Inboxes for AI agents

Email,
built for
agents.

Give every agent its own real address. It can send, receive, keep track of threads and wait for a human to reply, all through one API, with no OAuth or shared Gmail account and no bounced replies.

Create an inbox → See the API

$ npm i @waterr/agentinbox · first inbox in 40 seconds

from: maya@northwind.co
to: scheduler@waterrai.xyz
subj: Re: Moving our Thursday sync

“Thursday doesn't work any more. Could we do Friday at 3pm instead? I've attached the updated deck.”

// webhook → message.received
{ "thread": "thr_8Hq2", "turn": 4,
  "reply_text": "Could we do Friday at 3pm…",
  "attachments": ["deck-v3.pdf"],
  "sender_verified": true }

→ support@ replied to 1,204 tickets today → recruiter@ booked 38 interviews → ops@ received a 2FA code in 1.8s → sales@ followed up after 3 days of silence → billing@ read 412 invoices from PDFs → research@ signed up for 9 newsletters → support@ replied to 1,204 tickets today → recruiter@ booked 38 interviews → ops@ received a 2FA code in 1.8s → sales@ followed up after 3 days of silence → billing@ read 412 invoices from PDFs → research@ signed up for 9 newsletters

01 — Why

Your agent has a brain. It still doesn't have an address.

Borrowing a human's inbox

OAuth tokens that expire in the middle of a task
The agent can read your whole personal mailbox
Replies land in a thread nobody is watching
Rate limits written for people, not loops
HTML soup that has to be parsed into text

A Waterr AgentInbox

One API call creates a new address
Each inbox is scoped to one agent, with its own keys
Replies arrive as events, already threaded
Built for thousands of inboxes per account
Clean text, quoted history removed, attachments extracted

02 — Features

Everything a mailroom does, exposed as an API.

/01

Inboxes on demand

Create a new address for every agent, user or task. Throw it away when the job is done.

/02

Real-time events

Webhooks or a websocket deliver message.received within milliseconds of the message arriving.

/03

Threads that remember

Each reply comes with the full conversation, so your agent can pick up a thread three weeks later.

/04

Human approval

Agents write drafts. You approve them with one click or by replying from your phone, then they send.

/05

Injection shield

Each message gets a sender verdict and an untrusted-content flag before your agent reads it.

/06

Your own domain

Send from ava@yourco.com. SPF, DKIM and DMARC are set up automatically.

03 — API

Three calls, from nothing to a conversation.

Create an inboxName it whatever you like, or let us generate a name.
Send like a personPlain text in. Correctly formatted email out.
Wait for the replyWait on the thread, or subscribe to events.

agent.ts

import { AgentInbox } from "@waterr/agentinbox";

const mail = new AgentInbox(process.env.AGENTINBOX_KEY);

const inbox = await mail.inboxes.create({
  username: "scheduler",
  display_name: "Ava from Northwind",
});

console.log(inbox.address);
// → scheduler@waterrai.xyz

const thread = await inbox.send({
  to: "maya@northwind.co",
  subject: "Moving our Thursday sync",
  text: `Hi Maya, does Thursday at 2pm
still work for you? If not, send
me two times that do.`,
});

// tracked automatically: delivery, opens, bounces
console.log(thread.id); // → thr_8Hq2

// block until a human replies (or time out)
const reply = await thread.waitForReply({
  timeout: "3d",
});

if (!reply.sender_verified) return flag(reply);

const slot = await llm.extract(reply.reply_text);
await calendar.book(slot);
await thread.reply({ text: `Booked: ${slot}. See you then!` });