solidus_active_shipping extension

The solidus_active_shipping extension wraps Shopify's popular active_shipping gem to interface with carrier APIs (including USPS, FedEx, and UPS). This extension provides Solidus-compatible shipping calculators for the delivery services offered by supported carriers. This means that you can offer your customers accurate shipping estimates for their orders before checkout.

Throughout this article, we will demonstrate usage of the solidus_active_shipping extension with USPS delivery services. The other carriers supported by this extension would follow a similar pattern.

Install solidus_active_shipping

Follow the installation instructions provided by the solidus_active_shipping extension. You can get more detailed information on installation from the extension's documentation .

Now, you will be able to use any of the pre-configured shipping calculators that have been built into the extension.

Add required configuration variables for web services

In addition to installing the extension, we need to authenticate with any developer accounts we have with carriers. Administrators can add authentication keys from the /admin/active_shipping_settings page (Settings -> Stores -> Active Shipping Settings in the admin).

You can also set the keys from any initializer in your application. For example, you could create a new file, config/initializers/active_shipping.rb, with the contents:

      Rails.application.config.after_initialize do
  Spree::ActiveShipping::Config.set(:usps_login => "your-developer-key")


However, note that after the application has been initialized, any changes made in the admin will override the initial value. Then, if the application is restarted, the value in the initializer would overwrite the value set in the admin again.

Add optional configuration variables

You may also want to add shipping settings specifically for your store. The following settings are available:

  • Weight units
  • Unit multiplier (for unit conversion)
  • Default product weight
  • Handling fee
  • Maximum weight per package

You can configure these settings from the admin/active_shipping_settings page (Settings -> Store -> Active Shipping Settings in the admin) or from any initializer in your application. For example, you could create a new file, config/initializers/active_shipping.rb, with the contents:

      Rails.application.config.after_initialize do
  Spree::ActiveShipping::Config[:default_weight] = 3.0


See the extension's documentation for more information about available configuration settings.

Add shipping methods

When you set up a new shipping method (Settings -> Shipping -> Shipping Methods in the admin), such as "USPS Media Mail", you can choose the corresponding base calculator, "USPS Media Mail Parcel", from the list of available calculators.

Now, once an order has been assigned a shipping method, a shipping estimate can be provided to the customer before checkout.

If the delivery service you wish to use is not built into the extension (for example, a delivery service called "USPS Bogus First Class International"), it can be easily added as an additional calculator. See Add additional shipping calculators for more information.

Access pre-configured calculators

The solidus_active_shipping extension comes with pre-configured shipping calculators. Administrators can access these calculators when adding new shipping methods by picking them from the "Base Calculator" drop-down menu.

You can extend or override the pre-configured calculator classes, such as Spree::Calculator::Shipping::Usps::GlobalExpressGuaranteed.

You can see all of the extension's included shipping calculators in the list of the extension's shipping models .

Add additional shipping calculators

Additional delivery services that are not pre-configured as a calculator in the extension can be easily added.

Inherit from an existing service's base class

For example, you need to a delivery service called "Bogus First Class International" from USPS, you can add a new calculator class that inherits from the Spree::Calculator::Shipping::Usps::Base class:

      module Spree
  module Calculator::Shipping
    module Usps
      class BogusFirstClassInternational < Spree::Calculator::Shipping::Usps::Base
          "USPS Bogus First Class International"


Unlike shipping calculators that you write yourself, these calculators inherit from the existing superclasses built into solidus_active_shipping and do not require a compute instance method that returns a shipping amount.

Match the delivery service's provided name

The string returned by the description method must match the name of the USPS delivery service exactly. To determine the exact spelling, you should examine what the USPS API returns.

Register the new calculator

Finally, register the calculator you added. In extensions, this is accomplished with the activate method:

      def activate



Solidus is an open source platform supported by the community. We encourage everyone using Solidus to contribute back to the documentation and the code.

If you’re interested in contributing to the docs, get started with the contributing guidelines. If you see something that needs fixing and can’t do it yourself, please send us an email.