Resend

permdock/resend connects delivery to Resend (resend 6, an optional peer). It ships resendTransport, approvalEmail, resendWebhook and resendFailure. The entry never imports resend: you pass in your Resend client.

Send emailCopy Anchor Link

import { createPermDock } from "permdock/delivery";
import { resendTransport } from "permdock/resend";
import { Resend } from "resend";

const delivery = createPermDock(policy, {
  transports: {
    email: resendTransport(new Resend(process.env.RESEND_API_KEY), {
      from: "Acme <billing@acme.test>",
      tags: { app: "billing" },
    }),
  },
  principals,
  sink,
});

resendTransport(resend, options):

• Idempotency. Each email is sent with the recipient's idempotency key as Resend's idempotencyKey, so a retried delivery with the same id sends once.
• Batches. With two or more recipients, the router calls batch.send with up to 100 emails, keyed by a hash of the item keys.
• Tags. Every email carries permdock_delivery, permdock_key and permdock_category tags after your tags, so a webhook maps back to the delivery. A tag name or value outside [A-Za-z0-9_-] throws a TypeError when you build the transport.
• Headers. The router's Auto-Submitted and List-Unsubscribe headers are sent unchanged.

resendFailure(error) maps a Resend error to a DeliveryResult:

Approval emailsCopy Anchor Link

approvalEmail(prompt, { approvalUrl, product? }) returns an EmailMessage with category approval for an ApprovalPrompt. The subject is Approval needed: <title>. The body names the detail, the requester and any actor, the permission and resource, the risk and the expiry, and links once to the approval page. It has no approve or reject link. approvalUrl is an https base URL the request id is appended to, or a function of the prompt. Replace it with a React Email template by building the same EmailMessage.

WebhooksCopy Anchor Link

resendWebhook({ resend, secret, sink, replay }) returns a fetch handler for Resend's webhook endpoint:

import { resendWebhook } from "permdock/resend";
import { memoryReplayStore } from "permdock/server";

export const POST = resendWebhook({
  resend,
  secret: process.env.RESEND_WEBHOOK_SECRET!,
  sink,
  replay: memoryReplayStore(),
});

• Verification. resend.webhooks.verify checks the svix-* (or webhook-*) signature headers. A missing header or a bad signature answers 401 Problem Details, a body over 1 MB 413, and any method but POST 405.
• Replays. Each webhook id is claimed in the ReplayStore for 600 seconds. A repeat answers 200 and writes nothing.
• Events. email.delivered, email.bounced, email.complained, email.failed and email.suppressed become delivery events with the delivery id, key and category from the tags, and provider { name: 'resend', id }. Opens, clicks, sends and mail without PermDock tags write nothing.
• Sink failures. A sink that throws releases the claim and answers 503, so Resend retries.

Example appCopy Anchor Link

apps/examples/resend sends an invoice notice to a member, a client contact and an unlinked address, and an approval email to the other billing user. Without RESEND_API_KEY it uses memoryDeliveryTransport. src/webhook.ts serves resendWebhook.

WhyCopy Anchor Link

The client is passed in, so permdock takes no dependency on resend and one PermDock version works across Resend releases. Resend tags carry the delivery id and key because a webhook names only Resend's email id; without the tags, a bounce could not be tied to a recipient without storing addresses. Quota errors are retryable because they clear with time, while key and sender errors are final because a retry cannot fix configuration.