Audrow•2y ago

Websocket client with headers

I'm trying to create a websocket client that has an authorization header. It seems that a lot of the functionality of websockets has been moved out of the standard library, and I don't see much in the core. Any advice on how to proceed? For reference, I'm trying to do the following in Deno, rather than by using websocat: https://trading-api.readme.io/reference/introduction#connecting

Kalshi Developer Suite

Market Data Feed

Protocol overview Our websockets api is only served over an encrypted connection. There is a single endpoint to establish WS connections: wss://trading-api.kalshi.com/trade-api/ws/v2. We provide multiple channels of information over a single connection. So after establishing a WS connection, the cli...

21 Replies

Danielduel•2y ago

they are using this header in unintended way 😛 I believe it would look like this xD

new WebSocket("", ["Authorization: Bearer safoinasfoiasfoih"])

new WebSocket("", ["Authorization: Bearer safoinasfoiasfoih"])

because this header is used to specify "inner?" protocol

AudrowOP•2y ago

Interesting, when I try that I get an "Invalid protocol value" runtime error

Danielduel•2y ago

as I've said - they made it working like this server-side

AudrowOP•2y ago

I see

Danielduel•2y ago

they read and parse that "as protocol"... tbh it is genious if it is not somewhat insecure xD

AudrowOP•2y ago

haha Tools like websocat an uwsc have a headers flag, are they passing it as a protocol?

Danielduel•2y ago

no, w8, looks like I am uneducated, take a look here:

Danielduel•2y ago

https://medium.com/deno-the-complete-reference/websockets-client-server-in-deno-34d85a84c5e1

Medium

WebSockets (client & server) in Deno

Learn about WebSockets in Deno by writing a simple chat app

Danielduel•2y ago

they talk about authing your ws connection here hope it helps ^^

AudrowOP•2y ago

I'll take a look - thanks for the help!

Danielduel•2y ago

AudrowOP•2y ago

From the article:

If the client doesn’t support sending authorization headers, the secure token can be sent in URL:

> const ws=new WebSocket('ws://localhost:5000?accessToken=TOKEN-1');
>

> const ws=new WebSocket('ws://localhost:5000?accessToken=TOKEN-1');
>

How do you think you would send Authorization: Bearer ${token} in the URL? I think this is probably done on the server, too. So I don't think this is a general work around it, but rather a way around it if you control the client and server I'm thinking that it's probably that I need to make an HTTP request to the server and then upgrade the connection. I'm not exactly sure how to do that yet...

Danielduel•2y ago

TOKEN-1 is your token

AudrowOP•2y ago

I think I tried that, but let me make sure Yeah, it doesn't seem to work. I'm getting an authorization error trying to open the websocket (I'm able to connect with websocat with the same token)

Danielduel•2y ago

If you can open your source or invite me - I would be interested in what are you making 😄 I mean at this point most likely you know abot this topic more than me when I had to do this stuff I had some flow like this... I had "please give me session link" rest route, it gave you presigned url for websocket and I was assuming that the client that knows this random route is the same who asked on the rest route

AudrowOP•2y ago

I'm making a bot to run on Kalshi. At this point, there's not much to show. I have something that uses requests and makes trades, but they just recently introduced their websocket, and having an event-driven bot seems much better than a polling one. At the moment, I'm just trying to get the websocket to work on its own. Here's the code I'm working from

import "https://deno.land/x/dotenv@v3.2.0/load.ts";
import * as z from "https://deno.land/x/zod@v3.16.1/mod.ts";

const kalshiToken = z.string().parse(Deno.env.get('KALSHI_API_TOKEN'))
const kalshiUrl = 'wss://demo-api.kalshi.co/trade-api/ws/v2'

const url = `${kalshiUrl}?accessToken=${kalshiToken}`
const ws = new WebSocket(url)

ws.onopen = (event) => {
  console.log('Connected to Kalshi', event)
}

ws.onclose = (event) => {
  console.log('Disconnected from Kalshi', event)
}

ws.onmessage = (event) => {
  console.log('Message from Kalshi', event)
}

ws.onerror = (event) => {
  console.log('Error from Kalshi', event)
}

import "https://deno.land/x/dotenv@v3.2.0/load.ts";
import * as z from "https://deno.land/x/zod@v3.16.1/mod.ts";

const kalshiToken = z.string().parse(Deno.env.get('KALSHI_API_TOKEN'))
const kalshiUrl = 'wss://demo-api.kalshi.co/trade-api/ws/v2'

const url = `${kalshiUrl}?accessToken=${kalshiToken}`
const ws = new WebSocket(url)

ws.onopen = (event) => {
  console.log('Connected to Kalshi', event)
}

ws.onclose = (event) => {
  console.log('Disconnected from Kalshi', event)
}

ws.onmessage = (event) => {
  console.log('Message from Kalshi', event)
}

ws.onerror = (event) => {
  console.log('Error from Kalshi', event)
}

That might be the way to go - I'm new to using websockets so I'm very much trying to figure out how to use them at all

Danielduel•2y ago

I wish you only profits then 😄

AudrowOP•2y ago

Haha, thanks for your help so far!

Danielduel•2y ago

There is something like this https://deno.land/api@v1.29.1?unstable&s=WebSocketStream but. You have to enable unstable features, options here take headers

Deno

WebSocketStream | Runtime APIs | Deno

UNSTABLE: New API, yet to be vetted.

Danielduel•2y ago

@audrow ^ (Haven't tried it ever myself Kappa)

AudrowOP•2y ago

Ah, maybe that's what I'm looking for - thanks for finding it! I got it working - thanks for the help @danielduel!