Which flow fits your agent?

Six questions. Answer as many as you can; the recommendations update as you go and the address bar keeps your answers, so you can share the result.

1Whose authority is the agent using?

The single most important question. It decides whose name is on the token.

A specific person’sTheir data, their permissionsIts ownA service identity that an admin set up

2Is a person available when access is needed?

Yes, in the sessionThey can click through a sign-in nowReachable, but elsewherePhone, chat, emailNoScheduled, event-driven, overnight

3What is the agent calling?

An MCP serverAn HTTP APIAnother agentA public websiteServices inside my own infrastructure

4Who runs the thing being called?

We doSame organization, same identity systemA vendor we use at workBoth sides connected to our company identity providerSomeone else entirelyNo shared identity provider

5Where does the agent run?

On the user’s machineDesktop app, IDE, CLIRemote, with no browserContainer, SSH session, CI jobKubernetes or a cloud we operateA managed agent platformA sandbox that runs untrusted code

6What is the worst it could do?

Read dataChange things that can be undoneSomething irreversibleMove money, delete, send in someone’s name

The call

The guide needs JavaScript to compute recommendations. Without it, the flows page groups every option by whether a human is involved.

Who’s on First

A field guide to agent authentication and authorization. Who is acting, for whom, and who said they could?

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whosonfirst.ai · Standards status last reviewed November 2026. Drafts move quickly: check the linked source before you build on one.