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WARNING: After upgrading to version 3.3.2, if you use Google Checkout, or PayPal Pro, for processing your payments, or manually process your credit card payments, you will need to install these modules separately. Click to Add a new plugin, in the search dropdown select Tag and enter either "google-checkout", "paypal-pro" or "manualcc" in the text box.

YAK is an open source shopping cart plugin for WordPress. It associates products with weblog entries (in other words, posts), so the post ID also becomes the product code. It supports both pages and posts as products, handles different types of product through categorisation, and provides customisable purchase options -- cheque or deposit, basic credit card form (for manual credit card processing), basic Google Checkout integration, standard PayPal integration, PayPal Payments Pro, Authorize.net, Stripe and MiGS (Mastercard Internet Gateway Service, add-on only).

Detailed installation and configuration instructions can be found by purchasing the YAK Handbook, but basic installation instructions can be found here. If you want to do something more advanced, post a message in the forums, or consider buying the Handbook.

YAK includes the following features:

• Create products from either posts or pages
• Downloadable products
• Multiple product types -- price per type (i.e. small, medium, large) and quantity per type
• Order administration -- filtering by date, status and order number
• Customer order tracker
• Products page with paging (simple alternative to viewing by category)
• Configurable shipping (either flat rate or by weight unit)
• Configurable shipping address
• Configurable countries list
• Promotions -- percentage or fixed discounts, on shipping or order value
• Sales Reports (basic flash charts showing sales, best sellers, etc)
• Sales Tax (does not work with Google Checkout)
• Support for https (SSL)
• Tags for configurable emails
• Basic XML feed
• Support for multiple shops (function to retrieve product details from another shop)
• Checkout/order widget
• Customer interface has been translated into a number of languages: Japanese, Chinese, Taiwan Chinese, Thai, Slovakian, Czech, German, French, Italian, Spanish, Norwegian, Swedish, Indonesian
• Basic Sales Tax support

The following Payment Options are supported:

• Plain page -- custom payment such as providing information for your customers to pay by cheque, or direct deposit/debit
• Manual credit card -- requiring SSL, and a secure hosting environment
• PayPal Standard -- customers are redirected to PayPal for payments
• Google Checkout -- customers are redirected to Google for payments (note: Checkout is not fully integrated)
• Authorize.net -- Authorize's payments gateway is used to charge credit cards
• PayPal Payments Pro -- PayPal's payments gateway is used to charge credit cards
• Accounts Receivable
• Mastercard Internet Gateway Service -- via an add-on
• Stripe

The following free add-ons are available:

• Authorize.net - a plugin providing Authorize.net credit card payments
• Google Checkout - a plugin providing Google Checkout payments processing
• ManualCC - a plugin providing manual credit cards payments processing
• PayPal Payments Pro - a plugin providing PayPal Pro credit card payments processing
• Stripe - a plugin providing Stripe credit card payments

The following (non-free) add-ons are available:

• YAK Gallery - a gallery plugin for your products
• YAK AddInfo - configure additional fields on the final order confirmation
• YAK MiGS - a payment module supporting the Mastercard Internet Gateway Service (payment gateway)
• YAK Membership - a members module for YAK. Sell membership through YAK, and then restrict access to parts of your site.

Further discussion and support can be found in the forums (please post bugs or problems you find there). To keep up-to-date with releases, subscribe to the feed for the forums, or check the changelog.