diff --git a/docs/source/_static/rest-api.yml b/docs/source/_static/rest-api.yml
index 324e6d08..74b309b6 100644
--- a/docs/source/_static/rest-api.yml
+++ b/docs/source/_static/rest-api.yml
@@ -1176,8 +1176,16 @@ paths:
                         example: abc123
                       accept_url:
                         type: string
-                        description: The URL for accepting the code
+                        description: The URL path for accepting the code
                         example: /hub/accept-share?code=abc123
+                      full_accept_url:
+                        type:
+                          - string
+                          - "null"
+                        description: |
+                          The full URL for accepting the code,
+                          if JupyterHub.public_url configuration is defined.
+                        example: https://hub.example.org/hub/accept-share?code=abc123
       security:
         - oauth2:
             - shares
@@ -1877,7 +1885,14 @@ components:
           description: the server name. '' for the default server.
         url:
           type: string
-          description: the server's URL
+          description: the server's URL (path only when not using subdomains)
+        full_url:
+          type:
+            - string
+            - "null"
+          description: |
+            The full URL of the server (`https://hub.example.org/user/:name/:servername`).
+            `null` unless JupyterHub.public_url or subdomains are configured.
         ready:
           type: boolean
           description: whether the server is ready
diff --git a/docs/source/reference/sharing.md b/docs/source/reference/sharing.md
index f725a145..0ea589ac 100644
--- a/docs/source/reference/sharing.md
+++ b/docs/source/reference/sharing.md
@@ -286,6 +286,7 @@ The response contains the code itself:
 {
   "code": "abc1234....",
   "accept_url": "/hub/accept-share?code=abc1234",
+  "full_accept_url": "https://hub.example.org/hub/accept-share?code=abc1234",
   "id": "sc_1234",
   "scopes": [...],
   ...
diff --git a/docs/source/tutorial/sharing.md b/docs/source/tutorial/sharing.md
index 22e1705e..9612f581 100644
--- a/docs/source/tutorial/sharing.md
+++ b/docs/source/tutorial/sharing.md
@@ -159,11 +159,14 @@ which will have a JSON response:
   'last_exchanged_at': None,
   'code': 'U-eYLFT1lGstEqfMHpAIvTZ1MRjZ1Y1a-loGQ0K86to',
   'accept_url': '/hub/accept-share?code=U-eYLFT1lGstEqfMHpAIvTZ1MRjZ1Y1a-loGQ0K86to',
+  'full_accept_url': 'https://hub.example.org/accept-share?code=U-eYLFT1lGstEqfMHpAIvTZ1MRjZ1Y1a-loGQ0K86to',
 }
 ```
 
 The most relevant fields here are `code`, which contains the code itself, and `accept_url`, which is the URL path for the page another user.
 Note: it does not contain the _hostname_ of the hub, which JupyterHub often does not know.
+If `public_url` configuration is defined, `full_accept_url` will be the full URL including the host.
+Otherwise, it will be null.
 
 Share codes are guaranteed to be url-safe, so no encoding is required.
 
diff --git a/jupyterhub/apihandlers/shares.py b/jupyterhub/apihandlers/shares.py
index 7ff384fb..68166fde 100644
--- a/jupyterhub/apihandlers/shares.py
+++ b/jupyterhub/apihandlers/shares.py
@@ -5,6 +5,7 @@
 import json
 import re
 from typing import List, Optional
+from urllib.parse import urlunparse
 
 from pydantic import (
     BaseModel,
@@ -95,7 +96,7 @@ class _ShareAPIHandler(APIHandler):
             }
         }
         # subset keys for sharing
-        for key in ["name", "url", "ready"]:
+        for key in ["name", "url", "full_url", "ready"]:
             if key in full_model:
                 server_model[key] = full_model[key]
 
@@ -128,6 +129,12 @@ class _ShareAPIHandler(APIHandler):
             model["accept_url"] = url_concat(
                 self.hub.base_url + "accept-share", {"code": code}
             )
+            model["full_accept_url"] = None
+            public_url = self.settings.get("public_url")
+            if public_url:
+                model["full_accept_url"] = urlunparse(
+                    public_url._replace(path=model["accept_url"])
+                )
         return model
 
     def _init_share_query(self, kind="share"):