The IAM Permissions Agent: Tightly Scoped Investigations

IAM debugging is plumbing. The agent that walks a request through the permission graph and explains the decision in two paragraphs.

Walk the permission graph

Input: an ARN, an action, a resource. Question: should this combination be allowed; if yes by what path; if no, what is missing.

Walk: identity policy, group policy, role policy, resource policy, SCP. The agent reads each and reports which are involved in the decision.

Output: explicit allow path or explicit deny path; never "unsure." Deterministic walk produces deterministic answer.

Explain in two paragraphs

Paragraph one: the answer (allowed or denied) and the controlling policy.

Paragraph two: how to change the answer (which policy to modify; which statement to add or remove). The change is always shown as a diff.

What it catches that humans miss

SCPs that quietly deny what an identity policy would otherwise allow.

Resource policies that allow access not granted by identity policies.

Permission boundaries that limit max-permission below role.

Implicit deny vs explicit deny: the difference matters for IAM debugging and is often confused.

Safety considerations

Read-only by design. The agent never proposes changes; it explains the current state.

The proposed-diff in the explanation is just text; humans implement it. The agent does not have IAM-write capability.

The agent's analysis is logged for audit. "Why was this access granted" should be reproducible from the audit trail.

Eval cases

Standard allow case: identity policy allows; agent confirms.

Standard deny case: no policy grants; agent confirms.

SCP override case: identity policy allows but SCP denies; agent identifies the SCP.

Resource-policy case: identity policy denies but resource policy grants; agent identifies the resource policy.