From aaf881ff8d8c51e96188e764b51d0e1c66cc4b2b Mon Sep 17 00:00:00 2001
From: Willow Lopez <100782273+Oxygen56@users.noreply.github.com>
Date: Tue, 2 Jun 2026 02:13:37 +0800
Subject: [PATCH] fix(bedrock): pass aws_profile to _infer_region() for correct
 region detection

When aws_profile is specified in AnthropicBedrock or AnthropicBedrockClient
but AWS_REGION is not set, _infer_region() previously created a boto3.Session()
without profile_name, defaulting to the 'default' profile and ignoring the
caller's explicitly configured profile. This caused cross-region inference
failures for users with non-default AWS profiles.

Fix: accept an optional aws_profile parameter in _infer_region() and pass it
through to boto3.Session(profile_name=aws_profile).

Closes #892.
---
 src/anthropic/lib/bedrock/_client.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/anthropic/lib/bedrock/_client.py b/src/anthropic/lib/bedrock/_client.py
index cda0690df..ac571bc0b 100644
--- a/src/anthropic/lib/bedrock/_client.py
+++ b/src/anthropic/lib/bedrock/_client.py
@@ -67,7 +67,7 @@ def _prepare_options(input_options: FinalRequestOptions) -> FinalRequestOptions:
     return options
 
 
-def _infer_region() -> str:
+def _infer_region(aws_profile: str | None = None) -> str:
     """
     Infer the AWS region from the environment variables or
     from the boto3 session if available.
@@ -77,7 +77,7 @@ def _infer_region() -> str:
         try:
             import boto3
 
-            session = boto3.Session()
+            session = boto3.Session(profile_name=aws_profile)
             if session.region_name:
                 aws_region = session.region_name
         except ImportError:
@@ -178,7 +178,7 @@ def __init__(
 
         self.aws_access_key = aws_access_key
 
-        self.aws_region = _infer_region() if aws_region is None else aws_region
+        self.aws_region = _infer_region(aws_profile=aws_profile) if aws_region is None else aws_region
         self.aws_profile = aws_profile
 
         self.aws_session_token = aws_session_token
@@ -343,7 +343,7 @@ def __init__(
 
         self.aws_access_key = aws_access_key
 
-        self.aws_region = _infer_region() if aws_region is None else aws_region
+        self.aws_region = _infer_region(aws_profile=aws_profile) if aws_region is None else aws_region
         self.aws_profile = aws_profile
 
         self.aws_session_token = aws_session_token