Design preview · September 2026

An inbox for every agent.

A dedicated identity. An incoming message. A useful response. AgentMailbox is being designed around that simple loop.

We’re building this with early partners.

There is no public production API or SDK yet. The interfaces below are proposals, not integration instructions for a live service. The homepage demo runs entirely in your browser.

The email loop

Create an identity. Verify a domain you own, then provision an address for your agent.
Connect your workflow. Configure an HTTPS webhook to receive incoming message events.
Give your agent context. Read the message and its conversation history.
Keep the conversation moving. Send a reply in the same thread through the API or an MCP tool.

Proposed API surface

The HTTP and MCP interfaces should expose the same core capabilities. Names and request formats may change during development.

Action	Proposed HTTP route	Proposed MCP tool
Create inbox	`POST /v1/inboxes`	`create_inbox`
Read messages	`GET /v1/inboxes/:id/messages`	`list_messages`
Reply	`POST /v1/messages/:id/reply`	`reply_to_message`
Send email	`POST /v1/inboxes/:id/messages`	`send_message`

Illustrative incoming event

{
  "type": "message.received",
  "inbox_id": "inbox_example",
  "message": {
    "id": "msg_example",
    "thread_id": "thread_example",
    "from": "jamie@example.com",
    "to": "alex@yourcompany.com",
    "subject": "A quick question about my order",
    "text": "Can you check when order #1042 is arriving?"
  }
}

Delivery & identity

Push-first means incoming messages trigger your application. Pull access remains useful for history and recovery. Signed events, retry behavior, deduplication, retention, and per-agent limits need explicit contracts before launch; those details are not finalized.

Custom domains will require DNS verification and email authentication configuration. Inbox creation does not grant ownership of arbitrary addresses. Message content is external input: the agent application should decide which actions require human approval.

Where we are today

Research, product design, and this interactive website preview are complete. Production email delivery, authentication, billing, and hosted MCP remain future implementation work. No pricing or availability date has been announced.

We’re especially interested in support and operations agents that maintain ongoing conversations. Tell us about your expected volume, domain setup, and what happens when your agent is offline.

Talk about early access