From a4bf297c2363ea40350260beb434b15b93dc624c Mon Sep 17 00:00:00 2001
From: "mintlify[bot]" <109931778+mintlify[bot]@users.noreply.github.com>
Date: Wed, 9 Sep 2026 02:13:36 +0000
Subject: [PATCH] docs: add Sep 9 changelog entry for latency and auth updates
---
changelog.mdx | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/changelog.mdx b/changelog.mdx
index b965396ee..e29e4285c 100644
--- a/changelog.mdx
+++ b/changelog.mdx
@@ -7,6 +7,16 @@ 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).
+
+ ### Lower streaming latency
+
+ We improved P99 latency on the X API v2 [streaming endpoints](/x-api/fundamentals/consuming-streaming-data) from approximately 6-7 seconds to approximately **4-5 seconds**. This applies to streams that prioritize data hydration and delivery, including the [Filtered Stream](/x-api/posts/filtered-stream/introduction). You now receive fully hydrated Posts faster, with no changes required on your end. For the lowest-latency option, see [Powerstream](/x-api/powerstream/introduction).
+
+ ### User context authentication for webhooks and Activity subscriptions
+
+ [Webhook](/x-api/webhooks/introduction) management endpoints (`GET`/`POST /2/webhooks`, `PUT`/`DELETE /2/webhooks/{webhook_id}`) now accept OAuth 2.0 user context authentication. Updating or deleting an [X Activity API](/x-api/activity/introduction) subscription (`PUT`/`DELETE /2/activity/subscriptions/{subscription_id}`) now accepts OAuth 1.0a and OAuth 2.0 user context as well. App-only Bearer Token authentication continues to work on all of these endpoints.
+
+
### Media upload and Post-create size and duration limits