This is your reference for IAM when you need to write policies, set up roles, or debug permission errors. It covers the fundamentals well: service roles for Lambda, cross-account access patterns, and the difference between identity-based and resource-based policies. The troubleshooting section is genuinely useful, especially the policy simulator commands for debugging access denials. What makes this practical is the side-by-side CLI and boto3 examples for common tasks. IAM is one of those AWS services where you need the syntax right the first time, and having trust policy templates and the actual commands for attaching policies saves you from constantly context switching to the docs.
$ npx -y skills add itsmostafa/aws-agent-skills --skill iam --agent claude-codeInstalls into .claude/skills of the current project.
AWS Identity and Access Management (IAM) enables secure access control to AWS services and resources. IAM is foundational to AWS security—every AWS API call is authenticated and authorized through IAM.
Entities that can make requests to AWS: IAM users, roles, federated users, and applications.
JSON documents defining permissions. Types:
Identities with permissions that can be assumed by trusted entities. No permanent credentials—uses temporary security tokens.
Define which principals can assume a role. Configured via the role's trust policy.
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