There you can set:

* The "Item ID", used in the path.
* The "Token" used as a query parameter.

!!! tip
    Notice that the query `token` will be handled by a dependency.

With that you can connect the WebSocket and then send and receive messages:

<img src="/img/tutorial/websockets/image05.png">

## Handling disconnections and multiple clients

    In that case, you wouldn't have to worry about any of this. 🤷

### Examples of Previous Steps Strategies

This will **depend heavily** on the way you **deploy your system**, and it would probably be connected to the way you start programs, handling restarts, etc.

Here are some possible ideas:

* An "Init Container" in Kubernetes that runs before your app container

So, you would run **multiple containers** with different things, like a database, a Python application, a web server with a React frontend application, and connect them together via their internal network.

All the container management systems (like Docker or Kubernetes) have these networking features integrated into them.

## Containers and Processes

The user of your API (an external developer) will create an invoice in your API with a POST request.

Then your API will (let's imagine):

* Send the invoice to some customer of the external developer.
* Collect the money.
* Send a notification back to the API user (the external developer).
    * This will be done by sending a POST request (from *your API*) to some *external API* provided by that external developer (this is the "callback").