Agentmail

AgentMail — Email for AI Agents

AgentMail gives AI agents real email addresses (@theagentmail.net) with a REST API. Agents can send and receive email, sign up for services (GitHub, AWS, Slack, etc.), and get verification codes. A karma system prevents spam and keeps the shared domain's reputation high.

Base URL: https://api.theagentmail.net

When to Use

• An AI agent needs a real inbox/outbox for signups, verification flows, or transactional communication.
• You need to provision AgentMail accounts, send messages, read inbox contents, or register inbound webhooks.
• You need to monitor karma usage or wire email events into agent automation.

Quick start

All requests require Authorization: Bearer am_... header (API key from dashboard).

Create an email account (-10 karma)

curl -X POST https://api.theagentmail.net/v1/accounts \
  -H "Authorization: Bearer am_..." \
  -H "Content-Type: application/json" \
  -d '{"address": "my-agent@theagentmail.net"}'

Response: {"data": {"id": "...", "address": "my-agent@theagentmail.net", "displayName": null, "createdAt": 123}}

Send email (-1 karma)

curl -X POST https://api.theagentmail.net/v1/accounts/{accountId}/messages \
  -H "Authorization: Bearer am_..." \
  -H "Content-Type: application/json" \
  -d '{
    "to": ["recipient@example.com"],
    "subject": "Hello from my agent",
    "text": "Plain text body",
    "html": "<p>Optional HTML body</p>"
  }'

Optional fields: cc, bcc (string arrays), inReplyTo, references (strings for threading), attachments (array of {filename, contentType, content} where content is base64).

Read inbox

# List messages
curl https://api.theagentmail.net/v1/accounts/{accountId}/messages \
  -H "Authorization: Bearer am_..."

# Get full message (with body and attachments)
curl https://api.theagentmail.net/v1/accounts/{accountId}/messages/{messageId} \
  -H "Authorization: Bearer am_..."

Check karma

curl https://api.theagentmail.net/v1/karma \
  -H "Authorization: Bearer am_..."

Response: {"data": {"balance": 90, "events": [...]}}

Register webhook (real-time inbound)

curl -X POST https://api.theagentmail.net/v1/accounts/{accountId}/webhooks \
  -H "Authorization: Bearer am_..." \
  -H "Content-Type: application/json" \
  -d '{"url": "https://my-agent.example.com/inbox"}'

Webhook deliveries include two security headers:

• X-AgentMail-Signature -- HMAC-SHA256 hex digest of the request body, signed with the webhook secret
• X-AgentMail-Timestamp -- millisecond timestamp of when the delivery was sent

Verify the signature and reject requests with timestamps older than 5 minutes to prevent replay attacks:

import { createHmac } from "crypto";

const verifyWebhook = (body: string, signature: string, timestamp: string, secret: string) => {
  if (Date.now() - Number(timestamp) > 5 * 60 * 1000) return false;
  return createHmac("sha256", secret).update(body).digest("hex") === signature;
};

Download attachment

curl https://api.theagentmail.net/v1/accounts/{accountId}/messages/{messageId}/attachments/{attachmentId} \
  -H "Authorization: Bearer am_..."

Returns {"data": {"url": "https://signed-download-url..."}}.

Full API reference

Karma system

Every action has a karma cost or reward:

Important rules:

• Karma is only awarded for inbound emails from trusted providers (Gmail, Outlook, Yahoo, iCloud, ProtonMail, Fastmail, Hey, etc.). Emails from unknown/throwaway domains don't earn karma.
• You only earn karma once per sender until the agent replies. If sender X emails you 5 times without a reply, only the first earns karma. Reply to X, and the next email from X earns karma again.
• Deleting an account refunds the 10 karma it cost to create.

When karma reaches 0, sends and account creation r