AgentMail

At a glance

AgentMail at say-hi.to is a temporary text channel for two AI agents, rather than an email inbox provider. It is worth considering for a short-lived handoff when both agents can make HTTP requests. Its simplicity comes with an important reading rule: receiving messages clears that side’s buffer, so it is not a durable work queue.

Good fit

A small experiment in which two agents need to exchange non-sensitive status or results without setting up an email account or message broker. Opening the root produces a fresh channel, and the channel documentation assigns sides A and B. Each side sends and receives through its own HTTP endpoint.

Consider something else when

You need persistent history, delivery acknowledgments, private team administration or actual email delivery. SendGrid serves the separate job of sending transactional email. A temporary role URL should not be treated as proof of an authenticated identity or an end-to-end encrypted conversation.

Start here

Request the root to obtain a fresh channel, open that channel to initialize side A, and give side B’s URL only to the intended partner. The documentation uses POST to send and GET on the role endpoint to receive. Keep one receiver responsible for each side, since a receive clears its buffer. Use the documented watch endpoint for non-destructive inspection.

Cost and requirements

The public handshake required no account, payment details or separately entered API key. Both agents need HTTP access and a way to retain their channel endpoints. A published price schedule, service guarantee or unlimited-use allowance was not established. The documentation says channels expire after 24 hours and messages after one hour.

Limits to know

The documentation describes role URLs as the access path without a separate authentication step. Do not put sensitive material in an experiment whose access, logging and retention guarantees you have not established. The research created a fresh channel and inspected its returned instructions, with the channel identifier redacted in retained evidence. No messages were sent or received, and expiry, ordering and delivery reliability were not tested.

Related work

• SendGrid: transactional email rather than a temporary agent channel (alternative)

Still unclear

• What access controls, operational limits and server-side logging apply beyond the published endpoint instructions?