Part 23 · One Agent, Five Platforms

Security teams tend to ask one question before any other about an agent: which identity does it use? If the answer is "a service account someone set up" or "whoever is logged in", the review usually stops there.

Part 22 showed how Azure answers it. AWS is the last build, in Parts 24 and 25, but its identity model is worth putting next to Azure's now, because the two clouds take noticeably different routes to the same goal. This part compares them, neutrally and in one picture.

It's based on Microsoft Learn and the Amazon Bedrock AgentCore and AWS Well-Architected documentation as I read them on 11 November 2026, linked below.

Two ways an agent can act

Every agent call happens as somebody. There are two basic choices:

As itself. The agent has its own identity and its own permissions. Logs show the agent did it.

On behalf of a user. The agent carries a person's identity, usually through a token exchange, and acts within that person's permissions.…