Send a weekly digest

By the end of this recipe your team's inbox gets an email every Monday morning listing the posts published that week, each with its title, link and a summary taken from its markdown. A cron trigger starts the job, and a failed send is retried like any other job.

npm add @sdxc/jobs @sdxc/result

Publish posts from markdown#

The digest reads the same posts your site renders. Follow A markdown content pipeline, including HTML and plain text for everything else, whose summarize gives each post the plain-text summary an email shows and whose listPosts names the published posts newest first.

Send email from jobs#

Follow Send email through Publish a mailer to requests and jobs, declaring digests.weekly with props posts: s.array(s.object({ title: s.string(), url: s.string(), summary: s.string() })) and a template that lists each post with Email.Link and Email.Text.

Schedule the digest#

Follow Background jobs and cron for the queue, the dispatcher and the Worker's scheduled handler, then write the job with sdxc make job weekly-digest --cron "0 8 * * 1". The handler sends one digest of the last seven days' posts and skips a week with nothing new:

import { createJobHandler } from "@sdxc/jobs";
import { isFailure } from "@sdxc/result";

import emails from "~/app/emails";
import jobs from "~/app/jobs";
import { listPosts } from "~/app/services/content/list-posts";
import { readPost } from "~/app/services/content/posts";
import { summarize } from "~/app/services/content/render";
import { DIGEST_TO, SITE_URL } from "~/config/constants";
import routes from "~/routes/web";

const WEEK_MS = 7 * 86_400_000;

export default createJobHandler(jobs.weeklyDigest, async (ctx) => {
	let since = Date.now() - WEEK_MS;
	let recent = (await listPosts()).filter(
		(post) => post.publishedAt.getTime() >= since,
	);
	let posts = [];

	for (let { slug, title } of recent) {
		let post = await readPost(slug);
		if (post === null || isFailure(post)) continue;

		let url = new URL(routes.posts.show.href({ slug }), SITE_URL);
		posts.push({ title, url: url.href, summary: summarize(post.data.document) });
	}

	ctx.log.set({ digest: { posts: posts.length } });
	if (posts.length === 0) return;

	let sent = await ctx.email.send(emails.digests.weekly, {
		to: DIGEST_TO,
		locale: "en",
		props: { posts },
	});
	if (isFailure(sent)) return ctx.retry({ delay: "15 minutes", cause: sent.error });
});

DIGEST_TO is your team's address. The digest is one message, so the job sends it itself and a failed send retries with the job.

Test it#

Test each stage as its guide does: Run jobs in a test drains the job once you pin the clock to a Monday after one of your posts, and Test with the memory transport checks the digest that was sent.

Where to go next#

• Run a newsletter list — send the digest to readers who subscribed, from a platform built for lists.

• Validate a schedule someone typed — let each person pick when their digest arrives.

• Preview an email — check the digest's layout before the first Monday.