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Setting up Google Checkout

WebAsyst Shop-Script allows accepting payments via Google Checkout. Follow the steps described below to set up Google Checkout in your online store:

Create a Google Checkout account

Go to http://checkout.google.com/sell/ and click on "Sign up now" to obtain a Google Checkout merchant account.

Configure your Google Checkout account

  1. Log in to your Google Checkout seller account, go to "Settings -> Integration" and enter your secure API callback URL:



    Google will use this URL to send requests to your storefront store about new orders, order state changes and shipping/tax rate calculations.

    Important note: The URL you specify here should be accessible in SSL mode (via HTTPS)! This requirement is set by Google ("You must provide the URL of a server running 128-bit SSLv3 or TLS."). Thus, you must have a valid SSL certificate installed for the domain name where your online store is hosted. Try to open your storefront at a URL starting with https:// instead of http:// to verify that.

    Users of the WebAsyst online services shall enter the secure API callback URL as shown below:

  2. Make sure to leave the Callback Method option set to XML (default) as shown in the picture:

It is recommended to leave parameter My company will only post digitally signed carts enabled to be sure that your shopping carts are not tampered with during transmission.

Configure your WebAsyst Shop-Script store

Log in to your store backend and go to section "Settings -> Checkout Replacement". Click on "Enable" for the Google Checkout option and enter your Google merchant ID and Google merchant key (they are available in your Google Checkout seller account section "Settings -> Integration"). A correctly configured Google Checkout module in WebAsyst Shop-Script is shown in the picture below.

Note: The parameters in text fields are provided as sample values and should not be copied to your own online store configuration.


Note for UK merchants: WebAsyst Shop-Script currently supports integration with Google Checkout for US merchants only. Integration was developed and tested with US-based Google Checkout seller accounts. We did not test our integration with Google Checkout UK. If you are a UK merchant and experience problems with Google Checkout, please contact us.

Shipping & Tax

One important issue about Google Checkout that requires clarification is calculation of shipping and tax rates. The issue may arise in stores where real-time shipping quotes with UPS, USPS, DHL and tax calculations are used.

At the time customer clicks on the Google Checkout button to proceed to payment, the store does not "know" the customer's shipping address, so it cannot calculate the shipping rate and sales tax for the order. For this reason available shipping types and sales tax values are sent to Google when the Google Checkout button is clicked on.

When the customer signs in to his or her Google account, Google sends a request to the store have shipping and tax rates calculated for all addresses that customer has in the Google account. WebAsyst Shop-Script performs the calculations and sends the result back to Google. As described in Google Checkout API, Google allows only three seconds for shipping rates and taxes calculation. If the store does not respond within this time, Google will set rates for every passed shipping type and tax to zero ($0.00).

If you utilize real-time shipping quotes that require requesting information from third-party servers (e.g. UPS, USPS, DHL) three seconds may not be enough to process Google request because the store may simply not receive response from the third-party servers before they expire.

For example, requesting shipping quotes for a certain address from UPS takes about 1-1.5 seconds (in average). If you have several real-time shipping types installed; e.g., UPS and USPS, every shipping type will require time for shipping calculation, and it could be that 3 seconds will not be enough to get all shipping rates.

Besides, since a customer can have many addresses in his or her Google account, shipping rate calculation can take even more time.

WebAsyst Shop-Script allows you to disable passing information about taxes and available shipping types to Google using the "Calculate shipping costs and tax". With that option disabled, a customer will see only one shipping option "Call" rated $0.00.
Note for InterShipper users: WebAsyst Shop-Script does not provide shipping rate calculation with InterShipper when you use Google Checkout. For InterShipper shipping method customer will always see $0.00 shipping rate for all available InterShipper services.


Before you go live with Google Checkout we encourage you try a Google Checkout Sandbox account.

Note: If you have enabled the Google Checkout option, but nothing happens when your customers click on the Google Checkout button in the storefront, it means that you have entered Google account settings incorrectly. Check your storefront settings.