New Amazon Bedrock AgentCore runtimes now use AWS’s new execution environment by default in the regions listed in its November 12 announcement. The change applies to newly created runtimes; existing deployments remain on their current version until customers move them.
Each session starts from a snapshot of an initialized agent and runs in its own hardware-isolated Firecracker microVM. Compute and memory scale with demand, while idle agents scale to zero.
AWS says sessions can reach eight vCPUs and 32 GB of memory. Its tests with a 2 GB image reported startup times below two seconds at the 75th percentile, versus 29.7 seconds previously. These are AWS’s measurements.
Customers can select platformVersion V2 when creating or updating a runtime, or specify V1 to keep a new deployment on the previous generation.
AWS also reports up to 68% less billed memory per session for multi-turn agents. Total application costs also depend on other billed resources and services.
