agentcore-harness-builder

# AWS Bedrock AgentCore Harness Builder ## Overview A **Harness** is AWS Bedrock AgentCore's declarative, fully-managed way to run an agent. You hand AWS a JSON configuration — model, system prompt, tools, memory, skills, limits — and AWS runs the agent loop (Strands under the hood) inside a per-session Firecracker microVM with its own filesystem and shell. No container to build by default (a custom image via `environmentArtifact` is an advanced option), no agent loop to write. You change behavior by changing config, not redeploying code, and you can override model/prompt per invocation. This skill builds a **complete, best-practice Harness use case** that exercises every AgentCore capability the user needs, wired correctly the first time. Harness is **generally available** (GA 2026-06-17, all AWS Commercial Regions where AgentCore is available, plus GovCloud US-West since 2026-08; only Payments remains preview), but it is still fast-moving and the real API shapes often differ from the published docs — this skill encodes the hard-won facts so you don't rediscover them through validation errors. ### The two-plane mental model (internalize this first) AgentCore has two distinct API surfaces. Confusing them is the #1 source of wasted time. | Plane | What it is | How you call it | |---|---|---| | **Control plane** | Create/configure/inspect resources (harness, memory, runtimes) | `boto3.client("bedrock-agentcore-control")` — `create_harness`, `update_harness`, `create_memor...