diff --git a/changelog.mdx b/changelog.mdx
index b965396ee..f5d52e300 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 webhooks and X Activity API subscriptions
+
+  You can now authenticate [webhook management endpoints](/x-api/webhooks/introduction) (`GET`/`POST /2/webhooks`, `PUT`/`DELETE /2/webhooks/{webhook_id}`) with OAuth 2.0 user context, in addition to the existing app-only Bearer Token and OAuth 1.0a options.
+
+  The [X Activity API](/x-api/activity/introduction) subscription update and delete endpoints (`PUT`/`DELETE /2/activity/subscriptions/{subscription_id}`) now also accept OAuth 1.0a and OAuth 2.0 user context, in addition to app-only Bearer Tokens.
+
+  ### Lower streaming latency
+
+  We reduced the P99 latency of the X API v2 [streaming endpoints](/x-api/fundamentals/consuming-streaming-data), including the [Filtered Stream](/x-api/posts/filtered-stream/introduction), from approximately 6-7 seconds to approximately **4-5 seconds**. You receive fully hydrated Posts faster, with no changes required on your side. For the lowest-latency option, see [Powerstream](/x-api/powerstream/introduction).
+</Update>
+
 <Update label="Sep 1, 2026" description="X API v2">
   ### Media upload and Post-create size and duration limits