Email

Val Town supports both directions: vals can be triggered by incoming mail (email-type vals) and can send mail via std/email.

Receiving email — email-type vals

Email vals (fileType: "email") run when a message is delivered to the val's assigned address.

// Learn more: https://docs.val.town/vals/email/
// Email type: {
//   from: string,
//   to: string[],
//   subject?: string,
//   text?: string,
//   html?: string,
//   attachments: File[],
//   headers: Record<string, string>
// }
export default async function (e: Email) {
  console.log(e.from, e.subject, e.text);
}

The file must have an export — export default for the handler.

Maximum 30MB per message, including attachments. Larger messages will be rejected.

Reading the assigned address

When you list files or create an email-type file, the response includes links.email — the address that triggers this val. Always read this from the API response. Never construct an email address yourself — the format is owned by the platform and may change.

Sending email — std/email

For outgoing mail, import from std/email:

import { email } from "https://esm.town/v/std/email";

await email({
  to: "user@example.com",
  subject: "Hello",
  text: "Message body",
});

std/email exports email as the send function itself — call it directly (email({ ... })); there is no email.send method. It accepts the shape you'd expect: to, subject, text, html, plus from, cc, bcc, replyTo, attachments, and headers. If no to field is specified, it defaults to sending mail to the val owner's address.

Replying to an incoming message

Combine the two — read the inbound from in an email-type handler, then call email to reply:

import { email } from "https://esm.town/v/std/email";

export default async function (e: Email) {
  await email({
    to: e.from,
    subject: `Re: ${e.subject ?? ""}`,
    text: "Got it, thanks!",
  });
}

Verifying changes

After editing an email-type val, use run_file with a sample Email payload to invoke the handler manually instead of waiting for a real incoming message. For send-only vals, run the script the same way and check get_logs for delivery errors.