CoAP-Packet is a generator and parser of CoAP packets for node.js.
What is CoAP?
Constrained Application Protocol (CoAP) is a software protocol intended to be used in very simple electronics devices that allows them to communicate interactively over the Internet. - Wikipedia
This library follows RFC 7252 and RFC 8132.
It does not provide any CoAP semantics, it just parses the protocol.
CoAP-packet is an OPEN Open Source Project, see the Contributing section to find out what this means.
The library is being tested on Node versions 12, 14, and 16.
$: npm install coap-packet --save
The following example opens an UDP client and UDP server and sends a CoAP message between them:
const dgram = require('dgram')
const packet = require('coap-packet')
const parse = packet.parse
const generate = packet.generate
const payload = Buffer.from('Hello World')
const message = generate({ payload: payload })
const port = 41234
const client = dgram.createSocket('udp4')
const server = dgram.createSocket('udp4')
server.bind(port, function () {
client.send(message, 0, message.length, 41234, 'localhost', function (err, bytes) {
if (err) {
console.error(err.message)
}
client.close()
})
})
server.on('message', function (data) {
console.log(parse(data).payload.toString())
server.close()
})The parse function takes a buffer and returns a JS object that
follows a particular format.
The generate function takes a JS object that
follows a particular format and transform it into
a CoAP packet.
The JS representation of a CoAP packet is:
{
token: Buffer.alloc(4),
code: '0.01',
messageId: 42,
payload: Buffer.alloc(200),
options: [{
name: 'If-Match',
value: Buffer.alloc(5)
}, {
name: 'Uri-Path',
value: Buffer.from('hello')
}]
}Instead of numerical codes, it also supports humanized names, e.g.
GET, POST, PUT, DELETE.
Numerical codes can also be specified in HTTP format, like 500 or
'404'.
CoAP-Packet is an OPEN Open Source Project. This means that:
Individuals making significant and valuable contributions are given commit-access to the project to contribute as they see fit. This project is more like an open wiki than a standard guarded open source project.
See the CONTRIBUTING.md file for more details.
Coap-Packet is only possible due to the excellent work of the following contributors:
| Matteo Collina | GitHub/mcollina | Twitter/@matteocollina |
|---|
MIT, see LICENSE.md file.