# HTTP.jl Websockets- help getting started

**URL:** <https://discourse.julialang.org/t/http-jl-websockets-help-getting-started/102867>\
**Category:** Web Stack\
**Created:** [August 16, 2023, 3:50pm UTC](https://discourse.julialang.org/t/http-jl-websockets-help-getting-started/102867 "2023-08-16T15:50:41Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![NAS](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nas/32/47432_2.png) [@NAS](https://discourse.julialang.org/u/NAS)\
**Post date:** [August 16, 2023, 3:50pm UTC](https://discourse.julialang.org/t/http-jl-websockets-help-getting-started/102867/1 "2023-08-16T15:50:41Z")

</div>

Looking for some help getting started with websockets in HTTP.jl. For some reason I can’t seem to grasp the design and intended usage. For example, I can look at this Python example:

```python
import websocket
ws = websocket.WebSocket()
ws.connect("ws://echo.websocket.events")
ws.send("Hello, Server")
>>19
print(ws.recv())
>>echo.websocket.events sponsored by Lob.com
ws.close()

```

This makes perfect sense to me. The websocket is available as ws and you connect, then can send and receive and finally close.

In the HTTP.jl implementation I have no idea how to access a connection that I create. The example given in the docs is:

```julia
# simple websocket client
WebSockets.open("ws://websocket.org") do ws
    # we can iterate the websocket
    # where each iteration yields a received message
    # iteration finishes when the websocket is closed
    for msg in ws
        # do stuff with msg
        # send back message as String, Vector{UInt8}, or iterable of either
        send(ws, resp)
    end
end

```

But this seems to be a blocking infinite loop, REPL is locked and I have to kill it to do anything. Beyond that, the socket itself is not accessible anywhere except within the scope of the do block. What if I wanted to do some other process outside this block and then have the websocket send a new message?

I think I’m just missing the design intent as I can’t seem to figure out a way to work with this setup. I’ve tried to find some real examples but the only things I can fid are of the ` # do stuff with msg # send back message as String, Vector{UInt8}, or iterable of either` variety. Again, being within the blocking loop makes it so I can’t do that unless I already know what I want to do before initiating the connection.

Any guidance or working examples would be greatly appreciated.

---

<div class="post-metadata">

**Author:** ![ffevotte](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ffevotte/32/6587_2.png) [@ffevotte](https://discourse.julialang.org/u/ffevotte)\
**Post date:** [August 16, 2023, 4:22pm UTC](https://discourse.julialang.org/t/http-jl-websockets-help-getting-started/102867/2 "2023-08-16T16:22:08Z")

</div>

The equivalent of your Python snippet would probably be something along the lines of:

```julia
julia> using HTTP

julia> WebSockets.open("ws://echo.websocket.events") do ws
           WebSockets.send(ws, "Hello, Server")
           @show WebSockets.receive(ws)
       end;
WebSockets.receive(ws) = "echo.websocket.events sponsored by Lob.com"

```

- `open` will
  1. connect to the server,
  2. execute the anonymous function you give it, passing the websocket as the `ws` argument, and
  3. ensure the socket is closed in the end

- `send` and `receive` are self-explanatory I think

---

<div class="post-metadata">

**Author:** ![quinnj](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/quinnj/32/11_2.png) [@quinnj](https://discourse.julialang.org/u/quinnj)\
**Post date:** [August 16, 2023, 4:26pm UTC](https://discourse.julialang.org/t/http-jl-websockets-help-getting-started/102867/3 "2023-08-16T16:26:10Z")

</div>

You’re right that we don’t provide the same interface as python. It was a design decision to try and help users use websockets correctly and simplify usage. The `WebSockets.open` call is a single call to manage the lifetime of a websocket, ensuring the connection is made and closed appropriately. I agree that it could be nice to have a more interactive-friendly version where you call connect/close explicitly and that wouldn’t be very hard to add, so feel free to open an issue on the HTTP.jl repo (or even better, make a PR!).

---

<div class="post-metadata">

**Author:** ![NAS](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nas/32/47432_2.png) [@NAS](https://discourse.julialang.org/u/NAS)\
**Post date:** [August 18, 2023, 3:53pm UTC](https://discourse.julialang.org/t/http-jl-websockets-help-getting-started/102867/4 "2023-08-18T15:53:16Z")

</div>

Thanks for the input. I dug through the source a little and came up with this:

```julia
function rawws(url,headers =[])
    headers = [
        "Upgrade" => "websocket",
        "Connection" => "Upgrade",
        "Sec-WebSocket-Key" => base64encode(rand(Random.RandomDevice(), UInt8, 16)),
        "Sec-WebSocket-Version" => "13",
        headers...
    ]
    r = HTTP.openraw("GET",url,headers)[1]

    ws = WebSockets.WebSocket(r)
    return ws
end

```

This is just constructed from parts and pieces of the HTTP.jl package and essentially gives a raw web socket that you have to manage manually. I’m using this with SurrealDB and so far it is working well. I see the intent and benefit of having the full lifecycle of the WS managed and ensuring that it is closed, but also having a persistent socket has been handy for prototyping and troubleshooting.

I’d love to make this available for anyone else who might find it useful, but I’m not sure of a few things:

1. Is this a reasonable solution? (Works for me, but does it make sense beyond my use case?)
2. If yes, I don’t know how to submit a PR, but willing to learn. Any resources for a newbie?

---

<div class="post-metadata">

**Author:** ![freeman](https://avatars.discourse-cdn.com/v4/letter/f/ec9cab/32.png) [@freeman](https://discourse.julialang.org/u/freeman)\
**Post date:** [June 19, 2024, 6:06pm UTC](https://discourse.julialang.org/t/http-jl-websockets-help-getting-started/102867/5 "2024-06-19T18:06:30Z")

</div>

Would you give us an example of how you would use this? Do you do something like

```julia
ws = rawws(url)
@async begin
    for msg in ws
        handler(msg)
    end
end
HTTP.send(ws, some_message)

```

Does this work?

---

<div class="post-metadata">

**Author:** ![freeman](https://avatars.discourse-cdn.com/v4/letter/f/ec9cab/32.png) [@freeman](https://discourse.julialang.org/u/freeman)\
**Post date:** [June 19, 2024, 6:08pm UTC](https://discourse.julialang.org/t/http-jl-websockets-help-getting-started/102867/6 "2024-06-19T18:08:58Z")

</div>

Ok I just tested this. It appears that it does indeed work. This is fantastic.