medusa-plugin-resend

Resend email plugin to send transactional emails for Medusa using local Handlebars templates or local React templates

Documentation

If you are not familiar with Medusa, you can learn more on the project web site.

Medusa is a set of commerce modules and tools that allow you to build rich, reliable, and performant commerce applications without reinventing core commerce logic. The modules can be customized and used to build advanced ecommerce stores, marketplaces, or any product that needs foundational commerce primitives. All modules are open-source and freely available on npm.

Features

• Templates are stored locally.
• Templates can either be handlebars templates or compiled React templates
• You can refer to the Medusa template reference to see all data fields that are available for each event: Template Reference
• An API endpoint that is useful for testing and that can be used with other (non-Medusa) portions of your storefront application is included. By default, the endpoint does nothing for security reasons. See configuration options below to enable it.

Installation

Inside your medusa backend root folder, type:

yarn add medusa-plugin-resend

Replace "yarn add" with the correct command for your package manager if you are using (for example) npm, pnpm, or bun.

Configuration

Enable in your medusa-config.js file similar to other plugins:

{
resolve: `medusa-plugin-resend`,
   options: {
      api_key: process.env.RESEND_API_ID,
      from: process.env.SES_FROM,
      enable_endpoint: process.env.SES_ENABLE_ENDPOINT,
      template_path: process.env.SES_TEMPLATE_PATH,
      subject_template_type: process.env.RESEND_SUBJECT_TEMPLATE_TYPE,
      body_template_type: process.env.RESEND_BODY_TEMPLATE_TYPE,
      order_placed_template: 'order_placed',
      order_shipped_template: 'order_shipped',
      customer_password_reset_template: 'customer_password_reset',
      gift_card_created_template: 'gift_card_created',
      //order_canceled_template: 'order_canceled',
      //order_refund_created_template: 'order_refund_created',
      //order_return_requested_template: 'order_return_requested',
      //order_items_returned_template: 'order_items_returned',
      //swap_created_template: 'swap_created',
      //swap_shipment_created_template: 'swap_shipment_created',
      //swap_received_template: 'swap_received',
      //claim_shipment_created_template: 'claim_shipment_created',
      //user_password_reset_template: 'user_password_reset',
      //medusa_restock_template: 'medusa_restock',
   }
},

• Obtain an API key from your Resend dashboard

• The 'from' setting should be a valid email address on a domain you have properly configured with Resend

• The template path is the location of your email templates. It can be a full (absolute) path or a path relative to the medusa root folder, e.g., 'data/templates'.

• The 'subject_template_type' can be 'handlebars' or 'text'. The default is handlebars. If you choose text, you cannot include dynamic values (like customer name or order number) in your subject lines.

• The body_template_type' can be 'handlebars' or 'react'. The default is handlebars. See below for info on using React templates.

Why Resend?

Fortunately, there are now many options for notification providers that can be used with Medusa, including Sendgrid, AWS Simple Email Service (SES), Postmark, and Resend.

A major pro of Resend in some use cases is the ability to use React email templates. If your frontend is a Nextjs app, using React templates that can be added to version control is likely ideal for your use case. It allows your frontend developers to stay in one syntax and reuse assets and design elements.

• Easy and quick to set up with no initial sandbox mode that restricts recipients
• Uses local email templates that can be added to version control repos
• Uses Handlebars OR React templates

Templates

The templates used are stored locally. Create a 'data/templates' folder and include the entire path in the RESEND_TEMPLATE_PATH variable.

medusa-server  // root directory
|-data
   |-templates
      |-order_placed  // or whatever you name your templates and specify in the config file
         |-subject.hbs
         |-subject.text
         |-html.hbs
         |-html.jsx  // uncompiled React template
         |-html.js   // compiled React template
         |-text.hbs
      |- etc   

Not all of the above files are required. You only need either subject.hbs or subject.text, depending on whether you have opted to use text or handlebars subject type. If you have opted to use React body templates, you do not need html.hbs or text.hbs. If you have opted to use Handlebars body templates you do not need the React templates. You can use either html.hbs or text.hbs, or both. If you include both, both templates will be compiled and sent, and it will be up to the user's email client which gets rendered.

Transpiling React Templates

Inside your template folder (NOT your main medusa server folder), install babel:

npm i -D @babel/core @babel/cli @babel/preset-env @babel/preset-react

Example of compiling a template:

npx babel 'order_placed/html.jsx' --presets=@babel/preset-env,@babel/preset-react -o 'order_placed/html.js'

More options and convenient tooling for compiling Medusa email templates are in the works, including Tailwind CSS processing.

Testing

This plugin adds an endpoint at http://[server]/resend/send

By default, the endpoint will refuse to send any emails. This endpoint may be useful for testing purposes in a development environment or for use by related applications.

There is NO SECURITY on the endpoint by default. Most people will NOT need to enable this endpoint. If you are certain that you want to enable it and that you know what you are doing, set the environment variable RESEND_ENABLE_ENDPOINT to "42" (string). The unsual setting is meant to prevent enabling by accident or without thought. To use the endpoint, POST a json req.body with: template_id, from, to, and data to /ses/send.

Acknowledgement

This plugin borrows extensively from medusa-plugin-sendgrid by Oliver Juhl.