HTTP Server Premium
The premium version of Streamsheets allows every App to be a fully functional HTTP Server. Which allows for individual reponses (HTTP.RESPOND()). The OS version only supports webhooks.
Your app can be accessed via HTTP requests. Enable the HTTP Server endpoint for your app and allow requests to appear in a dedicated inbox.
Use the given URL to send the request. If you checked "Expect response by Streamsheet" the request will still be delivered to the configured inbox, but will need an HTTP.RESPOND() function to send a response. If not, the server will respond with a timeout message. Uncheck this option to automatically send a response.
If needed, add basic authorization for your server.
The OS version does not include a fully functional HTTP server. You are still able to send requests to your app, allowing the implementation of webhooks.
OPC UA Server Premium
The premium version supports the usage of OPC UA. To allow the app to host OPC UA nodes, check the "expose" box and use OPCUA.VARIABLES() within the sheet.