Email-Capable AI Assistants with Superagent

Connect Superagent's managed AI assistants to MultiMail for sending, reading, and managing email — with human oversight for production-deployed agents.


Superagent is a platform for building and deploying AI assistants with tool use, memory, and RAG capabilities. MultiMail provides the email infrastructure layer that gives Superagent assistants the ability to send, receive, and manage email on behalf of users in production environments.

When agents run in production without direct developer supervision, email oversight becomes critical. MultiMail's default gated_send mode ensures every email drafted by a Superagent assistant requires human approval before delivery, providing the safety layer that production-deployed agents need.

Connect Superagent to MultiMail by configuring MultiMail API endpoints as custom tools in your Superagent assistant. The REST API approach works with Superagent's tool registration system, giving your assistant structured email capabilities.

Built for Superagent developers

Production Safety for Managed Agents

Superagent assistants run in production without direct supervision. MultiMail's oversight modes provide the email safety layer that production agents need — from human approval for every send to fully autonomous operation.

Custom Tool Integration

Superagent supports custom tools that call external APIs. Register MultiMail's send_email, check_inbox, and reply_email as tools in your assistant for structured email capabilities.

Graduated Trust via Oversight Modes

Start with gated_send (assistant composes, human approves) and progress to autonomous as your Superagent assistant proves reliable. MultiMail's five oversight modes let you scale agent autonomy safely.

Built-in Observability Pairing

Superagent's built-in observability shows you how your assistant uses tools. Combined with MultiMail's audit logs, you get full visibility into every email action your agent takes.

Multi-LLM Provider Support

Superagent supports multiple LLM providers. Your MultiMail email tools work the same regardless of which model powers your assistant, so you can switch providers without changing the email integration.


Try it with your agent

No code, no dashboard. Paste this to your AI agent — it connects MultiMail, creates an inbox, and builds the flow for you.

1. Get MultiMail ready: read https://multimail.dev/llms.txt, connect the MultiMail MCP server exactly as documented there, create a free inbox, and set up a verified sending domain before attempting any outbound email. 2. Wire it into Superagent correctly: if you are using the current Superagent SDK, keep MultiMail available to the agent through its MCP tools in the host agent runtime, and use Superagent Guard as the real Superagent safety control around user input and any MultiMail send or schedule action. If this Superagent environment does not expose MCP tools to the agent runtime, stop and tell me that the integration cannot be completed without adding that host-level tool connection. 3. Give the agent three email capabilities only: check the inbox for new messages and summarize them, draft a reply for review without sending, and send or schedule email only through MultiMail. Never invent email APIs, webhooks, headers, or delivery settings. 4. Send a test email: compose a short test message from the verified sender to my own developer address, then use MultiMail to submit it. Report the subject, recipient, and current send status. 5. Run in gated_send: configure the inbox for gated_send oversight, keep it there for this test, and do not switch to monitored or autonomous. Before any email is delivered, show me the draft and wait for human approval through MultiMail’s review flow.

Step by step

1

Create a MultiMail Account and API Key

Sign up at multimail.dev, create a mailbox, and generate an API key from your dashboard. Your key will start with mm_live_.

2

Set Up Superagent

Sign up for Superagent and obtain your API key. You can use the hosted platform or self-host the open-source version.

3

Register Email Tools

Create custom tools in Superagent that map to MultiMail's API endpoints — send_email, check_inbox, reply_email, and others.

4

Create and Configure Your Assistant

Create a Superagent assistant with a system prompt that explains email oversight modes. Attach the MultiMail tools to the assistant.

5

Approve Pending Emails

If your mailbox uses gated_send mode (the default), review and approve pending emails in the MultiMail dashboard before they are delivered.


Common questions

How do I register MultiMail tools in Superagent?
Use Superagent's tool creation API to register MultiMail endpoints as custom function tools. Define the URL, HTTP method, headers (including your MultiMail API key), and parameter schemas. Then attach the tools to your assistant.
What happens when my assistant sends an email in gated_send mode?
In gated_send mode, the MultiMail API returns a success response with a pending status. The email is queued for human review in the MultiMail dashboard. Once approved, it is delivered. Your assistant can inform the user that the email is pending approval.
Can I use Superagent's memory features with email?
Yes. Superagent's memory system can store email context across conversations. The assistant can remember previous email interactions, contact preferences, and communication styles, improving email quality over time.
How do I monitor my assistant's email activity?
Use Superagent's built-in observability to track tool invocations and assistant behavior. Complement this with MultiMail's audit log endpoint to see the full lifecycle of every email — from draft to approval to delivery.
Is there rate limiting on the MultiMail API?
Rate limits depend on your plan tier. The Starter (free) plan allows 200 emails per month, while paid plans range from 5,000 to 150,000. The API returns standard 429 responses when limits are reached, which Superagent can handle with retry logic.

Explore more

The only agent email with a verifiable sender

Email infrastructure built for AI agents. Verifiable identity, graduated oversight, and a hosted MCP server. Formally verified in Lean 4.