Amazon Bedrock AgentCore Runtime

AWS's managed **stateful agent runtime** for the Bedrock platform, providing isolated **microVMs** (Firecracker-style lightweight VMs) per agent session that preserve stateful MCP-server features — elicitation, sampling, progress notifications — across the otherwise stateless transport layer of MCP 2026-07-28. AgentCore Runtime lets developers deploy MCP servers as managed AWS workloads without operating their own session-affinity-aware load balancers.

The MCP 2026-07-28 spec made the *protocol* stateless to enable horizontal scaling (no Mcp-Session-Id header, no initialize/initialized handshake), but agents still genuinely need stateful execution context across many tool calls. AgentCore Runtime resolves the layer split by managing statefulness *in the runtime* (isolated microVMs that survive across requests) while keeping the *protocol* stateless (so AWS can route requests freely across the microVM pool without the load balancer needing protocol awareness).

Production deployment of MCP servers on AWS without operating session-aware infrastructure; enterprise agentic workloads requiring AWS-native IAM + VPC + KMS integration; long-running agent sessions that must preserve elicitation/sampling/progress state across hours of execution; mission-critical agents needing the operational SLAs of managed AWS infrastructure.