From a6f49009f48baa0bf67c43b520294d6766b6c86a Mon Sep 17 00:00:00 2001
From: lindseymoore <71525840+lindseymoore@users.noreply.github.com>
Date: Thu, 6 Feb 2025 16:42:42 -0500
Subject: [PATCH] DOCSP-32752 Support for setting AWS region (#958)

* DOCSP-32752 Suppor for setting AWS region

* edits

* merge

* another merge attempt

* edit

* edit on title

* RM review

* update links

* default region

* tech review note

* change wanring msg

* wording changed

* change link

(cherry picked from commit 65f4f5ca479a92bd460c414022c0ed2779569248)
---
 .../authentication/mechanisms.txt             | 24 ++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/source/fundamentals/authentication/mechanisms.txt b/source/fundamentals/authentication/mechanisms.txt
index ecb1b9cea..2ce657ad8 100644
--- a/source/fundamentals/authentication/mechanisms.txt
+++ b/source/fundamentals/authentication/mechanisms.txt
@@ -229,7 +229,29 @@ The driver checks for your credentials in the following sources in order:
 
          export AWS_WEB_IDENTITY_TOKEN_FILE=<absolute path to file containing your OIDC token>
 
-      After you've set the preceding environment variable, specify the ``MONGODB-AWS``
+      AWS recommends using regional AWS STS endpoints instead of global 
+      endpoints to reduce latency, build-in redundancy, and increase session token validity.
+      To set the AWS region, set `AWS_REGION <https://docs.aws.amazon.com/sdkref/latest/guide/feature-region.html>`__ 
+      and `AWS_STS_REGIONAL_ENDPOINTS <https://docs.aws.amazon.com/sdkref/latest/guide/feature-sts-regionalized-endpoints.html>`__
+      as environment variables, as shown in the following example: 
+
+      .. code-block:: bash
+         
+         export AWS_STS_REGIONAL_ENDPOINTS=regional // Enables regional endpoints
+         export AWS_REGION=us-east-1 // Sets your AWS region
+         
+      If both these environment variables aren't set, the default region is 
+      ``us-east-1``. For a list of available AWS regions, see the
+      `Regional Endpoints <https://docs.aws.amazon.com/general/latest/gr/rande.html#regional-endpoints>`__ 
+      section of the AWS Service Endpoints reference in the AWS documentation. 
+
+      .. warning:: Consult your SDK's Documentation for Setting an AWS Region
+
+         You cannot set your AWS region with environment variables for all SDKs,
+         as in the above example. See your SDK's specific documentation for 
+         configuring an AWS region. 
+
+      After you've set the preceding environment variables, specify the ``MONGODB-AWS``
       authentication mechanism in your connection string as shown in the following example:
 
       .. literalinclude:: /code-snippets/authentication/aws-env-variable.js