strapi/docs/3.x.x/en/guides/services.md

Services

See the services concept for details.

How to create a service?

There is two ways to create a service.

• Using the CLI strapi generate:service user. Read the CLI documentation for more information.
• Manually create a JavaScript file named User.js in ./api/**/services/.

Example

The goal of a service is to store reusable functions. An email service could be useful, if we plan to send emails from different functions in our codebase:

Path — ./api/email/services/Email.js.

const nodemailer = require('nodemailer');

// Create reusable transporter object using SMTP transport.
const transporter = nodemailer.createTransport({
  service: 'Gmail',
  auth: {
    user: 'user@gmail.com',
    pass: 'password'
  }
});

module.exports = {
  send: (from, to, subject, text) => {  
    // Setup e-mail data.
    const options = {
      from,
      to,
      subject,
      text
    };

    // Return a promise of the function that sends the email.
    return transporter.sendMail(options);
  }
};

Note: please make sure you installed nodemailer (npm install nodemailer) for this example.

The service is now available through the strapi.services global variable. We can use it in another part of our codebase. For example a controller like below:

Path — ./api/user/controllers/User.js.

module.exports = {
  // GET /hello
  signup: async (ctx) => {
    // Store the new user in database.
    const user = await User.create(ctx.params);

    // Send an email to validate his subscriptions.
    strapi.services.email.send('welcome@mysite.com', user.email, 'Welcome', '...');

    // Send response to the server.
    ctx.send({
      ok: true
    });
  }
};