Why Isn't the AWS Blocks Agent Built on AgentCore? What the Repository Reveals About What's Next

Since AWS Blocks entered public preview in June 2026, I have been making small contributions to the open-source project. AWS Blocks on GitHub In my previous post on AWS Blocks, Amplify, and App Studio , I looked at how these tools differ and what each is trying to achieve. While revisiting the Agent Block, one detail caught my attention: The AWS Blocks Agent is not currently running on Amazon Bedrock AgentCore. At a glance, it is easy to assume the relationship looks like this: AWS Blocks └─ Agent └─ Amazon Bedrock AgentCore But that is not how the current implementation works—at least not on main as of August 12, 2026. Then the story gets interesting. When I wondered whether an agent should simply use AgentCore directly, I found a fairly concrete set of pull requests that proposes moving the Agent Block's execution model to AgentCore Runtime. I contribute to AWS Blocks, but this is not an AWS statement or a roadmap. It is my reading of the public documentation and the open-source repository, from the perspective of both a user and a contributor. TL;DR The Agent Block on the current main branch does not run on AgentCore Runtime. It combines the Strands Agents SDK with AsyncJob , Realtime , FileBucket , and DistributedTable . A five-PR stack proposes migrating the Agent Block's execution model to AgentCore Runtime. As of August 12, 2026, all five migration PRs are still draft and unmerged. They are not an official roadmap. A separate open PR proposes Blocks for AgentCore Memory, Gateway, and Identity. So the most accurate conclusion today is this: AWS Blocks Agent is not AgentCore today, but the repository contains concrete proposals for bringing the two together. The Agent Block today is not AgentCore Let's start with the implementation on main . The Agent Block uses the Strands Agents SDK . But it is not a standalone agent runtime; it composes several Blocks to handle execution, streaming, and persistence. At a high level, the structure looks like this: Agent ├─ St