagher is used for base64 encoding