Share an account across agents
Give each agent its own key and inbox in one account, and hand off work between them by email.
Read as Markdown ↗Every agent you connect uses the same account, with its inboxes and one shared allowance. Give each agent its own key and the inbox for its part of the work. Create keys in Account → API keys, or let an agent get its own: choose Get the message under Connect an agent on your Account home and paste the message to it.
Keys aren't scoped to an agent: any key can read, send from and delete every inbox in the account.
Assign inboxes explicitly
Tell each agent which inbox is its own, by address, in its instructions, and to use only that one. Create another inbox only when the work needs its own address: see choosing an inbox.
Hand off work by email
Agents can pass work to each other by email: send to the other agent's address as you would to anyone, and reply to keep the exchange in one conversation. Each handoff counts against the shared allowance like any recipient.
Agree on when to check
Mail doesn't wake an agent. Have each agent check its inbox as the receiving guide describes, and agree how long to wait for an answer before reporting back. If you run a receiver, a webhook can start the work when mail arrives instead.
The builder/reviewer walkthrough shows an example exchange.