diff --git a/changelog.mdx b/changelog.mdx
index b965396ee..66de7c03d 100644
--- a/changelog.mdx
+++ b/changelog.mdx
@@ -7,6 +7,18 @@ keywords: ["changelog", "API updates", "release notes", "what's new", "API chang
 
 To subscribe to updates, please [**“Turn on notifications”**](https://help.x.com/en/managing-your-account/notifications-on-mobile-devices#:~:text=In%20the%20top%20menu,%20you,you%20would%20like%20to%20receive) for [**@API**](https://x.com/api). You can also follow this changelog in your feed reader via the [**RSS feed**](https://docs.x.com/changelog/rss.xml).
 
+<Update label="Sep 6, 2026" description="X API v2">
+  ### User-context authentication for webhook and X Activity subscription management
+
+  You can now manage [webhooks](/x-api/webhooks/introduction) with OAuth 2.0 user-context authentication. `GET /2/webhooks`, `POST /2/webhooks`, and `PUT` / `DELETE /2/webhooks/{webhook_id}` all accept OAuth 2.0 user context; `GET /2/webhooks` also now accepts OAuth 1.0a user context. Previously, listing webhooks required app-only (Bearer) authentication.
+
+  The [X Activity API](/x-api/activity/introduction) subscription endpoints `PUT` and `DELETE /2/activity/subscriptions/{subscription_id}` now also accept OAuth 2.0 and OAuth 1.0a user context in addition to app-only authentication. If your app manages webhooks and subscriptions on behalf of users, you no longer need to switch auth flows to do so.
+
+  ### Lower streaming latency
+
+  We reduced the P99 latency of the high-volume streaming endpoints from ~6-7 seconds to **~4-5 seconds**, including [Filtered Stream](/x-api/posts/filtered-stream/introduction). Streams still prioritize full data hydration; for the lowest possible latency, use [Powerstream](/x-api/powerstream/introduction). See [consuming streaming data](/x-api/fundamentals/consuming-streaming-data) for delivery guarantees.
+</Update>
+
 <Update label="Sep 1, 2026" description="X API v2">
   ### Media upload and Post-create size and duration limits