Example: Cron Task

This example builds a GitHub PR Digest task that runs every weekday at 9 AM, fetches open pull requests for a repository, posts a summary to Slack, and tracks changes between runs using the key-value store.

Directory structure

tasks/pr-digest/
  task.yaml
  task.ts

task.yaml

apiVersion: dicode/v1
kind: Task
name: PR Digest
description: |
  Posts a daily summary of open PRs to Slack.
  Runs weekdays at 09:00 and tracks PR count changes between runs.
runtime: deno

trigger:
  cron: "0 9 * * 1-5"   # weekdays at 09:00

params:
  repo:
    description: GitHub repo in owner/name format
    default: "myorg/myapp"
  slack_channel:
    description: Slack channel name (for display only)
    default: "#engineering"

permissions:
  env:
    - GITHUB_TOKEN
    - SLACK_WEBHOOK_URL
  net:
    - "api.github.com"
    - "hooks.slack.com"

timeout: 30s

Key points in the YAML:

• trigger.cron uses standard cron syntax. 0 9 * * 1-5 fires at 9 AM Monday through Friday.
• params declares task parameters with defaults. The task script reads them with await params.get("repo").
• permissions.env lists the environment variables the Deno sandbox is allowed to read. dicode passes these to --allow-env.
• permissions.net restricts outbound network access to specific hosts.

task.ts

import type { DicodeSdk } from "../../sdk.ts";

export default async function main({ params, kv, output }: DicodeSdk) {
  const repo = await params.get("repo");
  const slackChannel = await params.get("slack_channel");

  if (!repo) throw new Error("repo param is required");

  const githubToken = Deno.env.get("GITHUB_TOKEN");
  const slackWebhookUrl = Deno.env.get("SLACK_WEBHOOK_URL");

  if (!githubToken) throw new Error("GITHUB_TOKEN not set");
  if (!slackWebhookUrl) throw new Error("SLACK_WEBHOOK_URL not set");

  // ── Fetch open PRs from GitHub ────────────────────────────────────
  console.log(`Fetching open PRs for ${repo}...`);

  const res = await fetch(
    `https://api.github.com/repos/${repo}/pulls?state=open&per_page=100`,
    {
      headers: {
        Accept: "application/vnd.github+json",
        Authorization: `Bearer ${githubToken}`,
      },
    },
  );

  if (!res.ok) {
    throw new Error(`GitHub API error: ${res.status} ${res.statusText}`);
  }

  const pulls = (await res.json()) as Array<{
    number: number;
    title: string;
    user: { login: string };
    html_url: string;
    created_at: string;
    draft: boolean;
  }>;

  const prCount = pulls.length;
  console.log(`Found ${prCount} open PR(s)`);

  // ── Compare with previous run ─────────────────────────────────────
  const kvKey = `pr-digest:${repo}:count`;
  const prev = (await kv.get(kvKey)) as number | null;
  await kv.set(kvKey, prCount);

  const delta = prev !== null ? prCount - prev : null;
  const trend =
    delta === null
      ? "first run"
      : delta > 0
        ? `+${delta} since yesterday`
        : delta < 0
          ? `${delta} since yesterday`
          : "no change";

  console.log(`Trend: ${trend}`);

  // ── Post to Slack ─────────────────────────────────────────────────
  const prLines = pulls
    .slice(0, 15)
    .map((pr) => `- <${pr.html_url}|#${pr.number}> ${pr.title} (${pr.user.login})${pr.draft ? " [draft]" : ""}`)
    .join("\n");

  const slackPayload = {
    text: `*PR Digest for ${repo}*  (${prCount} open, ${trend})\n${prLines}`,
  };

  const slackRes = await fetch(slackWebhookUrl, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify(slackPayload),
  });

  if (!slackRes.ok) {
    throw new Error(`Slack webhook error: ${slackRes.status}`);
  }

  console.log(`Posted digest to ${slackChannel}`);

  return { prCount, changed: delta !== 0 };
}

Key patterns

This task demonstrates several core dicode features:

Pattern	How it is used
Cron trigger	trigger.cron in task.yaml schedules automatic runs
Parameters	await params.get("repo") reads declared params with defaults
Environment variables	Deno.env.get("GITHUB_TOKEN") reads secrets allowed by permissions.env
Native fetch	No HTTP library needed -- Deno's built-in fetch() calls GitHub and Slack
Key-value store	await kv.get() / await kv.set() persists the PR count across runs
Console logging	console.log() streams to the dicode run log in real time
Structured return	return { prCount, changed } is stored as the run result, visible in the UI and accessible via dicode.get_runs()

Setting up secrets

Before running this task, store the required tokens:

dicode secret set GITHUB_TOKEN ghp_xxxxxxxxxxxx
dicode secret set SLACK_WEBHOOK_URL https://hooks.slack.com/services/T.../B.../xxx

dicode injects secrets as environment variables at runtime. The permissions.env list in task.yaml controls which variables the Deno sandbox can access.

Testing manually

You can trigger the task outside its cron schedule:

dicode run pr-digest
dicode run pr-digest --param repo=denoland/deno