August 19th, 2026

New this release:

• 🎉 (client, smithy-rs#4767) Add a deterministic connection-level test harness to the wire-mock feature under aws_smithy_http_client::test_util::wire::connection. It supports per-connection HTTP/1.1 scripts, raw socket actions, synchronization gates, and recorded connection events.
• 🎉 (client) Add pool_max_idle_per_host setter to HTTP client Builder and ConnectorBuilder,
  exposing hyper's pool_max_idle_per_host setting to control the maximum number of idle
  connections kept alive per host.