diff --git a/changelog.mdx b/changelog.mdx
index b965396ee..b1b69b318 100644
--- a/changelog.mdx
+++ b/changelog.mdx
@@ -7,6 +7,25 @@ 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 8, 2026" description="X API v2">
+  ### User-context authentication for webhook and X Activity subscription endpoints
+
+  Webhook management and X Activity API subscription endpoints now accept user-context authentication in addition to app-only bearer tokens:
+
+  - [`GET /2/webhooks`](/x-api/webhooks/get-webhook), [`POST /2/webhooks`](/x-api/webhooks/create-webhook), and `PUT`/`DELETE` [`/2/webhooks/{webhook_id}`](/x-api/webhooks/delete-webhook) now support **OAuth 2.0 user context**. `GET /2/webhooks` also now accepts OAuth 1.0a user context.
+  - `PUT`/`DELETE` [`/2/activity/subscriptions/{subscription_id}`](/x-api/activity/update-x-activity-subscription) now support **OAuth 2.0 user context** and **OAuth 1.0a user context**.
+
+  You can now manage webhooks and update or delete X Activity subscriptions with the same user-context tokens you use elsewhere, without switching to an app-only bearer token. Existing bearer token integrations continue to work unchanged.
+</Update>
+
+<Update label="Sep 8, 2026" description="X API v2">
+  ### Improved streaming latency
+
+  Streaming delivery is now faster. The P99 latency for X API v2 streaming endpoints improved from approximately 6-7 seconds to approximately **4-5 seconds**, while continuing to prioritize fully hydrated Post data. No changes are required on your side.
+
+  For details, see [consuming streaming data](/x-api/fundamentals/consuming-streaming-data) and the [filtered stream introduction](/x-api/posts/filtered-stream/introduction). If you need even lower latency, 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