JavaScript SDK

npm package

The Fostrom Device SDK for JavaScript is built to work in Node.js and Bun, on Linux and macOS.

Example

import Fostrom from 'fostrom';

const fostrom = new Fostrom({
  fleet_id: "<fleet-id>",
  device_id: "<device-id>",
  device_secret: "<device-secret>",
})

// Setup the onMail handler, to process incoming mail.
fostrom.onMail = async (mail) => {
  const {id, name, payload, mailbox_size} = mail
  console.debug(`Received Mail (${mailbox_size}): ${name} ${id}`)
  await mail.ack()
}

async function main() {
  await fostrom.connect()

  // To send a message to Fostrom
  await fostrom.sendMsg("<packet-schema-name>", { ...payload })

  // To send a datapoint to Fostrom
  await fostrom.sendDatapoint("<packet-schema-name>", { ...payload })
}

main()

Note that in Node.js, to ensure the import statement above works, you’ll need to add "type": "module" to your package.json file.

Library Reference

Fostrom Class

Fostrom {
  // --- Functions ---
  async connect()
  async sendDatapoint(name, payload)
  async sendMsg(name, payload)

  // Usually, there's no need to use the following
  // functions, as mail will be delivered to the
  // handler you define automatically.
  async mailboxStatus()
    // returns {mailbox_size, next_mail_id, next_mail_name}
  async nextMail()
    // return FostromMail{}

  // --- Replacable Callbacks ---
  connected()
  unauthorized(reason, reconnecting_in_ms)
  reconnecting(reason, reconnecting_in_ms)
  async onMail(mail = FostromMail{})
}

FostromMail Class

FostromMail {
  // --- Data ---
  id: string
  name: string
  payload: object
  mailbox_size: integer(u16)

  // --- Functions ---
  async ack()
  async reject()
  async requeue()
}