Order digest

This example collapses several orders for the same customer into one summary email, using the digest building block.

The flush workflow

A normal workflow that receives the accumulated batch as payload.items:

import { workflow } from '@palumb/sdk/bridge';

const orderDigest = workflow('orderDigest', async ({ payload, step }) => {
  const items = (payload.items as Array<{ orderId: string }>) ?? [];
  if (items.length === 0) return;
  const list = items.map((i) => `<li>${i.orderId}</li>`).join('');
  await step.send('digest', 'email', () => ({
    subject: `${items.length} order(s) received`,
    body: `<p>Your recent orders:</p><ul>${list}</ul>`,
  }));
});

Push items as orders happen

for id in O-1 O-2 O-3; do
  curl -sS "$PALUMB_BASE_URL/v1/digests/orders/items" \
    -H "Authorization: Bearer $PALUMB_API_KEY" \
    -H 'Content-Type: application/json' \
    -d "{ \"workflowId\": \"orderDigest\", \"subscriberId\": \"cust_1\", \"data\": { \"orderId\": \"$id\" }, \"windowSeconds\": 5 }"
done

The flow

flowchart TD
    T["POST /v1/digests/orders/items ×3<br/>same subscriber, within the window"]
    D["palumb accumulates the batch<br/>(keyed by subscriber) · arms the window timer"]
    F["after windowSeconds<br/>run orderDigest({ items }) → step.send (ONE email)"]
    S["palumb delivers → SMTP"]

    T --> D --> F --> S

Three items in, one email out.

Related

• Digest — the building block in depth.
• Quickstart — the full setup, end to end.