docs about getting user plan in spaces

Author: coyotte508

docs/hub/_toctree.yml

@@ -378,6 +378,8 @@
       title: Cookie limitations in Spaces
     - local: spaces-handle-url-parameters
       title: Set URL query and hash
+    - local: spaces-get-user-plan
+      title: Get User Plan
 
 - local: other
   title: Other

docs/hub/spaces-get-user-status.md

@@ -0,0 +1,29 @@
+# How to get a user's status in Spaces
+
+You can check if a user is logged in or not on the main site, and if they have a PRO subscription or one of their orgs has a paid subscription.
+
+```js
+window.addEventListener("message", (event) => {
+    if (event.data.type === "USER_PLAN") {
+        console.log("plan", event.data.plan);
+    }
+})
+
+window.parent.postMessage({
+    type: "USER_PLAN_REQUEST"
+}, "https://huggingface.co");
+```
+
+`event.data.plan` will be of type:
+
+```ts
+{
+    user: "anonymoous",
+    org: undefined
+} | {
+    user: "pro" | "free",
+    org: undefined | "team" | "enterprise" | "plus" | "academia"
+}
+```
+
+You will get both the user's status (logged-out = `"anonymous"`) and their <a href="https://huggingface.co/pricing">plan</a>.