How AgentCore Gateway supports the MCP 2026-07-28 spec

The Model Context Protocol published its 2026-07-28 specification, the largest revision since launch. Amazon Bedrock AgentCore Gateway now supports that specification, as detailed on the AWS Machine Learning Blog. Operators can enable the new MCP version on an existing gateway with a single UpdateGateway call.

Under the 2026-07-28 revision, MCP is stateless. The specification also introduces a governed extensions system and hardened authorization. AgentCore Gateway surfaces these protocol changes so gateways can adopt the new contract without a multi-step migration path beyond that UpdateGateway update.

For engineers building agent stacks on Amazon Bedrock, the shift is operational as much as protocol-level. Stateless MCP reduces long-lived session assumptions at the gateway boundary. The governed extensions model and stronger authorization change how tools, clients, and gateways negotiate capabilities and access, so builders should treat the 2026-07-28 cut as a real compatibility boundary rather than a silent patch.

MCP has become a common integration surface for agent tooling. A revision this large, with Amazon Bedrock AgentCore Gateway already wired for enablement, raises the bar for platforms that still pin older MCP behavior. Teams comparing gateways and agent runtimes will care whether a product can turn on the new stateless, extension-governed, authorization-hardened model with a controlled API update.

If you run AgentCore Gateway today, plan a deliberate UpdateGateway cutover to the 2026-07-28 MCP version and retest tool discovery, extension negotiation, and auth flows against the new contract. Watch for follow-on AWS guidance on default versions, client compatibility, and any extension catalogs that depend on the governed extensions system.