diff --git a/readthedocs/projects/migrations/0135_addons_customscript.py b/readthedocs/projects/migrations/0135_addons_customscript.py
new file mode 100644
index 00000000000..d82ab66cc0a
--- /dev/null
+++ b/readthedocs/projects/migrations/0135_addons_customscript.py
@@ -0,0 +1,35 @@
+# Generated by Django 4.2.16 on 2024-11-13 13:34
+
+from django.db import migrations, models
+from django_safemigrate import Safe
+
+
+class Migration(migrations.Migration):
+    safe = Safe.before_deploy
+
+    dependencies = [
+        ('projects', '0134_addons_load_when_embedded_notnull'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='addonsconfig',
+            name='customscript_enabled',
+            field=models.BooleanField(default=False, null=True),
+        ),
+        migrations.AddField(
+            model_name='addonsconfig',
+            name='customscript_src',
+            field=models.CharField(blank=True, help_text='URL to a JavaScript file to inject at serve time', max_length=512, null=True),
+        ),
+        migrations.AddField(
+            model_name='historicaladdonsconfig',
+            name='customscript_enabled',
+            field=models.BooleanField(default=False, null=True),
+        ),
+        migrations.AddField(
+            model_name='historicaladdonsconfig',
+            name='customscript_src',
+            field=models.CharField(blank=True, help_text='URL to a JavaScript file to inject at serve time', max_length=512, null=True),
+        ),
+    ]
diff --git a/readthedocs/projects/migrations/0136_addons_customscript_notnull.py b/readthedocs/projects/migrations/0136_addons_customscript_notnull.py
new file mode 100644
index 00000000000..18ea9b495ac
--- /dev/null
+++ b/readthedocs/projects/migrations/0136_addons_customscript_notnull.py
@@ -0,0 +1,25 @@
+# Generated by Django 4.2.16 on 2024-11-13 13:36
+
+from django.db import migrations, models
+from django_safemigrate import Safe
+
+
+class Migration(migrations.Migration):
+    safe = Safe.after_deploy
+
+    dependencies = [
+        ('projects', '0135_addons_customscript'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='addonsconfig',
+            name='customscript_enabled',
+            field=models.BooleanField(default=False),
+        ),
+        migrations.AlterField(
+            model_name='historicaladdonsconfig',
+            name='customscript_enabled',
+            field=models.BooleanField(default=False),
+        ),
+    ]
diff --git a/readthedocs/projects/models.py b/readthedocs/projects/models.py
index d4d655ff0cb..285035f2a48 100644
--- a/readthedocs/projects/models.py
+++ b/readthedocs/projects/models.py
@@ -222,6 +222,18 @@ class AddonsConfig(TimeStampedModel):
     search_enabled = models.BooleanField(default=True)
     search_default_filter = models.CharField(null=True, blank=True, max_length=128)
 
+    # User JavaScript File
+    customscript_enabled = models.BooleanField(default=False)
+
+    # This is a user-defined file that will be injected at serve time by our
+    # Cloudflare Worker if defined
+    customscript_src = models.CharField(
+        max_length=512,
+        null=True,
+        blank=True,
+        help_text="URL to a JavaScript file to inject at serve time",
+    )
+
     # Notifications
     notifications_enabled = models.BooleanField(default=True)
     notifications_show_on_latest = models.BooleanField(default=True)
diff --git a/readthedocs/proxito/tests/responses/v1.json b/readthedocs/proxito/tests/responses/v1.json
index 9739d2e614c..f6a293be783 100644
--- a/readthedocs/proxito/tests/responses/v1.json
+++ b/readthedocs/proxito/tests/responses/v1.json
@@ -164,6 +164,10 @@
       "default_filter": "project:project/latest",
       "filters": []
     },
+    "customscript": {
+      "enabled": false,
+      "src": null
+    },
     "linkpreviews": {
       "enabled": false,
       "root_selector": "[role=main] a.internal",
diff --git a/readthedocs/proxito/views/hosting.py b/readthedocs/proxito/views/hosting.py
index 3df2c3d37f6..b24cdcd4237 100644
--- a/readthedocs/proxito/views/hosting.py
+++ b/readthedocs/proxito/views/hosting.py
@@ -490,6 +490,10 @@ def _v1(self, project, version, build, filename, url, request):
                     #     "filepath": "/docs/index.rst",
                     # },
                 },
+                "customscript": {
+                    "enabled": project.addons.customscript_enabled,
+                    "src": project.addons.customscript_src,
+                },
                 "search": {
                     "enabled": project.addons.search_enabled,
                     # TODO: figure it out where this data comes from.