Building Adapters

Sails Flare uses an adapter pattern to support any notification channel. Each adapter is a class that implements the Adapter interface. This guide shows you how to build one.

The Adapter interface

Every adapter must implement initialize() and fire(). The teardown() method is optional:

class MyAdapter {
  async initialize(config) {
    /* ... */
  }
  async fire(subscription, payload) {
    /* ... */
  }
  async teardown() {
    /* ... */
  }
}

module.exports = MyAdapter

Method	Required	Description
initialize(config)	Yes	Called once during sails.lift(). Set up connections, validate credentials.
fire(subscription, payload)	Yes	Deliver a notification to a single subscription/device.
teardown()	No	Clean up resources on sails.lower().

TIP

Flare uses duck typing — no class inheritance required. Any object with initialize() and fire() methods qualifies as an adapter.

Scaffold a new adapter

Create a new package:

my-adapter/
  index.js
  package.json

{
  "name": "@flare/my-channel",
  "version": "0.0.1",
  "main": "index.js"
}

Example: SMS adapter

Here's a minimal SMS adapter using Twilio:

class TwilioSmsAdapter {
  async initialize(config) {
    this.client = require('twilio')(config.accountSid, config.authToken)
    this.fromNumber = config.fromNumber
  }

  async fire(subscription, payload) {
    // subscription.phone is the user's phone number
    await this.client.messages.create({
      to: subscription.phone,
      from: this.fromNumber,
      body: `${payload.title}: ${payload.body}`
    })
  }

  async teardown() {
    // Twilio client is stateless — no cleanup needed
  }
}

module.exports = TwilioSmsAdapter

How adapters are loaded

When Sails lifts, Flare loads adapters in this order:

1. Built-in adapters: Check if the adapter name matches a file in lib/adapters/ (currently just web-push)
2. External adapters: If not built-in, resolve from the app's node_modules using require()

This means built-in adapters work with zero dependencies, while external adapters are installed as separate npm packages.

Configuration flow

The adapter receives the full provider config object in initialize():

// config/notifications.js
module.exports.notifications = {
  providers: {
    sms: {
      adapter: '@flare/sms', // ← resolved via require()
      accountSid: '...', // ← passed to initialize()
      authToken: '...', // ← passed to initialize()
      fromNumber: '+1234567890' // ← passed to initialize()
    }
  }
}

Additionally, Flare injects:

• config.appPath — the absolute path to your Sails app
• config.log — the sails.log instance

Subscription model

The fire() method receives a single subscription record from the PushSubscription model. For Web Push, this contains { endpoint, keys }. For an SMS adapter, you might store phone numbers in a different model and override how subscriptions are queried.

Currently, Flare always queries PushSubscription.find({ user: userId }). Future versions may support adapter-specific subscription models.

Using your adapter

Install it and add it to config/notifications.js:

module.exports.notifications = {
  provider: 'sms',
  providers: {
    sms: {
      adapter: '@flare/sms',
      accountSid: process.env.TWILIO_SID,
      authToken: process.env.TWILIO_TOKEN,
      fromNumber: process.env.TWILIO_FROM
    }
  }
}

Official adapters

Adapter	Channel	Package
Web Push	Browser push notifications	Built-in

Check the GitHub repository for the latest list.