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Network

DeviceScript supports TCP, TLS, MQTT and HTTP/HTTPS sockets on specific devices.

Limitations
  • Only one socket can be open at a time. On most devices, a TLS will use a large part of the usable memory.
  • Sockets can be connect to server but not listen so it is not possible to implement a HTTP server currently.

fetch​

DeviceScript provides the familiar fetch function to issue HTTP/HTTPS requests. fetch is designed to match the browser Fetch API.

import { fetch } from "@devicescript/net"

const res = await fetch(`https://github.com/status.json`)
const body = await res.json()
console.log(`GitHub is ${body.status}`)
tip

The fetch sources can help you with understanding how to use sockets.

encryptedFetch​

The encryptedFetch function lets you HTTP POST encrypted data and read encrypted responses using symmetric encryption (AES-256-CCM).

MQTT client​

The startMQTTClient function connects to a MQTT broker using TCP or TLS.

import { startMQTTClient } from "@devicescript/net"

const mqtt = await startMQTTClient({
    host: "broker.hivemq.com",
    proto: "tcp",
    port: 1883,
})
await mqtt.publish("devs/log", "hello!")

TCP/TLS Sockets​

The connect function to open a socket TCP or TLS socket.

This example issues is HTTPS request to the Github.com status API.

import { connect } from "@devicescript/net"

const socket = await connect({ proto: "tls", host: "github.com", port: 443 })
await socket.send(`GET /status.json HTTP/1.1
user-agent: DeviceScript fetch()
accept: */*
host: github.com
connection: close

`)
const status = await socket.readLine()
console.log(status)
await socket.close()