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 return HTTP 402. Always check balance before operations that cost karma.

TypeScript SDK

import { createClient } from "@agentmail/sdk";

const mail = createClient({ apiKey: "am_..." });

// Create account
const account = await mail.accounts.create({
  address: "my-agent@theagentmail.net",
});

// Send email
await mail.messages.send(account.id, {
  to: ["human@example.com"],
  subject: "Hello",
  text: "Sent by an AI agent.",
});

// Read inbox
const messages = await mail.messages.list(account.id);
const detail = await mail.messages.get(account.id, messages[0].id);

// Attachments
const att = await mail.attachments.getUrl(accountId, messageId, attachmentId);
// att.url is a signed download URL

// Webhooks
await mail.webhooks.create(account.id, {
  url: "https://my-agent.example.com/inbox",
});

// Karma
const karma = await mail.karma.getBalance();
console.log(karma.balance);

Error handling

import { AgentMailError } from "@agentmail/sdk";

try {
  await mail.messages.send(accountId, { to: ["a@b.com"], subject: "Hi", text: "Hey" });
} catch (e) {
  if (e instanceof AgentMailError) {
    console.log(e.status);   // 402, 404, 401, etc.
    console.log(e.code);     // "INSUFFICIENT_KARMA", "NOT_FOUND", etc.
    console.log(e.message);
  }
}

Common patterns

Sign up for a service and read verification email

const account = await mail.accounts.create({
  address: "signup-bot@theagentmail.net",
});

// Use the address to sign up (browser automation, API, etc.)

// Poll for verification email
for (let i = 0; i < 30; i++) {
  const messages = await mail.messages.list(account.id);
  const verification = messages.find(m =>
    m.subject.toLowerCase().includes("verify") ||
    m.subject.toLowerCase().includes("confirm")
  );
  if (verification) {
    const detail = await mail.messages.get(account.id, verification.id);
    // Parse verification link/code from detail.bodyText or detail.bodyHtml
    break;
  }
  await new Promise(r => setTimeout(r, 2000));
}

Send email and wait for reply

const sent = await mail.messages.send(account.id, {
  to: ["human@company.com"],
  subject: "Question about order #12345",
  text: "Can you check the status?",
});

for (let i = 0; i < 60; i++) {
  const messages = await mail.messages.list(account.id);
  const reply = messages.find(m =>
    m.direction === "inbound" && m.timestamp > sent.timestamp
  );
  if (reply) {
    const detail = await mail.messages.get(account.id, reply.id);
    // Process reply
    break;
  }
  await new Promise(r => setTimeout(r, 5000));
}

Types

type Account = { id: string; address: string; displayName: string | null; createdAt: number };
type Message = { id: string; from: string; to: string[]; subject: string; direction: "inbound" | "outbound"; status: string; timestamp: number };
type MessageDetail = Message & { cc: string[] | null; bcc: string[] | null; bodyText: string | null; bodyHtml: string | null; inReplyTo: string | null; references: string | null; attachments: AttachmentMeta[] };
type AttachmentMeta = { id: string; filename: string; contentType: string; size: number };
type KarmaBalance = { balance: number; events: KarmaEvent[] };
type KarmaEvent = { id: string; type: string; amount: number; timestamp: number; metadata?: Record<string, unknown> };