AWS adds build hooks to prepare AgentCore sessions before requests

AWS says Amazon Bedrock AgentCore runtime now supports build hooks on V2 runtimes, allowing developers to prepare files and tools while the platform builds a snapshot for new agent sessions. The hooks run before the snapshot and after a test restore. They can retain data in memory or prime file access for tools such as browsers and command-line programs. V2 restores a prepared environment instead of initializing the container for every session. The two hook calls share 120 seconds. A failed call fails the runtime creation or update, and AgentCore does not retry it. Keeping more data in memory also increases the snapshot size and the memory billed in every session.