2.55.0 2026-09-17

AWS CRT HTTP Client

• Features

  • Added an opt-in read/write (socket) inactivity timeout for the CRT-based HTTP clients (AwsCrtHttpClient and AwsCrtAsyncHttpClient). It is not enabled unless you set the AWS_ENABLE_DEFAULT_SOCKET_TIMEOUT_2026 environment variable or the aws.enableDefaultSocketTimeout2026 system property. Once enabled, an SDK-managed CRT HTTP client that has no explicit connectionHealthConfiguration set receives a per-service read/write timeout; a connection that makes no read or write progress within that window is closed and the in-flight request fails with a retryable IOException. The timeout is not applied to an HTTP client you build and supply yourself via httpClient(...).

AWS End User Messaging Social

• Features

  • Add support for WhatsApp Calling APIs.

AWS IoT Wireless

• Features

  • Adds Multi-frame GNSS support to the AWS IoT Core Device Location GetPositionEstimate API. The new GnssMultiFrame measurement type improves location accuracy by combining multiple GNSS signal captures (2, 4, 8, 16, or 32) from the same device to estimate its position.

AWS User Notifications

• Features

  • Added support for attachments on managed notification events. Added support to access and subscribe sensitive managed notification events.

Amazon Bedrock AgentCore

• Features

  • Batch evaluation now supports evaluating specific traces within a session. Each session can specify up to 100 trace IDs to evaluate.

Amazon Connect Service

• Features

  • Made the replicaAlias attribute optional in the ReplicateInstance API to support Global routing for Amazon Connect Global Resiliency (ACGR) instances. This change maintains backward compatibility. When onboarding to ACGR without Global routing, you must specify a custom replicaAlias in your API call

Amazon Elastic Compute Cloud

• Features

  • Adding support for "Tunnel" VPC Endpoint

Amazon GuardDuty

• Features

  • This change surfaces AI Protection resources on existing public IAM attack sequences. Customers will now see which model was accessed and whether a guardrail intervened as part of the credential-compromise sequence.

Amazon Simple Email Service

• Features

  • Added support to query the tenant name for BatchGetMetricData and CreateExportJob APIs to filter metrics and messages at the tenant level.

Amazon Simple Notification Service

• Features

  • SNS API reference documentation update

Amazon VPC Lattice

• Features

  • Adding support for CIDR Resource Configuration