How do I get the deal_stage on a deal?

I’d like to take action on my side when a deal is in the won stage. When I get it from the API I see this:

{
    "id": 4003193555,
    "name": "The Deal Name",
    // ....
    "deal_stage_id": 4000166948,
}

I tried including the deal_stage with ?include=deal_stage in the URL, but it doesn’t seem to do anything. I can’t find a way to list the deal stages on this page: Freshsales | Refreshingly new CRM & Deal Management Software

Getting /deal_stages yields a 404.
Getting /deals/stages yields a 404.

How do I either list the stages from an API call, or get the include to work so I can get the text description of a deal stage with a deal?

The answer to this is:

?include=deal_stage does in fact work, but it doesn’t embed the deal stages in the deal itself, they come down like this:

{
    "deal": {},
    "deal_stages": [{ /* any deal stages that are referenced in the deals above /* }]
}

Because my code was only looking at the deal key in the response, I missed it.